mm/vmalloc.c: switch to WARN_ON() and move it under unlink_va() (460e42d1) · Commits · 戴 / test

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>

mm/vmalloc.c

+10 −15

Original line number	Diff line number	Diff line
		@@ -534,11 +534,9 @@ 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 (WARN_ON(RB_EMPTY_NODE(&va->rb_node)))
		return;

		if (root == &free_vmap_area_root)
		rb_erase_augmented(&va->rb_node,
		root, &free_vmap_area_rb_augment_cb);
		@@ -548,7 +546,6 @@ unlink_va(struct vmap_area va, struct rb_root root)
		list_del(&va->list);
		RB_CLEAR_NODE(&va->rb_node);
		}
		}

		#if DEBUG_AUGMENT_PROPAGATE_CHECK
		static void
		@@ -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.
		*/

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