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

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Date:   Fri, 18 Nov 2016 14:03:53 +0100
From:   Christoph Hellwig <hch@....de>
To:     akpm@...ux-foundation.org
Cc:     aryabinin@...tuozzo.com, joelaf@...gle.com, jszhang@...vell.com,
        chris@...is-wilson.co.uk, joaodias@...gle.com, linux-mm@...ck.org,
        linux-rt-users@...r.kernel.org, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [PATCH 07/10] mm: warn about vfree from atomic context

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@....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