| Message ID | 20190108153601.GA11557@embeddedor |
|---|---|
| State | Accepted |
| Delegated to: | Boris Brezillon |
| Headers | show |
| Series | mtd: gen_probe: Use struct_size() in kmalloc() | expand |
From: Boris Brezillon <boris.brezillon@bootlin.com> On Tue, 2019-01-08 at 15:36:01 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/gen_probe.c b/drivers/mtd/chips/gen_probe.c index 837b04ab96a9..839ed40625d6 100644 --- a/drivers/mtd/chips/gen_probe.c +++ b/drivers/mtd/chips/gen_probe.c @@ -135,7 +135,7 @@ static struct cfi_private *genprobe_ident_chips(struct map_info *map, struct chi * our caller, and copy the appropriate data into them. */ - retcfi = kmalloc(sizeof(struct cfi_private) + cfi.numchips * sizeof(struct flchip), GFP_KERNEL); + retcfi = kmalloc(struct_size(retcfi, chips, cfi.numchips), GFP_KERNEL); if (!retcfi) { kfree(cfi.cfiq);
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/gen_probe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)