Merge branch 'master' of ssh://parabolagnulinux.org:1863/srv/git/abslibre

1 files changed, 66 insertions, 0 deletions

diff --git a/libre/linux-libre/module-symbol-waiting-3.6.patch b/libre/linux-libre/module-symbol-waiting-3.6.patch
new file mode 100644
index 000000000..b87a38ff5
--- /dev/null
+++ b/libre/linux-libre/module-symbol-waiting-3.6.patch
@@ -0,0 +1,66 @@
+From: Rusty Russell <rusty@rustcorp.com.au>
+Date: Fri, 28 Sep 2012 05:01:03 +0000 (+0930)
+Subject: module: fix symbol waiting when module fails before init
+X-Git-Tag: v3.7-rc1~2^2~33
+X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=6f13909f4fe9652f1
+
+module: fix symbol waiting when module fails before init
+
+We use resolve_symbol_wait(), which blocks if the module containing
+the symbol is still loading.  However:
+
+1) The module_wq we use is only woken after calling the modules' init
+   function, but there are other failure paths after the module is
+   placed in the linked list where we need to do the same thing.
+
+2) wake_up() only wakes one waiter, and our waitqueue is shared by all
+   modules, so we need to wake them all.
+
+3) wake_up_all() doesn't imply a memory barrier: I feel happier calling
+   it after we've grabbed and dropped the module_mutex, not just after
+   the state assignment.
+
+Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
+---
+
+diff --git a/kernel/module.c b/kernel/module.c
+index 7f2ee45f..63cf6e7 100644
+--- a/kernel/module.c
++++ b/kernel/module.c
+@@ -2959,7 +2959,7 @@ static struct module *load_module(void __user *umod,
+ 	/* Unlink carefully: kallsyms could be walking list. */
+ 	list_del_rcu(&mod->list);
+ 	module_bug_cleanup(mod);
+-
++	wake_up_all(&module_wq);
+  ddebug:
+ 	dynamic_debug_remove(info.debug);
+  unlock:
+@@ -3034,7 +3034,7 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
+ 		blocking_notifier_call_chain(&module_notify_list,
+ 					     MODULE_STATE_GOING, mod);
+ 		free_module(mod);
+-		wake_up(&module_wq);
++		wake_up_all(&module_wq);
+ 		return ret;
+ 	}
+ 	if (ret > 0) {
+@@ -3046,9 +3046,8 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
+ 		dump_stack();
+ 	}
+ 
+-	/* Now it's a first class citizen!  Wake up anyone waiting for it. */
++	/* Now it's a first class citizen! */
+ 	mod->state = MODULE_STATE_LIVE;
+-	wake_up(&module_wq);
+ 	blocking_notifier_call_chain(&module_notify_list,
+ 				     MODULE_STATE_LIVE, mod);
+ 
+@@ -3071,6 +3070,7 @@ SYSCALL_DEFINE3(init_module, void __user *, umod,
+ 	mod->init_ro_size = 0;
+ 	mod->init_text_size = 0;
+ 	mutex_unlock(&module_mutex);
++	wake_up_all(&module_wq);
+ 
+ 	return 0;
+ }