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 <jiong.wang@xxxxxxxxxxxxx>
Cc: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Heiko Carstens <heiko.carstens@xxxxxxxxxx>
---
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 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
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 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, int i
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);
--
2.16.4
