diff options
| -rw-r--r-- | include/linux/memory.h | 6 | ||||
| -rw-r--r-- | mm/memory.c | 10 |
2 files changed, 16 insertions, 0 deletions
diff --git a/include/linux/memory.h b/include/linux/memory.h index 3fdc10806d31..86a6c0f0518d 100644 --- a/include/linux/memory.h +++ b/include/linux/memory.h @@ -99,4 +99,10 @@ enum mem_add_context { BOOT, HOTPLUG }; #define hotplug_memory_notifier(fn, pri) do { } while (0) #endif +/* + * Kernel text modification mutex, used for code patching. Users of this lock + * can sleep. + */ +extern struct mutex text_mutex; + #endif /* _LINUX_MEMORY_H_ */ diff --git a/mm/memory.c b/mm/memory.c index baa999e87cd2..05fab3bc5b4b 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -48,6 +48,8 @@ #include <linux/rmap.h> #include <linux/module.h> #include <linux/delayacct.h> +#include <linux/kprobes.h> +#include <linux/mutex.h> #include <linux/init.h> #include <linux/writeback.h> #include <linux/memcontrol.h> @@ -99,6 +101,14 @@ int randomize_va_space __read_mostly = 2; #endif +/* + * 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); + static int __init disable_randmaps(char *s) { randomize_va_space = 0; |