[PATCH 4.2.y-ckt 29/53] arm64: bpf: jit JMP_JSET_{X,K}

[Kamal Mostafa]

4.2.8-ckt11 -stable review patch.  If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Zi Shen Lim <zlim.lnx@xxxxxxxxx>

commit 98397fc547e3f4553553a30ea56fa34d613f0a4c upstream.

Original implementation commit e54bcde3d69d ("arm64: eBPF JIT compiler")
had the relevant code paths, but due to an oversight always fail jiting.

As a result, we had been falling back to BPF interpreter whenever a BPF
program has JMP_JSET_{X,K} instructions.

With this fix, we confirm that the corresponding tests in lib/test_bpf
continue to pass, and also jited.

...
[    2.784553] test_bpf: #30 JSET jited:1 188 192 197 PASS
[    2.791373] test_bpf: #31 tcpdump port 22 jited:1 325 677 625 PASS
[    2.808800] test_bpf: #32 tcpdump complex jited:1 323 731 991 PASS
...
[    3.190759] test_bpf: #237 JMP_JSET_K: if (0x3 & 0x2) return 1 jited:1 110 PASS
[    3.192524] test_bpf: #238 JMP_JSET_K: if (0x3 & 0xffffffff) return 1 jited:1 98 PASS
[    3.211014] test_bpf: #249 JMP_JSET_X: if (0x3 & 0x2) return 1 jited:1 120 PASS
[    3.212973] test_bpf: #250 JMP_JSET_X: if (0x3 & 0xffffffff) return 1 jited:1 89 PASS
...

Fixes: e54bcde3d69d ("arm64: eBPF JIT compiler")
Signed-off-by: Zi Shen Lim <zlim.lnx@xxxxxxxxx>
Acked-by: Will Deacon <will.deacon@xxxxxxx>
Acked-by: Yang Shi <yang.shi@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
 arch/arm64/net/bpf_jit_comp.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 6217f80..5cc9097 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -449,6 +449,7 @@ emit_cond_jmp:
 		case BPF_JGE:
 			jmp_cond = A64_COND_CS;
 			break;
+		case BPF_JSET:
 		case BPF_JNE:
 			jmp_cond = A64_COND_NE;
 			break;
-- 
2.7.4