[PATCH 5.4 49/83] bpf, x86_32: Fix logic error in BPF_LDX zero-extension

[Greg Kroah-Hartman]

From: Wang YanQing <udkni...@gmail.com>

commit 5ca1ca01fae1e90f8d010eb1d83374f28dc11ee6 upstream.

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

Fixes: 836256bf5f37 ("x32: bpf: eliminate zero extension code-gen")
Signed-off-by: Wang YanQing <udkni...@gmail.com>
Signed-off-by: Alexei Starovoitov <a...@kernel.org>
Link: https://lore.kernel.org/bpf/20200423050637.GA4029@udknight
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 arch/x86/net/bpf_jit_comp32.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- 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_p
                        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),