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wedsonaf opened this issue May 28, 2021 · 0 comments
Open

Consider whether we want to shorten names in file module. #313

wedsonaf opened this issue May 28, 2021 · 0 comments
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• lib Related to the `rust/` library.

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@wedsonaf
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In particular, FileDescriptorReservation as discussed in #311.
@wedsonaf wedsonaf changed the title Consider whether we want to shorten names in File module. Consider whether we want to shorten names in file module. May 28, 2021
@wedsonaf wedsonaf mentioned this issue May 28, 2021
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@ojeda ojeda mentioned this issue May 28, 2021
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@ojeda ojeda added prio: normal • lib Related to the `rust/` library. labels May 28, 2021
ojeda pushed a commit that referenced this issue Dec 13, 2023
@seehearfeel @chenhuacai
LoongArch: BPF: Fix unconditional bswap instructions
e2f7b3d 
We can see that "bswap32: Takes an unsigned 32-bit number in either big-
or little-endian format and returns the equivalent number with the same
bit width but opposite endianness" in BPF Instruction Set Specification,
so it should clear the upper 32 bits in "case 32:" for both BPF_ALU and
BPF_ALU64.

[root@linux fedora]# echo 1 > /proc/sys/net/core/bpf_jit_enable
[root@linux fedora]# modprobe test_bpf

Before:
test_bpf: #313 BSWAP 32: 0x0123456789abcdef -> 0xefcdab89 jited:1 ret 1460850314 != -271733879 (0x5712ce8a != 0xefcdab89)FAIL (1 times)
test_bpf: #317 BSWAP 32: 0xfedcba9876543210 -> 0x10325476 jited:1 ret -1460850316 != 271733878 (0xa8ed3174 != 0x10325476)FAIL (1 times)

After:
test_bpf: #313 BSWAP 32: 0x0123456789abcdef -> 0xefcdab89 jited:1 4 PASS
test_bpf: #317 BSWAP 32: 0xfedcba9876543210 -> 0x10325476 jited:1 4 PASS

Fixes: 4ebf921 ("LoongArch: BPF: Support unconditional bswap instructions")
Acked-by: Hengqi Chen <[email protected]>
Signed-off-by: Tiezhu Yang <[email protected]>
Signed-off-by: Huacai Chen <[email protected]>
metaspace pushed a commit to metaspace/linux that referenced this issue Apr 16, 2024
@sm00th
arm64: bpf: fix 32bit unconditional bswap
a51cd6b 
In case when is64 == 1 in emit(A64_REV32(is64, dst, dst), ctx) the
generated insn reverses byte order for both high and low 32-bit words,
resuling in an incorrect swap as indicated by the jit test:

[ 9757.262607] test_bpf: Rust-for-Linux#312 BSWAP 16: 0x0123456789abcdef -> 0xefcd jited:1 8 PASS
[ 9757.264435] test_bpf: Rust-for-Linux#313 BSWAP 32: 0x0123456789abcdef -> 0xefcdab89 jited:1 ret 1460850314 != -271733879 (0x5712ce8a != 0xefcdab89)FAIL (1 times)
[ 9757.266260] test_bpf: Rust-for-Linux#314 BSWAP 64: 0x0123456789abcdef -> 0x67452301 jited:1 8 PASS
[ 9757.268000] test_bpf: Rust-for-Linux#315 BSWAP 64: 0x0123456789abcdef >> 32 -> 0xefcdab89 jited:1 8 PASS
[ 9757.269686] test_bpf: Rust-for-Linux#316 BSWAP 16: 0xfedcba9876543210 -> 0x1032 jited:1 8 PASS
[ 9757.271380] test_bpf: Rust-for-Linux#317 BSWAP 32: 0xfedcba9876543210 -> 0x10325476 jited:1 ret -1460850316 != 271733878 (0xa8ed3174 != 0x10325476)FAIL (1 times)
[ 9757.273022] test_bpf: Rust-for-Linux#318 BSWAP 64: 0xfedcba9876543210 -> 0x98badcfe jited:1 7 PASS
[ 9757.274721] test_bpf: Rust-for-Linux#319 BSWAP 64: 0xfedcba9876543210 >> 32 -> 0x10325476 jited:1 9 PASS

Fix this by forcing 32bit variant of rev32.

Fixes: 1104247 ("bpf, arm64: Support unconditional bswap")
Signed-off-by: Artem Savkov <[email protected]>
Tested-by: Puranjay Mohan <[email protected]>
Acked-by: Puranjay Mohan <[email protected]>
Acked-by: Xu Kuohai <[email protected]>
Message-ID: <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
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