diff options
| author | Bjorn Andersson <bjorn.andersson@linaro.org> | 2018-05-09 11:58:20 -0700 |
|---|---|---|
| committer | Bjorn Andersson <bjorn.andersson@linaro.org> | 2018-05-09 11:59:07 -0700 |
| commit | 9935448e207cc9e7e5fd3c6aa3282ff503f263c4 (patch) | |
| tree | a43f75f5dd940664f468418d59d3879ffff75b8f /arch/x86/net | |
| parent | 41a5985f173bf1f93d2634fc93d8aa53683067f9 (diff) | |
| parent | 75bc37fefc4471e718ba8e651aa74673d4e0a9eb (diff) | |
Merge tag 'v4.17-rc4' into rproc-next
Pick up fixes from rproc-v4.17-1
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Diffstat (limited to 'arch/x86/net')
| -rw-r--r-- | arch/x86/net/bpf_jit_comp.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/arch/x86/net/bpf_jit_comp.c b/arch/x86/net/bpf_jit_comp.c index b725154182cc..263c8453815e 100644 --- a/arch/x86/net/bpf_jit_comp.c +++ b/arch/x86/net/bpf_jit_comp.c @@ -1027,7 +1027,17 @@ emit_cond_jmp: /* convert BPF opcode to x86 */ break; case BPF_JMP | BPF_JA: - jmp_offset = addrs[i + insn->off] - addrs[i]; + if (insn->off == -1) + /* -1 jmp instructions will always jump + * backwards two bytes. Explicitly handling + * this case avoids wasting too many passes + * when there are long sequences of replaced + * dead code. + */ + jmp_offset = -2; + else + jmp_offset = addrs[i + insn->off] - addrs[i]; + if (!jmp_offset) /* optimize out nop jumps */ break; @@ -1226,6 +1236,7 @@ skip_init_addrs: for (pass = 0; pass < 20 || image; pass++) { proglen = do_jit(prog, addrs, image, oldproglen, &ctx); if (proglen <= 0) { +out_image: image = NULL; if (header) bpf_jit_binary_free(header); @@ -1236,8 +1247,7 @@ skip_init_addrs: if (proglen != oldproglen) { pr_err("bpf_jit: proglen=%d != oldproglen=%d\n", proglen, oldproglen); - prog = orig_prog; - goto out_addrs; + goto out_image; } break; } @@ -1273,7 +1283,7 @@ skip_init_addrs: prog = orig_prog; } - if (!prog->is_func || extra_pass) { + if (!image || !prog->is_func || extra_pass) { out_addrs: kfree(addrs); kfree(jit_data); |