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-rw-r--r--kernel/extable.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/kernel/extable.c b/kernel/extable.c
index 0df6253730b..25d39b0c3a1 100644
--- a/kernel/extable.c
+++ b/kernel/extable.c
@@ -15,11 +15,21 @@
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
+#include <linux/ftrace.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/init.h>
-#include <linux/ftrace.h>
-#include <asm/uaccess.h>
+
#include <asm/sections.h>
+#include <asm/uaccess.h>
+
+/*
+ * mutex protecting text section modification (dynamic code patching).
+ * some users need to sleep (allocating memory...) while they hold this lock.
+ *
+ * NOT exported to modules - patching kernel text is a really delicate matter.
+ */
+DEFINE_MUTEX(text_mutex);
extern struct exception_table_entry __start___ex_table[];
extern struct exception_table_entry __stop___ex_table[];