[PATCH v2 20/35] platform/x86/asus: Use kmemdup rather than duplicating its implementation

[PATCH v2 20/35] platform/x86/asus: Use kmemdup rather than duplicating its implementation

[Fuqian Huang]

kmemdup is introduced to duplicate a region of memory in a neat way.
Rather than kmalloc/kzalloc + memcpy, which the programmer needs to
write the size twice (sometimes lead to mistakes), kmemdup improves
readability, leads to smaller code and also reduce the chances of mistakes.
Suggestion to use kmemdup rather than using kmalloc/kzalloc + memcpy.

Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
---
Changes in v2:
  - Fix a typo in commit message (memset -> memcpy)
  - Split into two patches.

 drivers/platform/x86/asus-wmi.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
index 9b18a184e0aa..472b317ad814 100644
--- a/drivers/platform/x86/asus-wmi.c
+++ b/drivers/platform/x86/asus-wmi.c
@@ -260,12 +260,11 @@ static int asus_wmi_evaluate_method_agfn(const struct acpi_buffer args)
 	 * Copy to dma capable address otherwise memory corruption occurs as
 	 * bios has to be able to access it.
 	 */
-	input.pointer = kzalloc(args.length, GFP_DMA | GFP_KERNEL);
+	input.pointer = kmemdup(args.pointer, args.length, GFP_DMA | GFP_KERNEL);
 	input.length = args.length;
 	if (!input.pointer)
 		return -ENOMEM;
 	phys_addr = virt_to_phys(input.pointer);
-	memcpy(input.pointer, args.pointer, args.length);
 
 	status = asus_wmi_evaluate_method(ASUS_WMI_METHODID_AGFN,
 					phys_addr, 0, &retval);
-- 
2.11.0

Re: [PATCH v2 20/35] platform/x86/asus: Use kmemdup rather than duplicating its implementation

[Andy Shevchenko]

On Wed, Jul 3, 2019 at 7:30 PM Fuqian Huang <huangfq.daxian@gmail.com> wrote:
>
> kmemdup is introduced to duplicate a region of memory in a neat way.
> Rather than kmalloc/kzalloc + memcpy, which the programmer needs to
> write the size twice (sometimes lead to mistakes), kmemdup improves
> readability, leads to smaller code and also reduce the chances of mistakes.
> Suggestion to use kmemdup rather than using kmalloc/kzalloc + memcpy.
>

Pushed to my review and testing queue, thanks!

> Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
> ---
> Changes in v2:
>   - Fix a typo in commit message (memset -> memcpy)
>   - Split into two patches.
>
>  drivers/platform/x86/asus-wmi.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/platform/x86/asus-wmi.c b/drivers/platform/x86/asus-wmi.c
> index 9b18a184e0aa..472b317ad814 100644
> --- a/drivers/platform/x86/asus-wmi.c
> +++ b/drivers/platform/x86/asus-wmi.c
> @@ -260,12 +260,11 @@ static int asus_wmi_evaluate_method_agfn(const struct acpi_buffer args)
>          * Copy to dma capable address otherwise memory corruption occurs as
>          * bios has to be able to access it.
>          */
> -       input.pointer = kzalloc(args.length, GFP_DMA | GFP_KERNEL);
> +       input.pointer = kmemdup(args.pointer, args.length, GFP_DMA | GFP_KERNEL);
>         input.length = args.length;
>         if (!input.pointer)
>                 return -ENOMEM;
>         phys_addr = virt_to_phys(input.pointer);
> -       memcpy(input.pointer, args.pointer, args.length);
>
>         status = asus_wmi_evaluate_method(ASUS_WMI_METHODID_AGFN,
>                                         phys_addr, 0, &retval);
> --
> 2.11.0
>


-- 
With Best Regards,
Andy Shevchenko