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

From: Christoph Hellwig
Date: Fri Nov 18 2016 - 08:04:36 EST


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@xxxxxx>
---
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