Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

[linux-2.6-microblaze.git] / arch / s390 / net / bpf_jit_comp.c

diff --git a/arch/s390/net/bpf_jit_comp.c b/arch/s390/net/bpf_jit_comp.c
index 8fe7bdf..be4b853 100644 (file)
--- 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;