fgraph: Pass ftrace_regs to retfunc

mhiramat · rostedt · commit 2ca8c112c967 · 2024-12-26T10:50:03.000-05:00
Pass ftrace_regs to the fgraph_ops::retfunc(). If ftrace_regs is not available, it passes a NULL instead. User callback function can access some registers (including return address) via this ftrace_regs. Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com> Cc: Florent Revest <revest@chromium.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: bpf <bpf@vger.kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Alan Maguire <alan.maguire@oracle.com> Cc: Mark Rutland <mark.rutland@arm.com> Link: https://lore.kernel.org/173518992972.391279.14055405490327765506.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
@@ -1075,7 +1075,8 @@ struct fgraph_ops;
 
 /* Type of the callback handlers for tracing function graph*/
 typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *,
-				       struct fgraph_ops *); /* return */
+				       struct fgraph_ops *,
+				       struct ftrace_regs *); /* return */
 typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *,
 				      struct fgraph_ops *,
 				      struct ftrace_regs *); /* entry */
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
@@ -299,7 +299,8 @@ static int entry_run(struct ftrace_graph_ent *trace, struct fgraph_ops *ops,
 }
 
 /* ftrace_graph_return set to this to tell some archs to run function graph */
-static void return_run(struct ftrace_graph_ret *trace, struct fgraph_ops *ops)
+static void return_run(struct ftrace_graph_ret *trace, struct fgraph_ops *ops,
+		       struct ftrace_regs *fregs)
 {
 }
 
@@ -528,7 +529,8 @@ int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace,
 }
 
 static void ftrace_graph_ret_stub(struct ftrace_graph_ret *trace,
-				  struct fgraph_ops *gops)
+				  struct fgraph_ops *gops,
+				  struct ftrace_regs *fregs)
 {
 }
 
@@ -825,6 +827,9 @@ __ftrace_return_to_handler(struct ftrace_regs *fregs, unsigned long frame_pointe
 	}
 
 	trace.rettime = trace_clock_local();
+	if (fregs)
+		ftrace_regs_set_instruction_pointer(fregs, ret);
+
 #ifdef CONFIG_FUNCTION_GRAPH_RETVAL
 	trace.retval = ftrace_regs_get_return_value(fregs);
 #endif
@@ -834,7 +839,7 @@ __ftrace_return_to_handler(struct ftrace_regs *fregs, unsigned long frame_pointe
 #ifdef CONFIG_HAVE_STATIC_CALL
 	if (static_branch_likely(&fgraph_do_direct)) {
 		if (test_bit(fgraph_direct_gops->idx, &bitmap))
-			static_call(fgraph_retfunc)(&trace, fgraph_direct_gops);
+			static_call(fgraph_retfunc)(&trace, fgraph_direct_gops, fregs);
 	} else
 #endif
 	{
@@ -844,7 +849,7 @@ __ftrace_return_to_handler(struct ftrace_regs *fregs, unsigned long frame_pointe
 			if (gops == &fgraph_stub)
 				continue;
 
-			gops->retfunc(&trace, gops);
+			gops->retfunc(&trace, gops, fregs);
 		}
 	}
 
@@ -1016,7 +1021,8 @@ void ftrace_graph_sleep_time_control(bool enable)
  * Simply points to ftrace_stub, but with the proper protocol.
  * Defined by the linker script in linux/vmlinux.lds.h
  */
-void ftrace_stub_graph(struct ftrace_graph_ret *trace, struct fgraph_ops *gops);
+void ftrace_stub_graph(struct ftrace_graph_ret *trace, struct fgraph_ops *gops,
+		       struct ftrace_regs *fregs);
 
 /* The callbacks that hook a function */
 trace_func_graph_ret_t ftrace_graph_return = ftrace_stub_graph;
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
@@ -842,7 +842,8 @@ static int profile_graph_entry(struct ftrace_graph_ent *trace,
 }
 
 static void profile_graph_return(struct ftrace_graph_ret *trace,
-				 struct fgraph_ops *gops)
+				 struct fgraph_ops *gops,
+				 struct ftrace_regs *fregs)
 {
 	struct profile_fgraph_data *profile_data;
 	struct ftrace_profile_stat *stat;
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
@@ -693,7 +693,8 @@ void trace_latency_header(struct seq_file *m);
 void trace_default_header(struct seq_file *m);
 void print_trace_header(struct seq_file *m, struct trace_iterator *iter);
 
-void trace_graph_return(struct ftrace_graph_ret *trace, struct fgraph_ops *gops);
+void trace_graph_return(struct ftrace_graph_ret *trace, struct fgraph_ops *gops,
+			struct ftrace_regs *fregs);
 int trace_graph_entry(struct ftrace_graph_ent *trace, struct fgraph_ops *gops,
 		      struct ftrace_regs *fregs);
 
diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c
@@ -310,7 +310,7 @@ static void handle_nosleeptime(struct ftrace_graph_ret *trace,
 }
 
 void trace_graph_return(struct ftrace_graph_ret *trace,
-			struct fgraph_ops *gops)
+			struct fgraph_ops *gops, struct ftrace_regs *fregs)
 {
 	unsigned long *task_var = fgraph_get_task_var(gops);
 	struct trace_array *tr = gops->private;
@@ -348,7 +348,8 @@ void trace_graph_return(struct ftrace_graph_ret *trace,
 }
 
 static void trace_graph_thresh_return(struct ftrace_graph_ret *trace,
-				      struct fgraph_ops *gops)
+				      struct fgraph_ops *gops,
+				      struct ftrace_regs *fregs)
 {
 	struct fgraph_times *ftimes;
 	int size;
@@ -372,7 +373,7 @@ static void trace_graph_thresh_return(struct ftrace_graph_ret *trace,
 	    (trace->rettime - ftimes->calltime < tracing_thresh))
 		return;
 	else
-		trace_graph_return(trace, gops);
+		trace_graph_return(trace, gops, fregs);
 }
 
 static struct fgraph_ops funcgraph_ops = {
diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c
@@ -208,7 +208,8 @@ static int irqsoff_graph_entry(struct ftrace_graph_ent *trace,
 }
 
 static void irqsoff_graph_return(struct ftrace_graph_ret *trace,
-				 struct fgraph_ops *gops)
+				 struct fgraph_ops *gops,
+				 struct ftrace_regs *fregs)
 {
 	struct trace_array *tr = irqsoff_trace;
 	struct trace_array_cpu *data;
diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c
@@ -144,7 +144,8 @@ static int wakeup_graph_entry(struct ftrace_graph_ent *trace,
 }
 
 static void wakeup_graph_return(struct ftrace_graph_ret *trace,
-				struct fgraph_ops *gops)
+				struct fgraph_ops *gops,
+				struct ftrace_regs *fregs)
 {
 	struct trace_array *tr = wakeup_trace;
 	struct trace_array_cpu *data;
diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
@@ -808,7 +808,8 @@ static __init int store_entry(struct ftrace_graph_ent *trace,
 }
 
 static __init void store_return(struct ftrace_graph_ret *trace,
-				struct fgraph_ops *gops)
+				struct fgraph_ops *gops,
+				struct ftrace_regs *fregs)
 {
 	struct fgraph_fixture *fixture = container_of(gops, struct fgraph_fixture, gops);
 	const char *type = fixture->store_type_name;

Original file line number	Diff line number	Diff line change
`@@ -299,7 +299,8 @@ static int entry_run(struct ftrace_graph_ent trace, struct fgraph_ops ops,`
`299`	`299`	`}`
`300`	`300`
`301`	`301`	`/* ftrace_graph_return set to this to tell some archs to run function graph */`
`302`		`-static void return_run(struct ftrace_graph_ret trace, struct fgraph_ops ops)`
	`302`	`+static void return_run(struct ftrace_graph_ret trace, struct fgraph_ops ops,`
	`303`	`+ struct ftrace_regs *fregs)`
`303`	`304`	`{`
`304`	`305`	`}`
`305`	`306`
`@@ -528,7 +529,8 @@ int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace,`
`528`	`529`	`}`
`529`	`530`
`530`	`531`	`static void ftrace_graph_ret_stub(struct ftrace_graph_ret *trace,`
`531`		`- struct fgraph_ops *gops)`
	`532`	`+ struct fgraph_ops *gops,`
	`533`	`+ struct ftrace_regs *fregs)`
`532`	`534`	`{`
`533`	`535`	`}`
`534`	`536`
`@@ -825,6 +827,9 @@ __ftrace_return_to_handler(struct ftrace_regs *fregs, unsigned long frame_pointe`
`825`	`827`	`}`
`826`	`828`
`827`	`829`	`trace.rettime = trace_clock_local();`
	`830`	`+ if (fregs)`
	`831`	`+ ftrace_regs_set_instruction_pointer(fregs, ret);`
	`832`	`+`
`828`	`833`	`#ifdef CONFIG_FUNCTION_GRAPH_RETVAL`
`829`	`834`	`trace.retval = ftrace_regs_get_return_value(fregs);`
`830`	`835`	`#endif`
`@@ -834,7 +839,7 @@ __ftrace_return_to_handler(struct ftrace_regs *fregs, unsigned long frame_pointe`
`834`	`839`	`#ifdef CONFIG_HAVE_STATIC_CALL`
`835`	`840`	`if (static_branch_likely(&fgraph_do_direct)) {`
`836`	`841`	`if (test_bit(fgraph_direct_gops->idx, &bitmap))`
`837`		`- static_call(fgraph_retfunc)(&trace, fgraph_direct_gops);`
	`842`	`+ static_call(fgraph_retfunc)(&trace, fgraph_direct_gops, fregs);`
`838`	`843`	`} else`
`839`	`844`	`#endif`
`840`	`845`	`{`
`@@ -844,7 +849,7 @@ __ftrace_return_to_handler(struct ftrace_regs *fregs, unsigned long frame_pointe`
`844`	`849`	`if (gops == &fgraph_stub)`
`845`	`850`	`continue;`
`846`	`851`
`847`		`- gops->retfunc(&trace, gops);`
	`852`	`+ gops->retfunc(&trace, gops, fregs);`
`848`	`853`	`}`
`849`	`854`	`}`
`850`	`855`
`@@ -1016,7 +1021,8 @@ void ftrace_graph_sleep_time_control(bool enable)`
`1016`	`1021`	`* Simply points to ftrace_stub, but with the proper protocol.`
`1017`	`1022`	`* Defined by the linker script in linux/vmlinux.lds.h`
`1018`	`1023`	`*/`
`1019`		`-void ftrace_stub_graph(struct ftrace_graph_ret trace, struct fgraph_ops gops);`
	`1024`	`+void ftrace_stub_graph(struct ftrace_graph_ret trace, struct fgraph_ops gops,`
	`1025`	`+ struct ftrace_regs *fregs);`
`1020`	`1026`
`1021`	`1027`	`/* The callbacks that hook a function */`
`1022`	`1028`	`trace_func_graph_ret_t ftrace_graph_return = ftrace_stub_graph;`
Original file line number	Diff line number	Diff line change
`@@ -842,7 +842,8 @@ static int profile_graph_entry(struct ftrace_graph_ent *trace,`
`842`	`842`	`}`
`843`	`843`
`844`	`844`	`static void profile_graph_return(struct ftrace_graph_ret *trace,`
`845`		`- struct fgraph_ops *gops)`
	`845`	`+ struct fgraph_ops *gops,`
	`846`	`+ struct ftrace_regs *fregs)`
`846`	`847`	`{`
`847`	`848`	`struct profile_fgraph_data *profile_data;`
`848`	`849`	`struct ftrace_profile_stat *stat;`
Original file line number	Diff line number	Diff line change
`@@ -310,7 +310,7 @@ static void handle_nosleeptime(struct ftrace_graph_ret *trace,`
`310`	`310`	`}`
`311`	`311`
`312`	`312`	`void trace_graph_return(struct ftrace_graph_ret *trace,`
`313`		`- struct fgraph_ops *gops)`
	`313`	`+ struct fgraph_ops gops, struct ftrace_regs fregs)`
`314`	`314`	`{`
`315`	`315`	`unsigned long *task_var = fgraph_get_task_var(gops);`
`316`	`316`	`struct trace_array *tr = gops->private;`
`@@ -348,7 +348,8 @@ void trace_graph_return(struct ftrace_graph_ret *trace,`
`348`	`348`	`}`
`349`	`349`
`350`	`350`	`static void trace_graph_thresh_return(struct ftrace_graph_ret *trace,`
`351`		`- struct fgraph_ops *gops)`
	`351`	`+ struct fgraph_ops *gops,`
	`352`	`+ struct ftrace_regs *fregs)`
`352`	`353`	`{`
`353`	`354`	`struct fgraph_times *ftimes;`
`354`	`355`	`int size;`
`@@ -372,7 +373,7 @@ static void trace_graph_thresh_return(struct ftrace_graph_ret *trace,`
`372`	`373`	`(trace->rettime - ftimes->calltime < tracing_thresh))`
`373`	`374`	`return;`
`374`	`375`	`else`
`375`		`- trace_graph_return(trace, gops);`
	`376`	`+ trace_graph_return(trace, gops, fregs);`
`376`	`377`	`}`
`377`	`378`
`378`	`379`	`static struct fgraph_ops funcgraph_ops = {`
Original file line number	Diff line number	Diff line change
`@@ -208,7 +208,8 @@ static int irqsoff_graph_entry(struct ftrace_graph_ent *trace,`
`208`	`208`	`}`
`209`	`209`
`210`	`210`	`static void irqsoff_graph_return(struct ftrace_graph_ret *trace,`
`211`		`- struct fgraph_ops *gops)`
	`211`	`+ struct fgraph_ops *gops,`
	`212`	`+ struct ftrace_regs *fregs)`
`212`	`213`	`{`
`213`	`214`	`struct trace_array *tr = irqsoff_trace;`
`214`	`215`	`struct trace_array_cpu *data;`
Original file line number	Diff line number	Diff line change
`@@ -144,7 +144,8 @@ static int wakeup_graph_entry(struct ftrace_graph_ent *trace,`
`144`	`144`	`}`
`145`	`145`
`146`	`146`	`static void wakeup_graph_return(struct ftrace_graph_ret *trace,`
`147`		`- struct fgraph_ops *gops)`
	`147`	`+ struct fgraph_ops *gops,`
	`148`	`+ struct ftrace_regs *fregs)`
`148`	`149`	`{`
`149`	`150`	`struct trace_array *tr = wakeup_trace;`
`150`	`151`	`struct trace_array_cpu *data;`
Original file line number	Diff line number	Diff line change
`@@ -808,7 +808,8 @@ static __init int store_entry(struct ftrace_graph_ent *trace,`
`808`	`808`	`}`
`809`	`809`
`810`	`810`	`static __init void store_return(struct ftrace_graph_ret *trace,`
`811`		`- struct fgraph_ops *gops)`
	`811`	`+ struct fgraph_ops *gops,`
	`812`	`+ struct ftrace_regs *fregs)`
`812`	`813`	`{`
`813`	`814`	`struct fgraph_fixture *fixture = container_of(gops, struct fgraph_fixture, gops);`
`814`	`815`	`const char *type = fixture->store_type_name;`