Commit 8841c8b3 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-3.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Pull tracing cleanups and bugfixes from Steven Rostedt:
 "One bug fix that goes back to 3.10.  Accessing a non existent buffer
  if "possible cpus" is greater than actual CPUs (including offline
  CPUs).

  Namhyung Kim did some reviews of the patches I sent this merge window
  and found a memory leak and had a few clean ups"

* tag 'trace-3.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix check of ftrace_trace_arrays list_empty() check
  tracing: Fix leak of per cpu max data in instances
  tracing: Cleanup saved_cmdlines_size changes
  ring-buffer: Check if buffer exists before polling
parents b7c8c194 da9c3413

include/linux/ring_buffer.h

+1 −1
Original line number Diff line number Diff line
@@ -97,7 +97,7 @@ __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *k 
	__ring_buffer_alloc((size), (flags), &__key);	\

})



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

int ring_buffer_wait(struct ring_buffer *buffer, int cpu);

int ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu,

			  struct file *filp, poll_table *poll_table);

kernel/trace/ring_buffer.c

+4 −1
Original line number Diff line number Diff line
@@ -543,7 +543,7 @@ static void rb_wake_up_waiters(struct irq_work *work) 
 * as data is added to any of the @buffer's cpu buffers. Otherwise

 * it will wait for data to be added to a specific cpu buffer.

 */

void ring_buffer_wait(struct ring_buffer *buffer, int cpu)

int ring_buffer_wait(struct ring_buffer *buffer, int cpu)

{

	struct ring_buffer_per_cpu *cpu_buffer;

	DEFINE_WAIT(wait);
@@ -557,6 +557,8 @@ void ring_buffer_wait(struct ring_buffer *buffer, int cpu) 
	if (cpu == RING_BUFFER_ALL_CPUS)

		work = &buffer->irq_work;

	else {

		if (!cpumask_test_cpu(cpu, buffer->cpumask))

			return -ENODEV;

		cpu_buffer = buffer->buffers[cpu];

		work = &cpu_buffer->irq_work;

	}
@@ -591,6 +593,7 @@ void ring_buffer_wait(struct ring_buffer *buffer, int cpu) 
		schedule();



	finish_wait(&work->waiters, &wait);

	return 0;

}



/**

kernel/trace/trace.c

+31 −18
Original line number Diff line number Diff line
@@ -1085,13 +1085,13 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) 
}

#endif /* CONFIG_TRACER_MAX_TRACE */



static void wait_on_pipe(struct trace_iterator *iter)

static int wait_on_pipe(struct trace_iterator *iter)

{

	/* Iterators are static, they should be filled or empty */

	if (trace_buffer_iter(iter, iter->cpu_file))

		return;

		return 0;



	ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file);

	return ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file);

}



#ifdef CONFIG_FTRACE_STARTUP_TEST
@@ -1338,7 +1338,7 @@ static int trace_create_savedcmd(void) 
{

	int ret;



	savedcmd = kmalloc(sizeof(struct saved_cmdlines_buffer), GFP_KERNEL);

	savedcmd = kmalloc(sizeof(*savedcmd), GFP_KERNEL);

	if (!savedcmd)

		return -ENOMEM;
@@ -3840,7 +3840,7 @@ tracing_saved_cmdlines_size_read(struct file *filp, char __user *ubuf, 
	int r;



	arch_spin_lock(&trace_cmdline_lock);

	r = sprintf(buf, "%u\n", savedcmd->cmdline_num);

	r = scnprintf(buf, sizeof(buf), "%u\n", savedcmd->cmdline_num);

	arch_spin_unlock(&trace_cmdline_lock);



	return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
@@ -3857,7 +3857,7 @@ static int tracing_resize_saved_cmdlines(unsigned int val) 
{

	struct saved_cmdlines_buffer *s, *savedcmd_temp;



	s = kmalloc(sizeof(struct saved_cmdlines_buffer), GFP_KERNEL);

	s = kmalloc(sizeof(*s), GFP_KERNEL);

	if (!s)

		return -ENOMEM;
@@ -4378,6 +4378,7 @@ tracing_poll_pipe(struct file *filp, poll_table *poll_table) 
static int tracing_wait_pipe(struct file *filp)

{

	struct trace_iterator *iter = filp->private_data;

	int ret;



	while (trace_empty(iter)) {
@@ -4399,10 +4400,13 @@ static int tracing_wait_pipe(struct file *filp) 


		mutex_unlock(&iter->mutex);



		wait_on_pipe(iter);

		ret = wait_on_pipe(iter);



		mutex_lock(&iter->mutex);



		if (ret)

			return ret;



		if (signal_pending(current))

			return -EINTR;

	}
@@ -5327,8 +5331,12 @@ tracing_buffers_read(struct file *filp, char __user *ubuf, 
				goto out_unlock;

			}

			mutex_unlock(&trace_types_lock);

			wait_on_pipe(iter);

			ret = wait_on_pipe(iter);

			mutex_lock(&trace_types_lock);

			if (ret) {

				size = ret;

				goto out_unlock;

			}

			if (signal_pending(current)) {

				size = -EINTR;

				goto out_unlock;
@@ -5538,8 +5546,10 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, 
			goto out;

		}

		mutex_unlock(&trace_types_lock);

		wait_on_pipe(iter);

		ret = wait_on_pipe(iter);

		mutex_lock(&trace_types_lock);

		if (ret)

			goto out;

		if (signal_pending(current)) {

			ret = -EINTR;

			goto out;
@@ -6232,22 +6242,25 @@ static int allocate_trace_buffers(struct trace_array *tr, int size) 
	return 0;

}



static void free_trace_buffer(struct trace_buffer *buf)

{

	if (buf->buffer) {

		ring_buffer_free(buf->buffer);

		buf->buffer = NULL;

		free_percpu(buf->data);

		buf->data = NULL;

	}

}



static void free_trace_buffers(struct trace_array *tr)

{

	if (!tr)

		return;



	if (tr->trace_buffer.buffer) {

		ring_buffer_free(tr->trace_buffer.buffer);

		tr->trace_buffer.buffer = NULL;

		free_percpu(tr->trace_buffer.data);

	}

	free_trace_buffer(&tr->trace_buffer);



#ifdef CONFIG_TRACER_MAX_TRACE

	if (tr->max_buffer.buffer) {

		ring_buffer_free(tr->max_buffer.buffer);

		tr->max_buffer.buffer = NULL;

	}

	free_trace_buffer(&tr->max_buffer);

#endif

}

kernel/trace/trace.h

+1 −1
Original line number Diff line number Diff line
@@ -252,7 +252,7 @@ static inline struct trace_array *top_trace_array(void) 
{

	struct trace_array *tr;



	if (list_empty(ftrace_trace_arrays.prev))

	if (list_empty(&ftrace_trace_arrays))

		return NULL;



	tr = list_entry(ftrace_trace_arrays.prev,

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