Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3ebb6fb0 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-v4.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Pull tracing fixes from Steven Rostedt:
 "Various fixes to the tracing infrastructure:

   - Fix double free when the reg() call fails in
     event_trigger_callback()

   - Fix anomoly of snapshot causing tracing_on flag to change

   - Add selftest to test snapshot and tracing_on affecting each other

   - Fix setting of tracepoint flag on error that prevents probes from
     being deleted.

   - Fix another possible double free that is similar to
     event_trigger_callback()

   - Quiet a gcc warning of a false positive unused variable

   - Fix crash of partial exposed task->comm to trace events"

* tag 'trace-v4.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  kthread, tracing: Don't expose half-written comm when creating kthreads
  tracing: Quiet gcc warning about maybe unused link variable
  tracing: Fix possible double free in event_enable_trigger_func()
  tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure
  selftests/ftrace: Add snapshot and tracing_on test case
  ring_buffer: tracing: Inherit the tracing setting to next ring buffer
  tracing: Fix double free of event_trigger_data
parents f636d300 3e536e22

include/linux/ring_buffer.h

+1 −0
Original line number Diff line number Diff line
@@ -165,6 +165,7 @@ void ring_buffer_record_enable(struct ring_buffer *buffer); 
void ring_buffer_record_off(struct ring_buffer *buffer);

void ring_buffer_record_on(struct ring_buffer *buffer);

int ring_buffer_record_is_on(struct ring_buffer *buffer);

int ring_buffer_record_is_set_on(struct ring_buffer *buffer);

void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu);

void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu);

kernel/kthread.c

+7 −1
Original line number Diff line number Diff line
@@ -325,8 +325,14 @@ struct task_struct *__kthread_create_on_node(int (*threadfn)(void *data), 
	task = create->result;

	if (!IS_ERR(task)) {

		static const struct sched_param param = { .sched_priority = 0 };

		char name[TASK_COMM_LEN];



		vsnprintf(task->comm, sizeof(task->comm), namefmt, args);

		/*

		 * task is already visible to other tasks, so updating

		 * COMM must be protected.

		 */

		vsnprintf(name, sizeof(name), namefmt, args);

		set_task_comm(task, name);

		/*

		 * root may have changed our (kthreadd's) priority or CPU mask.

		 * The kernel thread should not inherit these properties.

kernel/trace/ring_buffer.c

+16 −0
Original line number Diff line number Diff line
@@ -3226,6 +3226,22 @@ int ring_buffer_record_is_on(struct ring_buffer *buffer) 
	return !atomic_read(&buffer->record_disabled);

}



/**

 * ring_buffer_record_is_set_on - return true if the ring buffer is set writable

 * @buffer: The ring buffer to see if write is set enabled

 *

 * Returns true if the ring buffer is set writable by ring_buffer_record_on().

 * Note that this does NOT mean it is in a writable state.

 *

 * It may return true when the ring buffer has been disabled by

 * ring_buffer_record_disable(), as that is a temporary disabling of

 * the ring buffer.

 */

int ring_buffer_record_is_set_on(struct ring_buffer *buffer)

{

	return !(atomic_read(&buffer->record_disabled) & RB_BUFFER_OFF);

}



/**

 * ring_buffer_record_disable_cpu - stop all writes into the cpu_buffer

 * @buffer: The ring buffer to stop writes to.

kernel/trace/trace.c

+6 −0
Original line number Diff line number Diff line
@@ -1373,6 +1373,12 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) 


	arch_spin_lock(&tr->max_lock);



	/* Inherit the recordable setting from trace_buffer */

	if (ring_buffer_record_is_set_on(tr->trace_buffer.buffer))

		ring_buffer_record_on(tr->max_buffer.buffer);

	else

		ring_buffer_record_off(tr->max_buffer.buffer);



	swap(tr->trace_buffer.buffer, tr->max_buffer.buffer);



	__update_max_tr(tr, tsk, cpu);

kernel/trace/trace_events_trigger.c

+13 −5
Original line number Diff line number Diff line
@@ -679,6 +679,8 @@ event_trigger_callback(struct event_command *cmd_ops, 
		goto out_free;



 out_reg:

	/* Up the trigger_data count to make sure reg doesn't free it on failure */

	event_trigger_init(trigger_ops, trigger_data);

	ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file);

	/*

	 * The above returns on success the # of functions enabled,
@@ -686,11 +688,13 @@ event_trigger_callback(struct event_command *cmd_ops, 
	 * Consider no functions a failure too.

	 */

	if (!ret) {

		cmd_ops->unreg(glob, trigger_ops, trigger_data, file);

		ret = -ENOENT;

		goto out_free;

	} else if (ret < 0)

		goto out_free;

	} else if (ret > 0)

		ret = 0;



	/* Down the counter of trigger_data or free it if not used anymore */

	event_trigger_free(trigger_ops, trigger_data);

 out:

	return ret;
@@ -1416,6 +1420,9 @@ int event_enable_trigger_func(struct event_command *cmd_ops, 
		goto out;

	}



	/* Up the trigger_data count to make sure nothing frees it on failure */

	event_trigger_init(trigger_ops, trigger_data);



	if (trigger) {

		number = strsep(&trigger, ":");
@@ -1466,6 +1473,7 @@ int event_enable_trigger_func(struct event_command *cmd_ops, 
		goto out_disable;

	/* Just return zero, not the number of enabled functions */

	ret = 0;

	event_trigger_free(trigger_ops, trigger_data);

 out:

	return ret;
@@ -1476,7 +1484,7 @@ int event_enable_trigger_func(struct event_command *cmd_ops, 
 out_free:

	if (cmd_ops->set_filter)

		cmd_ops->set_filter(NULL, trigger_data, NULL);

	kfree(trigger_data);

	event_trigger_free(trigger_ops, trigger_data);

	kfree(enable_data);

	goto out;

}