5 files changed, 63 insertions, 16 deletions

diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 0fd06fef9fac..26b4f2e13275 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.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 @@ static struct trace_event_functions ftrace_event_type_funcs_##call = {	\
         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 @@ ftrace_define_fields_##call(struct ftrace_event_call *event_call)	\
 #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)
 
@@ -550,6 +580,9 @@ static inline notrace int ftrace_get_offsets_##call(			\
 #undef __field
 #define __field(type, item)
 
+#undef __field_struct
+#define __field_struct(type, item)
+
 #undef __array
 #define __array(type, item, len)
 
diff --git a/include/trace/syscall.h b/include/trace/syscall.h
index fed853f3d7aa..9674145e2f6a 100644
--- a/include/trace/syscall.h
+++ b/include/trace/syscall.h
@@ -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>
 
@@ -32,4 +33,18 @@ struct syscall_metadata {
         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 */
diff --git a/kernel/fork.c b/kernel/fork.c
index d2799d1fc952..6a13c46cd87d 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1487,7 +1487,9 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 
         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)
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 33cbd8c203f8..3490407dc7b7 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -492,33 +492,29 @@ static int sys_tracepoint_refcount;
 
 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
diff --git a/samples/trace_events/trace-events-sample.h b/samples/trace_events/trace-events-sample.h
index 6af373236d73..4b0113f73ee9 100644
--- a/samples/trace_events/trace-events-sample.h
+++ b/samples/trace_events/trace-events-sample.h
@@ -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.