From: Zi Shen Lim <zlim.lnx@gmail.com>
Date: Thu, 9 Jun 2016 04:18:49 +0000 (-0700)
Subject: arm64: bpf: optimize JMP_CALL
X-Git-Tag: v4.8-rc1~140^2~369^2~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=997ce888324685a90fb5d0fa26293eb8826c767c;p=platform%2Fkernel%2Flinux-exynos.git

arm64: bpf: optimize JMP_CALL

Remove superfluous stack frame, saving us 3 instructions for
every JMP_CALL.

Signed-off-by: Zi Shen Lim <zlim.lnx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index 51abc979..7ae304e 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -578,11 +578,8 @@ emit_cond_jmp:
 		const u64 func = (u64)__bpf_call_base + imm;
 
 		emit_a64_mov_i64(tmp, func, ctx);
-		emit(A64_PUSH(A64_FP, A64_LR, A64_SP), ctx);
-		emit(A64_MOV(1, A64_FP, A64_SP), ctx);
 		emit(A64_BLR(tmp), ctx);
 		emit(A64_MOV(1, r0, A64_R(0)), ctx);
-		emit(A64_POP(A64_FP, A64_LR, A64_SP), ctx);
 		break;
 	}
 	/* tail call */