From: Jiri Olsa <jolsa@redhat.com>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>
Cc: netdev@vger.kernel.org, bpf@vger.kernel.org,
lkml <linux-kernel@vger.kernel.org>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@chromium.org>,
Steven Rostedt <rostedt@goodmis.org>,
Jiri Olsa <olsajiri@gmail.com>
Subject: [PATCH 2/8] bpf: Add bpf_get_func_ip kprobe helper for fprobe link
Date: Wed, 2 Feb 2022 14:53:27 +0100 [thread overview]
Message-ID: <20220202135333.190761-3-jolsa@kernel.org> (raw)
In-Reply-To: <20220202135333.190761-1-jolsa@kernel.org>
Adding support to call get_func_ip_fprobe helper from kprobe
programs attached by fprobe link.
Also adding support to inline it, because it's single load
instruction.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
kernel/bpf/verifier.c | 19 ++++++++++++++++++-
kernel/trace/bpf_trace.c | 16 +++++++++++++++-
2 files changed, 33 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 1ae41d0cf96c..a745ded00635 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -13625,7 +13625,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
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 */
@@ -13640,6 +13640,23 @@ static int do_misc_fixups(struct bpf_verifier_env *env)
continue;
}
+ /* Implement kprobe/fprobe bpf_get_func_ip inline. */
+ if (prog_type == BPF_PROG_TYPE_KPROBE &&
+ eatype == BPF_TRACE_FPROBE &&
+ 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;
+ }
+
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 a2024ba32a20..28e59e31e3db 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1036,6 +1036,19 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = {
.arg1_type = ARG_PTR_TO_CTX,
};
+BPF_CALL_1(bpf_get_func_ip_fprobe, struct pt_regs *, regs)
+{
+ /* This helper call is inlined by verifier. */
+ return regs->ip;
+}
+
+static const struct bpf_func_proto bpf_get_func_ip_proto_fprobe = {
+ .func = bpf_get_func_ip_fprobe,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+};
+
BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
{
struct bpf_trace_run_ctx *run_ctx;
@@ -1279,7 +1292,8 @@ kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_override_return_proto;
#endif
case BPF_FUNC_get_func_ip:
- return &bpf_get_func_ip_proto_kprobe;
+ return prog->expected_attach_type == BPF_TRACE_FPROBE ?
+ &bpf_get_func_ip_proto_fprobe : &bpf_get_func_ip_proto_kprobe;
case BPF_FUNC_get_attach_cookie:
return &bpf_get_attach_cookie_proto_trace;
default:
--
2.34.1
next prev parent reply other threads:[~2022-02-02 13:53 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-02 13:53 [PATCH 0/8] bpf: Add fprobe link Jiri Olsa
2022-02-02 13:53 ` [PATCH 1/8] bpf: Add support to attach kprobe program with fprobe Jiri Olsa
2022-02-07 18:59 ` Andrii Nakryiko
2022-02-08 8:56 ` Jiri Olsa
2022-02-02 13:53 ` Jiri Olsa [this message]
2022-02-07 18:59 ` [PATCH 2/8] bpf: Add bpf_get_func_ip kprobe helper for fprobe link Andrii Nakryiko
2022-02-07 21:01 ` Alexei Starovoitov
2022-02-09 15:01 ` Jiri Olsa
2022-02-09 16:05 ` Andrii Nakryiko
2022-02-09 19:14 ` Jiri Olsa
2022-02-02 13:53 ` [PATCH 3/8] bpf: Add bpf_cookie support to fprobe Jiri Olsa
2022-02-07 18:59 ` Andrii Nakryiko
2022-02-08 9:07 ` Jiri Olsa
2022-02-08 23:35 ` Andrii Nakryiko
2022-02-08 23:46 ` Jiri Olsa
2022-02-08 23:53 ` Andrii Nakryiko
2022-02-02 13:53 ` [PATCH 4/8] libbpf: Add libbpf__kallsyms_parse function Jiri Olsa
2022-02-07 18:59 ` Andrii Nakryiko
2022-02-08 9:08 ` Jiri Olsa
2022-02-02 13:53 ` [PATCH 5/8] libbpf: Add bpf_link_create support for multi kprobes Jiri Olsa
2022-02-02 13:53 ` [PATCH 6/8] libbpf: Add bpf_program__attach_kprobe_opts " Jiri Olsa
2022-02-07 18:59 ` Andrii Nakryiko
2022-02-08 9:12 ` Jiri Olsa
2022-02-02 13:53 ` [PATCH 7/8] selftest/bpf: Add fprobe attach test Jiri Olsa
2022-02-02 13:53 ` [PATCH 8/8] selftest/bpf: Add fprobe test for bpf_cookie values Jiri Olsa
2022-02-07 18:59 ` Andrii Nakryiko
2022-02-08 9:15 ` Jiri Olsa
2022-02-08 23:24 ` Andrii Nakryiko
2022-02-02 17:09 ` [PATCH 0/8] bpf: Add fprobe link Alexei Starovoitov
2022-02-02 17:24 ` Jiri Olsa
2022-02-02 17:30 ` Alexei Starovoitov
2022-02-03 15:06 ` Jiri Olsa
2022-02-04 0:46 ` Masami Hiramatsu
2022-02-04 1:34 ` Alexei Starovoitov
2022-02-04 2:07 ` Masami Hiramatsu
2022-02-04 2:12 ` Alexei Starovoitov
2022-02-04 2:19 ` Steven Rostedt
2022-02-04 2:42 ` Alexei Starovoitov
2022-02-04 3:17 ` Masami Hiramatsu
2022-02-04 3:59 ` Masami Hiramatsu
2022-02-15 13:21 ` Jiri Olsa
2022-02-16 18:27 ` Andrii Nakryiko
2022-02-17 14:03 ` Masami Hiramatsu
2022-02-17 22:01 ` Andrii Nakryiko
2022-02-18 4:07 ` Masami Hiramatsu
2022-02-18 19:46 ` Andrii Nakryiko
2022-02-19 2:10 ` Alexei Starovoitov
2022-02-21 7:18 ` Masami Hiramatsu
2022-02-22 12:42 ` Jiri Olsa
2022-02-04 3:14 ` Masami Hiramatsu
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