Re: [PATCH 1/4] sparc32: mm: Fix argument checking in __srmmu_get_nocache()

[Nick Desaulniers]

On Tue, Mar 24, 2020 at 3:52 AM Will Deacon <will@xxxxxxxxxx> wrote:
>
> The 'size' argument to __srmmu_get_nocache() is a number of bytes not
> a shift value, so fix up the sanity checking to treat it properly.
>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Signed-off-by: Will Deacon <will@xxxxxxxxxx>
> ---
>  arch/sparc/mm/srmmu.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/arch/sparc/mm/srmmu.c b/arch/sparc/mm/srmmu.c
> index f56c3c9a9793..a19863cac0c4 100644
> --- a/arch/sparc/mm/srmmu.c
> +++ b/arch/sparc/mm/srmmu.c
> @@ -175,18 +175,18 @@ pte_t *pte_offset_kernel(pmd_t *dir, unsigned long address)
>   */
>  static void *__srmmu_get_nocache(int size, int align)
>  {
> -       int offset;
> +       int offset, minsz = 1 << SRMMU_NOCACHE_BITMAP_SHIFT;
>         unsigned long addr;
>
> -       if (size < SRMMU_NOCACHE_BITMAP_SHIFT) {
> +       if (size < minsz) {
>                 printk(KERN_ERR "Size 0x%x too small for nocache request\n",
>                        size);
> -               size = SRMMU_NOCACHE_BITMAP_SHIFT;
> +               size = minsz;
>         }
> -       if (size & (SRMMU_NOCACHE_BITMAP_SHIFT - 1)) {
> -               printk(KERN_ERR "Size 0x%x unaligned int nocache request\n",
> +       if (size & (minsz - 1)) {
> +               printk(KERN_ERR "Size 0x%x unaligned in nocache request\n",

Was modifying the printk intentional? int vs in ?

>                        size);
> -               size += SRMMU_NOCACHE_BITMAP_SHIFT - 1;
> +               size += minsz - 1;
>         }
>         BUG_ON(align > SRMMU_NOCACHE_ALIGN_MAX);
>
> --
> 2.20.1
>


-- 
Thanks,
~Nick Desaulniers