Commit cb1c45fb authored by Jeff Xie's avatar Jeff Xie Committed by Steven Rostedt (Google)
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tracing: Make tp_printk work on syscall tracepoints 

Currently the tp_printk option has no effect on syscall tracepoint.
When adding the kernel option parameter tp_printk, then:

echo 1 > /sys/kernel/debug/tracing/events/syscalls/enable

When running any application, no trace information is printed on the
terminal.

Now added printk for syscall tracepoints.

Link: https://lkml.kernel.org/r/20220410145025.681144-1-xiehuan09@gmail.com



Signed-off-by: default avatarJeff Xie <xiehuan09@gmail.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 2f51efc6

kernel/trace/trace_syscalls.c

+11 −24
Original line number Diff line number Diff line
@@ -154,7 +154,7 @@ print_syscall_enter(struct trace_iterator *iter, int flags, 
			goto end;



		/* parameter types */

		if (tr->trace_flags & TRACE_ITER_VERBOSE)

		if (tr && tr->trace_flags & TRACE_ITER_VERBOSE)

			trace_seq_printf(s, "%s ", entry->types[i]);



		/* parameter values */
@@ -296,9 +296,7 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id) 
	struct trace_event_file *trace_file;

	struct syscall_trace_enter *entry;

	struct syscall_metadata *sys_data;

	struct ring_buffer_event *event;

	struct trace_buffer *buffer;

	unsigned int trace_ctx;

	struct trace_event_buffer fbuffer;

	unsigned long args[6];

	int syscall_nr;

	int size;
@@ -321,20 +319,16 @@ static void ftrace_syscall_enter(void *data, struct pt_regs *regs, long id) 


	size = sizeof(*entry) + sizeof(unsigned long) * sys_data->nb_args;



	trace_ctx = tracing_gen_ctx();



	event = trace_event_buffer_lock_reserve(&buffer, trace_file,

			sys_data->enter_event->event.type, size, trace_ctx);

	if (!event)

	entry = trace_event_buffer_reserve(&fbuffer, trace_file, size);

	if (!entry)

		return;



	entry = ring_buffer_event_data(event);

	entry = ring_buffer_event_data(fbuffer.event);

	entry->nr = syscall_nr;

	syscall_get_arguments(current, regs, args);

	memcpy(entry->args, args, sizeof(unsigned long) * sys_data->nb_args);



	event_trigger_unlock_commit(trace_file, buffer, event, entry,

				    trace_ctx);

	trace_event_buffer_commit(&fbuffer);

}



static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret)
@@ -343,9 +337,7 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret) 
	struct trace_event_file *trace_file;

	struct syscall_trace_exit *entry;

	struct syscall_metadata *sys_data;

	struct ring_buffer_event *event;

	struct trace_buffer *buffer;

	unsigned int trace_ctx;

	struct trace_event_buffer fbuffer;

	int syscall_nr;



	syscall_nr = trace_get_syscall_nr(current, regs);
@@ -364,20 +356,15 @@ static void ftrace_syscall_exit(void *data, struct pt_regs *regs, long ret) 
	if (!sys_data)

		return;



	trace_ctx = tracing_gen_ctx();



	event = trace_event_buffer_lock_reserve(&buffer, trace_file,

			sys_data->exit_event->event.type, sizeof(*entry),

			trace_ctx);

	if (!event)

	entry = trace_event_buffer_reserve(&fbuffer, trace_file, sizeof(*entry));

	if (!entry)

		return;



	entry = ring_buffer_event_data(event);

	entry = ring_buffer_event_data(fbuffer.event);

	entry->nr = syscall_nr;

	entry->ret = syscall_get_return_value(current, regs);



	event_trigger_unlock_commit(trace_file, buffer, event, entry,

				    trace_ctx);

	trace_event_buffer_commit(&fbuffer);

}



static int reg_event_syscall_enter(struct trace_event_file *file,