From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
To: David Howells <dhowells@redhat.com>
Cc: linux-afs@lists.infradead.org, linux-kernel@vger.kernel.org,
"Gustavo A. R. Silva" <gustavo@embeddedor.com>
Subject: [PATCH] afs: security: Use struct_size() in kzalloc()
Date: Tue, 4 Jun 2019 11:29:28 -0500 [thread overview]
Message-ID: <20190604162928.GA12389@embeddedor> (raw)
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:
struct foo {
int stuff;
struct boo entry[];
};
instance = kzalloc(sizeof(struct foo) + count * sizeof(struct boo), GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
fs/afs/security.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/fs/afs/security.c b/fs/afs/security.c
index 71e71c07568f..82753f3c097f 100644
--- a/fs/afs/security.c
+++ b/fs/afs/security.c
@@ -191,8 +191,7 @@ void afs_cache_permit(struct afs_vnode *vnode, struct key *key,
* yet.
*/
size++;
- new = kzalloc(sizeof(struct afs_permits) +
- sizeof(struct afs_permit) * size, GFP_NOFS);
+ new = kzalloc(struct_size(new, permits, size), GFP_NOFS);
if (!new)
goto out_put;
--
2.21.0
next reply other threads:[~2019-06-04 16:29 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-04 16:29 Gustavo A. R. Silva [this message]
-- strict thread matches above, loose matches on Subject: below --
2019-01-09 14:49 [PATCH] afs: security: Use struct_size() in kzalloc() Gustavo A. R. Silva
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