Commit 2ca8c112 authored by Masami Hiramatsu (Google)'s avatar Masami Hiramatsu (Google) Committed by Steven Rostedt (Google)
Browse files

fgraph: Pass ftrace_regs to retfunc 

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: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent a3ed4157

include/linux/ftrace.h

+2 −1
Original line number Diff line number Diff line
@@ -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 */

kernel/trace/fgraph.c

+11 −5
Original line number Diff line number Diff line
@@ -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;

kernel/trace/ftrace.c

+2 −1
Original line number Diff line number Diff line
@@ -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;

kernel/trace/trace.h

+2 −1
Original line number Diff line number Diff line
@@ -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);

kernel/trace/trace_functions_graph.c

+4 −3
Original line number Diff line number Diff line
@@ -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 = {