From: Michael Ellerman <mpe@ellerman.id.au>
To: Gavin Shan <gwshan@linux.vnet.ibm.com>, linux-mm@kvack.org
Cc: linuxppc-dev@lists.ozlabs.org, mgorman@suse.de,
zhlcindy@linux.vnet.ibm.com,
Gavin Shan <gwshan@linux.vnet.ibm.com>
Subject: Re: [RFC] mm: Fix memory corruption caused by deferred page initialization
Date: Sat, 26 Mar 2016 20:47:17 +1100 (AEDT) [thread overview]
Message-ID: <3qXFh60DRNz9sDH@ozlabs.org> (raw)
In-Reply-To: <1458921929-15264-1-git-send-email-gwshan@linux.vnet.ibm.com>
Hi Gavin,
On Fri, 2016-25-03 at 16:05:29 UTC, Gavin Shan wrote:
> During deferred page initialization, the pages are moved from memblock
> or bootmem to buddy allocator without checking they were reserved. Those
> reserved pages can be reallocated to somebody else by buddy/slab allocator.
> It leads to memory corruption and potential kernel crash eventually.
Can you give me a bit more detail on what the bug is?
I haven't seen any issues on my systems, but I realise now I haven't enabled
DEFERRED_STRUCT_PAGE_INIT - I assumed it was enabled by default.
How did this get tested before submission?
> This fixes above issue by:
>
> * Deferred releasing bootmem bitmap until the completion of deferred
> page initialization.
As I said in my other mail, we don't support bootmem anymore. So please resend
with just the non-bootmem fixes.
cheers
next prev parent reply other threads:[~2016-03-26 9:47 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-25 16:05 [PATCH RFC] mm: Fix memory corruption caused by deferred page initialization Gavin Shan
2016-03-26 9:47 ` Michael Ellerman [this message]
2016-03-26 13:37 ` [RFC] " Gavin Shan
2016-03-27 13:48 ` Gavin Shan
2016-03-31 2:27 ` Gavin Shan
2016-04-04 8:39 ` Mel Gorman
2016-04-04 11:24 ` Gavin Shan
2016-03-28 14:20 ` Aneesh Kumar K.V
2016-03-29 5:13 ` Li Zhang
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