Re: [PATCH mm-new 3/5] mm: mincore: replace __get_free_page() with kmalloc()

[Andrew Morton <akpm@linux-foundation.org>]

On Wed, 1 Jul 2026 22:40:45 +0800 Kefeng Wang <wangkefeng.wang@huawei.com> wrote:

> Remove ugly casts by using the more natural kmalloc/kfree allocation.
> 
> --- a/mm/mincore.c
> +++ b/mm/mincore.c
> @@ -13,6 +13,7 @@
>  #include <linux/pagewalk.h>
>  #include <linux/mman.h>
>  #include <linux/mmap_lock.h>
> +#include <linux/slab.h>
>  #include <linux/syscalls.h>
>  #include <linux/swap.h>
>  #include <linux/leafops.h>
> @@ -312,7 +313,7 @@ SYSCALL_DEFINE3(mincore, unsigned long, start, size_t, len,
>  	if (!access_ok(vec, pages))
>  		return -EFAULT;
>  
> -	tmp = (void *) __get_free_page(GFP_USER);
> +	tmp = kmalloc(PAGE_SIZE, GFP_USER);

kmalloc(GFP_USER) is a weird combination.  I don't think GFP_USER ever
made sense in here.

>  	if (!tmp)
>  		return -EAGAIN;
>  
> @@ -358,6 +359,6 @@ SYSCALL_DEFINE3(mincore, unsigned long, start, size_t, len,
>  		start += retval << PAGE_SHIFT;
>  		retval = 0;
>  	}
> -	free_page((unsigned long) tmp);
> +	kfree(tmp);
>  	return retval;
>  }