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 <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200717165326.6786-6-iii@linux.ibm.com
This commit is contained in:
Ilya Leoshkevich 2020-07-17 18:53:26 +02:00 committed by Alexei Starovoitov
parent 1491b73311
commit 94ad428df5

View File

@ -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) */ /* xc STK_OFF_TCCNT(4,%r15),STK_OFF_TCCNT(%r15) */
_EMIT6(0xd703f000 | STK_OFF_TCCNT, 0xf000 | STK_OFF_TCCNT); _EMIT6(0xd703f000 | STK_OFF_TCCNT, 0xf000 | STK_OFF_TCCNT);
} else { } else {
/* j tail_call_start: NOP if no tail calls are used */ /*
EMIT4_PCREL(0xa7f40000, 6); * There are no tail calls. Insert nops in order to have
/* bcr 0,%0 */ * tail_call_start at a predictable offset.
EMIT2(0x0700, 0, REG_0); */
bpf_skip(jit, 6);
} }
/* Tail calls have to skip above initialization */ /* Tail calls have to skip above initialization */
jit->tail_call_start = jit->prg; jit->tail_call_start = jit->prg;