| Message ID | 20190108155244.GA15339@embeddedor |
|---|---|
| State | Accepted |
| Delegated to: | Boris Brezillon |
| Headers | show |
| Series | mtd: cfi: cmdset_0001: Use struct_size() in kmalloc() | expand |
From: Boris Brezillon <boris.brezillon@bootlin.com> On Tue, 2019-01-08 at 15:52:44 UTC, "Gustavo A. R. Silva" wrote: > 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; > void *entry[]; > }; > > instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); > > Instead of leaving these open-coded and prone to type mistakes, we can > now use the new struct_size() helper: > > instance = kmalloc(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> Applied to http://git.infradead.org/linux-mtd.git mtd/next, thanks. Boris
diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c index 6e8e7b1bb34b..79a53cb8507b 100644 --- a/drivers/mtd/chips/cfi_cmdset_0001.c +++ b/drivers/mtd/chips/cfi_cmdset_0001.c @@ -756,7 +756,8 @@ static int cfi_intelext_partition_fixup(struct mtd_info *mtd, } numvirtchips = cfi->numchips * numparts; - newcfi = kmalloc(sizeof(struct cfi_private) + numvirtchips * sizeof(struct flchip), GFP_KERNEL); + newcfi = kmalloc(struct_size(newcfi, chips, numvirtchips), + GFP_KERNEL); if (!newcfi) return -ENOMEM; shared = kmalloc_array(cfi->numchips,
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; void *entry[]; }; instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL); Instead of leaving these open-coded and prone to type mistakes, we can now use the new struct_size() helper: instance = kmalloc(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> --- drivers/mtd/chips/cfi_cmdset_0001.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)