---

yaml --- r: 140882 b: refs/heads/master c: 0e39ac4 h: refs/heads/master v: v3
git-mirror · Mar 6, 2009 · 6cf103a · 6cf103a
1 parent d31b672
commit 6cf103a
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Showing 3 changed files with 17 additions and 1 deletion.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: f0ef03985130287c6c84ebe69416cf790e6cc00e
+refs/heads/master: 0e39ac444636ff5be39b26f1cb56d79594654dda
diff --git a/trunk/include/linux/memory.h b/trunk/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/trunk/mm/memory.c b/trunk/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;