From: Kefeng Wang <wangkefeng.wang@huawei.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: <linux-mm@kvack.org>, <linux-fsdevel@vger.kernel.org>,
<akpm@linux-foundation.org>,
William Kucharski <william.kucharski@oracle.com>,
Vlastimil Babka <vbabka@suse.cz>,
"Anshuman Khandual" <anshuman.khandual@arm.com>
Subject: Re: [PATCH 3/8] mm/debug: Factor PagePoisoned out of __dump_page
Date: Wed, 12 May 2021 11:53:22 +0800 [thread overview]
Message-ID: <83bcb26b-79ae-d47f-81c0-873e07d43f3b@huawei.com> (raw)
In-Reply-To: <YJtNxP5I8auBg/XL@casper.infradead.org>
On 2021/5/12 11:38, Matthew Wilcox wrote:
> On Wed, May 12, 2021 at 11:29:06AM +0800, Kefeng Wang wrote:
>>> void dump_page(struct page *page, const char *reason)
>>> {
>>> - __dump_page(page, reason);
>>> + if (PagePoisoned(page))
>>> + pr_warn("page:%p is uninitialized and poisoned", page);
>>> + else
>>> + __dump_page(page);
>>
>> Hi Matthew, dump_page_owenr() should be called when !PagePoisoned, right?
>>
>>
>>> + if (reason)
>>> + pr_warn("page dumped because: %s\n", reason);
>>> dump_page_owner(page);
>>> }
>>> EXPORT_SYMBOL(dump_page);
>
> dump_page_owner() is called whether the page is Poisoned or not ...
> both before and after this patch. Is there a problem with that?
struct page_ext *page_ext = lookup_page_ext(page);
unsigned long pfn = page_to_pfn(page);
struct mem_section *section = __pfn_to_section(pfn);
if (!section->page_ext)
If page is Poisoned, I guess the section maybe NULL,
so section->page_ext may meet NULL pointer dereference,
is it possible?
>
> .
>
next prev parent reply other threads:[~2021-05-12 3:53 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-30 14:55 [PATCH 0/8] Folio Prequel patches Matthew Wilcox (Oracle)
2021-04-30 14:55 ` [PATCH 1/8] mm: Optimise nth_page for contiguous memmap Matthew Wilcox (Oracle)
2021-04-30 14:55 ` [PATCH 2/8] mm: Make __dump_page static Matthew Wilcox (Oracle)
2021-04-30 14:55 ` [PATCH 3/8] mm/debug: Factor PagePoisoned out of __dump_page Matthew Wilcox (Oracle)
2021-05-12 3:29 ` Kefeng Wang
2021-05-12 3:38 ` Matthew Wilcox
2021-05-12 3:53 ` Kefeng Wang [this message]
2021-04-30 14:55 ` [PATCH 4/8] mm/page_owner: Constify dump_page_owner Matthew Wilcox (Oracle)
2021-04-30 14:55 ` [PATCH 5/8] mm: Make compound_head const-preserving Matthew Wilcox (Oracle)
2021-04-30 14:55 ` [PATCH 6/8] mm: Constify get_pfnblock_flags_mask and get_pfnblock_migratetype Matthew Wilcox (Oracle)
2021-04-30 14:55 ` [PATCH 7/8] mm: Constify page_count and page_ref_count Matthew Wilcox (Oracle)
2021-04-30 14:55 ` [PATCH 8/8] mm: Fix struct page layout on 32-bit systems Matthew Wilcox (Oracle)
2021-05-10 16:12 ` [PATCH 0/8] Folio Prequel patches Matteo Croce
2021-05-10 16:29 ` Matthew Wilcox
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