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bpf, x86_32: Fix logic error in BPF_LDX zero-extension

PATCH Applied Wang YanQing 2 participants 2 messages Apr 23, 2020 – Apr 25, 2020

Subsystems (5)
Networking Network drivers x86 BPF +1 more subsystems
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Wang YanQing

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#0 lore raw

PATCH 1/1 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(-)
arch/x86/net/bpf_jit_comp32.c +1 -1
index 4d2a7a764602..ed34dd16ebc5 100644
@@ -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),
Signature · 1 line
2.17.1
Applied
#1 lore raw
Quoted 7 lines · Wang YanQing

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.