lib/Kconfig.debug: unhide CONFIG_PANIC_ON_OOPS

[pandora-kernel.git] / kernel / kmod.c

diff --git a/kernel/kmod.c b/kernel/kmod.c
index 0023a87..56dd349 100644 (file)
--- a/kernel/kmod.c
+++ b/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);