From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Will Deacon <will.deacon@arm.com>,
"Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
linuxppc-dev@lists.ozlabs.org,
Catalin Marinas <catalin.marinas@arm.com>,
linux-arm-kernel@lists.infradead.org,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
linux-s390@vger.kernel.org,
Sebastian Ott <sebott@linux.vnet.ibm.com>
Subject: Re: [BUG] random kernel crashes after THP rework on s390 (maybe also on PowerPC and ARM)
Date: Wed, 24 Feb 2016 11:16:34 +0100 [thread overview]
Message-ID: <56CD8302.9080202@de.ibm.com> (raw)
In-Reply-To: <20160223202233.GE27281@arm.com>
On 02/23/2016 09:22 PM, Will Deacon wrote:
> On Tue, Feb 23, 2016 at 10:33:45PM +0300, Kirill A. Shutemov wrote:
>> On Tue, Feb 23, 2016 at 07:19:07PM +0100, Gerald Schaefer wrote:
>>> I'll check with Martin, maybe it is actually trivial, then we can
>>> do a quick test it to rule that one out.
>>
>> Oh. I found a bug in __split_huge_pmd_locked(). Although, not sure if it's
>> _the_ bug.
>>
>> pmdp_invalidate() is called for the wrong address :-/
>> I guess that can be destructive on the architecture, right?
>
> FWIW, arm64 ignores the address parameter for set_pmd_at, so this would
> only result in the TLBI nuking the wrong entries, which is going to be
> tricky to observe in practice given that we install a table entry
> immediately afterwards that maps the same pages. If s390 does more here
> (I see some magic asm using the address), that could be the answer...
This patch does not change the address for set_pmd_at, it does that for the
pmdp_invalidate here (by keeping haddr at the start of the pmd)
---> pmdp_invalidate(vma, haddr, pmd);
pmd_populate(mm, pmd, pgtable);
Without that fix we would clearly have stale tlb entries, no?
WARNING: multiple messages have this Message-ID (diff)
From: Christian Borntraeger <borntraeger@de.ibm.com>
To: Will Deacon <will.deacon@arm.com>,
"Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>,
"Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Michael Ellerman <mpe@ellerman.id.au>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
linuxppc-dev@lists.ozlabs.org,
Catalin Marinas <catalin.marinas@arm.com>,
linux-arm-kernel@lists.infradead.org,
Martin Schwidefsky <schwidefsky@de.ibm.com>,
Heiko Carstens <heiko.carstens@de.ibm.com>,
linux-s390@vger.kernel.org,
Sebastian Ott <sebott@linux.vnet.ibm.com>
Subject: Re: [BUG] random kernel crashes after THP rework on s390 (maybe also on PowerPC and ARM)
Date: Wed, 24 Feb 2016 11:16:34 +0100 [thread overview]
Message-ID: <56CD8302.9080202@de.ibm.com> (raw)
In-Reply-To: <20160223202233.GE27281@arm.com>
On 02/23/2016 09:22 PM, Will Deacon wrote:
> On Tue, Feb 23, 2016 at 10:33:45PM +0300, Kirill A. Shutemov wrote:
>> On Tue, Feb 23, 2016 at 07:19:07PM +0100, Gerald Schaefer wrote:
>>> I'll check with Martin, maybe it is actually trivial, then we can
>>> do a quick test it to rule that one out.
>>
>> Oh. I found a bug in __split_huge_pmd_locked(). Although, not sure if it's
>> _the_ bug.
>>
>> pmdp_invalidate() is called for the wrong address :-/
>> I guess that can be destructive on the architecture, right?
>
> FWIW, arm64 ignores the address parameter for set_pmd_at, so this would
> only result in the TLBI nuking the wrong entries, which is going to be
> tricky to observe in practice given that we install a table entry
> immediately afterwards that maps the same pages. If s390 does more here
> (I see some magic asm using the address), that could be the answer...
This patch does not change the address for set_pmd_at, it does that for the
pmdp_invalidate here (by keeping haddr at the start of the pmd)
---> pmdp_invalidate(vma, haddr, pmd);
pmd_populate(mm, pmd, pgtable);
Without that fix we would clearly have stale tlb entries, no?
--
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WARNING: multiple messages have this Message-ID (diff)
From: borntraeger@de.ibm.com (Christian Borntraeger)
To: linux-arm-kernel@lists.infradead.org
Subject: [BUG] random kernel crashes after THP rework on s390 (maybe also on PowerPC and ARM)
Date: Wed, 24 Feb 2016 11:16:34 +0100 [thread overview]
Message-ID: <56CD8302.9080202@de.ibm.com> (raw)
In-Reply-To: <20160223202233.GE27281@arm.com>
On 02/23/2016 09:22 PM, Will Deacon wrote:
> On Tue, Feb 23, 2016 at 10:33:45PM +0300, Kirill A. Shutemov wrote:
>> On Tue, Feb 23, 2016 at 07:19:07PM +0100, Gerald Schaefer wrote:
>>> I'll check with Martin, maybe it is actually trivial, then we can
>>> do a quick test it to rule that one out.
>>
>> Oh. I found a bug in __split_huge_pmd_locked(). Although, not sure if it's
>> _the_ bug.
>>
>> pmdp_invalidate() is called for the wrong address :-/
>> I guess that can be destructive on the architecture, right?
>
> FWIW, arm64 ignores the address parameter for set_pmd_at, so this would
> only result in the TLBI nuking the wrong entries, which is going to be
> tricky to observe in practice given that we install a table entry
> immediately afterwards that maps the same pages. If s390 does more here
> (I see some magic asm using the address), that could be the answer...
This patch does not change the address for set_pmd_at, it does that for the
pmdp_invalidate here (by keeping haddr at the start of the pmd)
---> pmdp_invalidate(vma, haddr, pmd);
pmd_populate(mm, pmd, pgtable);
Without that fix we would clearly have stale tlb entries, no?
next prev parent reply other threads:[~2016-02-24 10:16 UTC|newest]
Thread overview: 153+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-11 18:22 [BUG] random kernel crashes after THP rework on s390 (maybe also on PowerPC and ARM) Gerald Schaefer
2016-02-11 18:22 ` Gerald Schaefer
2016-02-11 18:22 ` Gerald Schaefer
2016-02-11 19:09 ` Kirill A. Shutemov
2016-02-11 19:09 ` Kirill A. Shutemov
2016-02-11 19:09 ` Kirill A. Shutemov
2016-02-11 19:12 ` Kirill A. Shutemov
2016-02-11 19:12 ` Kirill A. Shutemov
2016-02-11 19:12 ` Kirill A. Shutemov
2016-02-12 12:21 ` Sebastian Ott
2016-02-12 12:21 ` Sebastian Ott
2016-02-12 12:21 ` Sebastian Ott
2016-02-11 19:57 ` Gerald Schaefer
2016-02-11 19:57 ` Gerald Schaefer
2016-02-11 19:57 ` Gerald Schaefer
2016-02-12 4:04 ` Aneesh Kumar K.V
2016-02-12 4:04 ` Aneesh Kumar K.V
2016-02-12 4:04 ` Aneesh Kumar K.V
2016-02-12 11:59 ` Gerald Schaefer
2016-02-12 11:59 ` Gerald Schaefer
2016-02-12 11:59 ` Gerald Schaefer
2016-02-12 16:17 ` Aneesh Kumar K.V
2016-02-12 16:17 ` Aneesh Kumar K.V
2016-02-12 16:17 ` Aneesh Kumar K.V
2016-02-12 10:01 ` Will Deacon
2016-02-12 10:01 ` Will Deacon
2016-02-12 10:01 ` Will Deacon
2016-02-12 10:12 ` Sebastian Ott
2016-02-12 10:12 ` Sebastian Ott
2016-02-12 10:12 ` Sebastian Ott
2016-02-12 15:52 ` Will Deacon
2016-02-12 15:52 ` Will Deacon
2016-02-12 15:52 ` Will Deacon
2016-02-12 15:41 ` Kirill A. Shutemov
2016-02-12 15:41 ` Kirill A. Shutemov
2016-02-12 15:41 ` Kirill A. Shutemov
2016-02-12 15:57 ` Christian Borntraeger
2016-02-12 15:57 ` Christian Borntraeger
2016-02-12 15:57 ` Christian Borntraeger
2016-02-12 17:16 ` Gerald Schaefer
2016-02-12 17:16 ` Gerald Schaefer
2016-02-12 17:16 ` Gerald Schaefer
2016-02-12 23:15 ` Kirill A. Shutemov
2016-02-12 23:15 ` Kirill A. Shutemov
2016-02-12 23:15 ` Kirill A. Shutemov
2016-02-13 11:58 ` Sebastian Ott
2016-02-13 11:58 ` Sebastian Ott
2016-02-13 11:58 ` Sebastian Ott
2016-02-15 11:31 ` Kirill A. Shutemov
2016-02-15 11:31 ` Kirill A. Shutemov
2016-02-15 11:31 ` Kirill A. Shutemov
2016-02-15 16:38 ` Sebastian Ott
2016-02-15 16:38 ` Sebastian Ott
2016-02-15 16:38 ` Sebastian Ott
2016-02-15 18:37 ` Gerald Schaefer
2016-02-15 18:37 ` Gerald Schaefer
2016-02-15 18:37 ` Gerald Schaefer
2016-02-15 18:37 ` Gerald Schaefer
2016-02-15 21:35 ` Kirill A. Shutemov
2016-02-15 21:35 ` Kirill A. Shutemov
2016-02-15 21:35 ` Kirill A. Shutemov
2016-02-16 9:54 ` Sebastian Ott
2016-02-16 9:54 ` Sebastian Ott
2016-02-16 9:54 ` Sebastian Ott
2016-02-16 16:24 ` Gerald Schaefer
2016-02-16 16:24 ` Gerald Schaefer
2016-02-16 16:24 ` Gerald Schaefer
2016-02-16 16:24 ` Gerald Schaefer
2016-02-17 15:04 ` Kirill A. Shutemov
2016-02-17 15:04 ` Kirill A. Shutemov
2016-02-17 15:04 ` Kirill A. Shutemov
2016-02-17 19:04 ` Sebastian Ott
2016-02-17 19:04 ` Sebastian Ott
2016-02-17 19:04 ` Sebastian Ott
2016-02-16 18:46 ` Christian Borntraeger
2016-02-16 18:46 ` Christian Borntraeger
2016-02-16 18:46 ` Christian Borntraeger
2016-02-17 19:13 ` Gerald Schaefer
2016-02-17 19:13 ` Gerald Schaefer
2016-02-17 19:13 ` Gerald Schaefer
2016-02-17 23:58 ` Kirill A. Shutemov
2016-02-17 23:58 ` Kirill A. Shutemov
2016-02-17 23:58 ` Kirill A. Shutemov
2016-02-18 15:00 ` Gerald Schaefer
2016-02-18 15:00 ` Gerald Schaefer
2016-02-18 15:00 ` Gerald Schaefer
2016-02-18 17:06 ` Kirill A. Shutemov
2016-02-18 17:06 ` Kirill A. Shutemov
2016-02-18 17:06 ` Kirill A. Shutemov
2016-02-19 14:15 ` Sebastian Ott
2016-02-19 14:15 ` Sebastian Ott
2016-02-19 14:15 ` Sebastian Ott
2016-02-15 16:41 ` Gerald Schaefer
2016-02-15 16:41 ` Gerald Schaefer
2016-02-15 16:41 ` Gerald Schaefer
2016-02-23 10:32 ` Kirill A. Shutemov
2016-02-23 10:32 ` Kirill A. Shutemov
2016-02-23 10:32 ` Kirill A. Shutemov
2016-02-23 17:46 ` Linus Torvalds
2016-02-23 17:46 ` Linus Torvalds
2016-02-23 17:46 ` Linus Torvalds
2016-02-23 17:46 ` Linus Torvalds
2016-02-23 18:19 ` Gerald Schaefer
2016-02-23 18:19 ` Gerald Schaefer
2016-02-23 18:19 ` Gerald Schaefer
2016-02-23 18:47 ` Will Deacon
2016-02-23 18:47 ` Will Deacon
2016-02-23 18:47 ` Will Deacon
2016-02-25 15:49 ` Steve Capper
2016-02-25 15:49 ` Steve Capper
2016-02-25 15:49 ` Steve Capper
2016-02-25 15:49 ` Steve Capper
2016-02-25 16:01 ` Kirill A. Shutemov
2016-02-25 16:01 ` Kirill A. Shutemov
2016-02-25 16:01 ` Kirill A. Shutemov
2016-02-25 16:01 ` Kirill A. Shutemov
2016-02-25 16:08 ` Steve Capper
2016-02-25 16:08 ` Steve Capper
2016-02-25 16:08 ` Steve Capper
2016-02-25 16:08 ` Steve Capper
2016-02-23 19:33 ` Kirill A. Shutemov
2016-02-23 19:33 ` Kirill A. Shutemov
2016-02-23 19:33 ` Kirill A. Shutemov
2016-02-23 20:22 ` Will Deacon
2016-02-23 20:22 ` Will Deacon
2016-02-23 20:22 ` Will Deacon
2016-02-24 10:16 ` Christian Borntraeger [this message]
2016-02-24 10:16 ` Christian Borntraeger
2016-02-24 10:16 ` Christian Borntraeger
2016-02-24 10:41 ` Will Deacon
2016-02-24 10:41 ` Will Deacon
2016-02-24 10:41 ` Will Deacon
2016-02-24 10:51 ` Christian Borntraeger
2016-02-24 10:51 ` Christian Borntraeger
2016-02-24 10:51 ` Christian Borntraeger
2016-02-24 11:02 ` Will Deacon
2016-02-24 11:02 ` Will Deacon
2016-02-24 11:02 ` Will Deacon
2016-02-24 17:22 ` Aneesh Kumar K.V
2016-02-24 17:22 ` Aneesh Kumar K.V
2016-02-24 17:22 ` Aneesh Kumar K.V
2016-02-24 8:39 ` Martin Schwidefsky
2016-02-24 8:39 ` Martin Schwidefsky
2016-02-24 8:39 ` Martin Schwidefsky
2016-02-24 12:11 ` Sebastian Ott
2016-02-24 12:11 ` Sebastian Ott
2016-02-24 12:11 ` Sebastian Ott
2016-02-24 16:44 ` Gerald Schaefer
2016-02-24 16:44 ` Gerald Schaefer
2016-02-24 16:44 ` Gerald Schaefer
2016-02-24 8:22 ` Martin Schwidefsky
2016-02-24 8:22 ` Martin Schwidefsky
2016-02-24 8:22 ` Martin Schwidefsky
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