libbpf: Fix libbpf build on compilers missing __builtin_mul_overflow

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GCC compilers older than version 5 don't support __builtin_mul_overflow yet.
Given GCC 4.9 is the minimal supported compiler for building kernel and the
fact that libbpf is a dependency of resolve_btfids, which is dependency of
CONFIG_DEBUG_INFO_BTF=y, this needs to be handled. This patch fixes the issue
by falling back to slower detection of integer overflow in such cases.

Fixes: 029258d7b2 ("libbpf: Remove any use of reallocarray() in libbpf")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200820061411.1755905-2-andriin@fb.com

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Andrii Nakryiko 2020-08-19 23:14:09 -07:00 • committed by Daniel Borkmann

parent 9b2f6fecf3

commit dda1ec9fc7

1 changed files with 10 additions and 0 deletions

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tools/lib/bpf/libbpf_internal.h

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