diff options
Diffstat (limited to 'arch/s390/net/bpf_jit_comp.c')
| -rw-r--r-- | arch/s390/net/bpf_jit_comp.c | 63 |
1 files changed, 41 insertions, 22 deletions
diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c index 8fe7bdfc8d15..be4b8532dd3c 100644 --- a/arch/s390/net/bpf_jit_comp.c +++ b/arch/s390/net/bpf_jit_comp.c @@ -490,6 +490,24 @@ static void save_restore_regs(struct bpf_jit *jit, int op, u32 stack_depth) } while (re <= last); } +static void bpf_skip(struct bpf_jit *jit, int size) +{ + if (size >= 6 && !is_valid_rel(size)) { + /* brcl 0xf,size */ + EMIT6_PCREL_RIL(0xc0f4000000, size); + size -= 6; + } else if (size >= 4 && is_valid_rel(size)) { + /* brc 0xf,size */ + EMIT4_PCREL(0xa7f40000, size); + size -= 4; + } + while (size >= 2) { + /* bcr 0,%0 */ + _EMIT2(0x0700); + size -= 2; + } +} + /* * Emit function prologue * @@ -502,10 +520,11 @@ static void bpf_jit_prologue(struct bpf_jit *jit, u32 stack_depth) /* xc STK_OFF_TCCNT(4,%r15),STK_OFF_TCCNT(%r15) */ _EMIT6(0xd703f000 | STK_OFF_TCCNT, 0xf000 | STK_OFF_TCCNT); } else { - /* j tail_call_start: NOP if no tail calls are used */ - EMIT4_PCREL(0xa7f40000, 6); - /* bcr 0,%0 */ - EMIT2(0x0700, 0, REG_0); + /* + * There are no tail calls. Insert nops in order to have + * tail_call_start at a predictable offset. + */ + bpf_skip(jit, 6); } /* Tail calls have to skip above initialization */ jit->tail_call_start = jit->prg; @@ -1358,8 +1377,12 @@ static noinline int bpf_jit_insn(struct bpf_jit *jit, struct bpf_prog *fp, last = (i == fp->len - 1) ? 1 : 0; if (last) break; - /* j <exit> */ - EMIT4_PCREL(0xa7f40000, jit->exit_ip - jit->prg); + if (!is_first_pass(jit) && can_use_rel(jit, jit->exit_ip)) + /* brc 0xf, <exit> */ + EMIT4_PCREL_RIC(0xa7040000, 0xf, jit->exit_ip); + else + /* brcl 0xf, <exit> */ + EMIT6_PCREL_RILC(0xc0040000, 0xf, jit->exit_ip); break; /* * Branch relative (number of skipped instructions) to offset on @@ -1507,21 +1530,10 @@ branch_ks: } break; branch_ku: - is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32; - /* clfi or clgfi %dst,imm */ - EMIT6_IMM(is_jmp32 ? 0xc20f0000 : 0xc20e0000, - dst_reg, imm); - if (!is_first_pass(jit) && - can_use_rel(jit, addrs[i + off + 1])) { - /* brc mask,off */ - EMIT4_PCREL_RIC(0xa7040000, - mask >> 12, addrs[i + off + 1]); - } else { - /* brcl mask,off */ - EMIT6_PCREL_RILC(0xc0040000, - mask >> 12, addrs[i + off + 1]); - } - break; + /* lgfi %w1,imm (load sign extend imm) */ + src_reg = REG_1; + EMIT6_IMM(0xc0010000, src_reg, imm); + goto branch_xu; branch_xs: is_jmp32 = BPF_CLASS(insn->code) == BPF_JMP32; if (!is_first_pass(jit) && @@ -1617,7 +1629,14 @@ static bool bpf_is_new_addr_sane(struct bpf_jit *jit, int i) */ static int bpf_set_addr(struct bpf_jit *jit, int i) { - if (!bpf_is_new_addr_sane(jit, i)) + int delta; + + if (is_codegen_pass(jit)) { + delta = jit->prg - jit->addrs[i]; + if (delta < 0) + bpf_skip(jit, -delta); + } + if (WARN_ON_ONCE(!bpf_is_new_addr_sane(jit, i))) return -1; jit->addrs[i] = jit->prg; return 0; |