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 <jiong.wang@netronome.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Acked-by: Jiong Wang <jiong.wang@netronome.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index ce9defdff62a2fea57858795b27494ed660aee69..51dd0267d0148142bdac0849bd034c75c0b7c0ff 100644 (file)
--- 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);