summaryrefslogtreecommitdiff
path: root/kernel/module.c
diff options
context:
space:
mode:
authorKonstantin Khorenko <khorenko@virtuozzo.com>2019-11-13 12:29:50 +0300
committerJessica Yu <jeyu@kernel.org>2019-11-15 11:23:12 +0100
commit5d603311615f612320bb77bd2a82553ef1ced5b7 (patch)
tree96636fda25f3e088580c35356f90c5611774a619 /kernel/module.c
parente2854a1054ab171a2c5cad6e9b7f0c580bab409d (diff)
downloadlwn-5d603311615f612320bb77bd2a82553ef1ced5b7.tar.gz
lwn-5d603311615f612320bb77bd2a82553ef1ced5b7.zip
kernel/module.c: wakeup processes in module_wq on module unload
Fix the race between load and unload a kernel module. sys_delete_module() try_stop_module() mod->state = _GOING add_unformed_module() old = find_module_all() (old->state == _GOING => wait_event_interruptible()) During pre-condition finished_loading() rets 0 schedule() (never gets waken up later) free_module() mod->state = _UNFORMED list_del_rcu(&mod->list) (dels mod from "modules" list) return The race above leads to modprobe hanging forever on loading a module. Error paths on loading module call wake_up_all(&module_wq) after freeing module, so let's do the same on straight module unload. Fixes: 6e6de3dee51a ("kernel/module.c: Only return -EEXIST for modules that have finished loading") Reviewed-by: Prarit Bhargava <prarit@redhat.com> Signed-off-by: Konstantin Khorenko <khorenko@virtuozzo.com> Signed-off-by: Jessica Yu <jeyu@kernel.org>
Diffstat (limited to 'kernel/module.c')
-rw-r--r--kernel/module.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/module.c b/kernel/module.c
index 26c13173da3d..bdbf95726cb7 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1033,6 +1033,8 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user,
strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
free_module(mod);
+ /* someone could wait for the module in add_unformed_module() */
+ wake_up_all(&module_wq);
return 0;
out:
mutex_unlock(&module_mutex);