diff options
| author | Alexei Starovoitov <ast@kernel.org> | 2025-04-24 18:45:42 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-05-02 07:59:04 +0200 |
| commit | 955f9ede52b8617e454fcfd4528f90bd23a30753 (patch) | |
| tree | 236190ef6925eb94dd15943f457825f698e8a413 | |
| parent | 3decda1a3c19b416cf792e4c68e6669a1285d0be (diff) | |
bpf: Add namespace to BPF internal symbols
[ Upstream commit f88886de0927a2adf4c1b4c5c1f1d31d2023ef74 ]
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
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -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 0c63bc2cd895..56a81df7a9d7 100644 --- a/kernel/bpf/preload/bpf_preload_kern.c +++ b/kernel/bpf/preload/bpf_preload_kern.c @@ -89,4 +89,5 @@ static void __exit fini(void) } late_initcall(load); module_exit(fini); +MODULE_IMPORT_NS("BPF_INTERNAL"); MODULE_LICENSE("GPL"); diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 696e5a2cbea2..977c08457756 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1457,7 +1457,7 @@ 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) { @@ -3223,7 +3223,7 @@ 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) { @@ -5853,7 +5853,7 @@ 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, |