---

yaml --- r: 350308 b: refs/heads/master c: 0fdff3e h: refs/heads/master v: v3
git-mirror · Jan 23, 2013 · 292e005 · 292e005
1 parent 23164bd
commit 292e005
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Showing 2 changed files with 10 additions and 1 deletion.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 21c3c5d2800733b7a276725b8e1ae49a694adc1a
+refs/heads/master: 0fdff3ec6d87856cdcc99e69cf42143fdd6c56b4
diff --git a/trunk/kernel/kmod.c b/trunk/kernel/kmod.c
@@ -38,6 +38,7 @@
 #include <linux/suspend.h>
 #include <linux/rwsem.h>
 #include <linux/ptrace.h>
+#include <linux/async.h>
 #include <asm/uaccess.h>
 
 #include <trace/events/module.h>
@@ -130,6 +131,14 @@ int __request_module(bool wait, const char *fmt, ...)
 #define MAX_KMOD_CONCURRENT 50	/* Completely arbitrary value - KAO */
 	static int kmod_loop_msg;
 
+	/*
+	 * We don't allow synchronous module loading from async.  Module
+	 * init may invoke async_synchronize_full() which will end up
+	 * waiting for this task which already is waiting for the module
+	 * loading to complete, leading to a deadlock.
+	 */
+	WARN_ON_ONCE(wait && current_is_async());
+
 	va_start(args, fmt);
 	ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args);
 	va_end(args);