On Thu, 23 Sep 2021 20:26:42 +0800 Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx> wrote:
> The paired pte_unmap() call is missing before the
> dev_pagemap_mapping_shift() returns. So fix it.
>
> ...
>
> --- a/mm/memory-failure.c
> +++ b/mm/memory-failure.c
> @@ -306,6 +306,7 @@ static unsigned long dev_pagemap_mapping_shift(struct page *page,
> struct vm_area_struct *vma)
> {
> unsigned long address = vma_address(page, vma);
> + unsigned long ret = 0;
> pgd_t *pgd;
> p4d_t *p4d;
> pud_t *pud;
> @@ -330,10 +331,12 @@ static unsigned long dev_pagemap_mapping_shift(struct page *page,
> return PMD_SHIFT;
> pte = pte_offset_map(pmd, address);
> if (!pte_present(*pte))
> - return 0;
> + goto unmap;
> if (pte_devmap(*pte))
> - return PAGE_SHIFT;
> - return 0;
> + ret = PAGE_SHIFT;
> +unmap:
> + pte_unmap(pte);
> + return ret;
> }
>
This is neater?
+++ a/mm/memory-failure.c
@@ -330,11 +330,8 @@ static unsigned long dev_pagemap_mapping
if (pmd_devmap(*pmd))
return PMD_SHIFT;
pte = pte_offset_map(pmd, address);
- if (!pte_present(*pte))
- goto unmap;
- if (pte_devmap(*pte))
+ if (pte_present(*pte) && pte_devmap(*pte))
ret = PAGE_SHIFT;
-unmap:
pte_unmap(pte);
return ret;
}
_
