diff options
| author | Carlos Llamas <cmllamas@google.com> | 2025-03-30 21:13:23 +0000 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2025-04-04 08:52:37 -0700 |
| commit | 75011ad69bc54396703867b5434f1622343a848e (patch) | |
| tree | b71d26d5e79a4cb70b8c5ad6a5de5e35dfef0c9b | |
| parent | 06a22366d6a11ca8ed03c738171822ac9b714cfd (diff) | |
libbpf: Fix implicit memfd_create() for bionic
Since memfd_create() is not consistently available across different
bionic libc implementations, using memfd_create() directly can break
some Android builds:
tools/lib/bpf/linker.c:576:7: error: implicit declaration of function 'memfd_create' [-Werror,-Wimplicit-function-declaration]
576 | fd = memfd_create(filename, 0);
| ^
To fix this, relocate and inline the sys_memfd_create() helper so that
it can be used in "linker.c". Similar issues were previously fixed by
commit 9fa5e1a180aa ("libbpf: Call memfd_create() syscall directly").
Fixes: 6d5e5e5d7ce1 ("libbpf: Extend linker API to support in-memory ELF files")
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250330211325.530677-1-cmllamas@google.com
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 9 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf_internal.h | 9 | ||||
| -rw-r--r-- | tools/lib/bpf/linker.c | 2 |
3 files changed, 10 insertions, 10 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 6b85060f07b3..37d563e14051 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -1725,15 +1725,6 @@ 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); -} - #ifndef MFD_CLOEXEC #define MFD_CLOEXEC 0x0001U #endif diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h index 76669c73dcd1..477a3b3389a0 100644 --- a/tools/lib/bpf/libbpf_internal.h +++ b/tools/lib/bpf/libbpf_internal.h @@ -667,6 +667,15 @@ static inline int sys_dup3(int oldfd, int newfd, int flags) return syscall(__NR_dup3, oldfd, newfd, flags); } +/* Some versions of Android don't provide memfd_create() in their libc + * implementation, so avoid complications and just go straight to Linux + * syscall. + */ +static inline int sys_memfd_create(const char *name, unsigned flags) +{ + return syscall(__NR_memfd_create, name, flags); +} + /* Point *fixed_fd* to the same file that *tmp_fd* points to. * Regardless of success, *tmp_fd* is closed. * Whatever *fixed_fd* pointed to is closed silently. diff --git a/tools/lib/bpf/linker.c b/tools/lib/bpf/linker.c index 800e0ef09c37..56f5068e2eba 100644 --- a/tools/lib/bpf/linker.c +++ b/tools/lib/bpf/linker.c @@ -573,7 +573,7 @@ int bpf_linker__add_buf(struct bpf_linker *linker, void *buf, size_t buf_sz, snprintf(filename, sizeof(filename), "mem:%p+%zu", buf, buf_sz); - fd = memfd_create(filename, 0); + fd = sys_memfd_create(filename, 0); if (fd < 0) { ret = -errno; pr_warn("failed to create memfd '%s': %s\n", filename, errstr(ret)); |