From: Kefeng Wang <wangkefeng.wang@huawei.com>
To: Matthew Wilcox <willy@infradead.org>
Cc: <shakeelb@google.com>, <vbabka@suse.cz>,
Christoph Lameter <cl@linux.com>,
Pekka Enberg <penberg@kernel.org>,
David Rientjes <rientjes@google.com>,
Joonsoo Kim <iamjoonsoo.kim@lge.com>,
Andrew Morton <akpm@linux-foundation.org>, <linux-mm@kvack.org>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH resend] slub: Add back check for free nonslab objects
Date: Mon, 27 Sep 2021 11:06:27 +0800 [thread overview]
Message-ID: <5fbb67aa-9651-6fb8-4339-a74ac53acb33@huawei.com> (raw)
In-Reply-To: <YVEvgfJQJ1aRerg6@casper.infradead.org>
On 2021/9/27 10:42, Matthew Wilcox wrote:
> On Mon, Sep 27, 2021 at 10:15:38AM +0800, Kefeng Wang wrote:
>> Commit ("0937502af7c9 slub: Add check for kfree() of non slab objects.")
>> add the ability, which should be needed in any configs to catch the
>> invalid free, they even could be potential issue, eg, memory corruption,
>> use after free and double-free, so replace VM_BUG_ON_PAGE to WARN_ON, and
>> add dump_page() to help use to debug the issue.
> Is dump_page() really the best way to catch such a thing? I would have
> thought that printing the address of 'object' would be more helpful.
With no vmcore, dump_page() do help us to find a memory corruption issue.
We could add 'object ' address print too.
>
>> @@ -3522,7 +3522,8 @@ static inline void free_nonslab_page(struct page *page, void *object)
>> {
>> unsigned int order = compound_order(page);
>>
>> - VM_BUG_ON_PAGE(!PageCompound(page), page);
>> + if (WARN_ON(!PageCompound(page)))
>> + dump_page(page, "invalid free nonslab page");
> .
>
next prev parent reply other threads:[~2021-09-27 3:06 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-27 2:15 Kefeng Wang
2021-09-27 2:42 ` Matthew Wilcox
2021-09-27 3:06 ` Kefeng Wang [this message]
2021-09-27 7:22 ` Vlastimil Babka
2021-09-27 7:53 ` Kefeng Wang
2021-09-28 15:43 ` Matthew Wilcox
2021-09-29 2:06 ` Kefeng Wang
2021-09-29 16:39 ` Vlastimil Babka
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