linux-kernel - [PATCH] mm: check for sleepable context in kvfree

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Date:   Tue, 23 Jul 2019 09:12:12 -0400
From:   Jeff Layton <jlayton@...nel.org>
To:     akpm@...ux-foundation.org
Cc:     linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        viro@...iv.linux.org.uk, lhenriques@...e.com, cmaiolino@...hat.com
Subject: [PATCH] mm: check for sleepable context in kvfree

A lot of callers of kvfree only go down the vfree path under very rare
circumstances, and so may never end up hitting the might_sleep_if in it.
Ensure that when kvfree is called, that it is operating in a context
where it is allowed to sleep.

Cc: Alexander Viro <viro@...iv.linux.org.uk>
Cc: Luis Henriques <lhenriques@...e.com>
Signed-off-by: Jeff Layton <jlayton@...nel.org>
---
 mm/util.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/util.c b/mm/util.c
index e6351a80f248..81ec2a003c86 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -482,6 +482,8 @@ EXPORT_SYMBOL(kvmalloc_node);
  */
 void kvfree(const void *addr)
 {
+	might_sleep_if(!in_interrupt());
+
 	if (is_vmalloc_addr(addr))
 		vfree(addr);
 	else
-- 
2.21.0