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Test pull request. Ignore.

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Ignore

@LinuxMinion LinuxMinion closed this Dec 6, 2018
gregmarsden pushed a commit that referenced this pull request Dec 14, 2018
[ Upstream commit 46b3722 ]

We occasionaly hit following assert failure in 'perf top', when processing the
/proc info in multiple threads.

  perf: ...include/linux/refcount.h:109: refcount_inc:
        Assertion `!(!refcount_inc_not_zero(r))' failed.

The gdb backtrace looks like this:

  [Switching to Thread 0x7ffff11ba700 (LWP 13749)]
  0x00007ffff50839fb in raise () from /lib64/libc.so.6
  (gdb)
  #0  0x00007ffff50839fb in raise () from /lib64/libc.so.6
  #1  0x00007ffff5085800 in abort () from /lib64/libc.so.6
  #2  0x00007ffff507c0da in __assert_fail_base () from /lib64/libc.so.6
  #3  0x00007ffff507c152 in __assert_fail () from /lib64/libc.so.6
  #4  0x0000000000535373 in refcount_inc (r=0x7fffdc009be0)
      at ...include/linux/refcount.h:109
  #5  0x00000000005354f1 in comm_str__get (cs=0x7fffdc009bc0)
      at util/comm.c:24
  #6  0x00000000005356bd in __comm_str__findnew (str=0x7fffd000b260 ":2",
      root=0xbed5c0 <comm_str_root>) at util/comm.c:72
  #7  0x000000000053579e in comm_str__findnew (str=0x7fffd000b260 ":2",
      root=0xbed5c0 <comm_str_root>) at util/comm.c:95
  #8  0x000000000053582e in comm__new (str=0x7fffd000b260 ":2",
      timestamp=0, exec=false) at util/comm.c:111
  #9  0x00000000005363bc in thread__new (pid=2, tid=2) at util/thread.c:57
  #10 0x0000000000523da0 in ____machine__findnew_thread (machine=0xbfde38,
      threads=0xbfdf28, pid=2, tid=2, create=true) at util/machine.c:457
  #11 0x0000000000523eb4 in __machine__findnew_thread (machine=0xbfde38,
  ...

The failing assertion is this one:

  REFCOUNT_WARN(!refcount_inc_not_zero(r), ...

The problem is that we keep global comm_str_root list, which
is accessed by multiple threads during the 'perf top' startup
and following 2 paths can race:

  thread 1:
    ...
    thread__new
      comm__new
        comm_str__findnew
          down_write(&comm_str_lock);
          __comm_str__findnew
            comm_str__get

  thread 2:
    ...
    comm__override or comm__free
      comm_str__put
        refcount_dec_and_test
          down_write(&comm_str_lock);
          rb_erase(&cs->rb_node, &comm_str_root);

Because thread 2 first decrements the refcnt and only after then it removes the
struct comm_str from the list, the thread 1 can find this object on the list
with refcnt equls to 0 and hit the assert.

This patch fixes the thread 1 __comm_str__findnew path, by ignoring objects
that already dropped the refcnt to 0. For the rest of the objects we take the
refcnt before comparing its name and release it afterwards with comm_str__put,
which can also release the object completely.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Lukasz Odzioba <lukasz.odzioba@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: kernel-team@lge.com
Link: http://lkml.kernel.org/r/20180720101740.GA27176@krava
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregmarsden pushed a commit that referenced this pull request Jan 18, 2019
…error

The sequence that leads to this state is as follows.

1) First we see CQ error logged.

Sep 29 22:32:33 dm54cel14 kernel: [471472.784371] mlx4_core
0000:46:00.0: CQ access violation on CQN 000419 syndrome=0x2
vendor_error_syndrome=0x0

2) That is followed by the drop of the associated RDS connection.

Sep 29 22:32:33 dm54cel14 kernel: [471472.784403] RDS/IB: connection
<192.168.54.43,192.168.54.1,0> dropped due to 'qp event'

3) We don't get the WR_FLUSH_ERRs for the posted receive buffers after that.

4) RDS is stuck in rds_ib_conn_shutdown while shutting down that connection.

crash64> bt 62577
PID: 62577  TASK: ffff88143f045400  CPU: 4   COMMAND: "kworker/u224:1"
 #0 [ffff8813663bbb58] __schedule at ffffffff816ab68b
 #1 [ffff8813663bbbb0] schedule at ffffffff816abca7
 #2 [ffff8813663bbbd0] schedule_timeout at ffffffff816aee71
 #3 [ffff8813663bbc80] rds_ib_conn_shutdown at ffffffffa041f7d1 [rds_rdma]
 #4 [ffff8813663bbd10] rds_conn_shutdown at ffffffffa03dc6e2 [rds]
 #5 [ffff8813663bbdb0] rds_shutdown_worker at ffffffffa03e2699 [rds]
 #6 [ffff8813663bbe00] process_one_work at ffffffff8109cda1
 #7 [ffff8813663bbe50] worker_thread at ffffffff8109d92b
 #8 [ffff8813663bbec0] kthread at ffffffff810a304b
 #9 [ffff8813663bbf50] ret_from_fork at ffffffff816b0752
crash64>

It was stuck here in rds_ib_conn_shutdown for ever:

                /* quiesce tx and rx completion before tearing down */
                while (!wait_event_timeout(rds_ib_ring_empty_wait,
                                rds_ib_ring_empty(&ic->i_recv_ring) &&
                                (atomic_read(&ic->i_signaled_sends) == 0),
                                msecs_to_jiffies(5000))) {

                        /* Try to reap pending RX completions every 5 secs */
                        if (!rds_ib_ring_empty(&ic->i_recv_ring)) {
                                spin_lock_bh(&ic->i_rx_lock);
                                rds_ib_rx(ic);
                                spin_unlock_bh(&ic->i_rx_lock);
                        }
                }

The recv ring was not empty.
w_alloc_ptr = 560
w_free_ptr  = 256

This is what Mellanox had to say:
When CQ moves to error (e.g. due to CQ Overrun, CQ Access violation) FW will
generate Async event to notify this error, also the QPs that tries to access
this CQ will be put to error state but will not be flushed since we must not
post CQEs to a broken CQ. The QP that tries to access will also issue an
Async catas event.

In summary we cannot wait for any more WR_FLUSH_ERRs in that state.

Orabug: 29180452

Reviewed-by: Rama Nichanamatlu <rama.nichanamatlu@oracle.com>
Signed-off-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
gregmarsden pushed a commit that referenced this pull request Jan 18, 2019
The sequence that leads to this state is as follows.

1) First we see CQ error logged.

Sep 29 22:32:33 dm54cel14 kernel: [471472.784371] mlx4_core
0000:46:00.0: CQ access violation on CQN 000419 syndrome=0x2
vendor_error_syndrome=0x0

2) That is followed by the drop of the associated RDS connection.

Sep 29 22:32:33 dm54cel14 kernel: [471472.784403] RDS/IB: connection
<192.168.54.43,192.168.54.1,0> dropped due to 'qp event'

3) We don't get the WR_FLUSH_ERRs for the posted receive buffers after that.

4) RDS is stuck in rds_ib_conn_shutdown while shutting down that connection.

crash64> bt 62577
PID: 62577  TASK: ffff88143f045400  CPU: 4   COMMAND: "kworker/u224:1"
 #0 [ffff8813663bbb58] __schedule at ffffffff816ab68b
 #1 [ffff8813663bbbb0] schedule at ffffffff816abca7
 #2 [ffff8813663bbbd0] schedule_timeout at ffffffff816aee71
 #3 [ffff8813663bbc80] rds_ib_conn_shutdown at ffffffffa041f7d1 [rds_rdma]
 #4 [ffff8813663bbd10] rds_conn_shutdown at ffffffffa03dc6e2 [rds]
 #5 [ffff8813663bbdb0] rds_shutdown_worker at ffffffffa03e2699 [rds]
 #6 [ffff8813663bbe00] process_one_work at ffffffff8109cda1
 #7 [ffff8813663bbe50] worker_thread at ffffffff8109d92b
 #8 [ffff8813663bbec0] kthread at ffffffff810a304b
 #9 [ffff8813663bbf50] ret_from_fork at ffffffff816b0752
crash64>

It was stuck here in rds_ib_conn_shutdown for ever:

                /* quiesce tx and rx completion before tearing down */
                while (!wait_event_timeout(rds_ib_ring_empty_wait,
                                rds_ib_ring_empty(&ic->i_recv_ring) &&
                                (atomic_read(&ic->i_signaled_sends) == 0),
                                msecs_to_jiffies(5000))) {

                        /* Try to reap pending RX completions every 5 secs */
                        if (!rds_ib_ring_empty(&ic->i_recv_ring)) {
                                spin_lock_bh(&ic->i_rx_lock);
                                rds_ib_rx(ic);
                                spin_unlock_bh(&ic->i_rx_lock);
                        }
                }

The recv ring was not empty.
w_alloc_ptr = 560
w_free_ptr  = 256

This is what Mellanox had to say:
When CQ moves to error (e.g. due to CQ Overrun, CQ Access violation) FW will
generate Async event to notify this error, also the QPs that tries to access
this CQ will be put to error state but will not be flushed since we must not
post CQEs to a broken CQ. The QP that tries to access will also issue an
Async catas event.

In summary we cannot wait for any more WR_FLUSH_ERRs in that state.

Orabug: 28733324

Reviewed-by: Rama Nichanamatlu <rama.nichanamatlu@oracle.com>
Signed-off-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
Signed-off-by: Brian Maly <brian.maly@oracle.com>
LinuxMinion pushed a commit that referenced this pull request Feb 27, 2019
…error

The sequence that leads to this state is as follows.

1) First we see CQ error logged.

Sep 29 22:32:33 dm54cel14 kernel: [471472.784371] mlx4_core
0000:46:00.0: CQ access violation on CQN 000419 syndrome=0x2
vendor_error_syndrome=0x0

2) That is followed by the drop of the associated RDS connection.

Sep 29 22:32:33 dm54cel14 kernel: [471472.784403] RDS/IB: connection
<192.168.54.43,192.168.54.1,0> dropped due to 'qp event'

3) We don't get the WR_FLUSH_ERRs for the posted receive buffers after that.

4) RDS is stuck in rds_ib_conn_shutdown while shutting down that connection.

crash64> bt 62577
PID: 62577  TASK: ffff88143f045400  CPU: 4   COMMAND: "kworker/u224:1"
 #0 [ffff8813663bbb58] __schedule at ffffffff816ab68b
 #1 [ffff8813663bbbb0] schedule at ffffffff816abca7
 #2 [ffff8813663bbbd0] schedule_timeout at ffffffff816aee71
 #3 [ffff8813663bbc80] rds_ib_conn_shutdown at ffffffffa041f7d1 [rds_rdma]
 #4 [ffff8813663bbd10] rds_conn_shutdown at ffffffffa03dc6e2 [rds]
 #5 [ffff8813663bbdb0] rds_shutdown_worker at ffffffffa03e2699 [rds]
 #6 [ffff8813663bbe00] process_one_work at ffffffff8109cda1
 #7 [ffff8813663bbe50] worker_thread at ffffffff8109d92b
 #8 [ffff8813663bbec0] kthread at ffffffff810a304b
 #9 [ffff8813663bbf50] ret_from_fork at ffffffff816b0752
crash64>

It was stuck here in rds_ib_conn_shutdown for ever:

                /* quiesce tx and rx completion before tearing down */
                while (!wait_event_timeout(rds_ib_ring_empty_wait,
                                rds_ib_ring_empty(&ic->i_recv_ring) &&
                                (atomic_read(&ic->i_signaled_sends) == 0),
                                msecs_to_jiffies(5000))) {

                        /* Try to reap pending RX completions every 5 secs */
                        if (!rds_ib_ring_empty(&ic->i_recv_ring)) {
                                spin_lock_bh(&ic->i_rx_lock);
                                rds_ib_rx(ic);
                                spin_unlock_bh(&ic->i_rx_lock);
                        }
                }

The recv ring was not empty.
w_alloc_ptr = 560
w_free_ptr  = 256

This is what Mellanox had to say:
When CQ moves to error (e.g. due to CQ Overrun, CQ Access violation) FW will
generate Async event to notify this error, also the QPs that tries to access
this CQ will be put to error state but will not be flushed since we must not
post CQEs to a broken CQ. The QP that tries to access will also issue an
Async catas event.

In summary we cannot wait for any more WR_FLUSH_ERRs in that state.

Orabug: 29180514

Reviewed-by: Rama Nichanamatlu <rama.nichanamatlu@oracle.com>
Signed-off-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
gregmarsden pushed a commit that referenced this pull request Mar 5, 2019
The customer hit this crash few times.

PID: 31556  TASK: ffff880f823caa00  CPU: 1   COMMAND: "cellsrv"
 #0 [ffff880f823db850] machine_kexec at ffffffff8105d93c
 #1 [ffff880f823db8b0] crash_kexec at ffffffff811103b3
 #2 [ffff880f823db980] oops_end at ffffffff8101a788
 #3 [ffff880f823db9b0] no_context at ffffffff8106b9cf
 #4 [ffff880f823dba20] __bad_area_nosemaphore at ffffffff8106bc9d
 #5 [ffff880f823dba70] bad_area at ffffffff8106be97
 #6 [ffff880f823dbaa0] __do_page_fault at ffffffff8106c71e
 #7 [ffff880f823dbb00] do_page_fault at ffffffff8106c81f
 #8 [ffff880f823dbb40] page_fault at ffffffff816b5a9f
    [exception RIP: rds_ib_inc_copy_to_user+104]
    RIP: ffffffffa04607b8  RSP: ffff880f823dbbf8  RFLAGS: 00010287
    RAX: 0000000000000340  RBX: 0000000000001000  RCX: 0000000000004000
    RDX: 0000000000001000  RSI: ffff88176cea2000  RDI: ffff8817d291f520
    RBP: ffff880f823dbc48   R8: 0000000000001340   R9: 0000000000001000
    R10: 0000000000001200  R11: ffff880f823dc000  R12: ffff880f823dbed0
    R13: 0000000000000000  R14: 0000000000000000  R15: 0000000000001000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
 #9 [ffff880f823dbc50] rds_recvmsg at ffffffffa041d837 [rds]

int rds_ib_inc_copy_to_user(struct rds_incoming *inc, struct iov_iter *to)
...
...
        ibinc = container_of(inc, struct rds_ib_incoming, ii_inc);
        frag = list_entry(ibinc->ii_frags.next, struct rds_page_frag, f_item);
        len = be32_to_cpu(inc->i_hdr.h_len);
        sg = frag->f_sg;

        while (iov_iter_count(to) && copied < len) {
                to_copy = min_t(unsigned long, iov_iter_count(to),
                                sg->length - frag_off);
                ...

sg is NULL and it crashes accessing sg->length above.

The cause looks like is due to ic->i_frag_sz returning incorrect value.
16KB when 4KB was expected.

                if (copied % ic->i_frag_sz == 0) {
                        frag = list_entry(frag->f_item.next,
                                          struct rds_page_frag, f_item);
                        frag_off = 0;
                        sg = frag->f_sg;
                }

The other end is using 4KB RDS fragsize (Solaris Super Cluster).
This end is UEK4 (4.1.12-94.8.4.el6uek.x86_64).

The message being copied arrived over 4KB RDS frag size connection.
But during the above check ic->i_frag_sz is 16KB.
This can happen during a reconnect at the connection setup phase.
We start off with ic->i_frag_sz as 16KB. Then settle down at 4KB.

Failing this check
  if (copied % ic->i_frag_sz == 0) {
can result in sg not getting set correctly.

Say, "copied" = 4KB but ic->i_frag_sz is 16KB when it should be 4KB.

During race condition with a reconnect, ic->i_frag_sz can be 16KB
even though once the connection is set up it settled down to 4KB.
It can change from 4KB to 16KB and back to 4KB during connection setup
due to reconnect.

We started seeing this crash after bug 26848749.
But prior to that the same scenario could result in data copied to user
from incorrect "sg" resulting in data corruption.

Orabug: 28748049

Reviewed-by: Rama Nichanamatlu <rama.nichanamatlu@oracle.com>
Signed-off-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
gregmarsden pushed a commit that referenced this pull request Mar 5, 2019
…error

The sequence that leads to this state is as follows.

1) First we see CQ error logged.

Sep 29 22:32:33 dm54cel14 kernel: [471472.784371] mlx4_core
0000:46:00.0: CQ access violation on CQN 000419 syndrome=0x2
vendor_error_syndrome=0x0

2) That is followed by the drop of the associated RDS connection.

Sep 29 22:32:33 dm54cel14 kernel: [471472.784403] RDS/IB: connection
<192.168.54.43,192.168.54.1,0> dropped due to 'qp event'

3) We don't get the WR_FLUSH_ERRs for the posted receive buffers after that.

4) RDS is stuck in rds_ib_conn_shutdown while shutting down that connection.

crash64> bt 62577
PID: 62577  TASK: ffff88143f045400  CPU: 4   COMMAND: "kworker/u224:1"
 #0 [ffff8813663bbb58] __schedule at ffffffff816ab68b
 #1 [ffff8813663bbbb0] schedule at ffffffff816abca7
 #2 [ffff8813663bbbd0] schedule_timeout at ffffffff816aee71
 #3 [ffff8813663bbc80] rds_ib_conn_shutdown at ffffffffa041f7d1 [rds_rdma]
 #4 [ffff8813663bbd10] rds_conn_shutdown at ffffffffa03dc6e2 [rds]
 #5 [ffff8813663bbdb0] rds_shutdown_worker at ffffffffa03e2699 [rds]
 #6 [ffff8813663bbe00] process_one_work at ffffffff8109cda1
 #7 [ffff8813663bbe50] worker_thread at ffffffff8109d92b
 #8 [ffff8813663bbec0] kthread at ffffffff810a304b
 #9 [ffff8813663bbf50] ret_from_fork at ffffffff816b0752
crash64>

It was stuck here in rds_ib_conn_shutdown for ever:

                /* quiesce tx and rx completion before tearing down */
                while (!wait_event_timeout(rds_ib_ring_empty_wait,
                                rds_ib_ring_empty(&ic->i_recv_ring) &&
                                (atomic_read(&ic->i_signaled_sends) == 0),
                                msecs_to_jiffies(5000))) {

                        /* Try to reap pending RX completions every 5 secs */
                        if (!rds_ib_ring_empty(&ic->i_recv_ring)) {
                                spin_lock_bh(&ic->i_rx_lock);
                                rds_ib_rx(ic);
                                spin_unlock_bh(&ic->i_rx_lock);
                        }
                }

The recv ring was not empty.
w_alloc_ptr = 560
w_free_ptr  = 256

This is what Mellanox had to say:
When CQ moves to error (e.g. due to CQ Overrun, CQ Access violation) FW will
generate Async event to notify this error, also the QPs that tries to access
this CQ will be put to error state but will not be flushed since we must not
post CQEs to a broken CQ. The QP that tries to access will also issue an
Async catas event.

In summary we cannot wait for any more WR_FLUSH_ERRs in that state.

Orabug: 29180535

Reviewed-by: Rama Nichanamatlu <rama.nichanamatlu@oracle.com>
Signed-off-by: Venkat Venkatsubra <venkat.x.venkatsubra@oracle.com>
gregmarsden pushed a commit that referenced this pull request Mar 22, 2019
[ Upstream commit f5e2848 ]

When enumerating page size definitions to check hardware support,
we construct a constant which is (1U << (def->shift - 10)).

However, the array of page size definitions is only initalised for
various MMU_PAGE_* constants, so it contains a number of 0-initialised
elements with def->shift == 0. This means we end up shifting by a
very large number, which gives the following UBSan splat:

================================================================================
UBSAN: Undefined behaviour in /home/dja/dev/linux/linux/arch/powerpc/mm/tlb_nohash.c:506:21
shift exponent 4294967286 is too large for 32-bit type 'unsigned int'
CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc3-00045-ga604f927b012-dirty #6
Call Trace:
[c00000000101bc20] [c000000000a13d54] .dump_stack+0xa8/0xec (unreliable)
[c00000000101bcb0] [c0000000004f20a8] .ubsan_epilogue+0x18/0x64
[c00000000101bd30] [c0000000004f2b10] .__ubsan_handle_shift_out_of_bounds+0x110/0x1a4
[c00000000101be20] [c000000000d21760] .early_init_mmu+0x1b4/0x5a0
[c00000000101bf10] [c000000000d1ba28] .early_setup+0x100/0x130
[c00000000101bf90] [c000000000000528] start_here_multiplatform+0x68/0x80
================================================================================

Fix this by first checking if the element exists (shift != 0) before
constructing the constant.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregmarsden pushed a commit that referenced this pull request Mar 29, 2019
[ Upstream commit ebaf39e ]

The *_frag_reasm() functions are susceptible to miscalculating the byte
count of packet fragments in case the truesize of a head buffer changes.
The truesize member may be changed by the call to skb_unclone(), leaving
the fragment memory limit counter unbalanced even if all fragments are
processed. This miscalculation goes unnoticed as long as the network
namespace which holds the counter is not destroyed.

Should an attempt be made to destroy a network namespace that holds an
unbalanced fragment memory limit counter the cleanup of the namespace
never finishes. The thread handling the cleanup gets stuck in
inet_frags_exit_net() waiting for the percpu counter to reach zero. The
thread is usually in running state with a stacktrace similar to:

 PID: 1073   TASK: ffff880626711440  CPU: 1   COMMAND: "kworker/u48:4"
  #5 [ffff880621563d48] _raw_spin_lock at ffffffff815f5480
  #6 [ffff880621563d48] inet_evict_bucket at ffffffff8158020b
  #7 [ffff880621563d80] inet_frags_exit_net at ffffffff8158051c
  #8 [ffff880621563db0] ops_exit_list at ffffffff814f5856
  #9 [ffff880621563dd8] cleanup_net at ffffffff814f67c0
 #10 [ffff880621563e38] process_one_work at ffffffff81096f14

It is not possible to create new network namespaces, and processes
that call unshare() end up being stuck in uninterruptible sleep state
waiting to acquire the net_mutex.

The bug was observed in the IPv6 netfilter code by Per Sundstrom.
I thank him for his analysis of the problem. The parts of this patch
that apply to IPv4 and IPv6 fragment reassembly are preemptive measures.

Signed-off-by: Jiri Wiesner <jwiesner@suse.com>
Reported-by: Per Sundstrom <per.sundstrom@redqube.se>
Acked-by: Peter Oskolkov <posk@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregmarsden pushed a commit that referenced this pull request Mar 29, 2019
[ Upstream commit c5a94f4 ]

It was observed that a process blocked indefintely in
__fscache_read_or_alloc_page(), waiting for FSCACHE_COOKIE_LOOKING_UP
to be cleared via fscache_wait_for_deferred_lookup().

At this time, ->backing_objects was empty, which would normaly prevent
__fscache_read_or_alloc_page() from getting to the point of waiting.
This implies that ->backing_objects was cleared *after*
__fscache_read_or_alloc_page was was entered.

When an object is "killed" and then "dropped",
FSCACHE_COOKIE_LOOKING_UP is cleared in fscache_lookup_failure(), then
KILL_OBJECT and DROP_OBJECT are "called" and only in DROP_OBJECT is
->backing_objects cleared.  This leaves a window where
something else can set FSCACHE_COOKIE_LOOKING_UP and
__fscache_read_or_alloc_page() can start waiting, before
->backing_objects is cleared

There is some uncertainty in this analysis, but it seems to be fit the
observations.  Adding the wake in this patch will be handled correctly
by __fscache_read_or_alloc_page(), as it checks if ->backing_objects
is empty again, after waiting.

Customer which reported the hang, also report that the hang cannot be
reproduced with this fix.

The backtrace for the blocked process looked like:

PID: 29360  TASK: ffff881ff2ac0f80  CPU: 3   COMMAND: "zsh"
 #0 [ffff881ff43efbf8] schedule at ffffffff815e56f1
 #1 [ffff881ff43efc58] bit_wait at ffffffff815e64ed
 #2 [ffff881ff43efc68] __wait_on_bit at ffffffff815e61b8
 #3 [ffff881ff43efca0] out_of_line_wait_on_bit at ffffffff815e625e
 #4 [ffff881ff43efd08] fscache_wait_for_deferred_lookup at ffffffffa04f2e8f [fscache]
 #5 [ffff881ff43efd18] __fscache_read_or_alloc_page at ffffffffa04f2ffe [fscache]
 #6 [ffff881ff43efd58] __nfs_readpage_from_fscache at ffffffffa0679668 [nfs]
 #7 [ffff881ff43efd78] nfs_readpage at ffffffffa067092b [nfs]
 #8 [ffff881ff43efda0] generic_file_read_iter at ffffffff81187a73
 #9 [ffff881ff43efe50] nfs_file_read at ffffffffa066544b [nfs]
#10 [ffff881ff43efe70] __vfs_read at ffffffff811fc756
#11 [ffff881ff43efee8] vfs_read at ffffffff811fccfa
#12 [ffff881ff43eff18] sys_read at ffffffff811fda62
#13 [ffff881ff43eff50] entry_SYSCALL_64_fastpath at ffffffff815e986e

Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregmarsden pushed a commit that referenced this pull request Apr 19, 2019
This work around should be reverted when upstream commit (d8b91dd
Merge branch 'perf-core-for-linus' of
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip)
is available in uek.

Issue appear is fixed in upstream tag 4.16.0 . Tag 4.15.0 still has this
issue.

The lask known commit on the perf topic branch that solve this issue
is this: (c19d084 (tag: perf-core-for-mingo-4.16-20180125)
perf trace beauty flock: Move to separate object file).

Without this commit the perf topic branch has the below issue. With
this commit the branch does not have the issue.

Issue is that the above commit does not fix the issue on top of upstream
tag 4.15.0. So the issue is probably fixed by this commit and some additional
commits on the perf topic branch *or/and* on master branch below the point that
the perf branch was branched.

Also this specific commit is not a fix and the only possible relation to this
bug is that it touches the 'flock' code which is used by bash/scripts to
synchronize.

To find the additional commits via git bisect I need to re-order the commits so
that the above commit will be *below* the other commits that solve this issue.
To do that I need to know what's the lowest commit that relate to this fix.

I do not know and have no way to know that.

Attempt to merge the perf topic on top of uek5 produce ~20k commits and tons
of merge conflicts as uek5 is way behind the upstream. So can't even know if
the topic branch with it's ~270 commits fix this issue for uek5.

So I chose to work-around the issue and wait for the upstream topic merge to
obsolite this commit.

When issue occuer:

Serial is flooded with messages:

[71266.680745] bondib0: link status up for interface ib0, enabling it in 0 ms
[71266.682740] bondib0: link status up for interface ib0, enabling it in 0 ms
[71266.685738] bondib0: link status up for interface ib0, enabling it in 0 ms

Then panic occur:

[71266.695757] INFO: task NetworkManager:5837 blocked for more than 120 seconds.
[71266.695759]       Not tainted 4.14.35-1902.0.6.el7uek.x86_64 #2
[71266.695760] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[71266.695761] NetworkManager  D    0  5837      1 0x00000082
[71266.695765] Call Trace:
[71266.695778]  __schedule+0x2bc/0x8da
[71266.695782]  schedule+0x36/0x7c
[71266.695785]  schedule_preempt_disabled+0xe/0x10
[71266.695788]  __mutex_lock.isra.5+0x20c/0x634
[71266.695792]  __mutex_lock_slowpath+0x13/0x15
[71266.695794]  mutex_lock+0x2f/0x3a
[71266.695800]  rtnetlink_rcv_msg+0x1d0/0x289
[71266.695806]  ? __skb_try_recv_datagram+0xca/0x174
[71266.695809]  ? rtnl_calcit.isra.25+0x110/0x103
[71266.695812]  netlink_rcv_skb+0xdf/0x111
[71266.695816]  rtnetlink_rcv+0x15/0x17
[71266.695818]  netlink_unicast+0x18d/0x255
[71266.695820]  netlink_sendmsg+0x2df/0x3cc
[71266.695825]  sock_sendmsg+0x3e/0x4a
[71266.695828]  ___sys_sendmsg+0x2b5/0x2c6
[71266.695832]  ? arch_tlb_finish_mmu+0x1b/0xcb
[71266.695835]  ? tlb_finish_mmu+0x23/0x30
[71266.695838]  ? unmap_region+0xf4/0x12d
[71266.695844]  ? lockref_put_or_lock+0x44/0x72
[71266.695846]  ? __vma_rb_erase+0x10f/0x1f4
[71266.695850]  __sys_sendmsg+0x54/0x8d
[71266.695854]  SyS_sendmsg+0x12/0x1c
[71266.695860]  do_syscall_64+0x79/0x1ae
[71266.695864]  entry_SYSCALL_64_after_hwframe+0x151/0x0
[71266.695866] RIP: 0033:0x7f16f2553c5d
[71266.695867] RSP: 002b:00007ffff7a493f0 EFLAGS: 00000293 ORIG_RAX: 000000000000002e
[71266.695870] RAX: ffffffffffffffda RBX: 00005570a5026380 RCX: 00007f16f2553c5d
[71266.695874] RDX: 0000000000000000 RSI: 00007ffff7a49420 RDI: 0000000000000007
[71266.695875] RBP: 00007ffff7a49420 R08: 0000000000000001 R09: 0000000000000000
[71266.695876] R10: 0000000000000808 R11: 0000000000000293 R12: 00005570a5026380
[71266.695876] R13: 0000000000000000 R14: 0000000000000000 R15: 00007f16d4004b70

Issue analysis:

The ip process is hung in addrconf_notify while trying to print to serial
one of the below messages:
"ADDRCONF(NETDEV_UP): %s: link is not ready\n"
"ADDRCONF(NETDEV_CHANGE): %s: link becomes ready\n"
The ip process hold the rtnl_lock while network-manager process try to grab
this lock in 1 msec loop and every time it fail to grab the lock, the
network-manager send additional line to the serial log as seen in the dmesg:
"bondib0: link status up for interface ib0, enabling it in 0 ms"
So the bond device flood the serial while waiting for the rtnl_lock while ip
hold the rtnl_lock while waiting for the serial.

Offending stack trace from vmcore is this:

PID: 30063  TASK: ffff909c3f675a00  CPU: 7   COMMAND: "ip"
 #0 [fffffe000013ce38] crash_nmi_callback at ffffffff8e059ba7
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/include/asm/paravirt.h: 99
 #1 [fffffe000013ce48] nmi_handle at ffffffff8e032748
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/kernel/nmi.c: 137
 #2 [fffffe000013cea0] default_do_nmi at ffffffff8e032c96
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/kernel/nmi.c: 336
 #3 [fffffe000013cec8] do_nmi at ffffffff8e032e76
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/kernel/nmi.c: 521
 #4 [fffffe000013cef0] end_repeat_nmi at ffffffff8ea0436f
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/entry/entry_64.S: 1750
    [exception RIP: delay_tsc+51]
    RIP: ffffffff8e8558f3  RSP: ffff9f63c6c07390  RFLAGS: 00000046
    RAX: 0000000016d23977  RBX: ffffffff903fbc00  RCX: 00009b7616d23038
    RDX: 0000000000009b76  RSI: 0000000000000007  RDI: 000000000000095a
    RBP: ffff9f63c6c07390   R8: 00000000fffffffe   R9: 0000000000000000
    R10: 0000000000000005  R11: 0000000000020503  R12: 000000000000261f
    R13: 0000000000000020  R14: ffffffff8f96de2f  R15: ffffffff903fbc00
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/include/asm/msr.h: 193
    <NMI exception stack>
 #5 [ffff9f63c6c07390] delay_tsc at ffffffff8e8558f3
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/include/asm/msr.h: 193
 #6 [ffff9f63c6c07398] __const_udelay at ffffffff8e855838
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/lib/delay.c: 176
 #7 [ffff9f63c6c073a8] wait_for_xmitr at ffffffff8e510dcc
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/include/linux/nmi.h: 126
 #8 [ffff9f63c6c073d0] serial8250_console_putchar at ffffffff8e510e6c
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/include/linux/serial_core.h: 265
 #9 [ffff9f63c6c073f0] uart_console_write at ffffffff8e509573
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/drivers/tty/serial/serial_core.c: 1886
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/drivers/tty/serial/8250/8250_port.c: 3256
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/drivers/tty/serial/8250/8250_core.c: 598
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/printk/printk.c: 1574
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/printk/printk.c: 1766
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/printk/printk.c: 1808
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/printk/printk_safe.c: 402
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/printk/printk.c: 1842
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/ipv6/addrconf.c: 3532
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/notifier.c: 95
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/notifier.c: 402
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/dev.c: 1682
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/dev.c: 1697
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/dev.c: 6903
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/rtnetlink.c: 2072
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/rtnetlink.c: 2624
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/rtnetlink.c: 4255
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/netlink/af_netlink.c: 2433
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/rtnetlink.c: 4268
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/netlink/af_netlink.c: 1287
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/netlink/af_netlink.c: 1877
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/socket.c: 646
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/socket.c: 2061
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/include/linux/file.h: 26
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/socket.c: 2102
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/entry/common.c: 295
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/entry/entry_64.S: 247
    RIP: 00007faf75ccafd0  RSP: 00007ffc710a9368  RFLAGS: 00000246
    RAX: ffffffffffffffda  RBX: 000000005c65f66d  RCX: 00007faf75ccafd0
    RDX: 0000000000000000  RSI: 00007ffc710a93b0  RDI: 0000000000000003
    RBP: 00007ffc710a93b0   R8: 0000000000000000   R9: 0000000000000008
    R10: 00007ffc710a8f30  R11: 0000000000000246  R12: 0000000000000000
    R13: 000000000066a440  R14: 00007ffc710a9458  R15: 00007ffc710a9b88
    ORIG_RAX: 000000000000002e  CS: 0033  SS: 002b

Orabug: 29357838

Signed-off-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Signed-off-by: Aron Silverton <aron.silverton@oracle.com>
Reviewed-by: John Haxby <john.haxby@oracle.com>
gregmarsden pushed a commit that referenced this pull request May 17, 2019
This work around should be reverted when upstream commit (d8b91dd
Merge branch 'perf-core-for-linus' of
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip)
is available in uek.

Issue appear is fixed in upstream tag 4.16.0 . Tag 4.15.0 still has this
issue.

The lask known commit on the perf topic branch that solve this issue
is this: (c19d084 (tag: perf-core-for-mingo-4.16-20180125)
perf trace beauty flock: Move to separate object file).

Without this commit the perf topic branch has the below issue. With
this commit the branch does not have the issue.

Issue is that the above commit does not fix the issue on top of upstream
tag 4.15.0. So the issue is probably fixed by this commit and some additional
commits on the perf topic branch *or/and* on master branch below the point that
the perf branch was branched.

Also this specific commit is not a fix and the only possible relation to this
bug is that it touches the 'flock' code which is used by bash/scripts to
synchronize.

To find the additional commits via git bisect I need to re-order the commits so
that the above commit will be *below* the other commits that solve this issue.
To do that I need to know what's the lowest commit that relate to this fix.

I do not know and have no way to know that.

Attempt to merge the perf topic on top of uek5 produce ~20k commits and tons
of merge conflicts as uek5 is way behind the upstream. So can't even know if
the topic branch with it's ~270 commits fix this issue for uek5.

So I chose to work-around the issue and wait for the upstream topic merge to
obsolite this commit.

When issue occuer:

Serial is flooded with messages:

[71266.680745] bondib0: link status up for interface ib0, enabling it in 0 ms
[71266.682740] bondib0: link status up for interface ib0, enabling it in 0 ms
[71266.685738] bondib0: link status up for interface ib0, enabling it in 0 ms

Then panic occur:

[71266.695757] INFO: task NetworkManager:5837 blocked for more than 120 seconds.
[71266.695759]       Not tainted 4.14.35-1902.0.6.el7uek.x86_64 #2
[71266.695760] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[71266.695761] NetworkManager  D    0  5837      1 0x00000082
[71266.695765] Call Trace:
[71266.695778]  __schedule+0x2bc/0x8da
[71266.695782]  schedule+0x36/0x7c
[71266.695785]  schedule_preempt_disabled+0xe/0x10
[71266.695788]  __mutex_lock.isra.5+0x20c/0x634
[71266.695792]  __mutex_lock_slowpath+0x13/0x15
[71266.695794]  mutex_lock+0x2f/0x3a
[71266.695800]  rtnetlink_rcv_msg+0x1d0/0x289
[71266.695806]  ? __skb_try_recv_datagram+0xca/0x174
[71266.695809]  ? rtnl_calcit.isra.25+0x110/0x103
[71266.695812]  netlink_rcv_skb+0xdf/0x111
[71266.695816]  rtnetlink_rcv+0x15/0x17
[71266.695818]  netlink_unicast+0x18d/0x255
[71266.695820]  netlink_sendmsg+0x2df/0x3cc
[71266.695825]  sock_sendmsg+0x3e/0x4a
[71266.695828]  ___sys_sendmsg+0x2b5/0x2c6
[71266.695832]  ? arch_tlb_finish_mmu+0x1b/0xcb
[71266.695835]  ? tlb_finish_mmu+0x23/0x30
[71266.695838]  ? unmap_region+0xf4/0x12d
[71266.695844]  ? lockref_put_or_lock+0x44/0x72
[71266.695846]  ? __vma_rb_erase+0x10f/0x1f4
[71266.695850]  __sys_sendmsg+0x54/0x8d
[71266.695854]  SyS_sendmsg+0x12/0x1c
[71266.695860]  do_syscall_64+0x79/0x1ae
[71266.695864]  entry_SYSCALL_64_after_hwframe+0x151/0x0
[71266.695866] RIP: 0033:0x7f16f2553c5d
[71266.695867] RSP: 002b:00007ffff7a493f0 EFLAGS: 00000293 ORIG_RAX: 000000000000002e
[71266.695870] RAX: ffffffffffffffda RBX: 00005570a5026380 RCX: 00007f16f2553c5d
[71266.695874] RDX: 0000000000000000 RSI: 00007ffff7a49420 RDI: 0000000000000007
[71266.695875] RBP: 00007ffff7a49420 R08: 0000000000000001 R09: 0000000000000000
[71266.695876] R10: 0000000000000808 R11: 0000000000000293 R12: 00005570a5026380
[71266.695876] R13: 0000000000000000 R14: 0000000000000000 R15: 00007f16d4004b70

Issue analysis:

The ip process is hung in addrconf_notify while trying to print to serial
one of the below messages:
"ADDRCONF(NETDEV_UP): %s: link is not ready\n"
"ADDRCONF(NETDEV_CHANGE): %s: link becomes ready\n"
The ip process hold the rtnl_lock while network-manager process try to grab
this lock in 1 msec loop and every time it fail to grab the lock, the
network-manager send additional line to the serial log as seen in the dmesg:
"bondib0: link status up for interface ib0, enabling it in 0 ms"
So the bond device flood the serial while waiting for the rtnl_lock while ip
hold the rtnl_lock while waiting for the serial.

Offending stack trace from vmcore is this:

PID: 30063  TASK: ffff909c3f675a00  CPU: 7   COMMAND: "ip"
 #0 [fffffe000013ce38] crash_nmi_callback at ffffffff8e059ba7
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/include/asm/paravirt.h: 99
 #1 [fffffe000013ce48] nmi_handle at ffffffff8e032748
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/kernel/nmi.c: 137
 #2 [fffffe000013cea0] default_do_nmi at ffffffff8e032c96
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/kernel/nmi.c: 336
 #3 [fffffe000013cec8] do_nmi at ffffffff8e032e76
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/kernel/nmi.c: 521
 #4 [fffffe000013cef0] end_repeat_nmi at ffffffff8ea0436f
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/entry/entry_64.S: 1750
    [exception RIP: delay_tsc+51]
    RIP: ffffffff8e8558f3  RSP: ffff9f63c6c07390  RFLAGS: 00000046
    RAX: 0000000016d23977  RBX: ffffffff903fbc00  RCX: 00009b7616d23038
    RDX: 0000000000009b76  RSI: 0000000000000007  RDI: 000000000000095a
    RBP: ffff9f63c6c07390   R8: 00000000fffffffe   R9: 0000000000000000
    R10: 0000000000000005  R11: 0000000000020503  R12: 000000000000261f
    R13: 0000000000000020  R14: ffffffff8f96de2f  R15: ffffffff903fbc00
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/include/asm/msr.h: 193
    <NMI exception stack>
 #5 [ffff9f63c6c07390] delay_tsc at ffffffff8e8558f3
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/include/asm/msr.h: 193
 #6 [ffff9f63c6c07398] __const_udelay at ffffffff8e855838
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/lib/delay.c: 176
 #7 [ffff9f63c6c073a8] wait_for_xmitr at ffffffff8e510dcc
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/include/linux/nmi.h: 126
 #8 [ffff9f63c6c073d0] serial8250_console_putchar at ffffffff8e510e6c
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/include/linux/serial_core.h: 265
 #9 [ffff9f63c6c073f0] uart_console_write at ffffffff8e509573
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/drivers/tty/serial/serial_core.c: 1886
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/drivers/tty/serial/8250/8250_port.c: 3256
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/drivers/tty/serial/8250/8250_core.c: 598
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/printk/printk.c: 1574
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/printk/printk.c: 1766
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/printk/printk.c: 1808
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/printk/printk_safe.c: 402
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/printk/printk.c: 1842
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/ipv6/addrconf.c: 3532
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/notifier.c: 95
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/notifier.c: 402
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/dev.c: 1682
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/dev.c: 1697
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/dev.c: 6903
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/rtnetlink.c: 2072
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/rtnetlink.c: 2624
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/rtnetlink.c: 4255
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/netlink/af_netlink.c: 2433
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/rtnetlink.c: 4268
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/netlink/af_netlink.c: 1287
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/netlink/af_netlink.c: 1877
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/socket.c: 646
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/socket.c: 2061
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/include/linux/file.h: 26
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/socket.c: 2102
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/entry/common.c: 295
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/entry/entry_64.S: 247
    RIP: 00007faf75ccafd0  RSP: 00007ffc710a9368  RFLAGS: 00000246
    RAX: ffffffffffffffda  RBX: 000000005c65f66d  RCX: 00007faf75ccafd0
    RDX: 0000000000000000  RSI: 00007ffc710a93b0  RDI: 0000000000000003
    RBP: 00007ffc710a93b0   R8: 0000000000000000   R9: 0000000000000008
    R10: 00007ffc710a8f30  R11: 0000000000000246  R12: 0000000000000000
    R13: 000000000066a440  R14: 00007ffc710a9458  R15: 00007ffc710a9b88
    ORIG_RAX: 000000000000002e  CS: 0033  SS: 002b

Orabug: 29016284

Signed-off-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Reviewed-by: John Haxby <john.haxby@oracle.com>
gregmarsden pushed a commit that referenced this pull request May 17, 2019
This work around should be reverted when upstream commit (d8b91dd
Merge branch 'perf-core-for-linus' of
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip)
is available in uek.

Issue appear is fixed in upstream tag 4.16.0 . Tag 4.15.0 still has this
issue.

The lask known commit on the perf topic branch that solve this issue
is this: (c19d084 (tag: perf-core-for-mingo-4.16-20180125)
perf trace beauty flock: Move to separate object file).

Without this commit the perf topic branch has the below issue. With
this commit the branch does not have the issue.

Issue is that the above commit does not fix the issue on top of upstream
tag 4.15.0. So the issue is probably fixed by this commit and some additional
commits on the perf topic branch *or/and* on master branch below the point that
the perf branch was branched.

Also this specific commit is not a fix and the only possible relation to this
bug is that it touches the 'flock' code which is used by bash/scripts to
synchronize.

To find the additional commits via git bisect I need to re-order the commits so
that the above commit will be *below* the other commits that solve this issue.
To do that I need to know what's the lowest commit that relate to this fix.

I do not know and have no way to know that.

Attempt to merge the perf topic on top of uek5 produce ~20k commits and tons
of merge conflicts as uek5 is way behind the upstream. So can't even know if
the topic branch with it's ~270 commits fix this issue for uek5.

So I chose to work-around the issue and wait for the upstream topic merge to
obsolite this commit.

When issue occuer:

Serial is flooded with messages:

[71266.680745] bondib0: link status up for interface ib0, enabling it in 0 ms
[71266.682740] bondib0: link status up for interface ib0, enabling it in 0 ms
[71266.685738] bondib0: link status up for interface ib0, enabling it in 0 ms

Then panic occur:

[71266.695757] INFO: task NetworkManager:5837 blocked for more than 120 seconds.
[71266.695759]       Not tainted 4.14.35-1902.0.6.el7uek.x86_64 #2
[71266.695760] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[71266.695761] NetworkManager  D    0  5837      1 0x00000082
[71266.695765] Call Trace:
[71266.695778]  __schedule+0x2bc/0x8da
[71266.695782]  schedule+0x36/0x7c
[71266.695785]  schedule_preempt_disabled+0xe/0x10
[71266.695788]  __mutex_lock.isra.5+0x20c/0x634
[71266.695792]  __mutex_lock_slowpath+0x13/0x15
[71266.695794]  mutex_lock+0x2f/0x3a
[71266.695800]  rtnetlink_rcv_msg+0x1d0/0x289
[71266.695806]  ? __skb_try_recv_datagram+0xca/0x174
[71266.695809]  ? rtnl_calcit.isra.25+0x110/0x103
[71266.695812]  netlink_rcv_skb+0xdf/0x111
[71266.695816]  rtnetlink_rcv+0x15/0x17
[71266.695818]  netlink_unicast+0x18d/0x255
[71266.695820]  netlink_sendmsg+0x2df/0x3cc
[71266.695825]  sock_sendmsg+0x3e/0x4a
[71266.695828]  ___sys_sendmsg+0x2b5/0x2c6
[71266.695832]  ? arch_tlb_finish_mmu+0x1b/0xcb
[71266.695835]  ? tlb_finish_mmu+0x23/0x30
[71266.695838]  ? unmap_region+0xf4/0x12d
[71266.695844]  ? lockref_put_or_lock+0x44/0x72
[71266.695846]  ? __vma_rb_erase+0x10f/0x1f4
[71266.695850]  __sys_sendmsg+0x54/0x8d
[71266.695854]  SyS_sendmsg+0x12/0x1c
[71266.695860]  do_syscall_64+0x79/0x1ae
[71266.695864]  entry_SYSCALL_64_after_hwframe+0x151/0x0
[71266.695866] RIP: 0033:0x7f16f2553c5d
[71266.695867] RSP: 002b:00007ffff7a493f0 EFLAGS: 00000293 ORIG_RAX: 000000000000002e
[71266.695870] RAX: ffffffffffffffda RBX: 00005570a5026380 RCX: 00007f16f2553c5d
[71266.695874] RDX: 0000000000000000 RSI: 00007ffff7a49420 RDI: 0000000000000007
[71266.695875] RBP: 00007ffff7a49420 R08: 0000000000000001 R09: 0000000000000000
[71266.695876] R10: 0000000000000808 R11: 0000000000000293 R12: 00005570a5026380
[71266.695876] R13: 0000000000000000 R14: 0000000000000000 R15: 00007f16d4004b70

Issue analysis:

The ip process is hung in addrconf_notify while trying to print to serial
one of the below messages:
"ADDRCONF(NETDEV_UP): %s: link is not ready\n"
"ADDRCONF(NETDEV_CHANGE): %s: link becomes ready\n"
The ip process hold the rtnl_lock while network-manager process try to grab
this lock in 1 msec loop and every time it fail to grab the lock, the
network-manager send additional line to the serial log as seen in the dmesg:
"bondib0: link status up for interface ib0, enabling it in 0 ms"
So the bond device flood the serial while waiting for the rtnl_lock while ip
hold the rtnl_lock while waiting for the serial.

Offending stack trace from vmcore is this:

PID: 30063  TASK: ffff909c3f675a00  CPU: 7   COMMAND: "ip"
 #0 [fffffe000013ce38] crash_nmi_callback at ffffffff8e059ba7
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/include/asm/paravirt.h: 99
 #1 [fffffe000013ce48] nmi_handle at ffffffff8e032748
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/kernel/nmi.c: 137
 #2 [fffffe000013cea0] default_do_nmi at ffffffff8e032c96
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/kernel/nmi.c: 336
 #3 [fffffe000013cec8] do_nmi at ffffffff8e032e76
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/kernel/nmi.c: 521
 #4 [fffffe000013cef0] end_repeat_nmi at ffffffff8ea0436f
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/entry/entry_64.S: 1750
    [exception RIP: delay_tsc+51]
    RIP: ffffffff8e8558f3  RSP: ffff9f63c6c07390  RFLAGS: 00000046
    RAX: 0000000016d23977  RBX: ffffffff903fbc00  RCX: 00009b7616d23038
    RDX: 0000000000009b76  RSI: 0000000000000007  RDI: 000000000000095a
    RBP: ffff9f63c6c07390   R8: 00000000fffffffe   R9: 0000000000000000
    R10: 0000000000000005  R11: 0000000000020503  R12: 000000000000261f
    R13: 0000000000000020  R14: ffffffff8f96de2f  R15: ffffffff903fbc00
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/include/asm/msr.h: 193
    <NMI exception stack>
 #5 [ffff9f63c6c07390] delay_tsc at ffffffff8e8558f3
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/include/asm/msr.h: 193
 #6 [ffff9f63c6c07398] __const_udelay at ffffffff8e855838
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/lib/delay.c: 176
 #7 [ffff9f63c6c073a8] wait_for_xmitr at ffffffff8e510dcc
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/include/linux/nmi.h: 126
 #8 [ffff9f63c6c073d0] serial8250_console_putchar at ffffffff8e510e6c
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/include/linux/serial_core.h: 265
 #9 [ffff9f63c6c073f0] uart_console_write at ffffffff8e509573
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/drivers/tty/serial/serial_core.c: 1886
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/drivers/tty/serial/8250/8250_port.c: 3256
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/drivers/tty/serial/8250/8250_core.c: 598
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/printk/printk.c: 1574
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/printk/printk.c: 1766
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/printk/printk.c: 1808
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/printk/printk_safe.c: 402
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/printk/printk.c: 1842
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/ipv6/addrconf.c: 3532
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/notifier.c: 95
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/kernel/notifier.c: 402
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/dev.c: 1682
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/dev.c: 1697
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/dev.c: 6903
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/rtnetlink.c: 2072
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/rtnetlink.c: 2624
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/rtnetlink.c: 4255
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/netlink/af_netlink.c: 2433
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/core/rtnetlink.c: 4268
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/netlink/af_netlink.c: 1287
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/netlink/af_netlink.c: 1877
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/socket.c: 646
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/socket.c: 2061
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/include/linux/file.h: 26
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/net/socket.c: 2102
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/entry/common.c: 295
    /usr/src/debug/kernel-4.14.35/linux-4.14.35-1902.0.6.el7uek/arch/x86/entry/entry_64.S: 247
    RIP: 00007faf75ccafd0  RSP: 00007ffc710a9368  RFLAGS: 00000246
    RAX: ffffffffffffffda  RBX: 000000005c65f66d  RCX: 00007faf75ccafd0
    RDX: 0000000000000000  RSI: 00007ffc710a93b0  RDI: 0000000000000003
    RBP: 00007ffc710a93b0   R8: 0000000000000000   R9: 0000000000000008
    R10: 00007ffc710a8f30  R11: 0000000000000246  R12: 0000000000000000
    R13: 000000000066a440  R14: 00007ffc710a9458  R15: 00007ffc710a9b88
    ORIG_RAX: 000000000000002e  CS: 0033  SS: 002b

Orabug: 29631452

Signed-off-by: Shamir Rabinovitch <shamir.rabinovitch@oracle.com>
Signed-off-by: Aron Silverton <aron.silverton@oracle.com>
Reviewed-by: John Haxby <john.haxby@oracle.com>
LinuxMinion pushed a commit that referenced this pull request Sep 6, 2019
…_map

[ Upstream commit 39df730 ]

Detected via gcc's ASan:

  Direct leak of 2048 byte(s) in 64 object(s) allocated from:
    6     #0 0x7f606512e370 in __interceptor_realloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee370)
    7     #1 0x556b0f1d7ddd in thread_map__realloc util/thread_map.c:43
    8     #2 0x556b0f1d84c7 in thread_map__new_by_tid util/thread_map.c:85
    9     #3 0x556b0f0e045e in is_event_supported util/parse-events.c:2250
   10     #4 0x556b0f0e1aa1 in print_hwcache_events util/parse-events.c:2382
   11     #5 0x556b0f0e3231 in print_events util/parse-events.c:2514
   12     #6 0x556b0ee0a66e in cmd_list /home/changbin/work/linux/tools/perf/builtin-list.c:58
   13     #7 0x556b0f01e0ae in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
   14     #8 0x556b0f01e859 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
   15     #9 0x556b0f01edc8 in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
   16     #10 0x556b0f01f71f in main /home/changbin/work/linux/tools/perf/perf.c:520
   17     #11 0x7f6062ccf09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fixes: 8989605 ("perf tools: Do not put a variable sized type not at the end of a struct")
Link: http://lkml.kernel.org/r/20190316080556.3075-3-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
LinuxMinion pushed a commit that referenced this pull request Sep 6, 2019
[ Upstream commit 54569ba ]

Detected with gcc's ASan:

  Direct leak of 66 byte(s) in 5 object(s) allocated from:
      #0 0x7ff3b1f32070 in __interceptor_strdup (/usr/lib/x86_64-linux-gnu/libasan.so.5+0x3b070)
      #1 0x560c8761034d in collect_config util/config.c:597
      #2 0x560c8760d9cb in get_value util/config.c:169
      #3 0x560c8760dfd7 in perf_parse_file util/config.c:285
      #4 0x560c8760e0d2 in perf_config_from_file util/config.c:476
      #5 0x560c876108fd in perf_config_set__init util/config.c:661
      #6 0x560c87610c72 in perf_config_set__new util/config.c:709
      #7 0x560c87610d2f in perf_config__init util/config.c:718
      #8 0x560c87610e5d in perf_config util/config.c:730
      #9 0x560c875ddea0 in main /home/changbin/work/linux/tools/perf/perf.c:442
      #10 0x7ff3afb8609a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Taeung Song <treeze.taeung@gmail.com>
Fixes: 20105ca ("perf config: Introduce perf_config_set class")
Link: http://lkml.kernel.org/r/20190316080556.3075-6-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
LinuxMinion pushed a commit that referenced this pull request Sep 6, 2019
[ Upstream commit 8bde851 ]

Detected with gcc's ASan:

  Direct leak of 4356 byte(s) in 120 object(s) allocated from:
      #0 0x7ff1a2b5a070 in __interceptor_strdup (/usr/lib/x86_64-linux-gnu/libasan.so.5+0x3b070)
      #1 0x55719aef4814 in build_id_cache__origname util/build-id.c:215
      #2 0x55719af649b6 in print_sdt_events util/parse-events.c:2339
      #3 0x55719af66272 in print_events util/parse-events.c:2542
      #4 0x55719ad1ecaa in cmd_list /home/changbin/work/linux/tools/perf/builtin-list.c:58
      #5 0x55719aec745d in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #6 0x55719aec7d1a in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #7 0x55719aec8184 in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #8 0x55719aeca41a in main /home/changbin/work/linux/tools/perf/perf.c:520
      #9 0x7ff1a07ae09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fixes: 40218da ("perf list: Show SDT and pre-cached events")
Link: http://lkml.kernel.org/r/20190316080556.3075-7-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
LinuxMinion pushed a commit that referenced this pull request Sep 6, 2019
[ Upstream commit 42dfa45 ]

Using gcc's ASan, Changbin reports:

  =================================================================
  ==7494==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 48 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a89138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      #1 0x5625e5330a5e in zalloc util/util.h:23
      #2 0x5625e5330a9b in perf_counts__new util/counts.c:10
      #3 0x5625e5330ca0 in perf_evsel__alloc_counts util/counts.c:47
      #4 0x5625e520d8e5 in __perf_evsel__read_on_cpu util/evsel.c:1505
      #5 0x5625e517a985 in perf_evsel__read_on_cpu /home/work/linux/tools/perf/util/evsel.h:347
      #6 0x5625e517ad1a in test__openat_syscall_event tests/openat-syscall.c:47
      #7 0x5625e51528e6 in run_test tests/builtin-test.c:358
      #8 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      #9 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      #10 0x5625e515572f in cmd_test tests/builtin-test.c:722
      #11 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #12 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #13 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #14 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #15 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  Indirect leak of 72 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a89138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      #1 0x5625e532560d in zalloc util/util.h:23
      #2 0x5625e532566b in xyarray__new util/xyarray.c:10
      #3 0x5625e5330aba in perf_counts__new util/counts.c:15
      #4 0x5625e5330ca0 in perf_evsel__alloc_counts util/counts.c:47
      #5 0x5625e520d8e5 in __perf_evsel__read_on_cpu util/evsel.c:1505
      #6 0x5625e517a985 in perf_evsel__read_on_cpu /home/work/linux/tools/perf/util/evsel.h:347
      #7 0x5625e517ad1a in test__openat_syscall_event tests/openat-syscall.c:47
      #8 0x5625e51528e6 in run_test tests/builtin-test.c:358
      #9 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      #10 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      #11 0x5625e515572f in cmd_test tests/builtin-test.c:722
      #12 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #13 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #14 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #15 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #16 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

His patch took care of evsel->prev_raw_counts, but the above backtraces
are about evsel->counts, so fix that instead.

Reported-by: Changbin Du <changbin.du@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/n/tip-hd1x13g59f0nuhe4anxhsmfp@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
LinuxMinion pushed a commit that referenced this pull request Sep 6, 2019
…_event_on_all_cpus test

[ Upstream commit 93faa52 ]

  =================================================================
  ==7497==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 40 byte(s) in 1 object(s) allocated from:
      #0 0x7f0333a88f30 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedf30)
      #1 0x5625e5326213 in cpu_map__trim_new util/cpumap.c:45
      #2 0x5625e5326703 in cpu_map__read util/cpumap.c:103
      #3 0x5625e53267ef in cpu_map__read_all_cpu_map util/cpumap.c:120
      #4 0x5625e5326915 in cpu_map__new util/cpumap.c:135
      #5 0x5625e517b355 in test__openat_syscall_event_on_all_cpus tests/openat-syscall-all-cpus.c:36
      #6 0x5625e51528e6 in run_test tests/builtin-test.c:358
      #7 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      #8 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      #9 0x5625e515572f in cmd_test tests/builtin-test.c:722
      #10 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #11 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #12 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #13 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #14 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fixes: f30a79b ("perf tools: Add reference counting for cpu_map object")
Link: http://lkml.kernel.org/r/20190316080556.3075-15-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
LinuxMinion pushed a commit that referenced this pull request Sep 6, 2019
[ Upstream commit f97a899 ]

  =================================================================
  ==7506==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 13 byte(s) in 3 object(s) allocated from:
      #0 0x7f03339d6070 in __interceptor_strdup (/usr/lib/x86_64-linux-gnu/libasan.so.5+0x3b070)
      #1 0x5625e53aaef0 in expr__find_other util/expr.y:221
      #2 0x5625e51bcd3f in test__expr tests/expr.c:52
      #3 0x5625e51528e6 in run_test tests/builtin-test.c:358
      #4 0x5625e5152baf in test_and_print tests/builtin-test.c:388
      #5 0x5625e51543fe in __cmd_test tests/builtin-test.c:583
      #6 0x5625e515572f in cmd_test tests/builtin-test.c:722
      #7 0x5625e51c3fb8 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #8 0x5625e51c44f7 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #9 0x5625e51c48fb in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #10 0x5625e51c5069 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #11 0x7f033214d09a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fixes: 0751673 ("perf tools: Add a simple expression parser for JSON")
Link: http://lkml.kernel.org/r/20190316080556.3075-16-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
LinuxMinion pushed a commit that referenced this pull request Sep 6, 2019
[ Upstream commit d982b33 ]

  =================================================================
  ==20875==ERROR: LeakSanitizer: detected memory leaks

  Direct leak of 1160 byte(s) in 1 object(s) allocated from:
      #0 0x7f1b6fc84138 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xee138)
      #1 0x55bd50005599 in zalloc util/util.h:23
      #2 0x55bd500068f5 in perf_evsel__newtp_idx util/evsel.c:327
      #3 0x55bd4ff810fc in perf_evsel__newtp /home/work/linux/tools/perf/util/evsel.h:216
      #4 0x55bd4ff81608 in test__perf_evsel__tp_sched_test tests/evsel-tp-sched.c:69
      #5 0x55bd4ff528e6 in run_test tests/builtin-test.c:358
      #6 0x55bd4ff52baf in test_and_print tests/builtin-test.c:388
      #7 0x55bd4ff543fe in __cmd_test tests/builtin-test.c:583
      #8 0x55bd4ff5572f in cmd_test tests/builtin-test.c:722
      #9 0x55bd4ffc4087 in run_builtin /home/changbin/work/linux/tools/perf/perf.c:302
      #10 0x55bd4ffc45c6 in handle_internal_command /home/changbin/work/linux/tools/perf/perf.c:354
      #11 0x55bd4ffc49ca in run_argv /home/changbin/work/linux/tools/perf/perf.c:398
      #12 0x55bd4ffc5138 in main /home/changbin/work/linux/tools/perf/perf.c:520
      #13 0x7f1b6e34809a in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x2409a)

  Indirect leak of 19 byte(s) in 1 object(s) allocated from:
      #0 0x7f1b6fc83f30 in __interceptor_malloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xedf30)
      #1 0x7f1b6e3ac30f in vasprintf (/lib/x86_64-linux-gnu/libc.so.6+0x8830f)

Signed-off-by: Changbin Du <changbin.du@gmail.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Fixes: 6a6cd11 ("perf test: Add test for the sched tracepoint format fields")
Link: http://lkml.kernel.org/r/20190316080556.3075-17-changbin.du@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
LinuxMinion pushed a commit that referenced this pull request Sep 6, 2019
[ Upstream commit c34a838 ]

Clients may submit a new requests from the completion callback
context. The driver was not prepared to receive a request in this
state because it already held the request queue lock and a recursive
lock error is triggered.

Now all completions are queued up until we are ready to drop the queue
lock and then delivered.

The fault was triggered by TCP over an IPsec connection in the LTP
test suite:
  LTP: starting tcp4_ipsec02 (tcp_ipsec.sh -p ah -m transport -s "100 1000 65535")
  BUG: spinlock recursion on CPU#1, genload/943
   lock: 0xbf3c3094, .magic: dead4ead, .owner: genload/943, .owner_cpu: 1
  CPU: 1 PID: 943 Comm: genload Tainted: G           O    4.9.62-axis5-devel #6
  Hardware name: Axis ARTPEC-6 Platform
   (unwind_backtrace) from [<8010d134>] (show_stack+0x18/0x1c)
   (show_stack) from [<803a289c>] (dump_stack+0x84/0x98)
   (dump_stack) from [<8016e164>] (do_raw_spin_lock+0x124/0x128)
   (do_raw_spin_lock) from [<804de1a4>] (artpec6_crypto_submit+0x2c/0xa0)
   (artpec6_crypto_submit) from [<804def38>] (artpec6_crypto_prepare_submit_hash+0xd0/0x54c)
   (artpec6_crypto_prepare_submit_hash) from [<7f3165f0>] (ah_output+0x2a4/0x3dc [ah4])
   (ah_output [ah4]) from [<805df9bc>] (xfrm_output_resume+0x178/0x4a4)
   (xfrm_output_resume) from [<805d283c>] (xfrm4_output+0xac/0xbc)
   (xfrm4_output) from [<80587928>] (ip_queue_xmit+0x140/0x3b4)
   (ip_queue_xmit) from [<805a13b4>] (tcp_transmit_skb+0x4c4/0x95c)
   (tcp_transmit_skb) from [<8059f218>] (tcp_rcv_state_process+0xdf4/0xdfc)
   (tcp_rcv_state_process) from [<805a7530>] (tcp_v4_do_rcv+0x64/0x1ac)
   (tcp_v4_do_rcv) from [<805a9724>] (tcp_v4_rcv+0xa34/0xb74)
   (tcp_v4_rcv) from [<80581d34>] (ip_local_deliver_finish+0x78/0x2b0)
   (ip_local_deliver_finish) from [<8058259c>] (ip_local_deliver+0xe4/0x104)
   (ip_local_deliver) from [<805d23ec>] (xfrm4_transport_finish+0xf4/0x144)
   (xfrm4_transport_finish) from [<805df564>] (xfrm_input+0x4f4/0x74c)
   (xfrm_input) from [<804de420>] (artpec6_crypto_task+0x208/0x38c)
   (artpec6_crypto_task) from [<801271b0>] (tasklet_action+0x60/0xec)
   (tasklet_action) from [<801266d4>] (__do_softirq+0xcc/0x3a4)
   (__do_softirq) from [<80126d20>] (irq_exit+0xf4/0x15c)
   (irq_exit) from [<801741e8>] (__handle_domain_irq+0x68/0xbc)
   (__handle_domain_irq) from [<801014f0>] (gic_handle_irq+0x50/0x94)
   (gic_handle_irq) from [<80657370>] (__irq_usr+0x50/0x80)

Signed-off-by: Lars Persson <larper@axis.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregmarsden pushed a commit that referenced this pull request Nov 15, 2019
commit 7298e3b upstream.

Currently the calcuation of end_pfn can round up the pfn number to more
than the actual maximum number of pfns, causing an Oops.  Fix this by
ensuring end_pfn is never more than max_pfn.

This can be easily triggered when on systems where the end_pfn gets
rounded up to more than max_pfn using the idle-page stress-ng stress test:

sudo stress-ng --idle-page 0

  BUG: unable to handle kernel paging request at 00000000000020d8
  #PF error: [normal kernel read fault]
  PGD 0 P4D 0
  Oops: 0000 [#1] SMP PTI
  CPU: 1 PID: 11039 Comm: stress-ng-idle- Not tainted 5.0.0-5-generic #6-Ubuntu
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
  RIP: 0010:page_idle_get_page+0xc8/0x1a0
  Code: 0f b1 0a 75 7d 48 8b 03 48 89 c2 48 c1 e8 33 83 e0 07 48 c1 ea 36 48 8d 0c 40 4c 8d 24 88 49 c1 e4 07 4c 03 24 d5 00 89 c3 be <49> 8b 44 24 58 48 8d b8 80 a1 02 00 e8 07 d5 77 00 48 8b 53 08 48
  RSP: 0018:ffffafd7c672fde8 EFLAGS: 00010202
  RAX: 0000000000000005 RBX: ffffe36341fff700 RCX: 000000000000000f
  RDX: 0000000000000284 RSI: 0000000000000275 RDI: 0000000001fff700
  RBP: ffffafd7c672fe00 R08: ffffa0bc34056410 R09: 0000000000000276
  R10: ffffa0bc754e9b40 R11: ffffa0bc330f6400 R12: 0000000000002080
  R13: ffffe36341fff700 R14: 0000000000080000 R15: ffffa0bc330f6400
  FS: 00007f0ec1ea5740(0000) GS:ffffa0bc7db00000(0000) knlGS:0000000000000000
  CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 00000000000020d8 CR3: 0000000077d68000 CR4: 00000000000006e0
  Call Trace:
    page_idle_bitmap_write+0x8c/0x140
    sysfs_kf_bin_write+0x5c/0x70
    kernfs_fop_write+0x12e/0x1b0
    __vfs_write+0x1b/0x40
    vfs_write+0xab/0x1b0
    ksys_write+0x55/0xc0
    __x64_sys_write+0x1a/0x20
    do_syscall_64+0x5a/0x110
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

Link: http://lkml.kernel.org/r/20190618124352.28307-1-colin.king@canonical.com
Fixes: 33c3fc7 ("mm: introduce idle page tracking")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregmarsden pushed a commit that referenced this pull request Nov 22, 2019
…erycap

[ Upstream commit 5d2e73a ]

SyzKaller hit the null pointer deref while reading from uninitialized
udev->product in zr364xx_vidioc_querycap().

==================================================================
BUG: KASAN: null-ptr-deref in read_word_at_a_time+0xe/0x20
include/linux/compiler.h:274
Read of size 1 at addr 0000000000000000 by task v4l_id/5287

CPU: 1 PID: 5287 Comm: v4l_id Not tainted 5.1.0-rc3-319004-g43151d6 #6
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0xe8/0x16e lib/dump_stack.c:113
  kasan_report.cold+0x5/0x3c mm/kasan/report.c:321
  read_word_at_a_time+0xe/0x20 include/linux/compiler.h:274
  strscpy+0x8a/0x280 lib/string.c:207
  zr364xx_vidioc_querycap+0xb5/0x210 drivers/media/usb/zr364xx/zr364xx.c:706
  v4l_querycap+0x12b/0x340 drivers/media/v4l2-core/v4l2-ioctl.c:1062
  __video_do_ioctl+0x5bb/0xb40 drivers/media/v4l2-core/v4l2-ioctl.c:2874
  video_usercopy+0x44e/0xf00 drivers/media/v4l2-core/v4l2-ioctl.c:3056
  v4l2_ioctl+0x14e/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:364
  vfs_ioctl fs/ioctl.c:46 [inline]
  file_ioctl fs/ioctl.c:509 [inline]
  do_vfs_ioctl+0xced/0x12f0 fs/ioctl.c:696
  ksys_ioctl+0xa0/0xc0 fs/ioctl.c:713
  __do_sys_ioctl fs/ioctl.c:720 [inline]
  __se_sys_ioctl fs/ioctl.c:718 [inline]
  __x64_sys_ioctl+0x74/0xb0 fs/ioctl.c:718
  do_syscall_64+0xcf/0x4f0 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f3b56d8b347
Code: 90 90 90 48 8b 05 f1 fa 2a 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff
ff c3 90 90 90 90 90 90 90 90 90 90 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff
ff 73 01 c3 48 8b 0d c1 fa 2a 00 31 d2 48 29 c2 64
RSP: 002b:00007ffe005d5d68 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f3b56d8b347
RDX: 00007ffe005d5d70 RSI: 0000000080685600 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000400884
R13: 00007ffe005d5ec0 R14: 0000000000000000 R15: 0000000000000000
==================================================================

For this device udev->product is not initialized and accessing it causes a NULL pointer deref.

The fix is to check for NULL before strscpy() and copy empty string, if
product is NULL

Reported-by: syzbot+66010012fd4c531a1a96@syzkaller.appspotmail.com
Signed-off-by: Vandana BN <bnvandana@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit dbabee0cac1e3c5502ed0e9298226d81ca71a441)

Orabug: 30532773
CVE: CVE-2019-15217

Signed-off-by: Larry Bassel <larry.bassel@oracle.com>
Reviewed-by: John Donnelly <John.p.donnelly@oracle.com>
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
gregmarsden pushed a commit that referenced this pull request Nov 22, 2019
…erycap

[ Upstream commit 5d2e73a ]

SyzKaller hit the null pointer deref while reading from uninitialized
udev->product in zr364xx_vidioc_querycap().

==================================================================
BUG: KASAN: null-ptr-deref in read_word_at_a_time+0xe/0x20
include/linux/compiler.h:274
Read of size 1 at addr 0000000000000000 by task v4l_id/5287

CPU: 1 PID: 5287 Comm: v4l_id Not tainted 5.1.0-rc3-319004-g43151d6 #6
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0xe8/0x16e lib/dump_stack.c:113
  kasan_report.cold+0x5/0x3c mm/kasan/report.c:321
  read_word_at_a_time+0xe/0x20 include/linux/compiler.h:274
  strscpy+0x8a/0x280 lib/string.c:207
  zr364xx_vidioc_querycap+0xb5/0x210 drivers/media/usb/zr364xx/zr364xx.c:706
  v4l_querycap+0x12b/0x340 drivers/media/v4l2-core/v4l2-ioctl.c:1062
  __video_do_ioctl+0x5bb/0xb40 drivers/media/v4l2-core/v4l2-ioctl.c:2874
  video_usercopy+0x44e/0xf00 drivers/media/v4l2-core/v4l2-ioctl.c:3056
  v4l2_ioctl+0x14e/0x1a0 drivers/media/v4l2-core/v4l2-dev.c:364
  vfs_ioctl fs/ioctl.c:46 [inline]
  file_ioctl fs/ioctl.c:509 [inline]
  do_vfs_ioctl+0xced/0x12f0 fs/ioctl.c:696
  ksys_ioctl+0xa0/0xc0 fs/ioctl.c:713
  __do_sys_ioctl fs/ioctl.c:720 [inline]
  __se_sys_ioctl fs/ioctl.c:718 [inline]
  __x64_sys_ioctl+0x74/0xb0 fs/ioctl.c:718
  do_syscall_64+0xcf/0x4f0 arch/x86/entry/common.c:290
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f3b56d8b347
Code: 90 90 90 48 8b 05 f1 fa 2a 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff
ff c3 90 90 90 90 90 90 90 90 90 90 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff
ff 73 01 c3 48 8b 0d c1 fa 2a 00 31 d2 48 29 c2 64
RSP: 002b:00007ffe005d5d68 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f3b56d8b347
RDX: 00007ffe005d5d70 RSI: 0000000080685600 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000400884
R13: 00007ffe005d5ec0 R14: 0000000000000000 R15: 0000000000000000
==================================================================

For this device udev->product is not initialized and accessing it causes a NULL pointer deref.

The fix is to check for NULL before strscpy() and copy empty string, if
product is NULL

Reported-by: syzbot+66010012fd4c531a1a96@syzkaller.appspotmail.com
Signed-off-by: Vandana BN <bnvandana@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit dbabee0cac1e3c5502ed0e9298226d81ca71a441)

Orabug: 30532771
CVE: CVE-2019-15217

Signed-off-by: Larry Bassel <larry.bassel@oracle.com>
Reviewed-by: John Donnelly <John.p.donnelly@oracle.com>
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
gregmarsden pushed a commit that referenced this pull request Nov 29, 2019
commit d0a255e upstream.

A deadlock with this stacktrace was observed.

The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio
shrinker and the shrinker depends on I/O completion in the dm-bufio
subsystem.

In order to fix the deadlock (and other similar ones), we set the flag
PF_MEMALLOC_NOIO at loop thread entry.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

  PID: 14127  TASK: ffff881455749c00  CPU: 11  COMMAND: "loop1"
   #0 [ffff88272f5af228] __schedule at ffffffff8173f405
   #1 [ffff88272f5af280] schedule at ffffffff8173fa27
   #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e
   #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5
   #4 [ffff88272f5af330] mutex_lock at ffffffff81742133
   #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio]
   #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd
   #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778
   #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34
   #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8
  #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3
  #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71
  #12 [ffff88272f5af760] new_slab at ffffffff811f4523
  #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5
  #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b
  #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3
  #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3
  #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs]
  #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994
  #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs]
  #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop]
  #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop]
  #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c
  #23 [ffff88272f5afec0] kthread at ffffffff810a8428
  #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregmarsden pushed a commit that referenced this pull request Nov 29, 2019
commit cf3591e upstream.

Revert the commit bd293d0. The proper
fix has been made available with commit d0a255e ("loop: set
PF_MEMALLOC_NOIO for the worker thread").

Note that the fix offered by commit bd293d0 doesn't really prevent
the deadlock from occuring - if we look at the stacktrace reported by
Junxiao Bi, we see that it hangs in bit_wait_io and not on the mutex -
i.e. it has already successfully taken the mutex. Changing the mutex
from mutex_lock to mutex_trylock won't help with deadlocks that happen
afterwards.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Fixes: bd293d0 ("dm bufio: fix deadlock with loop device")
Depends-on: d0a255e ("loop: set PF_MEMALLOC_NOIO for the worker thread")
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregmarsden pushed a commit that referenced this pull request Nov 29, 2019
commit 314eed3 upstream.

When running on a system with >512MB RAM with a 32-bit kernel built with:

	CONFIG_DEBUG_VIRTUAL=y
	CONFIG_HIGHMEM=y
	CONFIG_HARDENED_USERCOPY=y

all execve()s will fail due to argv copying into kmap()ed pages, and on
usercopy checking the calls ultimately of virt_to_page() will be looking
for "bad" kmap (highmem) pointers due to CONFIG_DEBUG_VIRTUAL=y:

 ------------[ cut here ]------------
 kernel BUG at ../arch/x86/mm/physaddr.c:83!
 invalid opcode: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
 CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.3.0-rc8 #6
 Hardware name: Dell Inc. Inspiron 1318/0C236D, BIOS A04 01/15/2009
 EIP: __phys_addr+0xaf/0x100
 ...
 Call Trace:
  __check_object_size+0xaf/0x3c0
  ? __might_sleep+0x80/0xa0
  copy_strings+0x1c2/0x370
  copy_strings_kernel+0x2b/0x40
  __do_execve_file+0x4ca/0x810
  ? kmem_cache_alloc+0x1c7/0x370
  do_execve+0x1b/0x20
  ...

The check is from arch/x86/mm/physaddr.c:

	VIRTUAL_BUG_ON((phys_addr >> PAGE_SHIFT) > max_low_pfn);

Due to the kmap() in fs/exec.c:

		kaddr = kmap(kmapped_page);
	...
	if (copy_from_user(kaddr+offset, str, bytes_to_copy)) ...

Now we can fetch the correct page to avoid the pfn check. In both cases,
hardened usercopy will need to walk the page-span checker (if enabled)
to do sanity checking.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Fixes: f5509cc ("mm: Hardened usercopy")
Cc: Matthew Wilcox <willy@infradead.org>
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/201909171056.7F2FFD17@keescook
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregmarsden pushed a commit that referenced this pull request Mar 20, 2020
The req->body should be updated before req->state is updated and the
order should be guaranteed by a barrier.

Otherwise, read_reply() might return req->body = NULL.

Below is sample callstack when the issue is reproduced on purpose by
reordering the updates of req->body and req->state and adding delay in
code between updates of req->state and req->body.

[   22.356105] general protection fault: 0000 [#1] SMP PTI
[   22.361185] CPU: 2 PID: 52 Comm: xenwatch Not tainted 5.5.0xen+ #6
[   22.366727] Hardware name: Xen HVM domU, BIOS ...
[   22.372245] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60
... ...
[   22.392163] RSP: 0018:ffffb2d64023fdf0 EFLAGS: 00010246
[   22.395933] RAX: 0000000000000000 RBX: 75746e7562755f6d RCX: 0000000000000000
[   22.400871] RDX: 0000000000000000 RSI: ffffb2d64023fdfc RDI: 75746e7562755f6d
[   22.405874] RBP: 0000000000000000 R08: 00000000000001e8 R09: 0000000000cdcdcd
[   22.410945] R10: ffffb2d6402ffe00 R11: ffff9d95395eaeb0 R12: ffff9d9535935000
[   22.417613] R13: ffff9d9526d4a000 R14: ffff9d9526f4f340 R15: ffff9d9537654000
[   22.423726] FS:  0000000000000000(0000) GS:ffff9d953bc80000(0000) knlGS:0000000000000000
[   22.429898] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   22.434342] CR2: 000000c4206a9000 CR3: 00000001ea3fc002 CR4: 00000000001606e0
[   22.439645] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   22.444941] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   22.450342] Call Trace:
[   22.452509]  simple_strtoull+0x27/0x70
[   22.455572]  xenbus_transaction_start+0x31/0x50
[   22.459104]  netback_changed+0x76c/0xcc1 [xen_netfront]
[   22.463279]  ? find_watch+0x40/0x40
[   22.466156]  xenwatch_thread+0xb4/0x150
[   22.469309]  ? wait_woken+0x80/0x80
[   22.472198]  kthread+0x10e/0x130
[   22.474925]  ? kthread_park+0x80/0x80
[   22.477946]  ret_from_fork+0x35/0x40
[   22.480968] Modules linked in: xen_kbdfront xen_fbfront(+) xen_netfront xen_blkfront
[   22.486783] ---[ end trace a9222030a747c3f7 ]---
[   22.490424] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60

The virt_rmb() is added in the 'true' path of test_reply(). The "while"
is changed to "do while" so that test_reply() is used as a read memory
barrier.

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Link: https://lore.kernel.org/r/20200303221423.21962-1-dongli.zhang@oracle.com
Reviewed-by: Julien Grall <jgrall@amazon.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

(cherry picked from commit 1b6a51e)
Orabug: 31009566
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
gregmarsden pushed a commit that referenced this pull request Mar 20, 2020
The req->body should be updated before req->state is updated and the
order should be guaranteed by a barrier.

Otherwise, read_reply() might return req->body = NULL.

Below is sample callstack when the issue is reproduced on purpose by
reordering the updates of req->body and req->state and adding delay in
code between updates of req->state and req->body.

[   22.356105] general protection fault: 0000 [#1] SMP PTI
[   22.361185] CPU: 2 PID: 52 Comm: xenwatch Not tainted 5.5.0xen+ #6
[   22.366727] Hardware name: Xen HVM domU, BIOS ...
[   22.372245] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60
... ...
[   22.392163] RSP: 0018:ffffb2d64023fdf0 EFLAGS: 00010246
[   22.395933] RAX: 0000000000000000 RBX: 75746e7562755f6d RCX: 0000000000000000
[   22.400871] RDX: 0000000000000000 RSI: ffffb2d64023fdfc RDI: 75746e7562755f6d
[   22.405874] RBP: 0000000000000000 R08: 00000000000001e8 R09: 0000000000cdcdcd
[   22.410945] R10: ffffb2d6402ffe00 R11: ffff9d95395eaeb0 R12: ffff9d9535935000
[   22.417613] R13: ffff9d9526d4a000 R14: ffff9d9526f4f340 R15: ffff9d9537654000
[   22.423726] FS:  0000000000000000(0000) GS:ffff9d953bc80000(0000) knlGS:0000000000000000
[   22.429898] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   22.434342] CR2: 000000c4206a9000 CR3: 00000001ea3fc002 CR4: 00000000001606e0
[   22.439645] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   22.444941] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   22.450342] Call Trace:
[   22.452509]  simple_strtoull+0x27/0x70
[   22.455572]  xenbus_transaction_start+0x31/0x50
[   22.459104]  netback_changed+0x76c/0xcc1 [xen_netfront]
[   22.463279]  ? find_watch+0x40/0x40
[   22.466156]  xenwatch_thread+0xb4/0x150
[   22.469309]  ? wait_woken+0x80/0x80
[   22.472198]  kthread+0x10e/0x130
[   22.474925]  ? kthread_park+0x80/0x80
[   22.477946]  ret_from_fork+0x35/0x40
[   22.480968] Modules linked in: xen_kbdfront xen_fbfront(+) xen_netfront xen_blkfront
[   22.486783] ---[ end trace a9222030a747c3f7 ]---
[   22.490424] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60

The virt_rmb() is added in the 'true' path of test_reply(). The "while"
is changed to "do while" so that test_reply() is used as a read memory
barrier.

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Link: https://lore.kernel.org/r/20200303221423.21962-1-dongli.zhang@oracle.com
Reviewed-by: Julien Grall <jgrall@amazon.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

(cherry picked from commit 1b6a51e)
Orabug: 31009546
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
LinuxMinion pushed a commit that referenced this pull request Mar 20, 2020
Orabug: 30898016

Shrinker hold sb->s_umount lock and invoked .destroy_inode to reclaim
inode, if fs was freezed, Shrinker would hung by freeze lock. But
unfreeze could never happen because it would be hung by sb->s_umount.

Backgroud inode inactivation feature could fix this, but it was not
merged by mainline yet, according Darrick, even merged, it would be
nearly impossible to backport to 4.14. The effort here is to make a
one OFF-MAINLINE fix for uek, if future uek have that feature merged,
this patch should be dropped.

To avoid deadlock, add inode needing inactivation to list
and destroy them async.

 crash7latest> set 132
     PID: 132
 COMMAND: "kswapd0:0"
    TASK: ffff9cdc9dfb5f00  [THREAD_INFO: ffff9cdc9dfb5f00]
     CPU: 6
   STATE: TASK_UNINTERRUPTIBLE
 crash7latest> bt
 PID: 132    TASK: ffff9cdc9dfb5f00  CPU: 6   COMMAND: "kswapd0:0"
  #0 [ffffaa5d075bf900] __schedule at ffffffff8186487c
  #1 [ffffaa5d075bf998] schedule at ffffffff81864e96
  #2 [ffffaa5d075bf9b0] rwsem_down_read_failed at ffffffff818689ee
  #3 [ffffaa5d075bfa40] call_rwsem_down_read_failed at ffffffff81859308
  #4 [ffffaa5d075bfa90] __percpu_down_read at ffffffff810ebd38
  #5 [ffffaa5d075bfab0] __sb_start_write at ffffffff812859ef
  #6 [ffffaa5d075bfad0] xfs_trans_alloc at ffffffffc07ebe9c [xfs]
  #7 [ffffaa5d075bfb18] xfs_free_eofblocks at ffffffffc07c39d1 [xfs]
  #8 [ffffaa5d075bfb80] xfs_inactive at ffffffffc07de878 [xfs]
  #9 [ffffaa5d075bfba0] __dta_xfs_fs_destroy_inode_3543 at ffffffffc07e885e [xfs]
 #10 [ffffaa5d075bfbd0] destroy_inode at ffffffff812a25de
 #11 [ffffaa5d075bfbe8] evict at ffffffff812a2b73
 #12 [ffffaa5d075bfc10] dispose_list at ffffffff812a2c1d
 #13 [ffffaa5d075bfc38] prune_icache_sb at ffffffff812a421a
 #14 [ffffaa5d075bfc70] super_cache_scan at ffffffff812870a1
 #15 [ffffaa5d075bfcc8] shrink_slab at ffffffff811eebb3
 #16 [ffffaa5d075bfdb0] shrink_node at ffffffff811f4788
 #17 [ffffaa5d075bfe38] kswapd at ffffffff811f58c3
 #18 [ffffaa5d075bff08] kthread at ffffffff810b75d5
 #19 [ffffaa5d075bff50] ret_from_fork at ffffffff81a0035e
 crash7latest> set 31060
     PID: 31060
 COMMAND: "safefreeze"
    TASK: ffff9cd292868000  [THREAD_INFO: ffff9cd292868000]
     CPU: 2
   STATE: TASK_UNINTERRUPTIBLE
 crash7latest> bt
 PID: 31060  TASK: ffff9cd292868000  CPU: 2   COMMAND: "safefreeze"
  #0 [ffffaa5d10047c90] __schedule at ffffffff8186487c
  #1 [ffffaa5d10047d28] schedule at ffffffff81864e96
  #2 [ffffaa5d10047d40] rwsem_down_write_failed at ffffffff81868f18
  #3 [ffffaa5d10047dd8] call_rwsem_down_write_failed at ffffffff81859367
  #4 [ffffaa5d10047e20] down_write at ffffffff81867cfd
  #5 [ffffaa5d10047e38] thaw_super at ffffffff81285d2d
  #6 [ffffaa5d10047e60] do_vfs_ioctl at ffffffff81299566
  #7 [ffffaa5d10047ee8] sys_ioctl at ffffffff81299709
  #8 [ffffaa5d10047f28] do_syscall_64 at ffffffff81003949
  #9 [ffffaa5d10047f50] entry_SYSCALL_64_after_hwframe at ffffffff81a001ad
     RIP: 0000000000453d67  RSP: 00007ffff9c1ce78  RFLAGS: 00000206
     RAX: ffffffffffffffda  RBX: 0000000001cbe92c  RCX: 0000000000453d67
     RDX: 0000000000000000  RSI: 00000000c0045878  RDI: 0000000000000014
     RBP: 00007ffff9c1cf80   R8: 0000000000000000   R9: 0000000000000012
     R10: 0000000000000008  R11: 0000000000000206  R12: 0000000000401fb0
     R13: 0000000000402040  R14: 0000000000000000  R15: 0000000000000000
     ORIG_RAX: 0000000000000010  CS: 0033  SS: 002b

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
LinuxMinion pushed a commit that referenced this pull request Mar 20, 2020
The req->body should be updated before req->state is updated and the
order should be guaranteed by a barrier.

Otherwise, read_reply() might return req->body = NULL.

Below is sample callstack when the issue is reproduced on purpose by
reordering the updates of req->body and req->state and adding delay in
code between updates of req->state and req->body.

[   22.356105] general protection fault: 0000 [#1] SMP PTI
[   22.361185] CPU: 2 PID: 52 Comm: xenwatch Not tainted 5.5.0xen+ #6
[   22.366727] Hardware name: Xen HVM domU, BIOS ...
[   22.372245] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60
... ...
[   22.392163] RSP: 0018:ffffb2d64023fdf0 EFLAGS: 00010246
[   22.395933] RAX: 0000000000000000 RBX: 75746e7562755f6d RCX: 0000000000000000
[   22.400871] RDX: 0000000000000000 RSI: ffffb2d64023fdfc RDI: 75746e7562755f6d
[   22.405874] RBP: 0000000000000000 R08: 00000000000001e8 R09: 0000000000cdcdcd
[   22.410945] R10: ffffb2d6402ffe00 R11: ffff9d95395eaeb0 R12: ffff9d9535935000
[   22.417613] R13: ffff9d9526d4a000 R14: ffff9d9526f4f340 R15: ffff9d9537654000
[   22.423726] FS:  0000000000000000(0000) GS:ffff9d953bc80000(0000) knlGS:0000000000000000
[   22.429898] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   22.434342] CR2: 000000c4206a9000 CR3: 00000001ea3fc002 CR4: 00000000001606e0
[   22.439645] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   22.444941] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   22.450342] Call Trace:
[   22.452509]  simple_strtoull+0x27/0x70
[   22.455572]  xenbus_transaction_start+0x31/0x50
[   22.459104]  netback_changed+0x76c/0xcc1 [xen_netfront]
[   22.463279]  ? find_watch+0x40/0x40
[   22.466156]  xenwatch_thread+0xb4/0x150
[   22.469309]  ? wait_woken+0x80/0x80
[   22.472198]  kthread+0x10e/0x130
[   22.474925]  ? kthread_park+0x80/0x80
[   22.477946]  ret_from_fork+0x35/0x40
[   22.480968] Modules linked in: xen_kbdfront xen_fbfront(+) xen_netfront xen_blkfront
[   22.486783] ---[ end trace a9222030a747c3f7 ]---
[   22.490424] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60

The virt_rmb() is added in the 'true' path of test_reply(). The "while"
is changed to "do while" so that test_reply() is used as a read memory
barrier.

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Link: https://lore.kernel.org/r/20200303221423.21962-1-dongli.zhang@oracle.com
Reviewed-by: Julien Grall <jgrall@amazon.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

(cherry picked from commit 1b6a51e)
Orabug: 31009584
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
gregmarsden pushed a commit that referenced this pull request Mar 27, 2020
commit 42ffb0b upstream.

There exists a deadlock with range_cyclic that has existed forever.  If
we loop around with a bio already built we could deadlock with a writer
who has the page locked that we're attempting to write but is waiting on
a page in our bio to be written out.  The task traces are as follows

  PID: 1329874  TASK: ffff889ebcdf3800  CPU: 33  COMMAND: "kworker/u113:5"
   #0 [ffffc900297bb658] __schedule at ffffffff81a4c33f
   #1 [ffffc900297bb6e0] schedule at ffffffff81a4c6e3
   #2 [ffffc900297bb6f8] io_schedule at ffffffff81a4ca42
   #3 [ffffc900297bb708] __lock_page at ffffffff811f145b
   #4 [ffffc900297bb798] __process_pages_contig at ffffffff814bc502
   #5 [ffffc900297bb8c8] lock_delalloc_pages at ffffffff814bc684
   #6 [ffffc900297bb900] find_lock_delalloc_range at ffffffff814be9ff
   #7 [ffffc900297bb9a0] writepage_delalloc at ffffffff814bebd0
   #8 [ffffc900297bba18] __extent_writepage at ffffffff814bfbf2
   #9 [ffffc900297bba98] extent_write_cache_pages at ffffffff814bffbd

  PID: 2167901  TASK: ffff889dc6a59c00  CPU: 14  COMMAND:
  "aio-dio-invalid"
   #0 [ffffc9003b50bb18] __schedule at ffffffff81a4c33f
   #1 [ffffc9003b50bba0] schedule at ffffffff81a4c6e3
   #2 [ffffc9003b50bbb8] io_schedule at ffffffff81a4ca42
   #3 [ffffc9003b50bbc8] wait_on_page_bit at ffffffff811f24d6
   #4 [ffffc9003b50bc60] prepare_pages at ffffffff814b05a7
   #5 [ffffc9003b50bcd8] btrfs_buffered_write at ffffffff814b1359
   #6 [ffffc9003b50bdb0] btrfs_file_write_iter at ffffffff814b5933
   #7 [ffffc9003b50be38] new_sync_write at ffffffff8128f6a8
   #8 [ffffc9003b50bec8] vfs_write at ffffffff81292b9d
   #9 [ffffc9003b50bf00] ksys_pwrite64 at ffffffff81293032

I used drgn to find the respective pages we were stuck on

page_entry.page 0xffffea00fbfc7500 index 8148 bit 15 pid 2167901
page_entry.page 0xffffea00f9bb7400 index 7680 bit 0 pid 1329874

As you can see the kworker is waiting for bit 0 (PG_locked) on index
7680, and aio-dio-invalid is waiting for bit 15 (PG_writeback) on index
8148.  aio-dio-invalid has 7680, and the kworker epd looks like the
following

  crash> struct extent_page_data ffffc900297bbbb0
  struct extent_page_data {
    bio = 0xffff889f747ed830,
    tree = 0xffff889eed6ba448,
    extent_locked = 0,
    sync_io = 0
  }

Probably worth mentioning as well that it waits for writeback of the
page to complete while holding a lock on it (at prepare_pages()).

Using drgn I walked the bio pages looking for page
0xffffea00fbfc7500 which is the one we're waiting for writeback on

  bio = Object(prog, 'struct bio', address=0xffff889f747ed830)
  for i in range(0, bio.bi_vcnt.value_()):
      bv = bio.bi_io_vec[i]
      if bv.bv_page.value_() == 0xffffea00fbfc7500:
	  print("FOUND IT")

which validated what I suspected.

The fix for this is simple, flush the epd before we loop back around to
the beginning of the file during writeout.

Fixes: b293f02 ("Btrfs: Add writepages support")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
LinuxMinion pushed a commit that referenced this pull request Apr 2, 2020
The req->body should be updated before req->state is updated and the
order should be guaranteed by a barrier.

Otherwise, read_reply() might return req->body = NULL.

Below is sample callstack when the issue is reproduced on purpose by
reordering the updates of req->body and req->state and adding delay in
code between updates of req->state and req->body.

[   22.356105] general protection fault: 0000 [#1] SMP PTI
[   22.361185] CPU: 2 PID: 52 Comm: xenwatch Not tainted 5.5.0xen+ #6
[   22.366727] Hardware name: Xen HVM domU, BIOS ...
[   22.372245] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60
... ...
[   22.392163] RSP: 0018:ffffb2d64023fdf0 EFLAGS: 00010246
[   22.395933] RAX: 0000000000000000 RBX: 75746e7562755f6d RCX: 0000000000000000
[   22.400871] RDX: 0000000000000000 RSI: ffffb2d64023fdfc RDI: 75746e7562755f6d
[   22.405874] RBP: 0000000000000000 R08: 00000000000001e8 R09: 0000000000cdcdcd
[   22.410945] R10: ffffb2d6402ffe00 R11: ffff9d95395eaeb0 R12: ffff9d9535935000
[   22.417613] R13: ffff9d9526d4a000 R14: ffff9d9526f4f340 R15: ffff9d9537654000
[   22.423726] FS:  0000000000000000(0000) GS:ffff9d953bc80000(0000) knlGS:0000000000000000
[   22.429898] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   22.434342] CR2: 000000c4206a9000 CR3: 00000001ea3fc002 CR4: 00000000001606e0
[   22.439645] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   22.444941] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   22.450342] Call Trace:
[   22.452509]  simple_strtoull+0x27/0x70
[   22.455572]  xenbus_transaction_start+0x31/0x50
[   22.459104]  netback_changed+0x76c/0xcc1 [xen_netfront]
[   22.463279]  ? find_watch+0x40/0x40
[   22.466156]  xenwatch_thread+0xb4/0x150
[   22.469309]  ? wait_woken+0x80/0x80
[   22.472198]  kthread+0x10e/0x130
[   22.474925]  ? kthread_park+0x80/0x80
[   22.477946]  ret_from_fork+0x35/0x40
[   22.480968] Modules linked in: xen_kbdfront xen_fbfront(+) xen_netfront xen_blkfront
[   22.486783] ---[ end trace a9222030a747c3f7 ]---
[   22.490424] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60

The virt_rmb() is added in the 'true' path of test_reply(). The "while"
is changed to "do while" so that test_reply() is used as a read memory
barrier.

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Link: https://lore.kernel.org/r/20200303221423.21962-1-dongli.zhang@oracle.com
Reviewed-by: Julien Grall <jgrall@amazon.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

(cherry picked from commit 1b6a51e)
Orabug: 31011129
Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
gregmarsden pushed a commit that referenced this pull request Apr 3, 2020
[ Upstream commit c34f6dc ]

I see the following lockdep splat in the qcom pinctrl driver when
attempting to suspend the device.

 ============================================
 WARNING: possible recursive locking detected
 5.4.2 #2 Tainted: G S
 --------------------------------------------
 cat/6536 is trying to acquire lock:
 ffffff814787ccc0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94

 but task is already holding lock:
 ffffff81436740c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&irq_desc_lock_class);
   lock(&irq_desc_lock_class);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 7 locks held by cat/6536:
  #0: ffffff8140e0c420 (sb_writers#7){.+.+}, at: vfs_write+0xc8/0x19c
  #1: ffffff8121eec480 (&of->mutex){+.+.}, at: kernfs_fop_write+0x128/0x1f4
  #2: ffffff8147cad668 (kn->count#263){.+.+}, at: kernfs_fop_write+0x130/0x1f4
  #3: ffffffd011446000 (system_transition_mutex){+.+.}, at: pm_suspend+0x108/0x354
  #4: ffffff814302b970 (&dev->mutex){....}, at: __device_suspend+0x16c/0x420
  #5: ffffff81436740c0 (&irq_desc_lock_class){-.-.}, at: __irq_get_desc_lock+0x64/0x94
  #6: ffffff81479b8c10 (&pctrl->lock){....}, at: msm_gpio_irq_set_wake+0x48/0x7c

 stack backtrace:
 CPU: 4 PID: 6536 Comm: cat Tainted: G S                5.4.2 #2
 Call trace:
  dump_backtrace+0x0/0x174
  show_stack+0x20/0x2c
  dump_stack+0xdc/0x144
  __lock_acquire+0x52c/0x2268
  lock_acquire+0x1dc/0x220
  _raw_spin_lock_irqsave+0x64/0x80
  __irq_get_desc_lock+0x64/0x94
  irq_set_irq_wake+0x40/0x144
  msm_gpio_irq_set_wake+0x5c/0x7c
  set_irq_wake_real+0x40/0x5c
  irq_set_irq_wake+0x70/0x144
  cros_ec_rtc_suspend+0x38/0x4c
  platform_pm_suspend+0x34/0x60
  dpm_run_callback+0x64/0xcc
  __device_suspend+0x314/0x420
  dpm_suspend+0xf8/0x298
  dpm_suspend_start+0x84/0xb4
  suspend_devices_and_enter+0xbc/0x628
  pm_suspend+0x214/0x354
  state_store+0xb0/0x108
  kobj_attr_store+0x14/0x24
  sysfs_kf_write+0x4c/0x64
  kernfs_fop_write+0x158/0x1f4
  __vfs_write+0x54/0x18c
  vfs_write+0xdc/0x19c
  ksys_write+0x7c/0xe4
  __arm64_sys_write+0x20/0x2c
  el0_svc_common+0xa8/0x160
  el0_svc_compat_handler+0x2c/0x38
  el0_svc_compat+0x8/0x10

This is because the msm_gpio_irq_set_wake() function calls
irq_set_irq_wake() as a backup in case the irq comes in during the path
to idle. Given that we're calling irqchip functions from within an
irqchip we need to set the lockdep class to be different for this child
controller vs. the default one that the parent irqchip gets.

This used to be done before this driver was converted to hierarchical
irq domains in commit e35a6ae ("pinctrl/msm: Setup GPIO chip in
hierarchy") via the gpiochip_irq_map() function. With hierarchical irq
domains this function has been replaced by
gpiochip_hierarchy_irq_domain_alloc(). Therefore, set the lockdep class
like was done previously in the irq domain path so we can avoid this
lockdep warning.

Fixes: fdd61a0 ("gpio: Add support for hierarchical IRQ domains")
Cc: Thierry Reding <treding@nvidia.com>
Cc: Brian Masney <masneyb@onstation.org>
Cc: Lina Iyer <ilina@codeaurora.org>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Maulik Shah <mkshah@codeaurora.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20200114231103.85641-1-swboyd@chromium.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregmarsden pushed a commit that referenced this pull request Apr 3, 2020
[ Upstream commit 1b6a51e ]

The req->body should be updated before req->state is updated and the
order should be guaranteed by a barrier.

Otherwise, read_reply() might return req->body = NULL.

Below is sample callstack when the issue is reproduced on purpose by
reordering the updates of req->body and req->state and adding delay in
code between updates of req->state and req->body.

[   22.356105] general protection fault: 0000 [#1] SMP PTI
[   22.361185] CPU: 2 PID: 52 Comm: xenwatch Not tainted 5.5.0xen+ #6
[   22.366727] Hardware name: Xen HVM domU, BIOS ...
[   22.372245] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60
... ...
[   22.392163] RSP: 0018:ffffb2d64023fdf0 EFLAGS: 00010246
[   22.395933] RAX: 0000000000000000 RBX: 75746e7562755f6d RCX: 0000000000000000
[   22.400871] RDX: 0000000000000000 RSI: ffffb2d64023fdfc RDI: 75746e7562755f6d
[   22.405874] RBP: 0000000000000000 R08: 00000000000001e8 R09: 0000000000cdcdcd
[   22.410945] R10: ffffb2d6402ffe00 R11: ffff9d95395eaeb0 R12: ffff9d9535935000
[   22.417613] R13: ffff9d9526d4a000 R14: ffff9d9526f4f340 R15: ffff9d9537654000
[   22.423726] FS:  0000000000000000(0000) GS:ffff9d953bc80000(0000) knlGS:0000000000000000
[   22.429898] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   22.434342] CR2: 000000c4206a9000 CR3: 00000001ea3fc002 CR4: 00000000001606e0
[   22.439645] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   22.444941] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   22.450342] Call Trace:
[   22.452509]  simple_strtoull+0x27/0x70
[   22.455572]  xenbus_transaction_start+0x31/0x50
[   22.459104]  netback_changed+0x76c/0xcc1 [xen_netfront]
[   22.463279]  ? find_watch+0x40/0x40
[   22.466156]  xenwatch_thread+0xb4/0x150
[   22.469309]  ? wait_woken+0x80/0x80
[   22.472198]  kthread+0x10e/0x130
[   22.474925]  ? kthread_park+0x80/0x80
[   22.477946]  ret_from_fork+0x35/0x40
[   22.480968] Modules linked in: xen_kbdfront xen_fbfront(+) xen_netfront xen_blkfront
[   22.486783] ---[ end trace a9222030a747c3f7 ]---
[   22.490424] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60

The virt_rmb() is added in the 'true' path of test_reply(). The "while"
is changed to "do while" so that test_reply() is used as a read memory
barrier.

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Link: https://lore.kernel.org/r/20200303221423.21962-1-dongli.zhang@oracle.com
Reviewed-by: Julien Grall <jgrall@amazon.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregmarsden pushed a commit that referenced this pull request Apr 17, 2020
Orabug: 30944736

Shrinker hold sb->s_umount lock and invoked .destroy_inode to reclaim
inode, if fs was freezed, Shrinker would hung by freeze lock. But
unfreeze could never happen because it would be hung by sb->s_umount.

Backgroud inode inactivation feature could fix this, but it was not
merged by mainline yet, according Darrick, even merged, it would be
nearly impossible to backport to 4.14. The effort here is to make a
one OFF-MAINLINE fix for uek, if future uek have that feature merged,
this patch should be dropped.

To avoid deadlock, add inode needing inactivation to list
and destroy them async.

 crash7latest> set 132
     PID: 132
 COMMAND: "kswapd0:0"
    TASK: ffff9cdc9dfb5f00  [THREAD_INFO: ffff9cdc9dfb5f00]
     CPU: 6
   STATE: TASK_UNINTERRUPTIBLE
 crash7latest> bt
 PID: 132    TASK: ffff9cdc9dfb5f00  CPU: 6   COMMAND: "kswapd0:0"
  #0 [ffffaa5d075bf900] __schedule at ffffffff8186487c
  #1 [ffffaa5d075bf998] schedule at ffffffff81864e96
  #2 [ffffaa5d075bf9b0] rwsem_down_read_failed at ffffffff818689ee
  #3 [ffffaa5d075bfa40] call_rwsem_down_read_failed at ffffffff81859308
  #4 [ffffaa5d075bfa90] __percpu_down_read at ffffffff810ebd38
  #5 [ffffaa5d075bfab0] __sb_start_write at ffffffff812859ef
  #6 [ffffaa5d075bfad0] xfs_trans_alloc at ffffffffc07ebe9c [xfs]
  #7 [ffffaa5d075bfb18] xfs_free_eofblocks at ffffffffc07c39d1 [xfs]
  #8 [ffffaa5d075bfb80] xfs_inactive at ffffffffc07de878 [xfs]
  #9 [ffffaa5d075bfba0] __dta_xfs_fs_destroy_inode_3543 at ffffffffc07e885e [xfs]
 #10 [ffffaa5d075bfbd0] destroy_inode at ffffffff812a25de
 #11 [ffffaa5d075bfbe8] evict at ffffffff812a2b73
 #12 [ffffaa5d075bfc10] dispose_list at ffffffff812a2c1d
 #13 [ffffaa5d075bfc38] prune_icache_sb at ffffffff812a421a
 #14 [ffffaa5d075bfc70] super_cache_scan at ffffffff812870a1
 #15 [ffffaa5d075bfcc8] shrink_slab at ffffffff811eebb3
 #16 [ffffaa5d075bfdb0] shrink_node at ffffffff811f4788
 #17 [ffffaa5d075bfe38] kswapd at ffffffff811f58c3
 #18 [ffffaa5d075bff08] kthread at ffffffff810b75d5
 #19 [ffffaa5d075bff50] ret_from_fork at ffffffff81a0035e
 crash7latest> set 31060
     PID: 31060
 COMMAND: "safefreeze"
    TASK: ffff9cd292868000  [THREAD_INFO: ffff9cd292868000]
     CPU: 2
   STATE: TASK_UNINTERRUPTIBLE
 crash7latest> bt
 PID: 31060  TASK: ffff9cd292868000  CPU: 2   COMMAND: "safefreeze"
  #0 [ffffaa5d10047c90] __schedule at ffffffff8186487c
  #1 [ffffaa5d10047d28] schedule at ffffffff81864e96
  #2 [ffffaa5d10047d40] rwsem_down_write_failed at ffffffff81868f18
  #3 [ffffaa5d10047dd8] call_rwsem_down_write_failed at ffffffff81859367
  #4 [ffffaa5d10047e20] down_write at ffffffff81867cfd
  #5 [ffffaa5d10047e38] thaw_super at ffffffff81285d2d
  #6 [ffffaa5d10047e60] do_vfs_ioctl at ffffffff81299566
  #7 [ffffaa5d10047ee8] sys_ioctl at ffffffff81299709
  #8 [ffffaa5d10047f28] do_syscall_64 at ffffffff81003949
  #9 [ffffaa5d10047f50] entry_SYSCALL_64_after_hwframe at ffffffff81a001ad
     RIP: 0000000000453d67  RSP: 00007ffff9c1ce78  RFLAGS: 00000206
     RAX: ffffffffffffffda  RBX: 0000000001cbe92c  RCX: 0000000000453d67
     RDX: 0000000000000000  RSI: 00000000c0045878  RDI: 0000000000000014
     RBP: 00007ffff9c1cf80   R8: 0000000000000000   R9: 0000000000000012
     R10: 0000000000000008  R11: 0000000000000206  R12: 0000000000401fb0
     R13: 0000000000402040  R14: 0000000000000000  R15: 0000000000000000
     ORIG_RAX: 0000000000000010  CS: 0033  SS: 002b

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Brian Maly <brian.maly@oracle.com>
gregmarsden pushed a commit that referenced this pull request Apr 17, 2020
[ Upstream commit 42ffb0b ]

There exists a deadlock with range_cyclic that has existed forever.  If
we loop around with a bio already built we could deadlock with a writer
who has the page locked that we're attempting to write but is waiting on
a page in our bio to be written out.  The task traces are as follows

  PID: 1329874  TASK: ffff889ebcdf3800  CPU: 33  COMMAND: "kworker/u113:5"
   #0 [ffffc900297bb658] __schedule at ffffffff81a4c33f
   #1 [ffffc900297bb6e0] schedule at ffffffff81a4c6e3
   #2 [ffffc900297bb6f8] io_schedule at ffffffff81a4ca42
   #3 [ffffc900297bb708] __lock_page at ffffffff811f145b
   #4 [ffffc900297bb798] __process_pages_contig at ffffffff814bc502
   #5 [ffffc900297bb8c8] lock_delalloc_pages at ffffffff814bc684
   #6 [ffffc900297bb900] find_lock_delalloc_range at ffffffff814be9ff
   #7 [ffffc900297bb9a0] writepage_delalloc at ffffffff814bebd0
   #8 [ffffc900297bba18] __extent_writepage at ffffffff814bfbf2
   #9 [ffffc900297bba98] extent_write_cache_pages at ffffffff814bffbd

  PID: 2167901  TASK: ffff889dc6a59c00  CPU: 14  COMMAND:
  "aio-dio-invalid"
   #0 [ffffc9003b50bb18] __schedule at ffffffff81a4c33f
   #1 [ffffc9003b50bba0] schedule at ffffffff81a4c6e3
   #2 [ffffc9003b50bbb8] io_schedule at ffffffff81a4ca42
   #3 [ffffc9003b50bbc8] wait_on_page_bit at ffffffff811f24d6
   #4 [ffffc9003b50bc60] prepare_pages at ffffffff814b05a7
   #5 [ffffc9003b50bcd8] btrfs_buffered_write at ffffffff814b1359
   #6 [ffffc9003b50bdb0] btrfs_file_write_iter at ffffffff814b5933
   #7 [ffffc9003b50be38] new_sync_write at ffffffff8128f6a8
   #8 [ffffc9003b50bec8] vfs_write at ffffffff81292b9d
   #9 [ffffc9003b50bf00] ksys_pwrite64 at ffffffff81293032

I used drgn to find the respective pages we were stuck on

page_entry.page 0xffffea00fbfc7500 index 8148 bit 15 pid 2167901
page_entry.page 0xffffea00f9bb7400 index 7680 bit 0 pid 1329874

As you can see the kworker is waiting for bit 0 (PG_locked) on index
7680, and aio-dio-invalid is waiting for bit 15 (PG_writeback) on index
8148.  aio-dio-invalid has 7680, and the kworker epd looks like the
following

  crash> struct extent_page_data ffffc900297bbbb0
  struct extent_page_data {
    bio = 0xffff889f747ed830,
    tree = 0xffff889eed6ba448,
    extent_locked = 0,
    sync_io = 0
  }

Probably worth mentioning as well that it waits for writeback of the
page to complete while holding a lock on it (at prepare_pages()).

Using drgn I walked the bio pages looking for page
0xffffea00fbfc7500 which is the one we're waiting for writeback on

  bio = Object(prog, 'struct bio', address=0xffff889f747ed830)
  for i in range(0, bio.bi_vcnt.value_()):
      bv = bio.bi_io_vec[i]
      if bv.bv_page.value_() == 0xffffea00fbfc7500:
	  print("FOUND IT")

which validated what I suspected.

The fix for this is simple, flush the epd before we loop back around to
the beginning of the file during writeout.

Fixes: b293f02 ("Btrfs: Add writepages support")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregmarsden pushed a commit that referenced this pull request Apr 24, 2020
[ Upstream commit 1bc7896 ]

When experimenting with bpf_send_signal() helper in our production
environment (5.2 based), we experienced a deadlock in NMI mode:
   #5 [ffffc9002219f770] queued_spin_lock_slowpath at ffffffff8110be24
   #6 [ffffc9002219f770] _raw_spin_lock_irqsave at ffffffff81a43012
   #7 [ffffc9002219f780] try_to_wake_up at ffffffff810e7ecd
   #8 [ffffc9002219f7e0] signal_wake_up_state at ffffffff810c7b55
   #9 [ffffc9002219f7f0] __send_signal at ffffffff810c8602
  #10 [ffffc9002219f830] do_send_sig_info at ffffffff810ca31a
  #11 [ffffc9002219f868] bpf_send_signal at ffffffff8119d227
  #12 [ffffc9002219f988] bpf_overflow_handler at ffffffff811d4140
  #13 [ffffc9002219f9e0] __perf_event_overflow at ffffffff811d68cf
  #14 [ffffc9002219fa10] perf_swevent_overflow at ffffffff811d6a09
  #15 [ffffc9002219fa38] ___perf_sw_event at ffffffff811e0f47
  #16 [ffffc9002219fc30] __schedule at ffffffff81a3e04d
  #17 [ffffc9002219fc90] schedule at ffffffff81a3e219
  #18 [ffffc9002219fca0] futex_wait_queue_me at ffffffff8113d1b9
  #19 [ffffc9002219fcd8] futex_wait at ffffffff8113e529
  #20 [ffffc9002219fdf0] do_futex at ffffffff8113ffbc
  #21 [ffffc9002219fec0] __x64_sys_futex at ffffffff81140d1c
  #22 [ffffc9002219ff38] do_syscall_64 at ffffffff81002602
  #23 [ffffc9002219ff50] entry_SYSCALL_64_after_hwframe at ffffffff81c00068

The above call stack is actually very similar to an issue
reported by Commit eac9153 ("bpf/stackmap: Fix deadlock with
rq_lock in bpf_get_stack()") by Song Liu. The only difference is
bpf_send_signal() helper instead of bpf_get_stack() helper.

The above deadlock is triggered with a perf_sw_event.
Similar to Commit eac9153, the below almost identical reproducer
used tracepoint point sched/sched_switch so the issue can be easily caught.
  /* stress_test.c */
  #include <stdio.h>
  #include <stdlib.h>
  #include <sys/mman.h>
  #include <pthread.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <fcntl.h>

  #define THREAD_COUNT 1000
  char *filename;
  void *worker(void *p)
  {
        void *ptr;
        int fd;
        char *pptr;

        fd = open(filename, O_RDONLY);
        if (fd < 0)
                return NULL;
        while (1) {
                struct timespec ts = {0, 1000 + rand() % 2000};

                ptr = mmap(NULL, 4096 * 64, PROT_READ, MAP_PRIVATE, fd, 0);
                usleep(1);
                if (ptr == MAP_FAILED) {
                        printf("failed to mmap\n");
                        break;
                }
                munmap(ptr, 4096 * 64);
                usleep(1);
                pptr = malloc(1);
                usleep(1);
                pptr[0] = 1;
                usleep(1);
                free(pptr);
                usleep(1);
                nanosleep(&ts, NULL);
        }
        close(fd);
        return NULL;
  }

  int main(int argc, char *argv[])
  {
        void *ptr;
        int i;
        pthread_t threads[THREAD_COUNT];

        if (argc < 2)
                return 0;

        filename = argv[1];

        for (i = 0; i < THREAD_COUNT; i++) {
                if (pthread_create(threads + i, NULL, worker, NULL)) {
                        fprintf(stderr, "Error creating thread\n");
                        return 0;
                }
        }

        for (i = 0; i < THREAD_COUNT; i++)
                pthread_join(threads[i], NULL);
        return 0;
  }
and the following command:
  1. run `stress_test /bin/ls` in one windown
  2. hack bcc trace.py with the following change:
#     --- a/tools/trace.py
#     +++ b/tools/trace.py
     @@ -513,6 +513,7 @@ BPF_PERF_OUTPUT(%s);
              __data.tgid = __tgid;
              __data.pid = __pid;
              bpf_get_current_comm(&__data.comm, sizeof(__data.comm));
     +        bpf_send_signal(10);
      %s
      %s
              %s.perf_submit(%s, &__data, sizeof(__data));
  3. in a different window run
     ./trace.py -p $(pidof stress_test) t:sched:sched_switch

The deadlock can be reproduced in our production system.

Similar to Song's fix, the fix is to delay sending signal if
irqs is disabled to avoid deadlocks involving with rq_lock.
With this change, my above stress-test in our production system
won't cause deadlock any more.

I also implemented a scale-down version of reproducer in the
selftest (a subsequent commit). With latest bpf-next,
it complains for the following potential deadlock.
  [   32.832450] -> #1 (&p->pi_lock){-.-.}:
  [   32.833100]        _raw_spin_lock_irqsave+0x44/0x80
  [   32.833696]        task_rq_lock+0x2c/0xa0
  [   32.834182]        task_sched_runtime+0x59/0xd0
  [   32.834721]        thread_group_cputime+0x250/0x270
  [   32.835304]        thread_group_cputime_adjusted+0x2e/0x70
  [   32.835959]        do_task_stat+0x8a7/0xb80
  [   32.836461]        proc_single_show+0x51/0xb0
  ...
  [   32.839512] -> #0 (&(&sighand->siglock)->rlock){....}:
  [   32.840275]        __lock_acquire+0x1358/0x1a20
  [   32.840826]        lock_acquire+0xc7/0x1d0
  [   32.841309]        _raw_spin_lock_irqsave+0x44/0x80
  [   32.841916]        __lock_task_sighand+0x79/0x160
  [   32.842465]        do_send_sig_info+0x35/0x90
  [   32.842977]        bpf_send_signal+0xa/0x10
  [   32.843464]        bpf_prog_bc13ed9e4d3163e3_send_signal_tp_sched+0x465/0x1000
  [   32.844301]        trace_call_bpf+0x115/0x270
  [   32.844809]        perf_trace_run_bpf_submit+0x4a/0xc0
  [   32.845411]        perf_trace_sched_switch+0x10f/0x180
  [   32.846014]        __schedule+0x45d/0x880
  [   32.846483]        schedule+0x5f/0xd0
  ...

  [   32.853148] Chain exists of:
  [   32.853148]   &(&sighand->siglock)->rlock --> &p->pi_lock --> &rq->lock
  [   32.853148]
  [   32.854451]  Possible unsafe locking scenario:
  [   32.854451]
  [   32.855173]        CPU0                    CPU1
  [   32.855745]        ----                    ----
  [   32.856278]   lock(&rq->lock);
  [   32.856671]                                lock(&p->pi_lock);
  [   32.857332]                                lock(&rq->lock);
  [   32.857999]   lock(&(&sighand->siglock)->rlock);

  Deadlock happens on CPU0 when it tries to acquire &sighand->siglock
  but it has been held by CPU1 and CPU1 tries to grab &rq->lock
  and cannot get it.

  This is not exactly the callstack in our production environment,
  but sympotom is similar and both locks are using spin_lock_irqsave()
  to acquire the lock, and both involves rq_lock. The fix to delay
  sending signal when irq is disabled also fixed this issue.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200304191104.2796501-1-yhs@fb.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregmarsden pushed a commit that referenced this pull request Apr 24, 2020
commit 791c13b upstream.

Undefined rproc_ops .kick method in remoteproc driver will result in
"Unable to handle kernel NULL pointer dereference" in rproc_virtio_notify,
after firmware loading if:

 1) .kick method wasn't defined in driver
 2) resource_table exists in firmware and has "Virtio device entry" defined

Let's refuse to register an rproc-induced virtio device if no kick method was
defined for rproc.

[   13.180049][  T415] 8<--- cut here ---
[   13.190558][  T415] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[   13.212544][  T415] pgd = (ptrval)
[   13.217052][  T415] [00000000] *pgd=00000000
[   13.224692][  T415] Internal error: Oops: 80000005 [#1] PREEMPT SMP ARM
[   13.231318][  T415] Modules linked in: rpmsg_char imx_rproc virtio_rpmsg_bus rpmsg_core [last unloaded: imx_rproc]
[   13.241687][  T415] CPU: 0 PID: 415 Comm: unload-load.sh Not tainted 5.5.2-00002-g707df13bbbdd #6
[   13.250561][  T415] Hardware name: Freescale i.MX7 Dual (Device Tree)
[   13.257009][  T415] PC is at 0x0
[   13.260249][  T415] LR is at rproc_virtio_notify+0x2c/0x54
[   13.265738][  T415] pc : [<00000000>]    lr : [<8050f6b0>]    psr: 60010113
[   13.272702][  T415] sp : b8d47c48  ip : 00000001  fp : bc04de00
[   13.278625][  T415] r10: bc04c000  r9 : 00000cc0  r8 : b8d46000
[   13.284548][  T415] r7 : 00000000  r6 : b898f200  r5 : 00000000  r4 : b8a29800
[   13.291773][  T415] r3 : 00000000  r2 : 990a3ad4  r1 : 00000000  r0 : b8a29800
[   13.299000][  T415] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
[   13.306833][  T415] Control: 10c5387d  Table: b8b4806a  DAC: 00000051
[   13.313278][  T415] Process unload-load.sh (pid: 415, stack limit = 0x(ptrval))
[   13.320591][  T415] Stack: (0xb8d47c48 to 0xb8d48000)
[   13.325651][  T415] 7c40:                   b895b680 00000001 b898f200 803c6430 b895bc80 7f00ae18
[   13.334531][  T415] 7c60: 00000035 00000000 00000000 b9393200 80b3ed80 00004000 b9393268 bbf5a9a2
[   13.343410][  T415] 7c80: 00000e00 00000200 00000000 7f00aff0 7f00a014 b895b680 b895b800 990a3ad4
[   13.352290][  T415] 7ca0: 00000001 b898f210 b898f200 00000000 00000000 7f00e000 00000001 00000000
[   13.361170][  T415] 7cc0: 00000000 803c62e0 80b2169c 802a0924 b898f210 00000000 00000000 b898f210
[   13.370049][  T415] 7ce0: 80b9ba44 00000000 80b9ba48 00000000 7f00e000 00000008 80b2169c 80400114
[   13.378929][  T415] 7d00: 80b2169c 8061fd64 b898f210 7f00e000 80400744 b8d46000 80b21634 80b21634
[   13.387809][  T415] 7d20: 80b2169c 80400614 80b21634 80400718 7f00e000 00000000 b8d47d7c 80400744
[   13.396689][  T415] 7d40: b8d46000 80b21634 80b21634 803fe338 b898f254 b80fe76c b8d32e38 990a3ad4
[   13.405569][  T415] 7d60: fffffff3 b898f210 b8d46000 00000001 b898f254 803ffe7c 80857a90 b898f210
[   13.414449][  T415] 7d80: 00000001 990a3ad4 b8d46000 b898f210 b898f210 80b17aec b8a29c20 803ff0a4
[   13.423328][  T415] 7da0: b898f210 00000000 b8d46000 803fb8e0 b898f200 00000000 80b17aec b898f210
[   13.432209][  T415] 7dc0: b8a29c20 990a3ad4 b895b900 b898f200 8050fb7c 80b17aec b898f210 b8a29c20
[   13.441088][  T415] 7de0: b8a29800 b895b900 b8a29a04 803c5ec0 b8a29c00 b898f200 b8a29a20 00000007
[   13.449968][  T415] 7e00: b8a29c20 8050fd78 b8a29800 00000000 b8a29a20 b8a29c04 b8a29820 b8a299d0
[   13.458848][  T415] 7e20: b895b900 8050e5a4 b8a29800 b8a299d8 b8d46000 b8a299e0 b8a29820 b8a299d0
[   13.467728][  T415] 7e40: b895b900 8050e008 000041ed 00000000 b8b8c440 b8a299d8 b8a299e0 b8a299d8
[   13.476608][  T415] 7e60: b8b8c440 990a3ad4 00000000 b8a29820 b8b8c400 00000006 b8a29800 b895b880
[   13.485487][  T415] 7e80: b8d47f78 00000000 00000000 8050f4b4 00000006 b895b890 b8b8c400 008fbea0
[   13.494367][  T415] 7ea0: b895b880 8029f530 00000000 00000000 b8d46000 00000006 b8d46000 008fbea0
[   13.503246][  T415] 7ec0: 8029f434 00000000 b8d46000 00000000 00000000 8021e2e4 0000000a 8061fd0c
[   13.512125][  T415] 7ee0: 0000000a b8af0c00 0000000a b8af0c40 00000001 b8af0c40 00000000 8061f910
[   13.521005][  T415] 7f00: 0000000a 80240af4 00000002 b8d46000 00000000 8061fd0c 00000002 80232d7c
[   13.529884][  T415] 7f20: 00000000 b8d46000 00000000 990a3ad4 00000000 00000006 b8a62d80 008fbea0
[   13.538764][  T415] 7f40: b8d47f78 00000000 b8d46000 00000000 00000000 802210c0 b88f2900 00000000
[   13.547644][  T415] 7f60: b8a62d80 b8a62d80 b8d46000 00000006 008fbea0 80221320 00000000 00000000
[   13.556524][  T415] 7f80: b8af0c00 990a3ad4 0000006c 008fbea0 76f1cda0 00000004 80101204 00000004
[   13.565403][  T415] 7fa0: 00000000 80101000 0000006c 008fbea0 00000001 008fbea0 00000006 00000000
[   13.574283][  T415] 7fc0: 0000006c 008fbea0 76f1cda0 00000004 00000006 00000006 00000000 00000000
[   13.583162][  T415] 7fe0: 00000004 7ebaf7d0 76eb4c0b 76e3f206 600d0030 00000001 00000000 00000000
[   13.592056][  T415] [<8050f6b0>] (rproc_virtio_notify) from [<803c6430>] (virtqueue_notify+0x1c/0x34)
[   13.601298][  T415] [<803c6430>] (virtqueue_notify) from [<7f00ae18>] (rpmsg_probe+0x280/0x380 [virtio_rpmsg_bus])
[   13.611663][  T415] [<7f00ae18>] (rpmsg_probe [virtio_rpmsg_bus]) from [<803c62e0>] (virtio_dev_probe+0x1f8/0x2c4)
[   13.622022][  T415] [<803c62e0>] (virtio_dev_probe) from [<80400114>] (really_probe+0x200/0x450)
[   13.630817][  T415] [<80400114>] (really_probe) from [<80400614>] (driver_probe_device+0x16c/0x1ac)
[   13.639873][  T415] [<80400614>] (driver_probe_device) from [<803fe338>] (bus_for_each_drv+0x84/0xc8)
[   13.649102][  T415] [<803fe338>] (bus_for_each_drv) from [<803ffe7c>] (__device_attach+0xd4/0x164)
[   13.658069][  T415] [<803ffe7c>] (__device_attach) from [<803ff0a4>] (bus_probe_device+0x84/0x8c)
[   13.666950][  T415] [<803ff0a4>] (bus_probe_device) from [<803fb8e0>] (device_add+0x444/0x768)
[   13.675572][  T415] [<803fb8e0>] (device_add) from [<803c5ec0>] (register_virtio_device+0xa4/0xfc)
[   13.684541][  T415] [<803c5ec0>] (register_virtio_device) from [<8050fd78>] (rproc_add_virtio_dev+0xcc/0x1b8)
[   13.694466][  T415] [<8050fd78>] (rproc_add_virtio_dev) from [<8050e5a4>] (rproc_start+0x148/0x200)
[   13.703521][  T415] [<8050e5a4>] (rproc_start) from [<8050e008>] (rproc_boot+0x384/0x5c0)
[   13.711708][  T415] [<8050e008>] (rproc_boot) from [<8050f4b4>] (state_store+0x3c/0xc8)
[   13.719723][  T415] [<8050f4b4>] (state_store) from [<8029f530>] (kernfs_fop_write+0xfc/0x214)
[   13.728348][  T415] [<8029f530>] (kernfs_fop_write) from [<8021e2e4>] (__vfs_write+0x30/0x1cc)
[   13.736971][  T415] [<8021e2e4>] (__vfs_write) from [<802210c0>] (vfs_write+0xac/0x17c)
[   13.744985][  T415] [<802210c0>] (vfs_write) from [<80221320>] (ksys_write+0x64/0xe4)
[   13.752825][  T415] [<80221320>] (ksys_write) from [<80101000>] (ret_fast_syscall+0x0/0x54)
[   13.761178][  T415] Exception stack(0xb8d47fa8 to 0xb8d47ff0)
[   13.766932][  T415] 7fa0:                   0000006c 008fbea0 00000001 008fbea0 00000006 00000000
[   13.775811][  T415] 7fc0: 0000006c 008fbea0 76f1cda0 00000004 00000006 00000006 00000000 00000000
[   13.784687][  T415] 7fe0: 00000004 7ebaf7d0 76eb4c0b 76e3f206
[   13.790442][  T415] Code: bad PC value
[   13.839214][  T415] ---[ end trace 1fe21ecfc9f28852 ]---

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Nikita Shubin <NShubin@topcon.com>
Fixes: 7a18694 ("remoteproc: remove the single rpmsg vdev limitation")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200306072452.24743-1-NShubin@topcon.com
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregmarsden pushed a commit that referenced this pull request Apr 24, 2020
[ Upstream commit a866759 ]

This reverts commit 64e62bd.

This commit ends up causing some lockdep splats due to trying to grab the
payload lock while holding the mgr's lock:

[   54.010099]
[   54.011765] ======================================================
[   54.018670] WARNING: possible circular locking dependency detected
[   54.025577] 5.5.0-rc6-02274-g77381c23ee63 #47 Not tainted
[   54.031610] ------------------------------------------------------
[   54.038516] kworker/1:6/1040 is trying to acquire lock:
[   54.044354] ffff888272af3228 (&mgr->payload_lock){+.+.}, at:
drm_dp_mst_topology_mgr_set_mst+0x218/0x2e4
[   54.054957]
[   54.054957] but task is already holding lock:
[   54.061473] ffff888272af3060 (&mgr->lock){+.+.}, at:
drm_dp_mst_topology_mgr_set_mst+0x3c/0x2e4
[   54.071193]
[   54.071193] which lock already depends on the new lock.
[   54.071193]
[   54.080334]
[   54.080334] the existing dependency chain (in reverse order) is:
[   54.088697]
[   54.088697] -> #1 (&mgr->lock){+.+.}:
[   54.094440]        __mutex_lock+0xc3/0x498
[   54.099015]        drm_dp_mst_topology_get_port_validated+0x25/0x80
[   54.106018]        drm_dp_update_payload_part1+0xa2/0x2e2
[   54.112051]        intel_mst_pre_enable_dp+0x144/0x18f
[   54.117791]        intel_encoders_pre_enable+0x63/0x70
[   54.123532]        hsw_crtc_enable+0xa1/0x722
[   54.128396]        intel_update_crtc+0x50/0x194
[   54.133455]        skl_commit_modeset_enables+0x40c/0x540
[   54.139485]        intel_atomic_commit_tail+0x5f7/0x130d
[   54.145418]        intel_atomic_commit+0x2c8/0x2d8
[   54.150770]        drm_atomic_helper_set_config+0x5a/0x70
[   54.156801]        drm_mode_setcrtc+0x2ab/0x833
[   54.161862]        drm_ioctl+0x2e5/0x424
[   54.166242]        vfs_ioctl+0x21/0x2f
[   54.170426]        do_vfs_ioctl+0x5fb/0x61e
[   54.175096]        ksys_ioctl+0x55/0x75
[   54.179377]        __x64_sys_ioctl+0x1a/0x1e
[   54.184146]        do_syscall_64+0x5c/0x6d
[   54.188721]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
[   54.194946]
[   54.194946] -> #0 (&mgr->payload_lock){+.+.}:
[   54.201463]
[   54.201463] other info that might help us debug this:
[   54.201463]
[   54.210410]  Possible unsafe locking scenario:
[   54.210410]
[   54.217025]        CPU0                    CPU1
[   54.222082]        ----                    ----
[   54.227138]   lock(&mgr->lock);
[   54.230643]                                lock(&mgr->payload_lock);
[   54.237742]                                lock(&mgr->lock);
[   54.244062]   lock(&mgr->payload_lock);
[   54.248346]
[   54.248346]  *** DEADLOCK ***
[   54.248346]
[   54.254959] 7 locks held by kworker/1:6/1040:
[   54.259822]  #0: ffff888275c4f528 ((wq_completion)events){+.+.},
at: worker_thread+0x455/0x6e2
[   54.269451]  #1: ffffc9000119beb0
((work_completion)(&(&dev_priv->hotplug.hotplug_work)->work)){+.+.},
at: worker_thread+0x455/0x6e2
[   54.282768]  #2: ffff888272a403f0 (&dev->mode_config.mutex){+.+.},
at: i915_hotplug_work_func+0x4b/0x2be
[   54.293368]  #3: ffffffff824fc6c0 (drm_connector_list_iter){.+.+},
at: i915_hotplug_work_func+0x17e/0x2be
[   54.304061]  #4: ffffc9000119bc58 (crtc_ww_class_acquire){+.+.},
at: drm_helper_probe_detect_ctx+0x40/0xfd
[   54.314855]  #5: ffff888272a40470 (crtc_ww_class_mutex){+.+.}, at:
drm_modeset_lock+0x74/0xe2
[   54.324385]  #6: ffff888272af3060 (&mgr->lock){+.+.}, at:
drm_dp_mst_topology_mgr_set_mst+0x3c/0x2e4
[   54.334597]
[   54.334597] stack backtrace:
[   54.339464] CPU: 1 PID: 1040 Comm: kworker/1:6 Not tainted
5.5.0-rc6-02274-g77381c23ee63 #47
[   54.348893] Hardware name: Google Fizz/Fizz, BIOS
Google_Fizz.10139.39.0 01/04/2018
[   54.357451] Workqueue: events i915_hotplug_work_func
[   54.362995] Call Trace:
[   54.365724]  dump_stack+0x71/0x9c
[   54.369427]  check_noncircular+0x91/0xbc
[   54.373809]  ? __lock_acquire+0xc9e/0xf66
[   54.378286]  ? __lock_acquire+0xc9e/0xf66
[   54.382763]  ? lock_acquire+0x175/0x1ac
[   54.387048]  ? drm_dp_mst_topology_mgr_set_mst+0x218/0x2e4
[   54.393177]  ? __mutex_lock+0xc3/0x498
[   54.397362]  ? drm_dp_mst_topology_mgr_set_mst+0x218/0x2e4
[   54.403492]  ? drm_dp_mst_topology_mgr_set_mst+0x218/0x2e4
[   54.409620]  ? drm_dp_dpcd_access+0xd9/0x101
[   54.414390]  ? drm_dp_mst_topology_mgr_set_mst+0x218/0x2e4
[   54.420517]  ? drm_dp_mst_topology_mgr_set_mst+0x218/0x2e4
[   54.426645]  ? intel_digital_port_connected+0x34d/0x35c
[   54.432482]  ? intel_dp_detect+0x227/0x44e
[   54.437056]  ? ww_mutex_lock+0x49/0x9a
[   54.441242]  ? drm_helper_probe_detect_ctx+0x75/0xfd
[   54.446789]  ? intel_encoder_hotplug+0x4b/0x97
[   54.451752]  ? intel_ddi_hotplug+0x61/0x2e0
[   54.456423]  ? mark_held_locks+0x53/0x68
[   54.460803]  ? _raw_spin_unlock_irqrestore+0x3a/0x51
[   54.466347]  ? lockdep_hardirqs_on+0x187/0x1a4
[   54.471310]  ? drm_connector_list_iter_next+0x89/0x9a
[   54.476953]  ? i915_hotplug_work_func+0x206/0x2be
[   54.482208]  ? worker_thread+0x4d5/0x6e2
[   54.486587]  ? worker_thread+0x455/0x6e2
[   54.490966]  ? queue_work_on+0x64/0x64
[   54.495151]  ? kthread+0x1e9/0x1f1
[   54.498946]  ? queue_work_on+0x64/0x64
[   54.503130]  ? kthread_unpark+0x5e/0x5e
[   54.507413]  ? ret_from_fork+0x3a/0x50

The proper fix for this is probably cleanup the VCPI allocations when we're
enabling the topology, or on the first payload allocation. For now though,
let's just revert.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Fixes: 64e62bd ("drm/dp_mst: Remove VCPI while disabling topology mgr")
Cc: Sean Paul <sean@poorly.run>
Cc: Wayne Lin <Wayne.Lin@amd.com>
Reviewed-by: Sean Paul <sean@poorly.run>
Link: https://patchwork.freedesktop.org/patch/msgid/20200117205149.97262-1-lyude@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregmarsden pushed a commit that referenced this pull request May 8, 2020
A deadlock with this stacktrace was observed.

The loop thread does a GFP_KERNEL allocation, it calls into dm-bufio
shrinker and the shrinker depends on I/O completion in the dm-bufio
subsystem.

In order to fix the deadlock (and other similar ones), we set the flag
PF_MEMALLOC_NOIO at loop thread entry.

PID: 474    TASK: ffff8813e11f4600  CPU: 10  COMMAND: "kswapd0"
   #0 [ffff8813dedfb938] __schedule at ffffffff8173f405
   #1 [ffff8813dedfb990] schedule at ffffffff8173fa27
   #2 [ffff8813dedfb9b0] schedule_timeout at ffffffff81742fec
   #3 [ffff8813dedfba60] io_schedule_timeout at ffffffff8173f186
   #4 [ffff8813dedfbaa0] bit_wait_io at ffffffff8174034f
   #5 [ffff8813dedfbac0] __wait_on_bit at ffffffff8173fec8
   #6 [ffff8813dedfbb10] out_of_line_wait_on_bit at ffffffff8173ff81
   #7 [ffff8813dedfbb90] __make_buffer_clean at ffffffffa038736f [dm_bufio]
   #8 [ffff8813dedfbbb0] __try_evict_buffer at ffffffffa0387bb8 [dm_bufio]
   #9 [ffff8813dedfbbd0] dm_bufio_shrink_scan at ffffffffa0387cc3 [dm_bufio]
  #10 [ffff8813dedfbc40] shrink_slab at ffffffff811a87ce
  #11 [ffff8813dedfbd30] shrink_zone at ffffffff811ad778
  #12 [ffff8813dedfbdc0] kswapd at ffffffff811ae92f
  #13 [ffff8813dedfbec0] kthread at ffffffff810a8428
  #14 [ffff8813dedfbf50] ret_from_fork at ffffffff81745242

  PID: 14127  TASK: ffff881455749c00  CPU: 11  COMMAND: "loop1"
   #0 [ffff88272f5af228] __schedule at ffffffff8173f405
   #1 [ffff88272f5af280] schedule at ffffffff8173fa27
   #2 [ffff88272f5af2a0] schedule_preempt_disabled at ffffffff8173fd5e
   #3 [ffff88272f5af2b0] __mutex_lock_slowpath at ffffffff81741fb5
   #4 [ffff88272f5af330] mutex_lock at ffffffff81742133
   #5 [ffff88272f5af350] dm_bufio_shrink_count at ffffffffa03865f9 [dm_bufio]
   #6 [ffff88272f5af380] shrink_slab at ffffffff811a86bd
   #7 [ffff88272f5af470] shrink_zone at ffffffff811ad778
   #8 [ffff88272f5af500] do_try_to_free_pages at ffffffff811adb34
   #9 [ffff88272f5af590] try_to_free_pages at ffffffff811adef8
  #10 [ffff88272f5af610] __alloc_pages_nodemask at ffffffff811a09c3
  #11 [ffff88272f5af710] alloc_pages_current at ffffffff811e8b71
  #12 [ffff88272f5af760] new_slab at ffffffff811f4523
  #13 [ffff88272f5af7b0] __slab_alloc at ffffffff8173a1b5
  #14 [ffff88272f5af880] kmem_cache_alloc at ffffffff811f484b
  #15 [ffff88272f5af8d0] do_blockdev_direct_IO at ffffffff812535b3
  #16 [ffff88272f5afb00] __blockdev_direct_IO at ffffffff81255dc3
  #17 [ffff88272f5afb30] xfs_vm_direct_IO at ffffffffa01fe3fc [xfs]
  #18 [ffff88272f5afb90] generic_file_read_iter at ffffffff81198994
  #19 [ffff88272f5afc50] __dta_xfs_file_read_iter_2398 at ffffffffa020c970 [xfs]
  #20 [ffff88272f5afcc0] lo_rw_aio at ffffffffa0377042 [loop]
  #21 [ffff88272f5afd70] loop_queue_work at ffffffffa0377c3b [loop]
  #22 [ffff88272f5afe60] kthread_worker_fn at ffffffff810a8a0c
  #23 [ffff88272f5afec0] kthread at ffffffff810a8428
  #24 [ffff88272f5aff50] ret_from_fork at ffffffff81745242

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
(cherry picked from commit d0a255e)

Orabug: 31292386

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
gregmarsden pushed a commit that referenced this pull request May 8, 2020
[ Upstream commit 1b6a51e ]

The req->body should be updated before req->state is updated and the
order should be guaranteed by a barrier.

Otherwise, read_reply() might return req->body = NULL.

Below is sample callstack when the issue is reproduced on purpose by
reordering the updates of req->body and req->state and adding delay in
code between updates of req->state and req->body.

[   22.356105] general protection fault: 0000 [#1] SMP PTI
[   22.361185] CPU: 2 PID: 52 Comm: xenwatch Not tainted 5.5.0xen+ #6
[   22.366727] Hardware name: Xen HVM domU, BIOS ...
[   22.372245] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60
... ...
[   22.392163] RSP: 0018:ffffb2d64023fdf0 EFLAGS: 00010246
[   22.395933] RAX: 0000000000000000 RBX: 75746e7562755f6d RCX: 0000000000000000
[   22.400871] RDX: 0000000000000000 RSI: ffffb2d64023fdfc RDI: 75746e7562755f6d
[   22.405874] RBP: 0000000000000000 R08: 00000000000001e8 R09: 0000000000cdcdcd
[   22.410945] R10: ffffb2d6402ffe00 R11: ffff9d95395eaeb0 R12: ffff9d9535935000
[   22.417613] R13: ffff9d9526d4a000 R14: ffff9d9526f4f340 R15: ffff9d9537654000
[   22.423726] FS:  0000000000000000(0000) GS:ffff9d953bc80000(0000) knlGS:0000000000000000
[   22.429898] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   22.434342] CR2: 000000c4206a9000 CR3: 00000001ea3fc002 CR4: 00000000001606e0
[   22.439645] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   22.444941] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   22.450342] Call Trace:
[   22.452509]  simple_strtoull+0x27/0x70
[   22.455572]  xenbus_transaction_start+0x31/0x50
[   22.459104]  netback_changed+0x76c/0xcc1 [xen_netfront]
[   22.463279]  ? find_watch+0x40/0x40
[   22.466156]  xenwatch_thread+0xb4/0x150
[   22.469309]  ? wait_woken+0x80/0x80
[   22.472198]  kthread+0x10e/0x130
[   22.474925]  ? kthread_park+0x80/0x80
[   22.477946]  ret_from_fork+0x35/0x40
[   22.480968] Modules linked in: xen_kbdfront xen_fbfront(+) xen_netfront xen_blkfront
[   22.486783] ---[ end trace a9222030a747c3f7 ]---
[   22.490424] RIP: 0010:_parse_integer_fixup_radix+0x6/0x60

The virt_rmb() is added in the 'true' path of test_reply(). The "while"
is changed to "do while" so that test_reply() is used as a read memory
barrier.

Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
Link: https://lore.kernel.org/r/20200303221423.21962-1-dongli.zhang@oracle.com
Reviewed-by: Julien Grall <jgrall@amazon.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
LinuxMinion pushed a commit that referenced this pull request May 29, 2020
A hang was observed in the fcport delete path when the device was
responding slow and an issue-lip path (results in session termination) was
taken.

Fix this by issuing logo requests unconditionally.

PID: 19491  TASK: ffff8e23e67bb150  CPU: 0   COMMAND: "kworker/0:0"
 #0 [ffff8e2370297bf8] __schedule at ffffffffb4f7dbb0
 #1 [ffff8e2370297c88] schedule at ffffffffb4f7e199
 #2 [ffff8e2370297c98] schedule_timeout at ffffffffb4f7ba68
 #3 [ffff8e2370297d40] msleep at ffffffffb48ad9ff
 #4 [ffff8e2370297d58] qlt_free_session_done at ffffffffc0c32052 [qla2xxx]
 #5 [ffff8e2370297e20] process_one_work at ffffffffb48bcfdf
 #6 [ffff8e2370297e68] worker_thread at ffffffffb48bdca6
 #7 [ffff8e2370297ec8] kthread at ffffffffb48c4f81

Signed-off-by: Quinn Tran <qutran@marvell.com>
Signed-off-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit f00b342)
Signed-off-by: Himanshu Madhani <hmadhani@marvell.com>

Orabug: 30846289
Signed-off-by: John Donnelly <john.p.donnelly@oracle.com>
Reviewed-by: Jack Vogel <jack.vogel@oracle.com>
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
gregmarsden pushed a commit that referenced this pull request Jul 3, 2020
A hang was observed in the fcport delete path when the device was
responding slow and an issue-lip path (results in session termination) was
taken.

Fix this by issuing logo requests unconditionally.

PID: 19491  TASK: ffff8e23e67bb150  CPU: 0   COMMAND: "kworker/0:0"
 #0 [ffff8e2370297bf8] __schedule at ffffffffb4f7dbb0
 #1 [ffff8e2370297c88] schedule at ffffffffb4f7e199
 #2 [ffff8e2370297c98] schedule_timeout at ffffffffb4f7ba68
 #3 [ffff8e2370297d40] msleep at ffffffffb48ad9ff
 #4 [ffff8e2370297d58] qlt_free_session_done at ffffffffc0c32052 [qla2xxx]
 #5 [ffff8e2370297e20] process_one_work at ffffffffb48bcfdf
 #6 [ffff8e2370297e68] worker_thread at ffffffffb48bdca6
 #7 [ffff8e2370297ec8] kthread at ffffffffb48c4f81

Signed-off-by: Quinn Tran <qutran@marvell.com>
Signed-off-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit f00b342)
Signed-off-by: Himanshu Madhani <hmadhani@marvell.com>

Orabug: 30846292
Signed-off-by: John Donnelly <john.p.donnelly@oracle.com>
Reviewed-by: Jack Vogel <jack.vogel@oracle.com>
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
gregmarsden pushed a commit that referenced this pull request Jul 3, 2020
For INVADER_SERIES, each set of 8 reply queues (0 - 7, 8 - 15,..), and for
VENTURA_SERIES, each set of 16 reply queues (0 - 15, 16 - 31,..) need to be
within the same 4 GB boundary. Driver uses limitation of VENTURA_SERIES to
manage INVADER_SERIES as well. The driver is allocating the DMA able
memory for RDPQs accordingly.

1) At driver load, set DMA mask to 64 and allocate memory for RDPQs

2) Check if allocated resources for RDPQ are in the same 4GB range

3) If #2 is true, continue with 64 bit DMA and go to #6

4) If #2 is false, then free all the resources from #1

5) Set DMA mask to 32 and allocate RDPQs

6) Proceed with driver loading and other allocations

Link: https://lore.kernel.org/r/1587626596-1044-5-git-send-email-suganath-prabu.subramani@broadcom.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Suganath Prabu <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit 8012209)

Conflicts:
	drivers/scsi/mpt3sas/mpt3sas_base.h

Orabug: 31486216
Signed-off-by: Jack Vogel <jack.vogel@oracle.com>
Reviewed-by: John Donnelly <john.p.donnelly@oracle.com>
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
gregmarsden pushed a commit that referenced this pull request Jul 3, 2020
For INVADER_SERIES, each set of 8 reply queues (0 - 7, 8 - 15,..), and for
VENTURA_SERIES, each set of 16 reply queues (0 - 15, 16 - 31,..) need to be
within the same 4 GB boundary. Driver uses limitation of VENTURA_SERIES to
manage INVADER_SERIES as well. The driver is allocating the DMA able
memory for RDPQs accordingly.

1) At driver load, set DMA mask to 64 and allocate memory for RDPQs

2) Check if allocated resources for RDPQ are in the same 4GB range

3) If #2 is true, continue with 64 bit DMA and go to #6

4) If #2 is false, then free all the resources from #1

5) Set DMA mask to 32 and allocate RDPQs

6) Proceed with driver loading and other allocations

Link: https://lore.kernel.org/r/1587626596-1044-5-git-send-email-suganath-prabu.subramani@broadcom.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Suganath Prabu <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit 8012209)

Conflicts:
	drivers/scsi/mpt3sas/mpt3sas_base.h

Orabug: 31434583
Signed-off-by: Jack Vogel <jack.vogel@oracle.com>
Reviewed-by: John Donnelly <john.p.donnelly@oracle.com>
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
gregmarsden pushed a commit that referenced this pull request Jul 3, 2020
commit 9b38cc7 upstream.

Ziqian reported lockup when adding retprobe on _raw_spin_lock_irqsave.
My test was also able to trigger lockdep output:

 ============================================
 WARNING: possible recursive locking detected
 5.6.0-rc6+ #6 Not tainted
 --------------------------------------------
 sched-messaging/2767 is trying to acquire lock:
 ffffffff9a492798 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_hash_lock+0x52/0xa0

 but task is already holding lock:
 ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(&(kretprobe_table_locks[i].lock));
   lock(&(kretprobe_table_locks[i].lock));

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 1 lock held by sched-messaging/2767:
  #0: ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50

 stack backtrace:
 CPU: 3 PID: 2767 Comm: sched-messaging Not tainted 5.6.0-rc6+ #6
 Call Trace:
  dump_stack+0x96/0xe0
  __lock_acquire.cold.57+0x173/0x2b7
  ? native_queued_spin_lock_slowpath+0x42b/0x9e0
  ? lockdep_hardirqs_on+0x590/0x590
  ? __lock_acquire+0xf63/0x4030
  lock_acquire+0x15a/0x3d0
  ? kretprobe_hash_lock+0x52/0xa0
  _raw_spin_lock_irqsave+0x36/0x70
  ? kretprobe_hash_lock+0x52/0xa0
  kretprobe_hash_lock+0x52/0xa0
  trampoline_handler+0xf8/0x940
  ? kprobe_fault_handler+0x380/0x380
  ? find_held_lock+0x3a/0x1c0
  kretprobe_trampoline+0x25/0x50
  ? lock_acquired+0x392/0xbc0
  ? _raw_spin_lock_irqsave+0x50/0x70
  ? __get_valid_kprobe+0x1f0/0x1f0
  ? _raw_spin_unlock_irqrestore+0x3b/0x40
  ? finish_task_switch+0x4b9/0x6d0
  ? __switch_to_asm+0x34/0x70
  ? __switch_to_asm+0x40/0x70

The code within the kretprobe handler checks for probe reentrancy,
so we won't trigger any _raw_spin_lock_irqsave probe in there.

The problem is in outside kprobe_flush_task, where we call:

  kprobe_flush_task
    kretprobe_table_lock
      raw_spin_lock_irqsave
        _raw_spin_lock_irqsave

where _raw_spin_lock_irqsave triggers the kretprobe and installs
kretprobe_trampoline handler on _raw_spin_lock_irqsave return.

The kretprobe_trampoline handler is then executed with already
locked kretprobe_table_locks, and first thing it does is to
lock kretprobe_table_locks ;-) the whole lockup path like:

  kprobe_flush_task
    kretprobe_table_lock
      raw_spin_lock_irqsave
        _raw_spin_lock_irqsave ---> probe triggered, kretprobe_trampoline installed

        ---> kretprobe_table_locks locked

        kretprobe_trampoline
          trampoline_handler
            kretprobe_hash_lock(current, &head, &flags);  <--- deadlock

Adding kprobe_busy_begin/end helpers that mark code with fake
probe installed to prevent triggering of another kprobe within
this code.

Using these helpers in kprobe_flush_task, so the probe recursion
protection check is hit and the probe is never set to prevent
above lockup.

Link: http://lkml.kernel.org/r/158927059835.27680.7011202830041561604.stgit@devnote2

Fixes: ef53d9c ("kprobes: improve kretprobe scalability with hashed locking")
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Gustavo A . R . Silva" <gustavoars@kernel.org>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Reported-by: "Ziqian SUN (Zamir)" <zsun@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
LinuxMinion pushed a commit that referenced this pull request Jul 23, 2020
[ Upstream commit 8523c00 ]

After entering kdb due to breakpoint, when we execute 'ss' or 'go' (will
delay installing breakpoints, do single-step first), it won't work
correctly, and it will enter kdb due to oops.

It's because the reason gotten in kdb_stub() is not as expected, and it
seems that the ex_vector for single-step should be 0, like what arch
powerpc/sh/parisc has implemented.

Before the patch:
Entering kdb (current=0xffff8000119e2dc0, pid 0) on processor 0 due to Keyboard Entry
[0]kdb> bp printk
Instruction(i) BP #0 at 0xffff8000101486cc (printk)
    is enabled   addr at ffff8000101486cc, hardtype=0 installed=0

[0]kdb> g

/ # echo h > /proc/sysrq-trigger

Entering kdb (current=0xffff0000fa878040, pid 266) on processor 3 due to Breakpoint @ 0xffff8000101486cc
[3]kdb> ss

Entering kdb (current=0xffff0000fa878040, pid 266) on processor 3 Oops: (null)
due to oops @ 0xffff800010082ab8
CPU: 3 PID: 266 Comm: sh Not tainted 5.7.0-rc4-13839-gf0e5ad491718 #6
Hardware name: linux,dummy-virt (DT)
pstate: 00000085 (nzcv daIf -PAN -UAO)
pc : el1_irq+0x78/0x180
lr : __handle_sysrq+0x80/0x190
sp : ffff800015003bf0
x29: ffff800015003d20 x28: ffff0000fa878040
x27: 0000000000000000 x26: ffff80001126b1f0
x25: ffff800011b6a0d8 x24: 0000000000000000
x23: 0000000080200005 x22: ffff8000101486cc
x21: ffff800015003d30 x20: 0000ffffffffffff
x19: ffff8000119f2000 x18: 0000000000000000
x17: 0000000000000000 x16: 0000000000000000
x15: 0000000000000000 x14: 0000000000000000
x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000
x9 : 0000000000000000 x8 : ffff800015003e50
x7 : 0000000000000002 x6 : 00000000380b9990
x5 : ffff8000106e99e8 x4 : ffff0000fadd83c0
x3 : 0000ffffffffffff x2 : ffff800011b6a0d8
x1 : ffff800011b6a000 x0 : ffff80001130c9d8
Call trace:
 el1_irq+0x78/0x180
 printk+0x0/0x84
 write_sysrq_trigger+0xb0/0x118
 proc_reg_write+0xb4/0xe0
 __vfs_write+0x18/0x40
 vfs_write+0xb0/0x1b8
 ksys_write+0x64/0xf0
 __arm64_sys_write+0x14/0x20
 el0_svc_common.constprop.2+0xb0/0x168
 do_el0_svc+0x20/0x98
 el0_sync_handler+0xec/0x1a8
 el0_sync+0x140/0x180

[3]kdb>

After the patch:
Entering kdb (current=0xffff8000119e2dc0, pid 0) on processor 0 due to Keyboard Entry
[0]kdb> bp printk
Instruction(i) BP #0 at 0xffff8000101486cc (printk)
    is enabled   addr at ffff8000101486cc, hardtype=0 installed=0

[0]kdb> g

/ # echo h > /proc/sysrq-trigger

Entering kdb (current=0xffff0000fa852bc0, pid 268) on processor 0 due to Breakpoint @ 0xffff8000101486cc
[0]kdb> g

Entering kdb (current=0xffff0000fa852bc0, pid 268) on processor 0 due to Breakpoint @ 0xffff8000101486cc
[0]kdb> ss

Entering kdb (current=0xffff0000fa852bc0, pid 268) on processor 0 due to SS trap @ 0xffff800010082ab8
[0]kdb>

Fixes: 44679a4 ("arm64: KGDB: Add step debugging support")
Signed-off-by: Wei Li <liwei391@huawei.com>
Tested-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200509214159.19680-2-liwei391@huawei.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregmarsden pushed a commit that referenced this pull request Aug 14, 2020
[ Upstream commit e24c644 ]

I compiled with AddressSanitizer and I had these memory leaks while I
was using the tep_parse_format function:

    Direct leak of 28 byte(s) in 4 object(s) allocated from:
        #0 0x7fb07db49ffe in __interceptor_realloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10dffe)
        #1 0x7fb07a724228 in extend_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:985
        #2 0x7fb07a724c21 in __read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1140
        #3 0x7fb07a724f78 in read_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1206
        #4 0x7fb07a725191 in __read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1291
        #5 0x7fb07a7251df in read_expect_type /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1299
        #6 0x7fb07a72e6c8 in process_dynamic_array_len /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:2849
        #7 0x7fb07a7304b8 in process_function /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3161
        #8 0x7fb07a730900 in process_arg_token /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3207
        #9 0x7fb07a727c0b in process_arg /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:1786
        #10 0x7fb07a731080 in event_read_print_args /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3285
        #11 0x7fb07a731722 in event_read_print /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:3369
        #12 0x7fb07a740054 in __tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6335
        #13 0x7fb07a74047a in __parse_event /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6389
        #14 0x7fb07a740536 in tep_parse_format /home/pduplessis/repo/linux/tools/lib/traceevent/event-parse.c:6431
        #15 0x7fb07a785acf in parse_event ../../../src/fs-src/fs.c:251
        #16 0x7fb07a785ccd in parse_systems ../../../src/fs-src/fs.c:284
        #17 0x7fb07a786fb3 in read_metadata ../../../src/fs-src/fs.c:593
        #18 0x7fb07a78760e in ftrace_fs_source_init ../../../src/fs-src/fs.c:727
        #19 0x7fb07d90c19c in add_component_with_init_method_data ../../../../src/lib/graph/graph.c:1048
        #20 0x7fb07d90c87b in add_source_component_with_initialize_method_data ../../../../src/lib/graph/graph.c:1127
        #21 0x7fb07d90c92a in bt_graph_add_source_component ../../../../src/lib/graph/graph.c:1152
        #22 0x55db11aa632e in cmd_run_ctx_create_components_from_config_components ../../../src/cli/babeltrace2.c:2252
        #23 0x55db11aa6fda in cmd_run_ctx_create_components ../../../src/cli/babeltrace2.c:2347
        #24 0x55db11aa780c in cmd_run ../../../src/cli/babeltrace2.c:2461
        #25 0x55db11aa8a7d in main ../../../src/cli/babeltrace2.c:2673
        #26 0x7fb07d5460b2 in __libc_start_main (/lib/x86_64-linux-gnu/libc.so.6+0x270b2)

The token variable in the process_dynamic_array_len function is
allocated in the read_expect_type function, but is not freed before
calling the read_token function.

Free the token variable before calling read_token in order to plug the
leak.

Signed-off-by: Philippe Duplessis-Guindon <pduplessis@efficios.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lore.kernel.org/linux-trace-devel/20200730150236.5392-1-pduplessis@efficios.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
gregmarsden pushed a commit that referenced this pull request Aug 21, 2020
The following deadlock was captured. The first process is holding 'kernfs_mutex'
and hung by io. The io was staging in 'r1conf.pending_bio_list' of raid1 device,
this pending bio list would be flushed by second process 'md127_raid1', but
it was hung by 'kernfs_mutex'. Using sysfs_notify_dirent_safe() to replace
sysfs_notify() can fix it. There were other sysfs_notify() invoked from io
path, removed all of them.

 PID: 40430  TASK: ffff8ee9c8c65c40  CPU: 29  COMMAND: "probe_file"
  #0 [ffffb87c4df37260] __schedule at ffffffff9a8678ec
  #1 [ffffb87c4df372f8] schedule at ffffffff9a867f06
  #2 [ffffb87c4df37310] io_schedule at ffffffff9a0c73e6
  #3 [ffffb87c4df37328] __dta___xfs_iunpin_wait_3443 at ffffffffc03a4057 [xfs]
  #4 [ffffb87c4df373a0] xfs_iunpin_wait at ffffffffc03a6c79 [xfs]
  #5 [ffffb87c4df373b0] __dta_xfs_reclaim_inode_3357 at ffffffffc039a46c [xfs]
  #6 [ffffb87c4df37400] xfs_reclaim_inodes_ag at ffffffffc039a8b6 [xfs]
  #7 [ffffb87c4df37590] xfs_reclaim_inodes_nr at ffffffffc039bb33 [xfs]
  #8 [ffffb87c4df375b0] xfs_fs_free_cached_objects at ffffffffc03af0e9 [xfs]
  #9 [ffffb87c4df375c0] super_cache_scan at ffffffff9a287ec7
 #10 [ffffb87c4df37618] shrink_slab at ffffffff9a1efd93
 #11 [ffffb87c4df37700] shrink_node at ffffffff9a1f5968
 #12 [ffffb87c4df37788] do_try_to_free_pages at ffffffff9a1f5ea2
 #13 [ffffb87c4df377f0] try_to_free_mem_cgroup_pages at ffffffff9a1f6445
 #14 [ffffb87c4df37880] try_charge at ffffffff9a26cc5f
 #15 [ffffb87c4df37920] memcg_kmem_charge_memcg at ffffffff9a270f6a
 #16 [ffffb87c4df37958] new_slab at ffffffff9a251430
 #17 [ffffb87c4df379c0] ___slab_alloc at ffffffff9a251c85
 #18 [ffffb87c4df37a80] __slab_alloc at ffffffff9a25635d
 #19 [ffffb87c4df37ac0] kmem_cache_alloc at ffffffff9a251f89
 #20 [ffffb87c4df37b00] alloc_inode at ffffffff9a2a2b10
 #21 [ffffb87c4df37b20] iget_locked at ffffffff9a2a4854
 #22 [ffffb87c4df37b60] kernfs_get_inode at ffffffff9a311377
 #23 [ffffb87c4df37b80] kernfs_iop_lookup at ffffffff9a311e2b
 #24 [ffffb87c4df37ba8] lookup_slow at ffffffff9a290118
 #25 [ffffb87c4df37c10] walk_component at ffffffff9a291e83
 #26 [ffffb87c4df37c78] path_lookupat at ffffffff9a293619
 #27 [ffffb87c4df37cd8] filename_lookup at ffffffff9a2953af
 #28 [ffffb87c4df37de8] user_path_at_empty at ffffffff9a295566
 #29 [ffffb87c4df37e10] vfs_statx at ffffffff9a289787
 #30 [ffffb87c4df37e70] SYSC_newlstat at ffffffff9a289d5d
 #31 [ffffb87c4df37f18] sys_newlstat at ffffffff9a28a60e
 #32 [ffffb87c4df37f28] do_syscall_64 at ffffffff9a003949
 #33 [ffffb87c4df37f50] entry_SYSCALL_64_after_hwframe at ffffffff9aa001ad
     RIP: 00007f617a5f2905  RSP: 00007f607334f838  RFLAGS: 00000246
     RAX: ffffffffffffffda  RBX: 00007f6064044b20  RCX: 00007f617a5f2905
     RDX: 00007f6064044b20  RSI: 00007f6064044b20  RDI: 00007f6064005890
     RBP: 00007f6064044aa0   R8: 0000000000000030   R9: 000000000000011c
     R10: 0000000000000013  R11: 0000000000000246  R12: 00007f606417e6d0
     R13: 00007f6064044aa0  R14: 00007f6064044b10  R15: 00000000ffffffff
     ORIG_RAX: 0000000000000006  CS: 0033  SS: 002b

 PID: 927    TASK: ffff8f15ac5dbd80  CPU: 42  COMMAND: "md127_raid1"
  #0 [ffffb87c4df07b28] __schedule at ffffffff9a8678ec
  #1 [ffffb87c4df07bc0] schedule at ffffffff9a867f06
  #2 [ffffb87c4df07bd8] schedule_preempt_disabled at ffffffff9a86825e
  #3 [ffffb87c4df07be8] __mutex_lock at ffffffff9a869bcc
  #4 [ffffb87c4df07ca0] __mutex_lock_slowpath at ffffffff9a86a013
  #5 [ffffb87c4df07cb0] mutex_lock at ffffffff9a86a04f
  #6 [ffffb87c4df07cc8] kernfs_find_and_get_ns at ffffffff9a311d83
  #7 [ffffb87c4df07cf0] sysfs_notify at ffffffff9a314b3a
  #8 [ffffb87c4df07d18] md_update_sb at ffffffff9a688696
  #9 [ffffb87c4df07d98] md_update_sb at ffffffff9a6886d5
 #10 [ffffb87c4df07da8] md_check_recovery at ffffffff9a68ad9c
 #11 [ffffb87c4df07dd0] raid1d at ffffffffc01f0375 [raid1]
 #12 [ffffb87c4df07ea0] md_thread at ffffffff9a680348
 #13 [ffffb87c4df07f08] kthread at ffffffff9a0b8005
 #14 [ffffb87c4df07f50] ret_from_fork at ffffffff9aa00344

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
(cherry picked from commit e1a86db)

Orabug: 31602420
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joe Jin <joe.jin@oracle.com>

 Conflicts:
	drivers/md/md-bitmap.c

Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
gregmarsden pushed a commit that referenced this pull request Aug 28, 2020
The following deadlock was captured. The first process is holding 'kernfs_mutex'
and hung by io. The io was staging in 'r1conf.pending_bio_list' of raid1 device,
this pending bio list would be flushed by second process 'md127_raid1', but
it was hung by 'kernfs_mutex'. Using sysfs_notify_dirent_safe() to replace
sysfs_notify() can fix it. There were other sysfs_notify() invoked from io
path, removed all of them.

 PID: 40430  TASK: ffff8ee9c8c65c40  CPU: 29  COMMAND: "probe_file"
  #0 [ffffb87c4df37260] __schedule at ffffffff9a8678ec
  #1 [ffffb87c4df372f8] schedule at ffffffff9a867f06
  #2 [ffffb87c4df37310] io_schedule at ffffffff9a0c73e6
  #3 [ffffb87c4df37328] __dta___xfs_iunpin_wait_3443 at ffffffffc03a4057 [xfs]
  #4 [ffffb87c4df373a0] xfs_iunpin_wait at ffffffffc03a6c79 [xfs]
  #5 [ffffb87c4df373b0] __dta_xfs_reclaim_inode_3357 at ffffffffc039a46c [xfs]
  #6 [ffffb87c4df37400] xfs_reclaim_inodes_ag at ffffffffc039a8b6 [xfs]
  #7 [ffffb87c4df37590] xfs_reclaim_inodes_nr at ffffffffc039bb33 [xfs]
  #8 [ffffb87c4df375b0] xfs_fs_free_cached_objects at ffffffffc03af0e9 [xfs]
  #9 [ffffb87c4df375c0] super_cache_scan at ffffffff9a287ec7
 #10 [ffffb87c4df37618] shrink_slab at ffffffff9a1efd93
 #11 [ffffb87c4df37700] shrink_node at ffffffff9a1f5968
 #12 [ffffb87c4df37788] do_try_to_free_pages at ffffffff9a1f5ea2
 #13 [ffffb87c4df377f0] try_to_free_mem_cgroup_pages at ffffffff9a1f6445
 #14 [ffffb87c4df37880] try_charge at ffffffff9a26cc5f
 #15 [ffffb87c4df37920] memcg_kmem_charge_memcg at ffffffff9a270f6a
 #16 [ffffb87c4df37958] new_slab at ffffffff9a251430
 #17 [ffffb87c4df379c0] ___slab_alloc at ffffffff9a251c85
 #18 [ffffb87c4df37a80] __slab_alloc at ffffffff9a25635d
 #19 [ffffb87c4df37ac0] kmem_cache_alloc at ffffffff9a251f89
 #20 [ffffb87c4df37b00] alloc_inode at ffffffff9a2a2b10
 #21 [ffffb87c4df37b20] iget_locked at ffffffff9a2a4854
 #22 [ffffb87c4df37b60] kernfs_get_inode at ffffffff9a311377
 #23 [ffffb87c4df37b80] kernfs_iop_lookup at ffffffff9a311e2b
 #24 [ffffb87c4df37ba8] lookup_slow at ffffffff9a290118
 #25 [ffffb87c4df37c10] walk_component at ffffffff9a291e83
 #26 [ffffb87c4df37c78] path_lookupat at ffffffff9a293619
 #27 [ffffb87c4df37cd8] filename_lookup at ffffffff9a2953af
 #28 [ffffb87c4df37de8] user_path_at_empty at ffffffff9a295566
 #29 [ffffb87c4df37e10] vfs_statx at ffffffff9a289787
 #30 [ffffb87c4df37e70] SYSC_newlstat at ffffffff9a289d5d
 #31 [ffffb87c4df37f18] sys_newlstat at ffffffff9a28a60e
 #32 [ffffb87c4df37f28] do_syscall_64 at ffffffff9a003949
 #33 [ffffb87c4df37f50] entry_SYSCALL_64_after_hwframe at ffffffff9aa001ad
     RIP: 00007f617a5f2905  RSP: 00007f607334f838  RFLAGS: 00000246
     RAX: ffffffffffffffda  RBX: 00007f6064044b20  RCX: 00007f617a5f2905
     RDX: 00007f6064044b20  RSI: 00007f6064044b20  RDI: 00007f6064005890
     RBP: 00007f6064044aa0   R8: 0000000000000030   R9: 000000000000011c
     R10: 0000000000000013  R11: 0000000000000246  R12: 00007f606417e6d0
     R13: 00007f6064044aa0  R14: 00007f6064044b10  R15: 00000000ffffffff
     ORIG_RAX: 0000000000000006  CS: 0033  SS: 002b

 PID: 927    TASK: ffff8f15ac5dbd80  CPU: 42  COMMAND: "md127_raid1"
  #0 [ffffb87c4df07b28] __schedule at ffffffff9a8678ec
  #1 [ffffb87c4df07bc0] schedule at ffffffff9a867f06
  #2 [ffffb87c4df07bd8] schedule_preempt_disabled at ffffffff9a86825e
  #3 [ffffb87c4df07be8] __mutex_lock at ffffffff9a869bcc
  #4 [ffffb87c4df07ca0] __mutex_lock_slowpath at ffffffff9a86a013
  #5 [ffffb87c4df07cb0] mutex_lock at ffffffff9a86a04f
  #6 [ffffb87c4df07cc8] kernfs_find_and_get_ns at ffffffff9a311d83
  #7 [ffffb87c4df07cf0] sysfs_notify at ffffffff9a314b3a
  #8 [ffffb87c4df07d18] md_update_sb at ffffffff9a688696
  #9 [ffffb87c4df07d98] md_update_sb at ffffffff9a6886d5
 #10 [ffffb87c4df07da8] md_check_recovery at ffffffff9a68ad9c
 #11 [ffffb87c4df07dd0] raid1d at ffffffffc01f0375 [raid1]
 #12 [ffffb87c4df07ea0] md_thread at ffffffff9a680348
 #13 [ffffb87c4df07f08] kthread at ffffffff9a0b8005
 #14 [ffffb87c4df07f50] ret_from_fork at ffffffff9aa00344

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
(cherry picked from commit e1a86db)

Orabug: 31682033
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joe Jin <joe.jin@oracle.com>
gregmarsden pushed a commit that referenced this pull request Aug 28, 2020
The following deadlock was captured. The first process is holding 'kernfs_mutex'
and hung by io. The io was staging in 'r1conf.pending_bio_list' of raid1 device,
this pending bio list would be flushed by second process 'md127_raid1', but
it was hung by 'kernfs_mutex'. Using sysfs_notify_dirent_safe() to replace
sysfs_notify() can fix it. There were other sysfs_notify() invoked from io
path, removed all of them.

 PID: 40430  TASK: ffff8ee9c8c65c40  CPU: 29  COMMAND: "probe_file"
  #0 [ffffb87c4df37260] __schedule at ffffffff9a8678ec
  #1 [ffffb87c4df372f8] schedule at ffffffff9a867f06
  #2 [ffffb87c4df37310] io_schedule at ffffffff9a0c73e6
  #3 [ffffb87c4df37328] __dta___xfs_iunpin_wait_3443 at ffffffffc03a4057 [xfs]
  #4 [ffffb87c4df373a0] xfs_iunpin_wait at ffffffffc03a6c79 [xfs]
  #5 [ffffb87c4df373b0] __dta_xfs_reclaim_inode_3357 at ffffffffc039a46c [xfs]
  #6 [ffffb87c4df37400] xfs_reclaim_inodes_ag at ffffffffc039a8b6 [xfs]
  #7 [ffffb87c4df37590] xfs_reclaim_inodes_nr at ffffffffc039bb33 [xfs]
  #8 [ffffb87c4df375b0] xfs_fs_free_cached_objects at ffffffffc03af0e9 [xfs]
  #9 [ffffb87c4df375c0] super_cache_scan at ffffffff9a287ec7
 #10 [ffffb87c4df37618] shrink_slab at ffffffff9a1efd93
 #11 [ffffb87c4df37700] shrink_node at ffffffff9a1f5968
 #12 [ffffb87c4df37788] do_try_to_free_pages at ffffffff9a1f5ea2
 #13 [ffffb87c4df377f0] try_to_free_mem_cgroup_pages at ffffffff9a1f6445
 #14 [ffffb87c4df37880] try_charge at ffffffff9a26cc5f
 #15 [ffffb87c4df37920] memcg_kmem_charge_memcg at ffffffff9a270f6a
 #16 [ffffb87c4df37958] new_slab at ffffffff9a251430
 #17 [ffffb87c4df379c0] ___slab_alloc at ffffffff9a251c85
 #18 [ffffb87c4df37a80] __slab_alloc at ffffffff9a25635d
 #19 [ffffb87c4df37ac0] kmem_cache_alloc at ffffffff9a251f89
 #20 [ffffb87c4df37b00] alloc_inode at ffffffff9a2a2b10
 #21 [ffffb87c4df37b20] iget_locked at ffffffff9a2a4854
 #22 [ffffb87c4df37b60] kernfs_get_inode at ffffffff9a311377
 #23 [ffffb87c4df37b80] kernfs_iop_lookup at ffffffff9a311e2b
 #24 [ffffb87c4df37ba8] lookup_slow at ffffffff9a290118
 #25 [ffffb87c4df37c10] walk_component at ffffffff9a291e83
 #26 [ffffb87c4df37c78] path_lookupat at ffffffff9a293619
 #27 [ffffb87c4df37cd8] filename_lookup at ffffffff9a2953af
 #28 [ffffb87c4df37de8] user_path_at_empty at ffffffff9a295566
 #29 [ffffb87c4df37e10] vfs_statx at ffffffff9a289787
 #30 [ffffb87c4df37e70] SYSC_newlstat at ffffffff9a289d5d
 #31 [ffffb87c4df37f18] sys_newlstat at ffffffff9a28a60e
 #32 [ffffb87c4df37f28] do_syscall_64 at ffffffff9a003949
 #33 [ffffb87c4df37f50] entry_SYSCALL_64_after_hwframe at ffffffff9aa001ad
     RIP: 00007f617a5f2905  RSP: 00007f607334f838  RFLAGS: 00000246
     RAX: ffffffffffffffda  RBX: 00007f6064044b20  RCX: 00007f617a5f2905
     RDX: 00007f6064044b20  RSI: 00007f6064044b20  RDI: 00007f6064005890
     RBP: 00007f6064044aa0   R8: 0000000000000030   R9: 000000000000011c
     R10: 0000000000000013  R11: 0000000000000246  R12: 00007f606417e6d0
     R13: 00007f6064044aa0  R14: 00007f6064044b10  R15: 00000000ffffffff
     ORIG_RAX: 0000000000000006  CS: 0033  SS: 002b

 PID: 927    TASK: ffff8f15ac5dbd80  CPU: 42  COMMAND: "md127_raid1"
  #0 [ffffb87c4df07b28] __schedule at ffffffff9a8678ec
  #1 [ffffb87c4df07bc0] schedule at ffffffff9a867f06
  #2 [ffffb87c4df07bd8] schedule_preempt_disabled at ffffffff9a86825e
  #3 [ffffb87c4df07be8] __mutex_lock at ffffffff9a869bcc
  #4 [ffffb87c4df07ca0] __mutex_lock_slowpath at ffffffff9a86a013
  #5 [ffffb87c4df07cb0] mutex_lock at ffffffff9a86a04f
  #6 [ffffb87c4df07cc8] kernfs_find_and_get_ns at ffffffff9a311d83
  #7 [ffffb87c4df07cf0] sysfs_notify at ffffffff9a314b3a
  #8 [ffffb87c4df07d18] md_update_sb at ffffffff9a688696
  #9 [ffffb87c4df07d98] md_update_sb at ffffffff9a6886d5
 #10 [ffffb87c4df07da8] md_check_recovery at ffffffff9a68ad9c
 #11 [ffffb87c4df07dd0] raid1d at ffffffffc01f0375 [raid1]
 #12 [ffffb87c4df07ea0] md_thread at ffffffff9a680348
 #13 [ffffb87c4df07f08] kthread at ffffffff9a0b8005
 #14 [ffffb87c4df07f50] ret_from_fork at ffffffff9aa00344

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
(cherry picked from commit e1a86db)

Orabug: 31682031
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joe Jin <joe.jin@oracle.com>
gregmarsden pushed a commit that referenced this pull request Aug 28, 2020
For INVADER_SERIES, each set of 8 reply queues (0 - 7, 8 - 15,..), and for
VENTURA_SERIES, each set of 16 reply queues (0 - 15, 16 - 31,..) need to be
within the same 4 GB boundary. Driver uses limitation of VENTURA_SERIES to
manage INVADER_SERIES as well. The driver is allocating the DMA able
memory for RDPQs accordingly.

1) At driver load, set DMA mask to 64 and allocate memory for RDPQs

2) Check if allocated resources for RDPQ are in the same 4GB range

3) If #2 is true, continue with 64 bit DMA and go to #6

4) If #2 is false, then free all the resources from #1

5) Set DMA mask to 32 and allocate RDPQs

6) Proceed with driver loading and other allocations

Link: https://lore.kernel.org/r/1587626596-1044-5-git-send-email-suganath-prabu.subramani@broadcom.com
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Suganath Prabu <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
(cherry picked from commit 8012209)

Orabug: 31741029
Signed-off-by: Jack Vogel <jack.vogel@oracle.com>
Reviewed-by: John Donnelly <john.p.donnelly@oracle.com>
gregmarsden pushed a commit that referenced this pull request Aug 28, 2020
commit 18c850f upstream.

There's long existed a lockdep splat because we open our bdev's under
the ->device_list_mutex at mount time, which acquires the bd_mutex.
Usually this goes unnoticed, but if you do loopback devices at all
suddenly the bd_mutex comes with a whole host of other dependencies,
which results in the splat when you mount a btrfs file system.

======================================================
WARNING: possible circular locking dependency detected
5.8.0-0.rc3.1.fc33.x86_64+debug #1 Not tainted
------------------------------------------------------
systemd-journal/509 is trying to acquire lock:
ffff970831f84db0 (&fs_info->reloc_mutex){+.+.}-{3:3}, at: btrfs_record_root_in_trans+0x44/0x70 [btrfs]

but task is already holding lock:
ffff97083144d598 (sb_pagefaults){.+.+}-{0:0}, at: btrfs_page_mkwrite+0x59/0x560 [btrfs]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

 -> #6 (sb_pagefaults){.+.+}-{0:0}:
       __sb_start_write+0x13e/0x220
       btrfs_page_mkwrite+0x59/0x560 [btrfs]
       do_page_mkwrite+0x4f/0x130
       do_wp_page+0x3b0/0x4f0
       handle_mm_fault+0xf47/0x1850
       do_user_addr_fault+0x1fc/0x4b0
       exc_page_fault+0x88/0x300
       asm_exc_page_fault+0x1e/0x30

 -> #5 (&mm->mmap_lock#2){++++}-{3:3}:
       __might_fault+0x60/0x80
       _copy_from_user+0x20/0xb0
       get_sg_io_hdr+0x9a/0xb0
       scsi_cmd_ioctl+0x1ea/0x2f0
       cdrom_ioctl+0x3c/0x12b4
       sr_block_ioctl+0xa4/0xd0
       block_ioctl+0x3f/0x50
       ksys_ioctl+0x82/0xc0
       __x64_sys_ioctl+0x16/0x20
       do_syscall_64+0x52/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

 -> #4 (&cd->lock){+.+.}-{3:3}:
       __mutex_lock+0x7b/0x820
       sr_block_open+0xa2/0x180
       __blkdev_get+0xdd/0x550
       blkdev_get+0x38/0x150
       do_dentry_open+0x16b/0x3e0
       path_openat+0x3c9/0xa00
       do_filp_open+0x75/0x100
       do_sys_openat2+0x8a/0x140
       __x64_sys_openat+0x46/0x70
       do_syscall_64+0x52/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

 -> #3 (&bdev->bd_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7b/0x820
       __blkdev_get+0x6a/0x550
       blkdev_get+0x85/0x150
       blkdev_get_by_path+0x2c/0x70
       btrfs_get_bdev_and_sb+0x1b/0xb0 [btrfs]
       open_fs_devices+0x88/0x240 [btrfs]
       btrfs_open_devices+0x92/0xa0 [btrfs]
       btrfs_mount_root+0x250/0x490 [btrfs]
       legacy_get_tree+0x30/0x50
       vfs_get_tree+0x28/0xc0
       vfs_kern_mount.part.0+0x71/0xb0
       btrfs_mount+0x119/0x380 [btrfs]
       legacy_get_tree+0x30/0x50
       vfs_get_tree+0x28/0xc0
       do_mount+0x8c6/0xca0
       __x64_sys_mount+0x8e/0xd0
       do_syscall_64+0x52/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

 -> #2 (&fs_devs->device_list_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7b/0x820
       btrfs_run_dev_stats+0x36/0x420 [btrfs]
       commit_cowonly_roots+0x91/0x2d0 [btrfs]
       btrfs_commit_transaction+0x4e6/0x9f0 [btrfs]
       btrfs_sync_file+0x38a/0x480 [btrfs]
       __x64_sys_fdatasync+0x47/0x80
       do_syscall_64+0x52/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

 -> #1 (&fs_info->tree_log_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7b/0x820
       btrfs_commit_transaction+0x48e/0x9f0 [btrfs]
       btrfs_sync_file+0x38a/0x480 [btrfs]
       __x64_sys_fdatasync+0x47/0x80
       do_syscall_64+0x52/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

 -> #0 (&fs_info->reloc_mutex){+.+.}-{3:3}:
       __lock_acquire+0x1241/0x20c0
       lock_acquire+0xb0/0x400
       __mutex_lock+0x7b/0x820
       btrfs_record_root_in_trans+0x44/0x70 [btrfs]
       start_transaction+0xd2/0x500 [btrfs]
       btrfs_dirty_inode+0x44/0xd0 [btrfs]
       file_update_time+0xc6/0x120
       btrfs_page_mkwrite+0xda/0x560 [btrfs]
       do_page_mkwrite+0x4f/0x130
       do_wp_page+0x3b0/0x4f0
       handle_mm_fault+0xf47/0x1850
       do_user_addr_fault+0x1fc/0x4b0
       exc_page_fault+0x88/0x300
       asm_exc_page_fault+0x1e/0x30

other info that might help us debug this:

Chain exists of:
  &fs_info->reloc_mutex --> &mm->mmap_lock#2 --> sb_pagefaults

Possible unsafe locking scenario:

     CPU0                    CPU1
     ----                    ----
 lock(sb_pagefaults);
                             lock(&mm->mmap_lock#2);
                             lock(sb_pagefaults);
 lock(&fs_info->reloc_mutex);

 *** DEADLOCK ***

3 locks held by systemd-journal/509:
 #0: ffff97083bdec8b8 (&mm->mmap_lock#2){++++}-{3:3}, at: do_user_addr_fault+0x12e/0x4b0
 #1: ffff97083144d598 (sb_pagefaults){.+.+}-{0:0}, at: btrfs_page_mkwrite+0x59/0x560 [btrfs]
 #2: ffff97083144d6a8 (sb_internal){.+.+}-{0:0}, at: start_transaction+0x3f8/0x500 [btrfs]

stack backtrace:
CPU: 0 PID: 509 Comm: systemd-journal Not tainted 5.8.0-0.rc3.1.fc33.x86_64+debug #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Call Trace:
 dump_stack+0x92/0xc8
 check_noncircular+0x134/0x150
 __lock_acquire+0x1241/0x20c0
 lock_acquire+0xb0/0x400
 ? btrfs_record_root_in_trans+0x44/0x70 [btrfs]
 ? lock_acquire+0xb0/0x400
 ? btrfs_record_root_in_trans+0x44/0x70 [btrfs]
 __mutex_lock+0x7b/0x820
 ? btrfs_record_root_in_trans+0x44/0x70 [btrfs]
 ? kvm_sched_clock_read+0x14/0x30
 ? sched_clock+0x5/0x10
 ? sched_clock_cpu+0xc/0xb0
 btrfs_record_root_in_trans+0x44/0x70 [btrfs]
 start_transaction+0xd2/0x500 [btrfs]
 btrfs_dirty_inode+0x44/0xd0 [btrfs]
 file_update_time+0xc6/0x120
 btrfs_page_mkwrite+0xda/0x560 [btrfs]
 ? sched_clock+0x5/0x10
 do_page_mkwrite+0x4f/0x130
 do_wp_page+0x3b0/0x4f0
 handle_mm_fault+0xf47/0x1850
 do_user_addr_fault+0x1fc/0x4b0
 exc_page_fault+0x88/0x300
 ? asm_exc_page_fault+0x8/0x30
 asm_exc_page_fault+0x1e/0x30
RIP: 0033:0x7fa3972fdbfe
Code: Bad RIP value.

Fix this by not holding the ->device_list_mutex at this point.  The
device_list_mutex exists to protect us from modifying the device list
while the file system is running.

However it can also be modified by doing a scan on a device.  But this
action is specifically protected by the uuid_mutex, which we are holding
here.  We cannot race with opening at this point because we have the
->s_mount lock held during the mount.  Not having the
->device_list_mutex here is perfectly safe as we're not going to change
the devices at this point.

CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add some comments ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gregmarsden pushed a commit that referenced this pull request Sep 4, 2020
The following deadlock was captured. The first process is holding 'kernfs_mutex'
and hung by io. The io was staging in 'r1conf.pending_bio_list' of raid1 device,
this pending bio list would be flushed by second process 'md127_raid1', but
it was hung by 'kernfs_mutex'. Using sysfs_notify_dirent_safe() to replace
sysfs_notify() can fix it. There were other sysfs_notify() invoked from io
path, removed all of them.

 PID: 40430  TASK: ffff8ee9c8c65c40  CPU: 29  COMMAND: "probe_file"
  #0 [ffffb87c4df37260] __schedule at ffffffff9a8678ec
  #1 [ffffb87c4df372f8] schedule at ffffffff9a867f06
  #2 [ffffb87c4df37310] io_schedule at ffffffff9a0c73e6
  #3 [ffffb87c4df37328] __dta___xfs_iunpin_wait_3443 at ffffffffc03a4057 [xfs]
  #4 [ffffb87c4df373a0] xfs_iunpin_wait at ffffffffc03a6c79 [xfs]
  #5 [ffffb87c4df373b0] __dta_xfs_reclaim_inode_3357 at ffffffffc039a46c [xfs]
  #6 [ffffb87c4df37400] xfs_reclaim_inodes_ag at ffffffffc039a8b6 [xfs]
  #7 [ffffb87c4df37590] xfs_reclaim_inodes_nr at ffffffffc039bb33 [xfs]
  #8 [ffffb87c4df375b0] xfs_fs_free_cached_objects at ffffffffc03af0e9 [xfs]
  #9 [ffffb87c4df375c0] super_cache_scan at ffffffff9a287ec7
 #10 [ffffb87c4df37618] shrink_slab at ffffffff9a1efd93
 #11 [ffffb87c4df37700] shrink_node at ffffffff9a1f5968
 #12 [ffffb87c4df37788] do_try_to_free_pages at ffffffff9a1f5ea2
 #13 [ffffb87c4df377f0] try_to_free_mem_cgroup_pages at ffffffff9a1f6445
 #14 [ffffb87c4df37880] try_charge at ffffffff9a26cc5f
 #15 [ffffb87c4df37920] memcg_kmem_charge_memcg at ffffffff9a270f6a
 #16 [ffffb87c4df37958] new_slab at ffffffff9a251430
 #17 [ffffb87c4df379c0] ___slab_alloc at ffffffff9a251c85
 #18 [ffffb87c4df37a80] __slab_alloc at ffffffff9a25635d
 #19 [ffffb87c4df37ac0] kmem_cache_alloc at ffffffff9a251f89
 #20 [ffffb87c4df37b00] alloc_inode at ffffffff9a2a2b10
 #21 [ffffb87c4df37b20] iget_locked at ffffffff9a2a4854
 #22 [ffffb87c4df37b60] kernfs_get_inode at ffffffff9a311377
 #23 [ffffb87c4df37b80] kernfs_iop_lookup at ffffffff9a311e2b
 #24 [ffffb87c4df37ba8] lookup_slow at ffffffff9a290118
 #25 [ffffb87c4df37c10] walk_component at ffffffff9a291e83
 #26 [ffffb87c4df37c78] path_lookupat at ffffffff9a293619
 #27 [ffffb87c4df37cd8] filename_lookup at ffffffff9a2953af
 #28 [ffffb87c4df37de8] user_path_at_empty at ffffffff9a295566
 #29 [ffffb87c4df37e10] vfs_statx at ffffffff9a289787
 #30 [ffffb87c4df37e70] SYSC_newlstat at ffffffff9a289d5d
 #31 [ffffb87c4df37f18] sys_newlstat at ffffffff9a28a60e
 #32 [ffffb87c4df37f28] do_syscall_64 at ffffffff9a003949
 #33 [ffffb87c4df37f50] entry_SYSCALL_64_after_hwframe at ffffffff9aa001ad
     RIP: 00007f617a5f2905  RSP: 00007f607334f838  RFLAGS: 00000246
     RAX: ffffffffffffffda  RBX: 00007f6064044b20  RCX: 00007f617a5f2905
     RDX: 00007f6064044b20  RSI: 00007f6064044b20  RDI: 00007f6064005890
     RBP: 00007f6064044aa0   R8: 0000000000000030   R9: 000000000000011c
     R10: 0000000000000013  R11: 0000000000000246  R12: 00007f606417e6d0
     R13: 00007f6064044aa0  R14: 00007f6064044b10  R15: 00000000ffffffff
     ORIG_RAX: 0000000000000006  CS: 0033  SS: 002b

 PID: 927    TASK: ffff8f15ac5dbd80  CPU: 42  COMMAND: "md127_raid1"
  #0 [ffffb87c4df07b28] __schedule at ffffffff9a8678ec
  #1 [ffffb87c4df07bc0] schedule at ffffffff9a867f06
  #2 [ffffb87c4df07bd8] schedule_preempt_disabled at ffffffff9a86825e
  #3 [ffffb87c4df07be8] __mutex_lock at ffffffff9a869bcc
  #4 [ffffb87c4df07ca0] __mutex_lock_slowpath at ffffffff9a86a013
  #5 [ffffb87c4df07cb0] mutex_lock at ffffffff9a86a04f
  #6 [ffffb87c4df07cc8] kernfs_find_and_get_ns at ffffffff9a311d83
  #7 [ffffb87c4df07cf0] sysfs_notify at ffffffff9a314b3a
  #8 [ffffb87c4df07d18] md_update_sb at ffffffff9a688696
  #9 [ffffb87c4df07d98] md_update_sb at ffffffff9a6886d5
 #10 [ffffb87c4df07da8] md_check_recovery at ffffffff9a68ad9c
 #11 [ffffb87c4df07dd0] raid1d at ffffffffc01f0375 [raid1]
 #12 [ffffb87c4df07ea0] md_thread at ffffffff9a680348
 #13 [ffffb87c4df07f08] kthread at ffffffff9a0b8005
 #14 [ffffb87c4df07f50] ret_from_fork at ffffffff9aa00344

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
(cherry picked from commit e1a86db)

Orabug: 31682035
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joe Jin <joe.jin@oracle.com>

 Conflicts:
	drivers/md/md-bitmap.c

Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
gregmarsden pushed a commit that referenced this pull request Sep 4, 2020
The following deadlock was captured. The first process is holding 'kernfs_mutex'
and hung by io. The io was staging in 'r1conf.pending_bio_list' of raid1 device,
this pending bio list would be flushed by second process 'md127_raid1', but
it was hung by 'kernfs_mutex'. Using sysfs_notify_dirent_safe() to replace
sysfs_notify() can fix it. There were other sysfs_notify() invoked from io
path, removed all of them.

 PID: 40430  TASK: ffff8ee9c8c65c40  CPU: 29  COMMAND: "probe_file"
  #0 [ffffb87c4df37260] __schedule at ffffffff9a8678ec
  #1 [ffffb87c4df372f8] schedule at ffffffff9a867f06
  #2 [ffffb87c4df37310] io_schedule at ffffffff9a0c73e6
  #3 [ffffb87c4df37328] __dta___xfs_iunpin_wait_3443 at ffffffffc03a4057 [xfs]
  #4 [ffffb87c4df373a0] xfs_iunpin_wait at ffffffffc03a6c79 [xfs]
  #5 [ffffb87c4df373b0] __dta_xfs_reclaim_inode_3357 at ffffffffc039a46c [xfs]
  #6 [ffffb87c4df37400] xfs_reclaim_inodes_ag at ffffffffc039a8b6 [xfs]
  #7 [ffffb87c4df37590] xfs_reclaim_inodes_nr at ffffffffc039bb33 [xfs]
  #8 [ffffb87c4df375b0] xfs_fs_free_cached_objects at ffffffffc03af0e9 [xfs]
  #9 [ffffb87c4df375c0] super_cache_scan at ffffffff9a287ec7
 #10 [ffffb87c4df37618] shrink_slab at ffffffff9a1efd93
 #11 [ffffb87c4df37700] shrink_node at ffffffff9a1f5968
 #12 [ffffb87c4df37788] do_try_to_free_pages at ffffffff9a1f5ea2
 #13 [ffffb87c4df377f0] try_to_free_mem_cgroup_pages at ffffffff9a1f6445
 #14 [ffffb87c4df37880] try_charge at ffffffff9a26cc5f
 #15 [ffffb87c4df37920] memcg_kmem_charge_memcg at ffffffff9a270f6a
 #16 [ffffb87c4df37958] new_slab at ffffffff9a251430
 #17 [ffffb87c4df379c0] ___slab_alloc at ffffffff9a251c85
 #18 [ffffb87c4df37a80] __slab_alloc at ffffffff9a25635d
 #19 [ffffb87c4df37ac0] kmem_cache_alloc at ffffffff9a251f89
 #20 [ffffb87c4df37b00] alloc_inode at ffffffff9a2a2b10
 #21 [ffffb87c4df37b20] iget_locked at ffffffff9a2a4854
 #22 [ffffb87c4df37b60] kernfs_get_inode at ffffffff9a311377
 #23 [ffffb87c4df37b80] kernfs_iop_lookup at ffffffff9a311e2b
 #24 [ffffb87c4df37ba8] lookup_slow at ffffffff9a290118
 #25 [ffffb87c4df37c10] walk_component at ffffffff9a291e83
 #26 [ffffb87c4df37c78] path_lookupat at ffffffff9a293619
 #27 [ffffb87c4df37cd8] filename_lookup at ffffffff9a2953af
 #28 [ffffb87c4df37de8] user_path_at_empty at ffffffff9a295566
 #29 [ffffb87c4df37e10] vfs_statx at ffffffff9a289787
 #30 [ffffb87c4df37e70] SYSC_newlstat at ffffffff9a289d5d
 #31 [ffffb87c4df37f18] sys_newlstat at ffffffff9a28a60e
 #32 [ffffb87c4df37f28] do_syscall_64 at ffffffff9a003949
 #33 [ffffb87c4df37f50] entry_SYSCALL_64_after_hwframe at ffffffff9aa001ad
     RIP: 00007f617a5f2905  RSP: 00007f607334f838  RFLAGS: 00000246
     RAX: ffffffffffffffda  RBX: 00007f6064044b20  RCX: 00007f617a5f2905
     RDX: 00007f6064044b20  RSI: 00007f6064044b20  RDI: 00007f6064005890
     RBP: 00007f6064044aa0   R8: 0000000000000030   R9: 000000000000011c
     R10: 0000000000000013  R11: 0000000000000246  R12: 00007f606417e6d0
     R13: 00007f6064044aa0  R14: 00007f6064044b10  R15: 00000000ffffffff
     ORIG_RAX: 0000000000000006  CS: 0033  SS: 002b

 PID: 927    TASK: ffff8f15ac5dbd80  CPU: 42  COMMAND: "md127_raid1"
  #0 [ffffb87c4df07b28] __schedule at ffffffff9a8678ec
  #1 [ffffb87c4df07bc0] schedule at ffffffff9a867f06
  #2 [ffffb87c4df07bd8] schedule_preempt_disabled at ffffffff9a86825e
  #3 [ffffb87c4df07be8] __mutex_lock at ffffffff9a869bcc
  #4 [ffffb87c4df07ca0] __mutex_lock_slowpath at ffffffff9a86a013
  #5 [ffffb87c4df07cb0] mutex_lock at ffffffff9a86a04f
  #6 [ffffb87c4df07cc8] kernfs_find_and_get_ns at ffffffff9a311d83
  #7 [ffffb87c4df07cf0] sysfs_notify at ffffffff9a314b3a
  #8 [ffffb87c4df07d18] md_update_sb at ffffffff9a688696
  #9 [ffffb87c4df07d98] md_update_sb at ffffffff9a6886d5
 #10 [ffffb87c4df07da8] md_check_recovery at ffffffff9a68ad9c
 #11 [ffffb87c4df07dd0] raid1d at ffffffffc01f0375 [raid1]
 #12 [ffffb87c4df07ea0] md_thread at ffffffff9a680348
 #13 [ffffb87c4df07f08] kthread at ffffffff9a0b8005
 #14 [ffffb87c4df07f50] ret_from_fork at ffffffff9aa00344

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
(cherry picked from commit e1a86db)

Orabug: 31683116
Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joe Jin <joe.jin@oracle.com>

 Conflicts:
	drivers/md/md-bitmap.c

Signed-off-by: Brian Maly <brian.maly@oracle.com>
gregmarsden pushed a commit that referenced this pull request Nov 17, 2020
[ Upstream commit d26383d ]

The following leaks were detected by ASAN:

  Indirect leak of 360 byte(s) in 9 object(s) allocated from:
    #0 0x7fecc305180e in calloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10780e)
    #1 0x560578f6dce5 in perf_pmu__new_format util/pmu.c:1333
    #2 0x560578f752fc in perf_pmu_parse util/pmu.y:59
    #3 0x560578f6a8b7 in perf_pmu__format_parse util/pmu.c:73
    #4 0x560578e07045 in test__pmu tests/pmu.c:155
    #5 0x560578de109b in run_test tests/builtin-test.c:410
    #6 0x560578de109b in test_and_print tests/builtin-test.c:440
    #7 0x560578de401a in __cmd_test tests/builtin-test.c:661
    #8 0x560578de401a in cmd_test tests/builtin-test.c:807
    #9 0x560578e49354 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    #10 0x560578ce71a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    #11 0x560578ce71a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    #12 0x560578ce71a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    #13 0x7fecc2b7acc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: cff7f95 ("perf tests: Move pmu tests into separate object")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200915031819.386559-12-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 1cf043baa068a5deecaf800e9122b462ac418159)
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