diff options
| author | Andrii Nakryiko <andrii@kernel.org> | 2024-05-29 15:32:39 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2024-05-31 20:35:55 -0700 |
| commit | 531876c80004ecff7bfdbd8ba6c6b48835ef5e22 (patch) | |
| tree | 2155c4d8b9eae681b2ac8081c12d43ce80c7c6e5 | |
| parent | 3f8fde319524411b96badee3c96f35831300388a (diff) | |
libbpf: keep FD_CLOEXEC flag when dup()'ing FD
Make sure to preserve and/or enforce FD_CLOEXEC flag on duped FDs.
Use dup3() with O_CLOEXEC flag for that.
Without this fix libbpf effectively clears FD_CLOEXEC flag on each of BPF
map/prog FD, which is definitely not the right or expected behavior.
Reported-by: Lennart Poettering <lennart@poettering.net>
Fixes: bc308d011ab8 ("libbpf: call dup2() syscall directly")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20240529223239.504241-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | tools/lib/bpf/libbpf_internal.h | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index a0dcfb82e455..7e7e686008c6 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -597,13 +597,9 @@ static inline int ensure_good_fd(int fd) return fd; } -static inline int sys_dup2(int oldfd, int newfd) +static inline int sys_dup3(int oldfd, int newfd, int flags) { -#ifdef __NR_dup2 - return syscall(__NR_dup2, oldfd, newfd); -#else - return syscall(__NR_dup3, oldfd, newfd, 0); -#endif + return syscall(__NR_dup3, oldfd, newfd, flags); } /* Point *fixed_fd* to the same file that *tmp_fd* points to. @@ -614,7 +610,7 @@ static inline int reuse_fd(int fixed_fd, int tmp_fd) { int err; - err = sys_dup2(tmp_fd, fixed_fd); + err = sys_dup3(tmp_fd, fixed_fd, O_CLOEXEC); err = err < 0 ? -errno : 0; close(tmp_fd); /* clean up temporary FD */ return err; |