2020-04-23 05:19:51

by Wang YanQing

Subject: [PATCH] bpf, x86_32: Fix logic error in BPF_LDX zero-extension

When verifier_zext is true, we don't need to emit code
for zero-extension.

Fixes: 836256bf ("x32: bpf: eliminate zero extension code-gen")

Signed-off-by: Wang YanQing <[email protected]>
---
arch/x86/net/bpf_jit_comp32.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/net/bpf_jit_comp32.c b/arch/x86/net/bpf_jit_comp32.c
index 4d2a7a764602..ed34dd16ebc5 100644
--- a/arch/x86/net/bpf_jit_comp32.c
+++ b/arch/x86/net/bpf_jit_comp32.c
@@ -1847,7 +1847,7 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image,
case BPF_B:
case BPF_H:
case BPF_W:
- if (!bpf_prog->aux->verifier_zext)
+ if (bpf_prog->aux->verifier_zext)
break;
if (dstk) {
EMIT3(0xC7, add_1reg(0x40, IA32_EBP),
--
2.17.1

2020-04-25 00:27:43

by Alexei Starovoitov

Subject: Re: [PATCH] bpf, x86_32: Fix logic error in BPF_LDX zero-extension

On Wed, Apr 22, 2020 at 10:18 PM Wang YanQing <[email protected]> wrote:
>
> When verifier_zext is true, we don't need to emit code
> for zero-extension.
>
> Fixes: 836256bf ("x32: bpf: eliminate zero extension code-gen")
>
> Signed-off-by: Wang YanQing <[email protected]>

Applied.
Please make sure fixes tag looks like this:
Fixes: 836256bf5f37 ("x32: bpf: eliminate zero extension code-gen")

all 12 digits.