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| author | Andrii Nakryiko <andrii@kernel.org> | 2024-02-01 09:20:23 -0800 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2024-02-01 22:16:11 +0100 |
| commit | 9fa5e1a180aa639fb156a16e453ab820b7e7860b (patch) | |
| tree | 31cb7e6da88097ca1880c6a8776ee4e56b4e469b | |
| parent | 1581e5118e485e82cfb5d04d636a79aaefb6f266 (diff) | |
| download | linux-stable-9fa5e1a180aa639fb156a16e453ab820b7e7860b.tar.gz linux-stable-9fa5e1a180aa639fb156a16e453ab820b7e7860b.tar.bz2 linux-stable-9fa5e1a180aa639fb156a16e453ab820b7e7860b.zip | |
libbpf: Call memfd_create() syscall directly
Some versions of Android do not implement memfd_create() wrapper in
their libc implementation, leading to build failures ([0]). On the other
hand, memfd_create() is available as a syscall on quite old kernels
(3.17+, while bpf() syscall itself is available since 3.18+), so it is
ok to assume that syscall availability and call into it with syscall()
helper to avoid Android-specific workarounds.
Validated in libbpf-bootstrap's CI ([1]).
[0] https://github.com/libbpf/libbpf-bootstrap/actions/runs/7701003207/job/20986080319#step:5:83
[1] https://github.com/libbpf/libbpf-bootstrap/actions/runs/7715988887/job/21031767212?pr=253
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20240201172027.604869-2-andrii@kernel.org
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index f6953d7faff1..6932f2c4ddfd 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1525,11 +1525,20 @@ static Elf64_Sym *find_elf_var_sym(const struct bpf_object *obj, const char *nam return ERR_PTR(-ENOENT); } +/* Some versions of Android don't provide memfd_create() in their libc + * implementation, so avoid complications and just go straight to Linux + * syscall. + */ +static int sys_memfd_create(const char *name, unsigned flags) +{ + return syscall(__NR_memfd_create, name, flags); +} + static int create_placeholder_fd(void) { int fd; - fd = ensure_good_fd(memfd_create("libbpf-placeholder-fd", MFD_CLOEXEC)); + fd = ensure_good_fd(sys_memfd_create("libbpf-placeholder-fd", MFD_CLOEXEC)); if (fd < 0) return -errno; return fd; |