diff options
| author | Jiri Olsa <jolsa@kernel.org> | 2022-03-16 13:24:11 +0100 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2022-03-17 20:17:19 -0700 |
| commit | 97ee4d20ee67eb462581a7af01442de6586e390b (patch) | |
| tree | 8c0568ba29f1abcd9427bc29c7bcbf50786d4014 /kernel | |
| parent | 42a5712094e89ef0a125ac0f9d0873f9233368b1 (diff) | |
| download | linux-97ee4d20ee67eb462581a7af01442de6586e390b.tar.bz2 | |
bpf: Add support to inline bpf_get_func_ip helper on x86
Adding support to inline it on x86, because it's single
load instruction.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220316122419.933957-6-jolsa@kernel.org
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/verifier.c | 21 | ||||
| -rw-r--r-- | kernel/trace/bpf_trace.c | 1 |
2 files changed, 21 insertions, 1 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index cf92f9c01556..0287176bfe9a 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -13678,7 +13678,7 @@ patch_map_ops_generic: continue; } - /* Implement bpf_get_func_ip inline. */ + /* Implement tracing bpf_get_func_ip inline. */ if (prog_type == BPF_PROG_TYPE_TRACING && insn->imm == BPF_FUNC_get_func_ip) { /* Load IP address from ctx - 16 */ @@ -13693,6 +13693,25 @@ patch_map_ops_generic: continue; } +#ifdef CONFIG_X86 + /* Implement kprobe_multi bpf_get_func_ip inline. */ + if (prog_type == BPF_PROG_TYPE_KPROBE && + eatype == BPF_TRACE_KPROBE_MULTI && + insn->imm == BPF_FUNC_get_func_ip) { + /* Load IP address from ctx (struct pt_regs) ip */ + insn_buf[0] = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_1, + offsetof(struct pt_regs, ip)); + + new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, 1); + if (!new_prog) + return -ENOMEM; + + env->prog = prog = new_prog; + insn = new_prog->insnsi + i + delta; + continue; + } +#endif + patch_call_imm: fn = env->ops->get_func_proto(insn->imm, env->prog); /* all functions that have prototype and verifier allowed diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 250750932228..0e7f8c9bc756 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1039,6 +1039,7 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) { + /* This helper call is inlined by verifier on x86. */ return instruction_pointer(regs); } |