Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.
This code was detected with the help of Coccinelle and, audited and
fixed manually.
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
include/linux/fb.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/linux/fb.h b/include/linux/fb.h
index 3b4b2f0c6994..2b530e6d86e4 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -506,8 +506,9 @@ struct fb_info {
};
static inline struct apertures_struct *alloc_apertures(unsigned int max_num) {
- struct apertures_struct *a = kzalloc(sizeof(struct apertures_struct)
- + max_num * sizeof(struct aperture), GFP_KERNEL);
+ struct apertures_struct *a;
+
+ a = kzalloc(struct_size(a, ranges, max_num), GFP_KERNEL);
if (!a)
return NULL;
a->count = max_num;
--
2.27.0
Hi Gustavo.
On Wed, Jun 17, 2020 at 12:56:47PM -0500, Gustavo A. R. Silva wrote:
> Make use of the struct_size() helper instead of an open-coded version
> in order to avoid any potential type mistakes.
>
> This code was detected with the help of Coccinelle and, audited and
> fixed manually.
>
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
struct_size is defined in overflow.h - which is not included by fs.h.
So we rely on overflow.h being pulled in by some other header - maybe
slab.h in this case.
Seems fragile, should this patch add an include of overflow.h?
Sam
> ---
> include/linux/fb.h | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/fb.h b/include/linux/fb.h
> index 3b4b2f0c6994..2b530e6d86e4 100644
> --- a/include/linux/fb.h
> +++ b/include/linux/fb.h
> @@ -506,8 +506,9 @@ struct fb_info {
> };
>
> static inline struct apertures_struct *alloc_apertures(unsigned int max_num) {
> - struct apertures_struct *a = kzalloc(sizeof(struct apertures_struct)
> - + max_num * sizeof(struct aperture), GFP_KERNEL);
> + struct apertures_struct *a;
> +
> + a = kzalloc(struct_size(a, ranges, max_num), GFP_KERNEL);
> if (!a)
> return NULL;
> a->count = max_num;
> --
> 2.27.0
>
> _______________________________________________
> dri-devel mailing list
> [email protected]
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
On 6/20/20 1:27 PM, Sam Ravnborg wrote:
> Hi Gustavo.
>
> On Wed, Jun 17, 2020 at 12:56:47PM -0500, Gustavo A. R. Silva wrote:
>> Make use of the struct_size() helper instead of an open-coded version
>> in order to avoid any potential type mistakes.
>>
>> This code was detected with the help of Coccinelle and, audited and
>> fixed manually.
>>
>> Signed-off-by: Gustavo A. R. Silva <[email protected]>
>
> struct_size is defined in overflow.h - which is not included by fs.h.
> So we rely on overflow.h being pulled in by some other header - maybe
> slab.h in this case.
> Seems fragile, should this patch add an include of overflow.h?
$ git grep struct_size drivers/|wc -l
697
$ git grep overflow\\.h drivers/|wc -l
8
$ git grep overflow\\.h include/linux/
include/linux/device.h:#include <linux/overflow.h>
include/linux/mm.h:#include <linux/overflow.h>
include/linux/slab.h:#include <linux/overflow.h>
include/linux/vmalloc.h:#include <linux/overflow.h>
so I've applied the patch as it is (hoping that the issue is so
widespread that no-one tries to remove overflow.h from slab.h
without fixing drivers at the same time)..
Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics
> Sam
>
>> ---
>> include/linux/fb.h | 5 +++--
>> 1 file changed, 3 insertions(+), 2 deletions(-)
>>
>> diff --git a/include/linux/fb.h b/include/linux/fb.h
>> index 3b4b2f0c6994..2b530e6d86e4 100644
>> --- a/include/linux/fb.h
>> +++ b/include/linux/fb.h
>> @@ -506,8 +506,9 @@ struct fb_info {
>> };
>>
>> static inline struct apertures_struct *alloc_apertures(unsigned int max_num) {
>> - struct apertures_struct *a = kzalloc(sizeof(struct apertures_struct)
>> - + max_num * sizeof(struct aperture), GFP_KERNEL);
>> + struct apertures_struct *a;
>> +
>> + a = kzalloc(struct_size(a, ranges, max_num), GFP_KERNEL);
>> if (!a)
>> return NULL;
>> a->count = max_num;
>> --
>> 2.27.0
>>
>> _______________________________________________
>> dri-devel mailing list
>> [email protected]
>> https://protect2.fireeye.com/url?k=7bae4d09-26604cda-7bafc646-000babff317b-7eab3a2caa4b8b73&q=1&u=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fdri-devel
On 6/17/20 7:56 PM, Gustavo A. R. Silva wrote:
> Make use of the struct_size() helper instead of an open-coded version
> in order to avoid any potential type mistakes.
>
> This code was detected with the help of Coccinelle and, audited and
> fixed manually.
>
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
Applied to drm-misc-next tree, thanks.
Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics
> ---
> include/linux/fb.h | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/fb.h b/include/linux/fb.h
> index 3b4b2f0c6994..2b530e6d86e4 100644
> --- a/include/linux/fb.h
> +++ b/include/linux/fb.h
> @@ -506,8 +506,9 @@ struct fb_info {
> };
>
> static inline struct apertures_struct *alloc_apertures(unsigned int max_num) {
> - struct apertures_struct *a = kzalloc(sizeof(struct apertures_struct)
> - + max_num * sizeof(struct aperture), GFP_KERNEL);
> + struct apertures_struct *a;
> +
> + a = kzalloc(struct_size(a, ranges, max_num), GFP_KERNEL);
> if (!a)
> return NULL;
> a->count = max_num;
>