Merge tag 'trace-fixes-v3.16-rc5-v2' of git://git.kernel.org/pub/scm/linux/kerne…

…l/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "A few more fixes for ftrace infrastructure. I was cleaning out my INBOX and found two fixes from zhangwei from a year ago that were lost in my mail. These fix an inconsistency between trace_puts() and the way trace_printk() works. The reason this is important to fix is because when trace_printk() doesn't have any arguments, it turns into a trace_puts(). Not being able to enable a stack trace against trace_printk() because it does not have any arguments is quite confusing. Also, the fix is rather trivial and low risk. While porting some changes to PowerPC I discovered that it still has the function graph tracer filter bug that if you also enable stack tracing the function graph tracer filter is ignored. I fixed that up. Finally, Martin Lau, fixed a bug that would cause readers of the ftrace ring buffer to block forever even though it was suppose to be NONBLOCK" This also includes the fix from an earlier pull request: "Oleg Nesterov fixed a memory leak that happens if a user creates a tracing instance, sets up a filter in an event, and then removes that instance. The filter allocates memory that is never freed when the instance is destroyed" * tag 'trace-fixes-v3.16-rc5-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ring-buffer: Fix polling on trace_pipe tracing: Add TRACE_ITER_PRINTK flag check in __trace_puts/__trace_bputs tracing: Fix graph tracer with stack tracer on other archs tracing: Add ftrace_trace_stack into __trace_puts/__trace_bputs tracing: instance_rmdir() leaks ftrace_event_file->filter

Merge tag 'trace-fixes-v3.16-rc5-v2' of git://git.kernel.org/pub/scm/linux/kerne…
…l/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "A few more fixes for ftrace infrastructure. I was cleaning out my INBOX and found two fixes from zhangwei from a year ago that were lost in my mail. These fix an inconsistency between trace_puts() and the way trace_printk() works. The reason this is important to fix is because when trace_printk() doesn't have any arguments, it turns into a trace_puts(). Not being able to enable a stack trace against trace_printk() because it does not have any arguments is quite confusing. Also, the fix is rather trivial and low risk. While porting some changes to PowerPC I discovered that it still has the function graph tracer filter bug that if you also enable stack tracing the function graph tracer filter is ignored. I fixed that up. Finally, Martin Lau, fixed a bug that would cause readers of the ftrace ring buffer to block forever even though it was suppose to be NONBLOCK" This also includes the fix from an earlier pull request: "Oleg Nesterov fixed a memory leak that happens if a user creates a tracing instance, sets up a filter in an event, and then removes that instance. The filter allocates memory that is never freed when the instance is destroyed" * tag 'trace-fixes-v3.16-rc5-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ring-buffer: Fix polling on trace_pipe tracing: Add TRACE_ITER_PRINTK flag check in __trace_puts/__trace_bputs tracing: Fix graph tracer with stack tracer on other archs tracing: Add ftrace_trace_stack into __trace_puts/__trace_bputs tracing: instance_rmdir() leaks ftrace_event_file->filter
Linus Torvalds
2 parents b6603fe574 97b8ee8453
Showing 4 changed files Side-by-side Diff
kernel/trace/ftrace.c
kernel/trace/ring_buffer.c
kernel/trace/trace.c
kernel/trace/trace_events.c
@@ -265,11 +265,11 @@
 		func = ftrace_ops_list_func;
 	}
  
+	update_function_graph_func();
+
 	/* If there's no change, then do nothing more here */
 	if (ftrace_trace_function == func)
 		return;
-
-	update_function_graph_func();
  
 	/*
 	 * If we are using the list function, it doesn't care
@@ -616,10 +616,6 @@
 	struct ring_buffer_per_cpu *cpu_buffer;
 	struct rb_irq_work *work;
  
-	if ((cpu == RING_BUFFER_ALL_CPUS && !ring_buffer_empty(buffer)) ||
-	    (cpu != RING_BUFFER_ALL_CPUS && !ring_buffer_empty_cpu(buffer, cpu)))
-		return POLLIN | POLLRDNORM;
-
 	if (cpu == RING_BUFFER_ALL_CPUS)
 		work = &buffer->irq_work;
 	else {
@@ -466,7 +466,13 @@
 	struct print_entry *entry;
 	unsigned long irq_flags;
 	int alloc;
+	int pc;
  
+	if (!(trace_flags & TRACE_ITER_PRINTK))
+		return 0;
+
+	pc = preempt_count();
+
 	if (unlikely(tracing_selftest_running || tracing_disabled))
 		return 0;
  
@@ -475,7 +481,7 @@
 	local_save_flags(irq_flags);
 	buffer = global_trace.trace_buffer.buffer;
 	event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc, 
-					  irq_flags, preempt_count());
+					  irq_flags, pc);
 	if (!event)
 		return 0;
  
@@ -492,6 +498,7 @@
 		entry->buf[size] = '\0';
  
 	__buffer_unlock_commit(buffer, event);
+	ftrace_trace_stack(buffer, irq_flags, 4, pc);
  
 	return size;
 }
  
  
@@ -509,14 +516,20 @@
 	struct bputs_entry *entry;
 	unsigned long irq_flags;
 	int size = sizeof(struct bputs_entry);
+	int pc;
  
+	if (!(trace_flags & TRACE_ITER_PRINTK))
+		return 0;
+
+	pc = preempt_count();
+
 	if (unlikely(tracing_selftest_running || tracing_disabled))
 		return 0;
  
 	local_save_flags(irq_flags);
 	buffer = global_trace.trace_buffer.buffer;
 	event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
-					  irq_flags, preempt_count());
+					  irq_flags, pc);
 	if (!event)
 		return 0;
  
@@ -525,6 +538,7 @@
 	entry->str			= str;
  
 	__buffer_unlock_commit(buffer, event);
+	ftrace_trace_stack(buffer, irq_flags, 4, pc);
  
 	return 1;
 }
@@ -470,6 +470,7 @@
  
 	list_del(&file->list);
 	remove_subsystem(file->system);
+	free_event_filter(file->filter);
 	kmem_cache_free(file_cachep, file);
 }
...	...	@@ -265,11 +265,11 @@
265	265	func = ftrace_ops_list_func;
266	266	}
267	267
	268	+ update_function_graph_func();
	269	+
268	270	/* If there's no change, then do nothing more here */
269	271	if (ftrace_trace_function == func)
270	272	return;
271		-
272		- update_function_graph_func();
273	273
274	274	/*
275	275	* If we are using the list function, it doesn't care
...	...	@@ -616,10 +616,6 @@
616	616	struct ring_buffer_per_cpu *cpu_buffer;
617	617	struct rb_irq_work *work;
618	618
619		- if ((cpu == RING_BUFFER_ALL_CPUS && !ring_buffer_empty(buffer)) \|\|
620		- (cpu != RING_BUFFER_ALL_CPUS && !ring_buffer_empty_cpu(buffer, cpu)))
621		- return POLLIN \| POLLRDNORM;
622		-
623	619	if (cpu == RING_BUFFER_ALL_CPUS)
624	620	work = &buffer->irq_work;
625	621	else {
...	...	@@ -466,7 +466,13 @@
466	466	struct print_entry *entry;
467	467	unsigned long irq_flags;
468	468	int alloc;
	469	+ int pc;
469	470
	471	+ if (!(trace_flags & TRACE_ITER_PRINTK))
	472	+ return 0;
	473	+
	474	+ pc = preempt_count();
	475	+
470	476	if (unlikely(tracing_selftest_running \|\| tracing_disabled))
471	477	return 0;
472	478
...	...	@@ -475,7 +481,7 @@
475	481	local_save_flags(irq_flags);
476	482	buffer = global_trace.trace_buffer.buffer;
477	483	event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
478		- irq_flags, preempt_count());
	484	+ irq_flags, pc);
479	485	if (!event)
480	486	return 0;
481	487
...	...	@@ -492,6 +498,7 @@
492	498	entry->buf[size] = '\0';
493	499
494	500	__buffer_unlock_commit(buffer, event);
	501	+ ftrace_trace_stack(buffer, irq_flags, 4, pc);
495	502
496	503	return size;
497	504	}
498	505
499	506
...	...	@@ -509,14 +516,20 @@
509	516	struct bputs_entry *entry;
510	517	unsigned long irq_flags;
511	518	int size = sizeof(struct bputs_entry);
	519	+ int pc;
512	520
	521	+ if (!(trace_flags & TRACE_ITER_PRINTK))
	522	+ return 0;
	523	+
	524	+ pc = preempt_count();
	525	+
513	526	if (unlikely(tracing_selftest_running \|\| tracing_disabled))
514	527	return 0;
515	528
516	529	local_save_flags(irq_flags);
517	530	buffer = global_trace.trace_buffer.buffer;
518	531	event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
519		- irq_flags, preempt_count());
	532	+ irq_flags, pc);
520	533	if (!event)
521	534	return 0;
522	535
...	...	@@ -525,6 +538,7 @@
525	538	entry->str = str;
526	539
527	540	__buffer_unlock_commit(buffer, event);
	541	+ ftrace_trace_stack(buffer, irq_flags, 4, pc);
528	542
529	543	return 1;
530	544	}
...	...	@@ -470,6 +470,7 @@
470	470
471	471	list_del(&file->list);
472	472	remove_subsystem(file->system);
	473	+ free_event_filter(file->filter);
473	474	kmem_cache_free(file_cachep, file);
474	475	}
475	476