diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2025-04-24 18:45:42 -0700 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2025-04-25 09:21:23 -0700 |
| commit | f88886de0927a2adf4c1b4c5c1f1d31d2023ef74 (patch) | |
| tree | 1f2b41b41d633f1d09d4c20b59505cf93e305b6a | |
| parent | 6ae003adc029c74e7f97cc65dc1e79109a1f2d67 (diff) | |
bpf: Add namespace to BPF internal symbols
Add namespace to BPF internal symbols used by light skeleton
to prevent abuse and document with the code their allowed usage.
Fixes: b1d18a7574d0 ("bpf: Extend sys_bpf commands for bpf_syscall programs.")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/bpf/20250425014542.62385-1-alexei.starovoitov@gmail.com
| -rw-r--r-- | Documentation/bpf/bpf_devel_QA.rst | 8 | ||||
| -rw-r--r-- | kernel/bpf/preload/bpf_preload_kern.c | 1 | ||||
| -rw-r--r-- | kernel/bpf/syscall.c | 6 |
3 files changed, 12 insertions, 3 deletions
diff --git a/Documentation/bpf/bpf_devel_QA.rst b/Documentation/bpf/bpf_devel_QA.rst index de27e1620821..0acb4c9b8d90 100644 --- a/Documentation/bpf/bpf_devel_QA.rst +++ b/Documentation/bpf/bpf_devel_QA.rst @@ -382,6 +382,14 @@ In case of new BPF instructions, once the changes have been accepted into the Linux kernel, please implement support into LLVM's BPF back end. See LLVM_ section below for further information. +Q: What "BPF_INTERNAL" symbol namespace is for? +----------------------------------------------- +A: Symbols exported as BPF_INTERNAL can only be used by BPF infrastructure +like preload kernel modules with light skeleton. Most symbols outside +of BPF_INTERNAL are not expected to be used by code outside of BPF either. +Symbols may lack the designation because they predate the namespaces, +or due to an oversight. + Stable submission ================= diff --git a/kernel/bpf/preload/bpf_preload_kern.c b/kernel/bpf/preload/bpf_preload_kern.c index 2fdf3c978db1..774e5a538811 100644 --- a/kernel/bpf/preload/bpf_preload_kern.c +++ b/kernel/bpf/preload/bpf_preload_kern.c @@ -89,5 +89,6 @@ static void __exit fini(void) } late_initcall(load); module_exit(fini); +MODULE_IMPORT_NS("BPF_INTERNAL"); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Embedded BPF programs for introspection in bpffs"); diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 9794446bc8c6..64c3393e8270 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1583,7 +1583,7 @@ struct bpf_map *bpf_map_get(u32 ufd) return map; } -EXPORT_SYMBOL(bpf_map_get); +EXPORT_SYMBOL_NS(bpf_map_get, "BPF_INTERNAL"); struct bpf_map *bpf_map_get_with_uref(u32 ufd) { @@ -3364,7 +3364,7 @@ struct bpf_link *bpf_link_get_from_fd(u32 ufd) bpf_link_inc(link); return link; } -EXPORT_SYMBOL(bpf_link_get_from_fd); +EXPORT_SYMBOL_NS(bpf_link_get_from_fd, "BPF_INTERNAL"); static void bpf_tracing_link_release(struct bpf_link *link) { @@ -6020,7 +6020,7 @@ int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size) return ____bpf_sys_bpf(cmd, attr, size); } } -EXPORT_SYMBOL(kern_sys_bpf); +EXPORT_SYMBOL_NS(kern_sys_bpf, "BPF_INTERNAL"); static const struct bpf_func_proto bpf_sys_bpf_proto = { .func = bpf_sys_bpf, |