On 3/20/18 5:58 AM, Thadeu Lima de Souza Cascardo wrote:
Function bpf_fill_maxinsns11 is designed to not be able to be JITed on
x86_64. So, it fails when CONFIG_BPF_JIT_ALWAYS_ON=y, and
commit 09584b406742 ("bpf: fix selftests/bpf test_kmod.sh failure when
CONFIG_BPF_JIT_ALWAYS_ON=y") makes sure that failure is detected on that
case.
However, it does not fail on other architectures, which have a different
JIT compiler design. So, test_bpf has started to fail to load on those.
Here, you mentioned that it did not fail on other architectures. Have
you verified all of them or just looked through the algorithm.
Could you give a little bit details about other architectures are okay
while x86 is not? Maybe, x86 JIT can be improved some how?
Thanks!
After this fix, test_bpf loads fine on both x86_64 and ppc64el.
Fixes: 09584b406742 ("bpf: fix selftests/bpf test_kmod.sh failure when
CONFIG_BPF_JIT_ALWAYS_ON=y")
Signed-off-by: Thadeu Lima de Souza Cascardo <casca...@canonical.com>
---
lib/test_bpf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/lib/test_bpf.c b/lib/test_bpf.c
index 2efb213716faa..3e9335493fe49 100644
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -5467,7 +5467,7 @@ static struct bpf_test tests[] = {
{
"BPF_MAXINSNS: Jump, gap, jump, ...",
{ },
-#ifdef CONFIG_BPF_JIT_ALWAYS_ON
+#if defined(CONFIG_BPF_JIT_ALWAYS_ON) && defined(CONFIG_X86)
CLASSIC | FLAG_NO_DATA | FLAG_EXPECTED_FAIL,
#else
CLASSIC | FLAG_NO_DATA,
