Re: [PATCH -next] bootmem: remove the vmemmap pages from kmemleak in free_bootmem_page

From: Liu Shixin <liushixin2@huawei.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Muchun Song <songmuchun@bytedance.com>,
	Matthew Wilcox <willy@infradead.org>,
	Mike Kravetz <mike.kravetz@oracle.com>,
	Oscar Salvador <osalvador@suse.de>,
	<linux-kernel@vger.kernel.org>, <linux-mm@kvack.org>
Subject: Re: [PATCH -next] bootmem: remove the vmemmap pages from kmemleak in free_bootmem_page
Date: Wed, 24 Aug 2022 14:27:25 +0800	[thread overview]
Message-ID: <ad8ddde7-6828-3af3-f162-cab29f38d044@huawei.com> (raw)
In-Reply-To: <20220818132104.2144770-1-liushixin2@huawei.com>

Hi Andrew,

This patch is superseded by latter patch so don't merge it in next. Just the latter is fine.

Thanks,

https://lore.kernel.org/all/20220819094005.2928241-1-liushixin2@huawei.com/T/#u

On 2022/8/18 21:21, Liu Shixin wrote:
> The vmemmap pages is marked by kmemleak when allocated from memblock.
> Remove it from kmemleak when free the page. Otherwise, when we reuse the
> page, kmemleak may report such an error and then stop working.
>
>  kmemleak: Cannot insert 0xffff98fb6eab3d40 into the object search tree (overlaps existing)
>  kmemleak: Kernel memory leak detector disabled
>  kmemleak: Object 0xffff98fb6be00000 (size 335544320):
>  kmemleak:   comm "swapper", pid 0, jiffies 4294892296
>  kmemleak:   min_count = 0
>  kmemleak:   count = 0
>  kmemleak:   flags = 0x1
>  kmemleak:   checksum = 0
>  kmemleak:   backtrace:
>
> Fixes: f41f2ed43ca5 ("mm: hugetlb: free the vmemmap pages associated with each HugeTLB page")
> Signed-off-by: Liu Shixin <liushixin2@huawei.com>
> ---
>  include/linux/bootmem_info.h | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/bootmem_info.h b/include/linux/bootmem_info.h
> index cc35d010fa94..899bc56948f7 100644
> --- a/include/linux/bootmem_info.h
> +++ b/include/linux/bootmem_info.h
> @@ -3,6 +3,7 @@
>  #define __LINUX_BOOTMEM_INFO_H
>  
>  #include <linux/mm.h>
> +#include <linux/kmemleak.h>
>  
>  /*
>   * Types for free bootmem stored in page->lru.next. These have to be in
> @@ -38,9 +39,10 @@ static inline void free_bootmem_page(struct page *page)
>  	 */
>  	VM_BUG_ON_PAGE(page_ref_count(page) != 2, page);
>  
> -	if (magic == SECTION_INFO || magic == MIX_SECTION_INFO)
> +	if (magic == SECTION_INFO || magic == MIX_SECTION_INFO) {
> +		kmemleak_free_part(page_to_virt(page), PAGE_SIZE);
>  		put_page_bootmem(page);
> -	else
> +	} else
>  		VM_BUG_ON_PAGE(1, page);
>  }
>  #else