linux-stable/tools/include
Anton Protopopov 7a7d4237e3 bpf: Pack struct bpf_fib_lookup
[ Upstream commit f917170072 ]

The struct bpf_fib_lookup is supposed to be of size 64. A recent commit
59b418c706 ("bpf: Add a check for struct bpf_fib_lookup size") added
a static assertion to check this property so that future changes to the
structure will not accidentally break this assumption.

As it immediately turned out, on some 32-bit arm systems, when AEABI=n,
the total size of the structure was equal to 68, see [1]. This happened
because the bpf_fib_lookup structure contains a union of two 16-bit
fields:

    union {
            __u16 tot_len;
            __u16 mtu_result;
    };

which was supposed to compile to a 16-bit-aligned 16-bit field. On the
aforementioned setups it was instead both aligned and padded to 32-bits.

Declare this inner union as __attribute__((packed, aligned(2))) such
that it always is of size 2 and is aligned to 16 bits.

  [1] https://lore.kernel.org/all/CA+G9fYtsoP51f-oP_Sp5MOq-Ffv8La2RztNpwvE6+R1VtFiLrw@mail.gmail.com/#t

Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Fixes: e1850ea9bd ("bpf: bpf_fib_lookup return MTU value as output when looked up")
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240403123303.1452184-1-aspsk@isovalent.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-06-12 11:11:38 +02:00
..
asm tools headers: Update the copy of x86's mem{cpy,set}_64.S used in 'perf bench' 2023-05-17 10:42:19 -03:00
asm-generic tools: KVM: selftests: Convert clear/set_bit() to actual atomics 2022-12-02 13:22:35 -05:00
linux memblock tests: fix undefined reference to `panic' 2024-05-17 12:02:14 +02:00
nolibc tools/nolibc/stdlib: fix memory error in realloc() 2024-06-12 11:11:19 +02:00
tools
trace/events
uapi bpf: Pack struct bpf_fib_lookup 2024-06-12 11:11:38 +02:00
vdso tools headers: Synchronize {linux,vdso}/bits.h with the kernel sources 2023-03-03 22:34:15 -03:00