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path: root/arch/x86/net/bpf_jit_comp.c
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Diffstat (limited to 'arch/x86/net/bpf_jit_comp.c')
-rw-r--r--arch/x86/net/bpf_jit_comp.c29
1 files changed, 15 insertions, 14 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c
index 0abd082786e7..d926ca637d8d 100644
--- a/arch/x86/net/bpf_jit_comp.c
+++ b/arch/x86/net/bpf_jit_comp.c
@@ -1138,16 +1138,15 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, u8 *rw_image
case BPF_ALU64 | BPF_RSH | BPF_X:
case BPF_ALU64 | BPF_ARSH | BPF_X:
- /* Check for bad case when dst_reg == rcx */
- if (dst_reg == BPF_REG_4) {
- /* mov r11, dst_reg */
- EMIT_mov(AUX_REG, dst_reg);
- dst_reg = AUX_REG;
- }
-
if (src_reg != BPF_REG_4) { /* common case */
- EMIT1(0x51); /* push rcx */
-
+ /* Check for bad case when dst_reg == rcx */
+ if (dst_reg == BPF_REG_4) {
+ /* mov r11, dst_reg */
+ EMIT_mov(AUX_REG, dst_reg);
+ dst_reg = AUX_REG;
+ } else {
+ EMIT1(0x51); /* push rcx */
+ }
/* mov rcx, src_reg */
EMIT_mov(BPF_REG_4, src_reg);
}
@@ -1159,12 +1158,14 @@ static int do_jit(struct bpf_prog *bpf_prog, int *addrs, u8 *image, u8 *rw_image
b3 = simple_alu_opcodes[BPF_OP(insn->code)];
EMIT2(0xD3, add_1reg(b3, dst_reg));
- if (src_reg != BPF_REG_4)
- EMIT1(0x59); /* pop rcx */
+ if (src_reg != BPF_REG_4) {
+ if (insn->dst_reg == BPF_REG_4)
+ /* mov dst_reg, r11 */
+ EMIT_mov(insn->dst_reg, AUX_REG);
+ else
+ EMIT1(0x59); /* pop rcx */
+ }
- if (insn->dst_reg == BPF_REG_4)
- /* mov dst_reg, r11 */
- EMIT_mov(insn->dst_reg, AUX_REG);
break;
case BPF_ALU | BPF_END | BPF_FROM_BE: