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author | Andrii Nakryiko <andriin@fb.com> | 2020-06-09 22:23:35 -0700 |
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committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-06-10 13:37:02 +0200 |
commit | 32022fd97ed34f6812802bf1288db27c313576f4 (patch) | |
tree | 1afdc5598b61e41a8114a4fe5c733e3ae8cb6ae6 /net/core/filter.c | |
parent | 8ca8d4a841730c02e77bf3c87bf658cc44f364b9 (diff) | |
download | linux-32022fd97ed34f6812802bf1288db27c313576f4.tar.bz2 |
libbpf: Handle GCC noreturn-turned-volatile quirk
Handle a GCC quirk of emitting extra volatile modifier in DWARF (and
subsequently preserved in BTF by pahole) for function pointers marked as
__attribute__((noreturn)). This was the way to mark such functions before GCC
2.5 added noreturn attribute. Drop such func_proto modifiers, similarly to how
it's done for array (also to handle GCC quirk/bug).
Such volatile attribute is emitted by GCC only, so existing selftests can't
express such test. Simple repro is like this (compiled with GCC + BTF
generated by pahole):
struct my_struct {
void __attribute__((noreturn)) (*fn)(int);
};
struct my_struct a;
Without this fix, output will be:
struct my_struct {
voidvolatile (*fn)(int);
};
With the fix:
struct my_struct {
void (*fn)(int);
};
Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion")
Reported-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/bpf/20200610052335.2862559-1-andriin@fb.com
Diffstat (limited to 'net/core/filter.c')
0 files changed, 0 insertions, 0 deletions