Merge tag 'trace-seq-buf-3.19-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixlet from Steven Rostedt:
 "Remove unnecessary preempt_disable in printk()"

* tag 'trace-seq-buf-3.19-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  printk: Do not disable preemption for accessing printk_func

1 files changed, 8 insertions, 2 deletions

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index f900dc9f6822..02d6b6d28796 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -1857,10 +1857,16 @@ asmlinkage __visible int printk(const char *fmt, ...)
         int r;
 
         va_start(args, fmt);
-        preempt_disable();
+
+        /*
+         * If a caller overrides the per_cpu printk_func, then it needs
+         * to disable preemption when calling printk(). Otherwise
+         * the printk_func should be set to the default. No need to
+         * disable preemption here.
+         */
         vprintk_func = this_cpu_read(printk_func);
         r = vprintk_func(fmt, args);
-        preempt_enable();
+
         va_end(args);
 
         return r;