From: Yonghong Song yhs@fb.com
[ Upstream commit ad96f1c9138e0897bee7f7c5e54b3e24f8b62f57 ]
The sysctl net/core/bpf_jit_enable does not work now due to commit 1022a5498f6f ("bpf, x86_64: Use bpf_jit_binary_pack_alloc"). The commit saved the jitted insns into 'rw_image' instead of 'image' which caused bpf_jit_dump not dumping proper content.
With 'echo 2 > /proc/sys/net/core/bpf_jit_enable', run './test_progs -t fentry_test'. Without this patch, one of jitted image for one particular prog is:
flen=17 proglen=92 pass=4 image=0000000014c64883 from=test_progs pid=1807 00000000: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 00000010: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 00000020: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 00000030: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 00000040: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 00000050: cc cc cc cc cc cc cc cc cc cc cc cc
With this patch, the jitte image for the same prog is:
flen=17 proglen=92 pass=4 image=00000000b90254b7 from=test_progs pid=1809 00000000: f3 0f 1e fa 0f 1f 44 00 00 66 90 55 48 89 e5 f3 00000010: 0f 1e fa 31 f6 48 8b 57 00 48 83 fa 07 75 2b 48 00000020: 8b 57 10 83 fa 09 75 22 48 8b 57 08 48 81 e2 ff 00000030: 00 00 00 48 83 fa 08 75 11 48 8b 7f 18 be 01 00 00000040: 00 00 48 83 ff 0a 74 02 31 f6 48 bf 18 d0 14 00 00000050: 00 c9 ff ff 48 89 77 00 31 c0 c9 c3
Fixes: 1022a5498f6f ("bpf, x86_64: Use bpf_jit_binary_pack_alloc") Signed-off-by: Yonghong Song yhs@fb.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Acked-by: Song Liu song@kernel.org Link: https://lore.kernel.org/bpf/20230609005439.3173569-1-yhs@fb.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 1056bbf55b172..438adb695daab 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -2570,7 +2570,7 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *prog) }
if (bpf_jit_enable > 1) - bpf_jit_dump(prog->len, proglen, pass + 1, image); + bpf_jit_dump(prog->len, proglen, pass + 1, rw_image);
if (image) { if (!prog->is_func || extra_pass) {