From: Rafael David Tinoco rafaeldtinoco@ubuntu.com
mainline inclusion from mainline-5.13-rc1 commit 155f556d64b1a48710f01305e14bb860734ed1e3 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5EUVD CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Unfortunately some distros don't have their kernel version defined accurately in <linux/version.h> due to different long term support reasons.
It is important to have a way to override the bpf kern_version attribute during runtime: some old kernels might still check for kern_version attribute during bpf_prog_load().
Signed-off-by: Rafael David Tinoco rafaeldtinoco@ubuntu.com Signed-off-by: Alexei Starovoitov ast@kernel.org Acked-by: Andrii Nakryiko andrii@kernel.org Acked-by: John Fastabend john.fastabend@gmail.com Link: https://lore.kernel.org/bpf/20210323040952.2118241-1-rafaeldtinoco@ubuntu.co... (cherry picked from commit 155f556d64b1a48710f01305e14bb860734ed1e3) Signed-off-by: Wang Yufen wangyufen@huawei.com --- tools/lib/bpf/libbpf.c | 10 ++++++++++ tools/lib/bpf/libbpf.h | 1 + tools/lib/bpf/libbpf.map | 1 + 3 files changed, 12 insertions(+)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 32360e75da1c..0c1c6de1e0b3 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -8327,6 +8327,16 @@ int bpf_object__btf_fd(const struct bpf_object *obj) return obj->btf ? btf__fd(obj->btf) : -1; }
+int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version) +{ + if (obj->loaded) + return -EINVAL; + + obj->kern_version = kern_version; + + return 0; +} + int bpf_object__set_priv(struct bpf_object *obj, void *priv, bpf_object_clear_priv_t clear_priv) { diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 41f4a1c9c432..4bb141b6727d 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -143,6 +143,7 @@ LIBBPF_API int bpf_object__unload(struct bpf_object *obj);
LIBBPF_API const char *bpf_object__name(const struct bpf_object *obj); LIBBPF_API unsigned int bpf_object__kversion(const struct bpf_object *obj); +LIBBPF_API int bpf_object__set_kversion(struct bpf_object *obj, __u32 kern_version);
struct btf; LIBBPF_API struct btf *bpf_object__btf(const struct bpf_object *obj); diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index e07bb4fb0923..0d3355c1b2e1 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -359,4 +359,5 @@ LIBBPF_0.4.0 { bpf_linker__finalize; bpf_linker__free; bpf_linker__new; + bpf_object__set_kversion; } LIBBPF_0.3.0;