lkml.org 
[lkml]   [2021]   [Sep]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] mm/memory_failure: Fix the missing pte_unmap() call
From
Date


On 9/24/21 7:17 AM, Andrew Morton wrote:
> On Thu, 23 Sep 2021 20:26:42 +0800 Qi Zheng <zhengqi.arch@bytedance.com> 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?

Yes, and I see this neater version has merged into your mm tree,
thanks. :)

>
> +++ 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;
> }
> _
>

\
 
 \ /
  Last update: 2021-09-24 04:24    [W:0.050 / U:1.184 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site