Thread (13 messages) 13 messages, 2 authors, 2016-11-23
STALE3485d

[PATCH 07/10] mm: warn about vfree from atomic context

From: Christoph Hellwig <hch@lst.de>
Date: 2016-11-18 13:04:32
Also in: linux-mm, lkml
Subsystem: memory management, the rest, vmalloc · Maintainers: Andrew Morton, Linus Torvalds, Uladzislau Rezki

We can't handle vfree itself from atomic context, but callers
can explicitly use vfree_atomic instead, which defers the actual
vfree to a workqueue.  Unfortunately in_atomic does not work
on non-preemptible kernels, so we can't just do the right thing
by default.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 mm/vmalloc.c | 1 +
 1 file changed, 1 insertion(+)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 80f3fae..e2030b4 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -1530,6 +1530,7 @@ void vfree_atomic(const void *addr)
 void vfree(const void *addr)
 {
 	BUG_ON(in_nmi());
+	WARN_ON_ONCE(in_atomic());
 
 	kmemleak_free(addr);
 
-- 
2.1.4

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