From ecc15f113c8e8748cc304ed6d8beb825a432b34c Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Mon, 4 Feb 2019 16:44:55 +0100 Subject: [PATCH] s390: bpf: fix JMP32 code-gen Commit 626a5f66da0d19 ("s390: bpf: implement jitting of JMP32") added JMP32 code-gen support for s390. However it triggers the warning below due to some unusual gotos in the original s390 bpf jit code. Add a couple of additional "is_jmp32" initializations to fix this. Also fix the wrong opcode for the "llilf" instruction that was introduced with the same commit. arch/s390/net/bpf_jit_comp.c: In function 'bpf_jit_insn': arch/s390/net/bpf_jit_comp.c:248:55: warning: 'is_jmp32' may be used uninitialized in this function [-Wmaybe-uninitialized] _EMIT6(op1 | reg(b1, b2) << 16 | (rel & 0xffff), op2 | mask); \ ^ arch/s390/net/bpf_jit_comp.c:1211:8: note: 'is_jmp32' was declared here bool is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32; Fixes: 626a5f66da0d19 ("s390: bpf: implement jitting of JMP32") Cc: Jiong Wang Cc: Martin Schwidefsky Signed-off-by: Heiko Carstens Acked-by: Jiong Wang Acked-by: David S. Miller Signed-off-by: Alexei Starovoitov --- arch/s390/net/bpf_jit_comp.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index ce9defdff62a..51dd0267d014 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -1154,7 +1154,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i mask = 0x7000; /* jnz */ if (BPF_CLASS(insn->code) == BPF_JMP32) { /* llilf %w1,imm (load zero extend imm) */ - EMIT6_IMM(0xc0010000, REG_W1, imm); + EMIT6_IMM(0xc00f0000, REG_W1, imm); /* nr %w1,%dst */ EMIT2(0x1400, REG_W1, dst_reg); } else { @@ -1216,6 +1216,7 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i REG_W1, dst_reg, src_reg); goto branch_oc; branch_ks: + is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32; /* lgfi %w1,imm (load sign extend imm) */ EMIT6_IMM(0xc0010000, REG_W1, imm); /* crj or cgrj %dst,%w1,mask,off */ @@ -1223,6 +1224,7 @@ branch_ks: dst_reg, REG_W1, i, off, mask); break; branch_ku: + is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32; /* lgfi %w1,imm (load sign extend imm) */ EMIT6_IMM(0xc0010000, REG_W1, imm); /* clrj or clgrj %dst,%w1,mask,off */ @@ -1230,11 +1232,13 @@ branch_ku: dst_reg, REG_W1, i, off, mask); break; branch_xs: + is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32; /* crj or cgrj %dst,%src,mask,off */ EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0076 : 0x0064), dst_reg, src_reg, i, off, mask); break; branch_xu: + is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32; /* clrj or clgrj %dst,%src,mask,off */ EMIT6_PCREL(0xec000000, (is_jmp32 ? 0x0077 : 0x0065), dst_reg, src_reg, i, off, mask); -- 2.30.2