From: Song Liu <song@kernel.org> mainline inclusion from mainline-v6.8-rc1 commit 38b8b58ae776bf748bd1bd7a24c3fd1d10f76f45 category: feature bugzilla: https://atomgit.com/openeuler/kernel/issues/8335 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ---------------------------------------------------------------------- x86's implementation of arch_prepare_bpf_trampoline() requires BPF_INSN_SAFETY buffer space between end of program and image_end. OTOH, the return value does not include BPF_INSN_SAFETY. This doesn't cause any real issue at the moment. However, "image" of size retval is not enough for arch_prepare_bpf_trampoline(). This will cause confusion when we introduce a new helper arch_bpf_trampoline_size(). To avoid future confusion, adjust the return value to include BPF_INSN_SAFETY. Signed-off-by: Song Liu <song@kernel.org> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/20231206224054.492250-5-song@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Luo Gengkun <luogengkun2@huawei.com> --- arch/x86/net/bpf_jit_comp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index d61f04743aad..cbcb409f6e14 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -2644,7 +2644,7 @@ int arch_prepare_bpf_trampoline(struct bpf_tramp_image *im, void *image, void *i ret = -EFAULT; goto cleanup; } - ret = prog - (u8 *)image; + ret = prog - (u8 *)image + BPF_INSN_SAFETY; cleanup: kfree(branches); -- 2.34.1