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From: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Florent Revest <revest@chromium.org>
Cc: linux-trace-kernel@vger.kernel.org,
	LKML <linux-kernel@vger.kernel.org>,
	Martin KaFai Lau <martin.lau@linux.dev>,
	bpf <bpf@vger.kernel.org>, Alexei Starovoitov <ast@kernel.org>,
	Jiri Olsa <jolsa@kernel.org>,
	Alan Maguire <alan.maguire@oracle.com>,
	Mark Rutland <mark.rutland@arm.com>,
	linux-arch@vger.kernel.org
Subject: [PATCH v22 05/20] fprobe: Use ftrace_regs in fprobe entry handler
Date: Thu, 26 Dec 2024 14:12:20 +0900	[thread overview]
Message-ID: <173518994037.391279.2786805566359674586.stgit@devnote2> (raw)
In-Reply-To: <173518987627.391279.3307342580035322889.stgit@devnote2>

From: Masami Hiramatsu (Google) <mhiramat@kernel.org>

This allows fprobes to be available with CONFIG_DYNAMIC_FTRACE_WITH_ARGS
instead of CONFIG_DYNAMIC_FTRACE_WITH_REGS, then we can enable fprobe
on arm64.

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Florent Revest <revest@chromium.org>
---
 Changes in v22:
  - Fix a build error: Pass ftrace_regs to trace_fprobe_entry_handler()
 Changes in v6:
  - Keep using SAVE_REGS flag to avoid breaking bpf kprobe-multi test.
---
 include/linux/fprobe.h          |    2 +-
 kernel/trace/Kconfig            |    3 ++-
 kernel/trace/bpf_trace.c        |   10 +++++++---
 kernel/trace/fprobe.c           |    3 ++-
 kernel/trace/trace_fprobe.c     |   11 ++++++++---
 lib/test_fprobe.c               |    4 ++--
 samples/fprobe/fprobe_example.c |    2 +-
 7 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/include/linux/fprobe.h b/include/linux/fprobe.h
index f39869588117..ca64ee5e45d2 100644
--- a/include/linux/fprobe.h
+++ b/include/linux/fprobe.h
@@ -10,7 +10,7 @@
 struct fprobe;
 
 typedef int (*fprobe_entry_cb)(struct fprobe *fp, unsigned long entry_ip,
-			       unsigned long ret_ip, struct pt_regs *regs,
+			       unsigned long ret_ip, struct ftrace_regs *regs,
 			       void *entry_data);
 
 typedef void (*fprobe_exit_cb)(struct fprobe *fp, unsigned long entry_ip,
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index c5ab2a561272..f10ca86fbfad 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -297,7 +297,7 @@ config DYNAMIC_FTRACE_WITH_ARGS
 config FPROBE
 	bool "Kernel Function Probe (fprobe)"
 	depends on FUNCTION_TRACER
-	depends on DYNAMIC_FTRACE_WITH_REGS
+	depends on DYNAMIC_FTRACE_WITH_REGS || DYNAMIC_FTRACE_WITH_ARGS
 	depends on HAVE_RETHOOK
 	select RETHOOK
 	default n
@@ -682,6 +682,7 @@ config FPROBE_EVENTS
 	select TRACING
 	select PROBE_EVENTS
 	select DYNAMIC_EVENTS
+	depends on DYNAMIC_FTRACE_WITH_REGS
 	default y
 	help
 	  This allows user to add tracing events on the function entry and
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 1b8db5aee9d3..7bb2e6ecd31f 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -2561,7 +2561,7 @@ struct bpf_session_run_ctx {
 	void *data;
 };
 
-#ifdef CONFIG_FPROBE
+#if defined(CONFIG_FPROBE) && defined(CONFIG_DYNAMIC_FTRACE_WITH_REGS)
 struct bpf_kprobe_multi_link {
 	struct bpf_link link;
 	struct fprobe fp;
@@ -2813,12 +2813,16 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link,
 
 static int
 kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
-			  unsigned long ret_ip, struct pt_regs *regs,
+			  unsigned long ret_ip, struct ftrace_regs *fregs,
 			  void *data)
 {
+	struct pt_regs *regs = ftrace_get_regs(fregs);
 	struct bpf_kprobe_multi_link *link;
 	int err;
 
+	if (!regs)
+		return 0;
+
 	link = container_of(fp, struct bpf_kprobe_multi_link, fp);
 	err = kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs, false, data);
 	return is_kprobe_session(link->link.prog) ? err : 0;
@@ -3093,7 +3097,7 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
 	kvfree(cookies);
 	return err;
 }
-#else /* !CONFIG_FPROBE */
+#else /* !CONFIG_FPROBE || !CONFIG_DYNAMIC_FTRACE_WITH_REGS */
 int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
 {
 	return -EOPNOTSUPP;
diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
index 9ff018245840..3d3789283873 100644
--- a/kernel/trace/fprobe.c
+++ b/kernel/trace/fprobe.c
@@ -46,7 +46,7 @@ static inline void __fprobe_handler(unsigned long ip, unsigned long parent_ip,
 	}
 
 	if (fp->entry_handler)
-		ret = fp->entry_handler(fp, ip, parent_ip, ftrace_get_regs(fregs), entry_data);
+		ret = fp->entry_handler(fp, ip, parent_ip, fregs, entry_data);
 
 	/* If entry_handler returns !0, nmissed is not counted. */
 	if (rh) {
@@ -182,6 +182,7 @@ static void fprobe_init(struct fprobe *fp)
 		fp->ops.func = fprobe_kprobe_handler;
 	else
 		fp->ops.func = fprobe_handler;
+
 	fp->ops.flags |= FTRACE_OPS_FL_SAVE_REGS;
 }
 
diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c
index c62d1629cffe..0f254685e26a 100644
--- a/kernel/trace/trace_fprobe.c
+++ b/kernel/trace/trace_fprobe.c
@@ -217,12 +217,13 @@ NOKPROBE_SYMBOL(fentry_trace_func);
 
 /* function exit handler */
 static int trace_fprobe_entry_handler(struct fprobe *fp, unsigned long entry_ip,
-				unsigned long ret_ip, struct pt_regs *regs,
+				unsigned long ret_ip, struct ftrace_regs *fregs,
 				void *entry_data)
 {
 	struct trace_fprobe *tf = container_of(fp, struct trace_fprobe, fp);
+	struct pt_regs *regs = ftrace_get_regs(fregs);
 
-	if (tf->tp.entry_arg)
+	if (regs && tf->tp.entry_arg)
 		store_trace_entry_data(entry_data, &tf->tp, regs);
 
 	return 0;
@@ -339,12 +340,16 @@ NOKPROBE_SYMBOL(fexit_perf_func);
 #endif	/* CONFIG_PERF_EVENTS */
 
 static int fentry_dispatcher(struct fprobe *fp, unsigned long entry_ip,
-			     unsigned long ret_ip, struct pt_regs *regs,
+			     unsigned long ret_ip, struct ftrace_regs *fregs,
 			     void *entry_data)
 {
 	struct trace_fprobe *tf = container_of(fp, struct trace_fprobe, fp);
+	struct pt_regs *regs = ftrace_get_regs(fregs);
 	int ret = 0;
 
+	if (!regs)
+		return 0;
+
 	if (trace_probe_test_flag(&tf->tp, TP_FLAG_TRACE))
 		fentry_trace_func(tf, entry_ip, regs);
 #ifdef CONFIG_PERF_EVENTS
diff --git a/lib/test_fprobe.c b/lib/test_fprobe.c
index 24de0e5ff859..ff607babba18 100644
--- a/lib/test_fprobe.c
+++ b/lib/test_fprobe.c
@@ -40,7 +40,7 @@ static noinline u32 fprobe_selftest_nest_target(u32 value, u32 (*nest)(u32))
 
 static notrace int fp_entry_handler(struct fprobe *fp, unsigned long ip,
 				    unsigned long ret_ip,
-				    struct pt_regs *regs, void *data)
+				    struct ftrace_regs *fregs, void *data)
 {
 	KUNIT_EXPECT_FALSE(current_test, preemptible());
 	/* This can be called on the fprobe_selftest_target and the fprobe_selftest_target2 */
@@ -81,7 +81,7 @@ static notrace void fp_exit_handler(struct fprobe *fp, unsigned long ip,
 
 static notrace int nest_entry_handler(struct fprobe *fp, unsigned long ip,
 				      unsigned long ret_ip,
-				      struct pt_regs *regs, void *data)
+				      struct ftrace_regs *fregs, void *data)
 {
 	KUNIT_EXPECT_FALSE(current_test, preemptible());
 	return 0;
diff --git a/samples/fprobe/fprobe_example.c b/samples/fprobe/fprobe_example.c
index 0a50b05add96..c234afae52d6 100644
--- a/samples/fprobe/fprobe_example.c
+++ b/samples/fprobe/fprobe_example.c
@@ -50,7 +50,7 @@ static void show_backtrace(void)
 
 static int sample_entry_handler(struct fprobe *fp, unsigned long ip,
 				unsigned long ret_ip,
-				struct pt_regs *regs, void *data)
+				struct ftrace_regs *fregs, void *data)
 {
 	if (use_trace)
 		/*


  parent reply	other threads:[~2024-12-26  5:12 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-12-26  5:11 [PATCH v22 00/20] tracing: fprobe: function_graph: Multi-function graph and fprobe on fgraph Masami Hiramatsu (Google)
2024-12-26  5:11 ` [PATCH v22 01/20] fgraph: Get ftrace recursion lock in function_graph_enter Masami Hiramatsu (Google)
2024-12-26  5:11 ` [PATCH v22 02/20] fgraph: Pass ftrace_regs to entryfunc Masami Hiramatsu (Google)
2024-12-26  5:11 ` [PATCH v22 03/20] fgraph: Replace fgraph_ret_regs with ftrace_regs Masami Hiramatsu (Google)
2024-12-26  5:12 ` [PATCH v22 04/20] fgraph: Pass ftrace_regs to retfunc Masami Hiramatsu (Google)
2024-12-26  5:12 ` Masami Hiramatsu (Google) [this message]
2024-12-26  5:12 ` [PATCH v22 06/20] fprobe: Use ftrace_regs in fprobe exit handler Masami Hiramatsu (Google)
2024-12-26  5:12 ` [PATCH v22 07/20] tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs Masami Hiramatsu (Google)
2024-12-26  5:12 ` [PATCH v22 08/20] tracing: Add ftrace_fill_perf_regs() for perf event Masami Hiramatsu (Google)
2024-12-26  5:13 ` [PATCH v22 09/20] tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS Masami Hiramatsu (Google)
2024-12-26  5:13 ` [PATCH v22 10/20] bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled Masami Hiramatsu (Google)
2024-12-26  5:13 ` [PATCH v22 11/20] ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC Masami Hiramatsu (Google)
2024-12-26  5:13 ` [PATCH v22 12/20] s390/tracing: Enable HAVE_FTRACE_GRAPH_FUNC Masami Hiramatsu (Google)
2024-12-26  5:13 ` [PATCH v22 13/20] fprobe: Rewrite fprobe on function-graph tracer Masami Hiramatsu (Google)
2024-12-26  5:14 ` [PATCH v22 14/20] fprobe: Add fprobe_header encoding feature Masami Hiramatsu (Google)
2024-12-26  5:14 ` [PATCH v22 15/20] tracing/fprobe: Remove nr_maxactive from fprobe Masami Hiramatsu (Google)
2024-12-26  5:14 ` [PATCH v22 16/20] selftests: ftrace: Remove obsolate maxactive syntax check Masami Hiramatsu (Google)
2024-12-26  5:14 ` [PATCH v22 17/20] selftests/ftrace: Add a test case for repeating register/unregister fprobe Masami Hiramatsu (Google)
2024-12-26  5:15 ` [PATCH v22 18/20] Documentation: probes: Update fprobe on function-graph tracer Masami Hiramatsu (Google)
2024-12-26  5:15 ` [PATCH v22 19/20] ftrace: Add ftrace_get_symaddr to convert fentry_ip to symaddr Masami Hiramatsu (Google)
2025-02-03 21:33   ` Gabriel de Perthuis
2025-02-04  9:19     ` Masami Hiramatsu
2025-02-04 14:19       ` Gabriel de Perthuis
2025-02-06  1:59         ` Masami Hiramatsu
2024-12-26  5:15 ` [PATCH v22 20/20] bpf: Use ftrace_get_symaddr() for kprobe_multi probes Masami Hiramatsu (Google)
2024-12-27  2:23   ` Steven Rostedt
2024-12-27  2:24     ` Steven Rostedt
2024-12-27 15:24       ` Steven Rostedt
2024-12-31 15:48         ` Masami Hiramatsu
2024-12-31 16:00         ` [PATCH v23] " Masami Hiramatsu (Google)
2025-01-02 13:20 ` [PATCH v22 00/20] tracing: fprobe: function_graph: Multi-function graph and fprobe on fgraph Jiri Olsa
2025-01-11  0:04   ` Andrii Nakryiko
2025-01-14 15:12     ` Jiri Olsa
2025-01-14 19:04       ` Andrii Nakryiko
2025-01-12  4:45   ` Masami Hiramatsu
2025-01-12  5:26   ` [PATCH] fgraph: Move trace_clock_local() for return time to function_graph tracer Masami Hiramatsu (Google)
2025-01-14  0:54     ` Steven Rostedt
2025-01-14  1:18       ` Masami Hiramatsu
2025-01-14 15:05         ` Steven Rostedt

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