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-rw-r--r--kernel/trace/ftrace.c16
1 files changed, 11 insertions, 5 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index c997f7371c6..df93392aad8 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3318,7 +3318,7 @@ static int ftrace_process_locs(struct module *mod,
{
unsigned long *p;
unsigned long addr;
- unsigned long flags;
+ unsigned long flags = 0; /* Shut up gcc */
mutex_lock(&ftrace_lock);
p = start;
@@ -3336,12 +3336,18 @@ static int ftrace_process_locs(struct module *mod,
}
/*
- * Disable interrupts to prevent interrupts from executing
- * code that is being modified.
+ * We only need to disable interrupts on start up
+ * because we are modifying code that an interrupt
+ * may execute, and the modification is not atomic.
+ * But for modules, nothing runs the code we modify
+ * until we are finished with it, and there's no
+ * reason to cause large interrupt latencies while we do it.
*/
- local_irq_save(flags);
+ if (!mod)
+ local_irq_save(flags);
ftrace_update_code(mod);
- local_irq_restore(flags);
+ if (!mod)
+ local_irq_restore(flags);
mutex_unlock(&ftrace_lock);
return 0;