Move unfit code out of `rust/kernel/types.rs` #1117

y86-dev · 2024-09-13T09:52:42Z

rust/kernel/types.rs is a rather non-descriptive, general file that contains code that might be better suited somewhere else:

ARef<T> and AlwaysRefCounted should be in rust/kernel/sync/aref.rs.
FromBytes and AsBytes traits and implementations should be in rust/kernel/transmute.rs.

Please create two separate patches for the above. Also take care to fix any imports and rustdoc examples.

This requires submitting a proper patch to the LKML and the Rust for Linux mailing list. Please recall to test your changes (including generating the documentation if changed, running the Rust doctests if changed, etc.), to use a proper title for the commit, to sign your commit under the Developer's Certificate of Origin and to add a Suggested-by: tag and a Link: tag to this issue. Please see https://rust-for-linux.com/contributing for details.

Please take this issue only if you are new to the kernel development process and you would like to use it as a test to submit your first patch to the kernel. Please do not take it if you do not plan to make other contributions to the kernel.

The text was updated successfully, but these errors were encountered:

nbdd0121 · 2024-09-13T09:55:18Z

I feel like convert doesn't coney the semantics of these traits are only performing byte-level transmutation. Maybe transmute.rs?

plinkr · 2024-09-16T06:47:40Z

Hey! I would like to give this issue a try if no one is working on it

This patch refactors the `FromBytes` and `AsBytes` traits from `types.rs` into a new `transmute.rs` module. The traits and their implementations remain unchanged. - Adds `rust/kernel/transmute.rs` with the definitions of `FromBytes` and `AsBytes` - Removes the same trait definitions from `rust/kernel/types.rs` - Updates `rust/kernel/uaccess.rs` to import `AsBytes` and `FromBytes` from `transmute.rs` Suggested-by: Benno Lossin <[email protected]> Link: Rust-for-Linux#1117 Signed-off-by: Aliet Exposito Garcia <[email protected]>

This patch refactors the `ARef` type and `AlwaysRefCounted` trait from `types.rs` into a new `sync/aref.rs` module. The type and trait definitions remain unchanged. - Adds `rust/kernel/sync/aref.rs` with the definitions of `ARef` and `AlwaysRefCounted` - Removes the same type and trait definitions from `rust/kernel/types.rs` - Updates relevant files to import `ARef` and `AlwaysRefCounted` from `sync/aref.rs` Suggested-by: Benno Lossin <[email protected]> Link: Rust-for-Linux#1117 Signed-off-by: Aliet Exposito Garcia <[email protected]>

plinkr · 2024-09-18T23:03:31Z

I sent the patches: https://lore.kernel.org/rust-for-linux/[email protected]/T/#t
Thank you very much for the opportunity to work on a good first issue

sergiocollado · 2024-09-19T15:16:01Z

The patch looks good .... but transmute.rs for me it feels a bit too eldritch and arcane .... convert or convertBytes or something similar sounded better, at least for me. Otherwise looks great!

…te` module Refactor the `FromBytes` and `AsBytes` traits from `types.rs` into a new `transmute.rs` module: - Add `rust/kernel/transmute.rs` with the definitions of `FromBytes` and `AsBytes`. - Remove the same trait definitions from `rust/kernel/types.rs`. - Update `rust/kernel/uaccess.rs` to import `AsBytes` and `FromBytes` from `transmute.rs`. The traits and their implementations remain unchanged. Suggested-by: Benno Lossin <[email protected]> Link: #1117 Signed-off-by: Aliet Exposito Garcia <[email protected]> Reviewed-by: Fiona Behrens <[email protected]> Reviewed-by: Benno Lossin <[email protected]> Link: https://lore.kernel.org/r/[email protected] [ Rebased on top of the lints series and slightly reworded. - Miguel ] Signed-off-by: Miguel Ojeda <[email protected]>

…f` module Refactor the `ARef` type and `AlwaysRefCounted` trait from `types.rs` into a new `sync/aref.rs` module: - Add `rust/kernel/sync/aref.rs` with the definitions of `ARef` and `AlwaysRefCounted`. - Remove the same type and trait definitions from `rust/kernel/types.rs`. - Update relevant files to import `ARef` and `AlwaysRefCounted` from `sync/aref.rs`. The type and trait definitions remain unchanged. Suggested-by: Benno Lossin <[email protected]> Link: #1117 Signed-off-by: Aliet Exposito Garcia <[email protected]> Reviewed-by: Fiona Behrens <[email protected]> Reviewed-by: Benno Lossin <[email protected]> Link: https://lore.kernel.org/r/[email protected] [ Rebased on top of the lints series, slightly reworded and removed unneeded `use AlwaysRefCounted` in example. - Miguel ] Signed-off-by: Miguel Ojeda <[email protected]>

ojeda · 2024-10-05T19:47:46Z

@sergiocollado I assume it is following std::mem::transmute.

Applied to rust-next -- thanks everyone!

…te` module Refactor the `FromBytes` and `AsBytes` traits from `types.rs` into a new `transmute.rs` module: - Add `rust/kernel/transmute.rs` with the definitions of `FromBytes` and `AsBytes`. - Remove the same trait definitions from `rust/kernel/types.rs`. - Update `rust/kernel/uaccess.rs` to import `AsBytes` and `FromBytes` from `transmute.rs`. The traits and their implementations remain unchanged. Suggested-by: Benno Lossin <[email protected]> Link: #1117 Signed-off-by: Aliet Exposito Garcia <[email protected]> Reviewed-by: Fiona Behrens <[email protected]> Reviewed-by: Benno Lossin <[email protected]> Link: https://lore.kernel.org/r/[email protected] [ Rebased on top of the lints series and slightly reworded. - Miguel ] Signed-off-by: Miguel Ojeda <[email protected]>

…f` module Refactor the `ARef` type and `AlwaysRefCounted` trait from `types.rs` into a new `sync/aref.rs` module: - Add `rust/kernel/sync/aref.rs` with the definitions of `ARef` and `AlwaysRefCounted`. - Remove the same type and trait definitions from `rust/kernel/types.rs`. - Update relevant files to import `ARef` and `AlwaysRefCounted` from `sync/aref.rs`. The type and trait definitions remain unchanged. Suggested-by: Benno Lossin <[email protected]> Link: #1117 Signed-off-by: Aliet Exposito Garcia <[email protected]> Reviewed-by: Fiona Behrens <[email protected]> Reviewed-by: Benno Lossin <[email protected]> Link: https://lore.kernel.org/r/[email protected] [ Rebased on top of the lints series, slightly reworded and removed unneeded `use AlwaysRefCounted` in example. - Miguel ] Signed-off-by: Miguel Ojeda <[email protected]>

…te` module Refactor the `FromBytes` and `AsBytes` traits from `types.rs` into a new `transmute.rs` module: - Add `rust/kernel/transmute.rs` with the definitions of `FromBytes` and `AsBytes`. - Remove the same trait definitions from `rust/kernel/types.rs`. - Update `rust/kernel/uaccess.rs` to import `AsBytes` and `FromBytes` from `transmute.rs`. The traits and their implementations remain unchanged. Suggested-by: Benno Lossin <[email protected]> Link: #1117 Signed-off-by: Aliet Exposito Garcia <[email protected]> Reviewed-by: Fiona Behrens <[email protected]> Reviewed-by: Benno Lossin <[email protected]> Link: https://lore.kernel.org/r/[email protected] [ Rebased on top of the lints series and slightly reworded. - Miguel ] Signed-off-by: Miguel Ojeda <[email protected]>

…f` module Refactor the `ARef` type and `AlwaysRefCounted` trait from `types.rs` into a new `sync/aref.rs` module: - Add `rust/kernel/sync/aref.rs` with the definitions of `ARef` and `AlwaysRefCounted`. - Remove the same type and trait definitions from `rust/kernel/types.rs`. - Update relevant files to import `ARef` and `AlwaysRefCounted` from `sync/aref.rs`. The type and trait definitions remain unchanged. Suggested-by: Benno Lossin <[email protected]> Link: #1117 Signed-off-by: Aliet Exposito Garcia <[email protected]> Reviewed-by: Fiona Behrens <[email protected]> Reviewed-by: Benno Lossin <[email protected]> Link: https://lore.kernel.org/r/[email protected] [ Rebased on top of the lints series, slightly reworded and removed unneeded `use AlwaysRefCounted` in example. - Miguel ] Signed-off-by: Miguel Ojeda <[email protected]>

…te` module Refactor the `FromBytes` and `AsBytes` traits from `types.rs` into a new `transmute.rs` module: - Add `rust/kernel/transmute.rs` with the definitions of `FromBytes` and `AsBytes`. - Remove the same trait definitions from `rust/kernel/types.rs`. - Update `rust/kernel/uaccess.rs` to import `AsBytes` and `FromBytes` from `transmute.rs`. The traits and their implementations remain unchanged. Suggested-by: Benno Lossin <[email protected]> Link: #1117 Signed-off-by: Aliet Exposito Garcia <[email protected]> Reviewed-by: Fiona Behrens <[email protected]> Reviewed-by: Benno Lossin <[email protected]> Link: https://lore.kernel.org/r/[email protected] [ Rebased on top of the lints series and slightly reworded. - Miguel ] Signed-off-by: Miguel Ojeda <[email protected]>

Most qdiscs maintain their backlog using qdisc_pkt_len(skb) on the assumption it is invariant between the enqueue() and dequeue() handlers. Unfortunately syzbot can crash a host rather easily using a TBF + SFQ combination, with an STAB on SFQ [1] We can't support TCA_STAB on arbitrary level, this would require to maintain per-qdisc storage. [1] [ 88.796496] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 88.798611] #PF: supervisor read access in kernel mode [ 88.799014] #PF: error_code(0x0000) - not-present page [ 88.799506] PGD 0 P4D 0 [ 88.799829] Oops: Oops: 0000 [#1] SMP NOPTI [ 88.800569] CPU: 14 UID: 0 PID: 2053 Comm: b371744477 Not tainted 6.12.0-rc1-virtme #1117 [ 88.801107] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 88.801779] RIP: 0010:sfq_dequeue (net/sched/sch_sfq.c:272 net/sched/sch_sfq.c:499) sch_sfq [ 88.802544] Code: 0f b7 50 12 48 8d 04 d5 00 00 00 00 48 89 d6 48 29 d0 48 8b 91 c0 01 00 00 48 c1 e0 03 48 01 c2 66 83 7a 1a 00 7e c0 48 8b 3a <4c> 8b 07 4c 89 02 49 89 50 08 48 c7 47 08 00 00 00 00 48 c7 07 00 All code ======== 0: 0f b7 50 12 movzwl 0x12(%rax),%edx 4: 48 8d 04 d5 00 00 00 lea 0x0(,%rdx,8),%rax b: 00 c: 48 89 d6 mov %rdx,%rsi f: 48 29 d0 sub %rdx,%rax 12: 48 8b 91 c0 01 00 00 mov 0x1c0(%rcx),%rdx 19: 48 c1 e0 03 shl $0x3,%rax 1d: 48 01 c2 add %rax,%rdx 20: 66 83 7a 1a 00 cmpw $0x0,0x1a(%rdx) 25: 7e c0 jle 0xffffffffffffffe7 27: 48 8b 3a mov (%rdx),%rdi 2a:* 4c 8b 07 mov (%rdi),%r8 <-- trapping instruction 2d: 4c 89 02 mov %r8,(%rdx) 30: 49 89 50 08 mov %rdx,0x8(%r8) 34: 48 c7 47 08 00 00 00 movq $0x0,0x8(%rdi) 3b: 00 3c: 48 rex.W 3d: c7 .byte 0xc7 3e: 07 (bad) ... Code starting with the faulting instruction =========================================== 0: 4c 8b 07 mov (%rdi),%r8 3: 4c 89 02 mov %r8,(%rdx) 6: 49 89 50 08 mov %rdx,0x8(%r8) a: 48 c7 47 08 00 00 00 movq $0x0,0x8(%rdi) 11: 00 12: 48 rex.W 13: c7 .byte 0xc7 14: 07 (bad) ... [ 88.803721] RSP: 0018:ffff9a1f892b7d58 EFLAGS: 00000206 [ 88.804032] RAX: 0000000000000000 RBX: ffff9a1f8420c800 RCX: ffff9a1f8420c800 [ 88.804560] RDX: ffff9a1f81bc1440 RSI: 0000000000000000 RDI: 0000000000000000 [ 88.805056] RBP: ffffffffc04bb0e0 R08: 0000000000000001 R09: 00000000ff7f9a1f [ 88.805473] R10: 000000000001001b R11: 0000000000009a1f R12: 0000000000000140 [ 88.806194] R13: 0000000000000001 R14: ffff9a1f886df400 R15: ffff9a1f886df4ac [ 88.806734] FS: 00007f445601a740(0000) GS:ffff9a2e7fd80000(0000) knlGS:0000000000000000 [ 88.807225] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 88.807672] CR2: 0000000000000000 CR3: 000000050cc46000 CR4: 00000000000006f0 [ 88.808165] Call Trace: [ 88.808459] <TASK> [ 88.808710] ? __die (arch/x86/kernel/dumpstack.c:421 arch/x86/kernel/dumpstack.c:434) [ 88.809261] ? page_fault_oops (arch/x86/mm/fault.c:715) [ 88.809561] ? exc_page_fault (./arch/x86/include/asm/irqflags.h:26 ./arch/x86/include/asm/irqflags.h:87 ./arch/x86/include/asm/irqflags.h:147 arch/x86/mm/fault.c:1489 arch/x86/mm/fault.c:1539) [ 88.809806] ? asm_exc_page_fault (./arch/x86/include/asm/idtentry.h:623) [ 88.810074] ? sfq_dequeue (net/sched/sch_sfq.c:272 net/sched/sch_sfq.c:499) sch_sfq [ 88.810411] sfq_reset (net/sched/sch_sfq.c:525) sch_sfq [ 88.810671] qdisc_reset (./include/linux/skbuff.h:2135 ./include/linux/skbuff.h:2441 ./include/linux/skbuff.h:3304 ./include/linux/skbuff.h:3310 net/sched/sch_generic.c:1036) [ 88.810950] tbf_reset (./include/linux/timekeeping.h:169 net/sched/sch_tbf.c:334) sch_tbf [ 88.811208] qdisc_reset (./include/linux/skbuff.h:2135 ./include/linux/skbuff.h:2441 ./include/linux/skbuff.h:3304 ./include/linux/skbuff.h:3310 net/sched/sch_generic.c:1036) [ 88.811484] netif_set_real_num_tx_queues (./include/linux/spinlock.h:396 ./include/net/sch_generic.h:768 net/core/dev.c:2958) [ 88.811870] __tun_detach (drivers/net/tun.c:590 drivers/net/tun.c:673) [ 88.812271] tun_chr_close (drivers/net/tun.c:702 drivers/net/tun.c:3517) [ 88.812505] __fput (fs/file_table.c:432 (discriminator 1)) [ 88.812735] task_work_run (kernel/task_work.c:230) [ 88.813016] do_exit (kernel/exit.c:940) [ 88.813372] ? trace_hardirqs_on (kernel/trace/trace_preemptirq.c:58 (discriminator 4)) [ 88.813639] ? handle_mm_fault (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:97 ./arch/x86/include/asm/irqflags.h:155 ./include/linux/memcontrol.h:1022 ./include/linux/memcontrol.h:1045 ./include/linux/memcontrol.h:1052 mm/memory.c:5928 mm/memory.c:6088) [ 88.813867] do_group_exit (kernel/exit.c:1070) [ 88.814138] __x64_sys_exit_group (kernel/exit.c:1099) [ 88.814490] x64_sys_call (??:?) [ 88.814791] do_syscall_64 (arch/x86/entry/common.c:52 (discriminator 1) arch/x86/entry/common.c:83 (discriminator 1)) [ 88.815012] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) [ 88.815495] RIP: 0033:0x7f44560f1975 Fixes: 175f9c1 ("net_sched: Add size table for qdiscs") Reported-by: syzbot <[email protected]> Signed-off-by: Eric Dumazet <[email protected]> Cc: Daniel Borkmann <[email protected]> Link: https://patch.msgid.link/[email protected] Signed-off-by: Jakub Kicinski <[email protected]>

…te` module Refactor the `FromBytes` and `AsBytes` traits from `types.rs` into a new `transmute.rs` module: - Add `rust/kernel/transmute.rs` with the definitions of `FromBytes` and `AsBytes`. - Remove the same trait definitions from `rust/kernel/types.rs`. - Update `rust/kernel/uaccess.rs` to import `AsBytes` and `FromBytes` from `transmute.rs`. The traits and their implementations remain unchanged. Suggested-by: Benno Lossin <[email protected]> Link: Rust-for-Linux#1117 Signed-off-by: Aliet Exposito Garcia <[email protected]> Reviewed-by: Fiona Behrens <[email protected]> Reviewed-by: Benno Lossin <[email protected]> Link: https://lore.kernel.org/r/[email protected] [ Rebased on top of the lints series and slightly reworded. - Miguel ] Signed-off-by: Miguel Ojeda <[email protected]>

…te` module Refactor the `FromBytes` and `AsBytes` traits from `types.rs` into a new `transmute.rs` module: - Add `rust/kernel/transmute.rs` with the definitions of `FromBytes` and `AsBytes`. - Remove the same trait definitions from `rust/kernel/types.rs`. - Update `rust/kernel/uaccess.rs` to import `AsBytes` and `FromBytes` from `transmute.rs`. The traits and their implementations remain unchanged. Suggested-by: Benno Lossin <[email protected]> Link: Rust-for-Linux/linux#1117 Signed-off-by: Aliet Exposito Garcia <[email protected]> Reviewed-by: Fiona Behrens <[email protected]> Reviewed-by: Benno Lossin <[email protected]> Link: https://lore.kernel.org/r/[email protected] [ Rebased on top of the lints series and slightly reworded. - Miguel ] Signed-off-by: Miguel Ojeda <[email protected]>