Merge tag 'trace-fixes-v3.16-rc1-v2' of git://git.kernel.org/pub/scm/linux/kerne…

…l/git/rostedt/linux-trace Pull tracing cleanups and fixes from Steven Rostedt: "This includes three patches from Oleg Nesterov. The first is a fix to a race condition that happens between enabling/disabling syscall tracepoints and new process creations (the check to go into the ptrace path for a process can be set when it shouldn't, or not set when it should). Not a major bug but one that should be fixed and even applied to stable. The other two patches are cleanup/fixes that are not that critical, but for an -rc1 release would be nice to have. They both deal with syscall tracepoints. It also includes a patch to introduce a new macro for the TRACE_EVENT() format called __field_struct(). Originally, __field() was used to record any variable into a trace event, but with the addition of setting the "is signed" attribute, the check causes anything but a primitive variable to fail to compile. That is, structs and unions can't be used as they once were. When the "is signed" check was introduce there were only primitive variables being recorded. But that will change soon and it was reported that __field() causes build failures. To solve the __field() issue, __field_struct() is introduced to allow trace_events to be able to record complex types too" * tag 'trace-fixes-v3.16-rc1-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Add __field_struct macro for TRACE_EVENT() tracing: syscall_regfunc() should not skip kernel threads tracing: Change syscall_*regfunc() to check PF_KTHREAD and use for_each_process_thread() tracing: Fix syscall_*regfunc() vs copy_process() race

Merge tag 'trace-fixes-v3.16-rc1-v2' of git://git.kernel.org/pub/scm/linux/kerne…
…l/git/rostedt/linux-trace Pull tracing cleanups and fixes from Steven Rostedt: "This includes three patches from Oleg Nesterov. The first is a fix to a race condition that happens between enabling/disabling syscall tracepoints and new process creations (the check to go into the ptrace path for a process can be set when it shouldn't, or not set when it should). Not a major bug but one that should be fixed and even applied to stable. The other two patches are cleanup/fixes that are not that critical, but for an -rc1 release would be nice to have. They both deal with syscall tracepoints. It also includes a patch to introduce a new macro for the TRACE_EVENT() format called __field_struct(). Originally, __field() was used to record any variable into a trace event, but with the addition of setting the "is signed" attribute, the check causes anything but a primitive variable to fail to compile. That is, structs and unions can't be used as they once were. When the "is signed" check was introduce there were only primitive variables being recorded. But that will change soon and it was reported that __field() causes build failures. To solve the __field() issue, __field_struct() is introduced to allow trace_events to be able to record complex types too" * tag 'trace-fixes-v3.16-rc1-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Add __field_struct macro for TRACE_EVENT() tracing: syscall_regfunc() should not skip kernel threads tracing: Change syscall_*regfunc() to check PF_KTHREAD and use for_each_process_thread() tracing: Fix syscall_*regfunc() vs copy_process() race
Linus Torvalds
2 parents 10b5b5361a 4d4c9cc839
Showing 5 changed files Side-by-side Diff
include/trace/ftrace.h
include/trace/syscall.h
kernel/fork.c
kernel/tracepoint.c
samples/trace_events/trace-events-sample.h
@@ -44,6 +44,12 @@
 #undef __field_ext
 #define __field_ext(type, item, filter_type)	type	item;
  
+#undef __field_struct
+#define __field_struct(type, item)	type	item;
+
+#undef __field_struct_ext
+#define __field_struct_ext(type, item, filter_type)	type	item;
+
 #undef __array
 #define __array(type, item, len)	type	item[len];
  
@@ -122,6 +128,12 @@
 #undef __field_ext
 #define __field_ext(type, item, filter_type)
  
+#undef __field_struct
+#define __field_struct(type, item)
+
+#undef __field_struct_ext
+#define __field_struct_ext(type, item, filter_type)
+
 #undef __array
 #define __array(type, item, len)
  
  
@@ -315,9 +327,21 @@
 	if (ret)							\
 		return ret;
  
+#undef __field_struct_ext
+#define __field_struct_ext(type, item, filter_type)			\
+	ret = trace_define_field(event_call, #type, #item,		\
+				 offsetof(typeof(field), item),		\
+				 sizeof(field.item),			\
+				 0, filter_type);			\
+	if (ret)							\
+		return ret;
+
 #undef __field
 #define __field(type, item)	__field_ext(type, item, FILTER_OTHER)
  
+#undef __field_struct
+#define __field_struct(type, item) __field_struct_ext(type, item, FILTER_OTHER)
+
 #undef __array
 #define __array(type, item, len)					\
 	do {								\
@@ -379,6 +403,12 @@
 #undef __field_ext
 #define __field_ext(type, item, filter_type)
  
+#undef __field_struct
+#define __field_struct(type, item)
+
+#undef __field_struct_ext
+#define __field_struct_ext(type, item, filter_type)
+
 #undef __array
 #define __array(type, item, len)
  
@@ -549,6 +579,9 @@
  
 #undef __field
 #define __field(type, item)
+
+#undef __field_struct
+#define __field_struct(type, item)
  
 #undef __array
 #define __array(type, item, len)
@@ -4,6 +4,7 @@
 #include <linux/tracepoint.h>
 #include <linux/unistd.h>
 #include <linux/ftrace_event.h>
+#include <linux/thread_info.h>
  
 #include <asm/ptrace.h>
  
@@ -31,6 +32,20 @@
 	struct ftrace_event_call *enter_event;
 	struct ftrace_event_call *exit_event;
 };
+
+#if defined(CONFIG_TRACEPOINTS) && defined(CONFIG_HAVE_SYSCALL_TRACEPOINTS)
+static inline void syscall_tracepoint_update(struct task_struct *p)
+{
+	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
+		set_tsk_thread_flag(p, TIF_SYSCALL_TRACEPOINT);
+	else
+		clear_tsk_thread_flag(p, TIF_SYSCALL_TRACEPOINT);
+}
+#else
+static inline void syscall_tracepoint_update(struct task_struct *p)
+{
+}
+#endif
  
 #endif /* _TRACE_SYSCALL_H */
@@ -1487,7 +1487,9 @@
  
 	total_forks++;
 	spin_unlock(&current->sighand->siglock);
+	syscall_tracepoint_update(p);
 	write_unlock_irq(&tasklist_lock);
+
 	proc_fork_connector(p);
 	cgroup_post_fork(p);
 	if (clone_flags & CLONE_THREAD)
@@ -492,33 +492,29 @@
  
 void syscall_regfunc(void)
 {
-	unsigned long flags;
-	struct task_struct *g, *t;
+	struct task_struct *p, *t;
  
 	if (!sys_tracepoint_refcount) {
-		read_lock_irqsave(&tasklist_lock, flags);
-		do_each_thread(g, t) {
-			/* Skip kernel threads. */
-			if (t->mm)
-				set_tsk_thread_flag(t, TIF_SYSCALL_TRACEPOINT);
-		} while_each_thread(g, t);
-		read_unlock_irqrestore(&tasklist_lock, flags);
+		read_lock(&tasklist_lock);
+		for_each_process_thread(p, t) {
+			set_tsk_thread_flag(t, TIF_SYSCALL_TRACEPOINT);
+		}
+		read_unlock(&tasklist_lock);
 	}
 	sys_tracepoint_refcount++;
 }
  
 void syscall_unregfunc(void)
 {
-	unsigned long flags;
-	struct task_struct *g, *t;
+	struct task_struct *p, *t;
  
 	sys_tracepoint_refcount--;
 	if (!sys_tracepoint_refcount) {
-		read_lock_irqsave(&tasklist_lock, flags);
-		do_each_thread(g, t) {
+		read_lock(&tasklist_lock);
+		for_each_process_thread(p, t) {
 			clear_tsk_thread_flag(t, TIF_SYSCALL_TRACEPOINT);
-		} while_each_thread(g, t);
-		read_unlock_irqrestore(&tasklist_lock, flags);
+		}
+		read_unlock(&tasklist_lock);
 	}
 }
 #endif
@@ -56,7 +56,8 @@
  * struct:  This defines the way the data will be stored in the ring buffer.
  *    There are currently two types of elements. __field and __array.
  *    a __field is broken up into (type, name). Where type can be any
- *    type but an array.
+ *    primitive type (integer, long or pointer). __field_struct() can
+ *    be any static complex data value (struct, union, but not an array).
  *    For an array. there are three fields. (type, name, size). The
  *    type of elements in the array, the name of the field and the size
  *    of the array.
...	...	@@ -44,6 +44,12 @@
44	44	#undef __field_ext
45	45	#define __field_ext(type, item, filter_type) type item;
46	46
	47	+#undef __field_struct
	48	+#define __field_struct(type, item) type item;
	49	+
	50	+#undef __field_struct_ext
	51	+#define __field_struct_ext(type, item, filter_type) type item;
	52	+
47	53	#undef __array
48	54	#define __array(type, item, len) type item[len];
49	55
...	...	@@ -122,6 +128,12 @@
122	128	#undef __field_ext
123	129	#define __field_ext(type, item, filter_type)
124	130
	131	+#undef __field_struct
	132	+#define __field_struct(type, item)
	133	+
	134	+#undef __field_struct_ext
	135	+#define __field_struct_ext(type, item, filter_type)
	136	+
125	137	#undef __array
126	138	#define __array(type, item, len)
127	139
128	140
...	...	@@ -315,9 +327,21 @@
315	327	if (ret) \
316	328	return ret;
317	329
	330	+#undef __field_struct_ext
	331	+#define __field_struct_ext(type, item, filter_type) \
	332	+ ret = trace_define_field(event_call, #type, #item, \
	333	+ offsetof(typeof(field), item), \
	334	+ sizeof(field.item), \
	335	+ 0, filter_type); \
	336	+ if (ret) \
	337	+ return ret;
	338	+
318	339	#undef __field
319	340	#define __field(type, item) __field_ext(type, item, FILTER_OTHER)
320	341
	342	+#undef __field_struct
	343	+#define __field_struct(type, item) __field_struct_ext(type, item, FILTER_OTHER)
	344	+
321	345	#undef __array
322	346	#define __array(type, item, len) \
323	347	do { \
...	...	@@ -379,6 +403,12 @@
379	403	#undef __field_ext
380	404	#define __field_ext(type, item, filter_type)
381	405
	406	+#undef __field_struct
	407	+#define __field_struct(type, item)
	408	+
	409	+#undef __field_struct_ext
	410	+#define __field_struct_ext(type, item, filter_type)
	411	+
382	412	#undef __array
383	413	#define __array(type, item, len)
384	414
...	...	@@ -549,6 +579,9 @@
549	579
550	580	#undef __field
551	581	#define __field(type, item)
	582	+
	583	+#undef __field_struct
	584	+#define __field_struct(type, item)
552	585
553	586	#undef __array
554	587	#define __array(type, item, len)
...	...	@@ -4,6 +4,7 @@
4	4	#include <linux/tracepoint.h>
5	5	#include <linux/unistd.h>
6	6	#include <linux/ftrace_event.h>
	7	+#include <linux/thread_info.h>
7	8
8	9	#include <asm/ptrace.h>
9	10
...	...	@@ -31,6 +32,20 @@
31	32	struct ftrace_event_call *enter_event;
32	33	struct ftrace_event_call *exit_event;
33	34	};
	35	+
	36	+#if defined(CONFIG_TRACEPOINTS) && defined(CONFIG_HAVE_SYSCALL_TRACEPOINTS)
	37	+static inline void syscall_tracepoint_update(struct task_struct *p)
	38	+{
	39	+ if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
	40	+ set_tsk_thread_flag(p, TIF_SYSCALL_TRACEPOINT);
	41	+ else
	42	+ clear_tsk_thread_flag(p, TIF_SYSCALL_TRACEPOINT);
	43	+}
	44	+#else
	45	+static inline void syscall_tracepoint_update(struct task_struct *p)
	46	+{
	47	+}
	48	+#endif
34	49
35	50	#endif /* _TRACE_SYSCALL_H */
...	...	@@ -1487,7 +1487,9 @@
1487	1487
1488	1488	total_forks++;
1489	1489	spin_unlock(&current->sighand->siglock);
	1490	+ syscall_tracepoint_update(p);
1490	1491	write_unlock_irq(&tasklist_lock);
	1492	+
1491	1493	proc_fork_connector(p);
1492	1494	cgroup_post_fork(p);
1493	1495	if (clone_flags & CLONE_THREAD)
...	...	@@ -492,33 +492,29 @@
492	492
493	493	void syscall_regfunc(void)
494	494	{
495		- unsigned long flags;
496		- struct task_struct g, t;
	495	+ struct task_struct p, t;
497	496
498	497	if (!sys_tracepoint_refcount) {
499		- read_lock_irqsave(&tasklist_lock, flags);
500		- do_each_thread(g, t) {
501		- /* Skip kernel threads. */
502		- if (t->mm)
503		- set_tsk_thread_flag(t, TIF_SYSCALL_TRACEPOINT);
504		- } while_each_thread(g, t);
505		- read_unlock_irqrestore(&tasklist_lock, flags);
	498	+ read_lock(&tasklist_lock);
	499	+ for_each_process_thread(p, t) {
	500	+ set_tsk_thread_flag(t, TIF_SYSCALL_TRACEPOINT);
	501	+ }
	502	+ read_unlock(&tasklist_lock);
506	503	}
507	504	sys_tracepoint_refcount++;
508	505	}
509	506
510	507	void syscall_unregfunc(void)
511	508	{
512		- unsigned long flags;
513		- struct task_struct g, t;
	509	+ struct task_struct p, t;
514	510
515	511	sys_tracepoint_refcount--;
516	512	if (!sys_tracepoint_refcount) {
517		- read_lock_irqsave(&tasklist_lock, flags);
518		- do_each_thread(g, t) {
	513	+ read_lock(&tasklist_lock);
	514	+ for_each_process_thread(p, t) {
519	515	clear_tsk_thread_flag(t, TIF_SYSCALL_TRACEPOINT);
520		- } while_each_thread(g, t);
521		- read_unlock_irqrestore(&tasklist_lock, flags);
	516	+ }
	517	+ read_unlock(&tasklist_lock);
522	518	}
523	519	}
524	520	#endif
...	...	@@ -56,7 +56,8 @@
56	56	* struct: This defines the way the data will be stored in the ring buffer.
57	57	* There are currently two types of elements. __field and __array.
58	58	* a __field is broken up into (type, name). Where type can be any
59		- * type but an array.
	59	+ * primitive type (integer, long or pointer). __field_struct() can
	60	+ * be any static complex data value (struct, union, but not an array).
60	61	* For an array. there are three fields. (type, name, size). The
61	62	* type of elements in the array, the name of the field and the size
62	63	* of the array.