mm/vmalloc.c: switch to WARN_ON() and move it under unlink_va()

Trigger a warning if an object that is about to be freed is detached.  We
used to have a BUG_ON(), but even though it is considered as faulty
behaviour that is not a good reason to break a system.

Link: http://lkml.kernel.org/r/20190606120411.8298-5-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Uladzislau Rezki (Sony) 2019-07-11 20:59:03 -07:00 committed by Linus Torvalds
parent 54f63d9d8a
commit 460e42d19a
1 changed files with 10 additions and 15 deletions

View File

@ -534,20 +534,17 @@ link_va(struct vmap_area *va, struct rb_root *root,
static __always_inline void
unlink_va(struct vmap_area *va, struct rb_root *root)
{
/*
* During merging a VA node can be empty, therefore
* not linked with the tree nor list. Just check it.
*/
if (!RB_EMPTY_NODE(&va->rb_node)) {
if (root == &free_vmap_area_root)
rb_erase_augmented(&va->rb_node,
root, &free_vmap_area_rb_augment_cb);
else
rb_erase(&va->rb_node, root);
if (WARN_ON(RB_EMPTY_NODE(&va->rb_node)))
return;
list_del(&va->list);
RB_CLEAR_NODE(&va->rb_node);
}
if (root == &free_vmap_area_root)
rb_erase_augmented(&va->rb_node,
root, &free_vmap_area_rb_augment_cb);
else
rb_erase(&va->rb_node, root);
list_del(&va->list);
RB_CLEAR_NODE(&va->rb_node);
}
#if DEBUG_AUGMENT_PROPAGATE_CHECK
@ -1162,8 +1159,6 @@ EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier);
static void __free_vmap_area(struct vmap_area *va)
{
BUG_ON(RB_EMPTY_NODE(&va->rb_node));
/*
* Remove from the busy tree/list.
*/