From 26f843848bae973817b3587780ce6b7b0200d3e4 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Mon, 6 Aug 2018 14:26:39 +0200 Subject: [PATCH] s390: fix br_r1_trampoline for machines without exrl For machines without the exrl instruction the BFP jit generates code that uses an "br %r1" instruction located in the lowcore page. Unfortunately there is a cut & paste error that puts an additional "larl %r1,.+14" instruction in the code that clobbers the branch target address in %r1. Remove the larl instruction. Cc: # v4.17+ Fixes: de5cb6eb51 ("s390: use expoline thunks in the BPF JIT") Signed-off-by: Martin Schwidefsky --- arch/s390/net/bpf_jit_comp.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index d2db8acb1a55..9d4399a87fa2 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -485,8 +485,6 @@ static void bpf_jit_epilogue(struct bpf_jit *jit, u32 stack_depth) /* br %r1 */ _EMIT2(0x07f1); } else { - /* larl %r1,.+14 */ - EMIT6_PCREL_RILB(0xc0000000, REG_1, jit->prg + 14); /* ex 0,S390_lowcore.br_r1_tampoline */ EMIT4_DISP(0x44000000, REG_0, REG_0, offsetof(struct lowcore, br_r1_trampoline));