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authorOleg Nesterov <oleg@redhat.com>2014-04-13 20:59:18 +0200
committerSteven Rostedt <rostedt@goodmis.org>2014-06-21 00:15:25 -0400
commit8063e41d2ffc0b0ce974ea802158be35902072f3 (patch)
tree27787dcbf46b42a1737c4668673eb249b9304038
parent4af4206be2bd1933cae20c2b6fb2058dbc887f7c (diff)
tracing: Change syscall_*regfunc() to check PF_KTHREAD and use for_each_process_thread()
1. Remove _irqsafe from syscall_regfunc/syscall_unregfunc, read_lock(tasklist) doesn't need to disable irqs. 2. Change this code to avoid the deprecated do_each_thread() and use for_each_process_thread() (stolen from the patch from Frederic). 3. Change syscall_regfunc() to check PF_KTHREAD to skip the kernel threads, ->mm != NULL is the common mistake. Note: probably this check should be simply removed, needs another patch. [fweisbec@gmail.com: s/do_each_thread/for_each_process_thread/] Link: http://lkml.kernel.org/p/20140413185918.GC20668@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--kernel/tracepoint.c24
1 files changed, 11 insertions, 13 deletions
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 33cbd8c203f8..9cf12640de5a 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -492,33 +492,31 @@ 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) {
+ read_lock(&tasklist_lock);
+ for_each_process_thread(p, t) {
/* Skip kernel threads. */
- if (t->mm)
+ if (!(t->flags & PF_KTHREAD))
set_tsk_thread_flag(t, TIF_SYSCALL_TRACEPOINT);
- } while_each_thread(g, t);
- read_unlock_irqrestore(&tasklist_lock, flags);
+ }
+ 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

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