[Xen-devel] [PATCH 4/37] drivers/block: Use kmemdup

[Julia Lawall <julia@xxxxxxx>]

From: Julia Lawall <julia@xxxxxxx>

Use kmemdup when some other buffer is immediately copied into the
allocated region.

A simplified version of the semantic patch that makes this change is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression from,to,size,flag;
statement S;
@@

-  to = \(kmalloc\|kzalloc\)(size,flag);
+  to = kmemdup(from,size,flag);
   if (to==NULL || ...) S
-  memcpy(to, from, size);
// </smpl>

Signed-off-by: Julia Lawall <julia@xxxxxxx>

---
 drivers/block/xen-blkfront.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff -u -p a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -775,11 +775,10 @@ static int blkif_recover(struct blkfront
        int j;
 
        /* Stage 1: Make a safe copy of the shadow state. */
-       copy = kmalloc(sizeof(info->shadow),
+       copy = kmemdup(info->shadow, sizeof(info->shadow),
                       GFP_NOIO | __GFP_REPEAT | __GFP_HIGH);
        if (!copy)
                return -ENOMEM;
-       memcpy(copy, info->shadow, sizeof(info->shadow));
 
        /* Stage 2: Set up free list. */
        memset(&info->shadow, 0, sizeof(info->shadow));

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