Re: [PATCH] x86/mce: Use kmalloc_array() in mce_chrdev_read()

From: Paolo Bonzini
Date: Thu Aug 25 2016 - 07:33:49 EST




On 25/08/2016 11:17, SF Markus Elfring wrote:
> From: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
> Date: Thu, 25 Aug 2016 11:00:05 +0200
>
> * A multiplication for the size determination of a memory allocation
> indicated that an array data structure should be processed.
> Thus reuse the corresponding function "kmalloc_array".
>
> This issue was detected by using the Coccinelle software.
>
> * Replace the specification of a data type by a pointer dereference
> to make the corresponding size determination a bit safer according to
> the Linux coding style convention.
>
> Signed-off-by: Markus Elfring <elfring@xxxxxxxxxxxxxxxxxxxxx>
> ---
> arch/x86/kernel/cpu/mcheck/mce.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
> index 79d8ec8..0bc831d 100644
> --- a/arch/x86/kernel/cpu/mcheck/mce.c
> +++ b/arch/x86/kernel/cpu/mcheck/mce.c
> @@ -1901,7 +1901,7 @@ static ssize_t mce_chrdev_read(struct file *filp, char __user *ubuf,
> unsigned prev, next;
> int i, err;
>
> - cpu_tsc = kmalloc(nr_cpu_ids * sizeof(long), GFP_KERNEL);
> + cpu_tsc = kmalloc_array(nr_cpu_ids, sizeof(*cpu_tsc), GFP_KERNEL);
> if (!cpu_tsc)
> return -ENOMEM;
>
>

Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>

I think you can post the patches with a larger granularity (e.g. one for
all of arch/x86/kernel).

Paolo