From 94ad428df53688a1f80ab55f2b1186101510a778 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Fri, 17 Jul 2020 18:53:26 +0200 Subject: [PATCH] s390/bpf: Use bpf_skip() in bpf_jit_prologue() Now that we have bpf_skip() for emitting nops, use it in bpf_jit_prologue() in order to reduce code duplication. Signed-off-by: Ilya Leoshkevich Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200717165326.6786-6-iii@linux.ibm.com --- arch/s390/net/bpf_jit_comp.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index a78c5b59e1ab..26f97a10e793 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -519,10 +519,11 @@ static void bpf_jit_prologue(struct bpf_jit *jit, u32 stack_depth) /* xc STK_OFF_TCCNT(4,%r15),STK_OFF_TCCNT(%r15) */ _EMIT6(0xd703f000 | STK_OFF_TCCNT, 0xf000 | STK_OFF_TCCNT); } else { - /* j tail_call_start: NOP if no tail calls are used */ - EMIT4_PCREL(0xa7f40000, 6); - /* bcr 0,%0 */ - EMIT2(0x0700, 0, REG_0); + /* + * There are no tail calls. Insert nops in order to have + * tail_call_start at a predictable offset. + */ + bpf_skip(jit, 6); } /* Tail calls have to skip above initialization */ jit->tail_call_start = jit->prg;