* [PATCH net-next] wan: wanxl: use struct_size() in kzalloc()
@ 2019-02-08 3:16 Gustavo A. R. Silva
2019-02-09 6:58 ` David Miller
0 siblings, 1 reply; 2+ messages in thread
From: Gustavo A. R. Silva @ 2019-02-08 3:16 UTC (permalink / raw)
To: Krzysztof Halasa, David S. Miller
Cc: netdev, linux-kernel, Gustavo A. R. Silva
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[];
};
size = sizeof(struct foo) + count * sizeof(struct boo);
instance = alloc(size, GFP_KERNEL)
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = alloc(struct_size(instance, entry, count), GFP_KERNEL)
Notice that, in this case, variable alloc_size is not necessary, hence
it is removed.
This code was detected with the help of Coccinelle.
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
drivers/net/wan/wanxl.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)
diff --git a/drivers/net/wan/wanxl.c b/drivers/net/wan/wanxl.c
index d573a57bc301..459ce52a0a4d 100644
--- a/drivers/net/wan/wanxl.c
+++ b/drivers/net/wan/wanxl.c
@@ -565,7 +565,7 @@ static int wanxl_pci_init_one(struct pci_dev *pdev,
u32 plx_phy; /* PLX PCI base address */
u32 mem_phy; /* memory PCI base addr */
u8 __iomem *mem; /* memory virtual base addr */
- int i, ports, alloc_size;
+ int i, ports;
#ifndef MODULE
pr_info_once("%s\n", version);
@@ -601,8 +601,7 @@ static int wanxl_pci_init_one(struct pci_dev *pdev,
default: ports = 4;
}
- alloc_size = sizeof(struct card) + ports * sizeof(struct port);
- card = kzalloc(alloc_size, GFP_KERNEL);
+ card = kzalloc(struct_size(card, ports, ports), GFP_KERNEL);
if (card == NULL) {
pci_release_regions(pdev);
pci_disable_device(pdev);
--
2.20.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH net-next] wan: wanxl: use struct_size() in kzalloc()
2019-02-08 3:16 [PATCH net-next] wan: wanxl: use struct_size() in kzalloc() Gustavo A. R. Silva
@ 2019-02-09 6:58 ` David Miller
0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2019-02-09 6:58 UTC (permalink / raw)
To: gustavo; +Cc: khc, netdev, linux-kernel
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Date: Thu, 7 Feb 2019 21:16:48 -0600
> 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[];
> };
>
> size = sizeof(struct foo) + count * sizeof(struct boo);
> instance = alloc(size, GFP_KERNEL)
>
> Instead of leaving these open-coded and prone to type mistakes, we can
> now use the new struct_size() helper:
>
> instance = alloc(struct_size(instance, entry, count), GFP_KERNEL)
>
> Notice that, in this case, variable alloc_size is not necessary, hence
> it is removed.
>
> This code was detected with the help of Coccinelle.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Applied.
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