<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/powerpc, branch v3.2.63</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>powerpc/mm: Use read barrier when creating real_pte</title>
<updated>2014-09-13T22:41:44+00:00</updated>
<author>
<name>Aneesh Kumar K.V</name>
<email>aneesh.kumar@linux.vnet.ibm.com</email>
</author>
<published>2014-08-13T07:02:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f9b211847bfb9c50483c7b62875e9aefbbce6f78'/>
<id>f9b211847bfb9c50483c7b62875e9aefbbce6f78</id>
<content type='text'>
commit 85c1fafd7262e68ad821ee1808686b1392b1167d upstream.

On ppc64 we support 4K hash pte with 64K page size. That requires
us to track the hash pte slot information on a per 4k basis. We do that
by storing the slot details in the second half of pte page. The pte bit
_PAGE_COMBO is used to indicate whether the second half need to be
looked while building real_pte. We need to use read memory barrier while
doing that so that load of hidx is not reordered w.r.t _PAGE_COMBO
check. On the store side we already do a lwsync in __hash_page_4K

Signed-off-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
[bwh: Backported to 3.2: include &lt;asm/system.h&gt; to ensure smp_rmb()
 is defined; cell_defconfig fails to build without this]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 85c1fafd7262e68ad821ee1808686b1392b1167d upstream.

On ppc64 we support 4K hash pte with 64K page size. That requires
us to track the hash pte slot information on a per 4k basis. We do that
by storing the slot details in the second half of pte page. The pte bit
_PAGE_COMBO is used to indicate whether the second half need to be
looked while building real_pte. We need to use read memory barrier while
doing that so that load of hidx is not reordered w.r.t _PAGE_COMBO
check. On the store side we already do a lwsync in __hash_page_4K

Signed-off-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
[bwh: Backported to 3.2: include &lt;asm/system.h&gt; to ensure smp_rmb()
 is defined; cell_defconfig fails to build without this]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Fix build errors STRICT_MM_TYPECHECKS</title>
<updated>2014-09-13T22:41:44+00:00</updated>
<author>
<name>Aneesh Kumar K.V</name>
<email>aneesh.kumar@linux.vnet.ibm.com</email>
</author>
<published>2013-05-06T10:51:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7a07d3c3824ca293447d4d9c48c0aeb378120835'/>
<id>7a07d3c3824ca293447d4d9c48c0aeb378120835</id>
<content type='text'>
commit 83d5e64b7efa7f39b10ff5e92792e807a720289c upstream.

Signed-off-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 83d5e64b7efa7f39b10ff5e92792e807a720289c upstream.

Signed-off-by: Aneesh Kumar K.V &lt;aneesh.kumar@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/mm/numa: Fix break placement</title>
<updated>2014-09-13T22:41:43+00:00</updated>
<author>
<name>Andrey Utkin</name>
<email>andrey.krieger.utkin@gmail.com</email>
</author>
<published>2014-08-04T20:13:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8b3e45d098afb0111679cb191e4b68bf121a23b3'/>
<id>8b3e45d098afb0111679cb191e4b68bf121a23b3</id>
<content type='text'>
commit b00fc6ec1f24f9d7af9b8988b6a198186eb3408c upstream.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=81631
Reported-by: David Binderman &lt;dcb314@hotmail.com&gt;
Signed-off-by: Andrey Utkin &lt;andrey.krieger.utkin@gmail.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit b00fc6ec1f24f9d7af9b8988b6a198186eb3408c upstream.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=81631
Reported-by: David Binderman &lt;dcb314@hotmail.com&gt;
Signed-off-by: Andrey Utkin &lt;andrey.krieger.utkin@gmail.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/mutex: Disable optimistic spinning on some architectures</title>
<updated>2014-08-06T17:07:38+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2014-06-06T17:53:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e87c95f8ac1ec35ebf4d144d4b46e2ecf153ffd4'/>
<id>e87c95f8ac1ec35ebf4d144d4b46e2ecf153ffd4</id>
<content type='text'>
commit 4badad352a6bb202ec68afa7a574c0bb961e5ebc upstream.

The optimistic spin code assumes regular stores and cmpxchg() play nice;
this is found to not be true for at least: parisc, sparc32, tile32,
metag-lock1, arc-!llsc and hexagon.

There is further wreckage, but this in particular seemed easy to
trigger, so blacklist this.

Opt in for known good archs.

Signed-off-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Reported-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Cc: Chris Metcalf &lt;cmetcalf@tilera.com&gt;
Cc: James Bottomley &lt;James.Bottomley@hansenpartnership.com&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Jason Low &lt;jason.low2@hp.com&gt;
Cc: Waiman Long &lt;waiman.long@hp.com&gt;
Cc: "James E.J. Bottomley" &lt;jejb@parisc-linux.org&gt;
Cc: Paul McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: John David Anglin &lt;dave.anglin@bell.net&gt;
Cc: James Hogan &lt;james.hogan@imgtec.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Davidlohr Bueso &lt;davidlohr@hp.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/20140606175316.GV13930@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
[bwh: Backported to 3.2:
 - Adjust context
 - Drop arm64 change]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 4badad352a6bb202ec68afa7a574c0bb961e5ebc upstream.

The optimistic spin code assumes regular stores and cmpxchg() play nice;
this is found to not be true for at least: parisc, sparc32, tile32,
metag-lock1, arc-!llsc and hexagon.

There is further wreckage, but this in particular seemed easy to
trigger, so blacklist this.

Opt in for known good archs.

Signed-off-by: Peter Zijlstra &lt;peterz@infradead.org&gt;
Reported-by: Mikulas Patocka &lt;mpatocka@redhat.com&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Cc: Chris Metcalf &lt;cmetcalf@tilera.com&gt;
Cc: James Bottomley &lt;James.Bottomley@hansenpartnership.com&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Jason Low &lt;jason.low2@hp.com&gt;
Cc: Waiman Long &lt;waiman.long@hp.com&gt;
Cc: "James E.J. Bottomley" &lt;jejb@parisc-linux.org&gt;
Cc: Paul McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: John David Anglin &lt;dave.anglin@bell.net&gt;
Cc: James Hogan &lt;james.hogan@imgtec.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Davidlohr Bueso &lt;davidlohr@hp.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Russell King &lt;linux@arm.linux.org.uk&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Link: http://lkml.kernel.org/r/20140606175316.GV13930@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
[bwh: Backported to 3.2:
 - Adjust context
 - Drop arm64 change]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Don't setup CPUs with bad status</title>
<updated>2014-07-11T12:33:49+00:00</updated>
<author>
<name>Michael Neuling</name>
<email>mikey@neuling.org</email>
</author>
<published>2014-06-06T04:28:51+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=335a4d5ba599428c32e6bdf726cd7f20553220a9'/>
<id>335a4d5ba599428c32e6bdf726cd7f20553220a9</id>
<content type='text'>
commit 59a53afe70fd530040bdc69581f03d880157f15a upstream.

OPAL will mark a CPU that is guarded as "bad" in the status property of the CPU
node.

Unfortunatley Linux doesn't check this property and will put the bad CPU in the
present map.  This has caused hangs on booting when we try to unsplit the core.

This patch checks the CPU is avaliable via this status property before putting
it in the present map.

Signed-off-by: Michael Neuling &lt;mikey@neuling.org&gt;
Tested-by: Anton Blanchard &lt;anton@samba.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 59a53afe70fd530040bdc69581f03d880157f15a upstream.

OPAL will mark a CPU that is guarded as "bad" in the status property of the CPU
node.

Unfortunatley Linux doesn't check this property and will put the bad CPU in the
present map.  This has caused hangs on booting when we try to unsplit the core.

This patch checks the CPU is avaliable via this status property before putting
it in the present map.

Signed-off-by: Michael Neuling &lt;mikey@neuling.org&gt;
Tested-by: Anton Blanchard &lt;anton@samba.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/serial: Use saner flags when creating legacy ports</title>
<updated>2014-07-11T12:33:46+00:00</updated>
<author>
<name>Benjamin Herrenschmidt</name>
<email>benh@kernel.crashing.org</email>
</author>
<published>2014-06-03T07:33:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=19e84f234b21b7cea051f109381c2f839e4dbc7e'/>
<id>19e84f234b21b7cea051f109381c2f839e4dbc7e</id>
<content type='text'>
commit c4cad90f9e9dcb85afc5e75a02ae3522ed077296 upstream.

We had a mix &amp; match of flags used when creating legacy ports
depending on where we found them in the device-tree. Among others
we were missing UPF_SKIP_TEST for some kind of ISA ports which is
a problem as quite a few UARTs out there don't support the loopback
test (such as a lot of BMCs).

Let's pick the set of flags used by the SoC code and generalize it
which means autoconf, no loopback test, irq maybe shared and fixed
port.

Sending to stable as the lack of UPF_SKIP_TEST is breaking
serial on some machines so I want this back into distros

Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c4cad90f9e9dcb85afc5e75a02ae3522ed077296 upstream.

We had a mix &amp; match of flags used when creating legacy ports
depending on where we found them in the device-tree. Among others
we were missing UPF_SKIP_TEST for some kind of ISA ports which is
a problem as quite a few UARTs out there don't support the loopback
test (such as a lot of BMCs).

Let's pick the set of flags used by the SoC code and generalize it
which means autoconf, no loopback test, irq maybe shared and fixed
port.

Sending to stable as the lack of UPF_SKIP_TEST is breaking
serial on some machines so I want this back into distros

Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Fix 64 bit builds with binutils 2.24</title>
<updated>2014-07-11T12:33:42+00:00</updated>
<author>
<name>Guenter Roeck</name>
<email>linux@roeck-us.net</email>
</author>
<published>2014-05-15T16:33:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1e2f98c52b3b79761f9969ae6aef9c079192448b'/>
<id>1e2f98c52b3b79761f9969ae6aef9c079192448b</id>
<content type='text'>
commit 7998eb3dc700aaf499f93f50b3d77da834ef9e1d upstream.

With binutils 2.24, various 64 bit builds fail with relocation errors
such as

arch/powerpc/kernel/built-in.o: In function `exc_debug_crit_book3e':
	(.text+0x165ee): relocation truncated to fit: R_PPC64_ADDR16_HI
	against symbol `interrupt_base_book3e' defined in .text section
	in arch/powerpc/kernel/built-in.o
arch/powerpc/kernel/built-in.o: In function `exc_debug_crit_book3e':
	(.text+0x16602): relocation truncated to fit: R_PPC64_ADDR16_HI
	against symbol `interrupt_end_book3e' defined in .text section
	in arch/powerpc/kernel/built-in.o

The assembler maintainer says:

 I changed the ABI, something that had to be done but unfortunately
 happens to break the booke kernel code.  When building up a 64-bit
 value with lis, ori, shl, oris, ori or similar sequences, you now
 should use @high and @higha in place of @h and @ha.  @h and @ha
 (and their associated relocs R_PPC64_ADDR16_HI and R_PPC64_ADDR16_HA)
 now report overflow if the value is out of 32-bit signed range.
 ie. @h and @ha assume you're building a 32-bit value. This is needed
 to report out-of-range -mcmodel=medium toc pointer offsets in @toc@h
 and @toc@ha expressions, and for consistency I did the same for all
 other @h and @ha relocs.

Replacing @h with @high in one strategic location fixes the relocation
errors. This has to be done conditionally since the assembler either
supports @h or @high but not both.

Signed-off-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 7998eb3dc700aaf499f93f50b3d77da834ef9e1d upstream.

With binutils 2.24, various 64 bit builds fail with relocation errors
such as

arch/powerpc/kernel/built-in.o: In function `exc_debug_crit_book3e':
	(.text+0x165ee): relocation truncated to fit: R_PPC64_ADDR16_HI
	against symbol `interrupt_base_book3e' defined in .text section
	in arch/powerpc/kernel/built-in.o
arch/powerpc/kernel/built-in.o: In function `exc_debug_crit_book3e':
	(.text+0x16602): relocation truncated to fit: R_PPC64_ADDR16_HI
	against symbol `interrupt_end_book3e' defined in .text section
	in arch/powerpc/kernel/built-in.o

The assembler maintainer says:

 I changed the ABI, something that had to be done but unfortunately
 happens to break the booke kernel code.  When building up a 64-bit
 value with lis, ori, shl, oris, ori or similar sequences, you now
 should use @high and @higha in place of @h and @ha.  @h and @ha
 (and their associated relocs R_PPC64_ADDR16_HI and R_PPC64_ADDR16_HA)
 now report overflow if the value is out of 32-bit signed range.
 ie. @h and @ha assume you're building a 32-bit value. This is needed
 to report out-of-range -mcmodel=medium toc pointer offsets in @toc@h
 and @toc@ha expressions, and for consistency I did the same for all
 other @h and @ha relocs.

Replacing @h with @high in one strategic location fixes the relocation
errors. This has to be done conditionally since the assembler either
supports @h or @high but not both.

Signed-off-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Add vr save/restore functions</title>
<updated>2014-06-09T12:28:54+00:00</updated>
<author>
<name>Andreas Schwab</name>
<email>schwab@linux-m68k.org</email>
</author>
<published>2013-12-30T14:31:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=705ec3cbfe64dbfeb60e9ad826c0342f77180022'/>
<id>705ec3cbfe64dbfeb60e9ad826c0342f77180022</id>
<content type='text'>
commit 8fe9c93e7453e67b8bd09f263ec1bb0783c733fc upstream.

GCC 4.8 now generates out-of-line vr save/restore functions when
optimizing for size.  They are needed for the raid6 altivec support.

Signed-off-by: Andreas Schwab &lt;schwab@linux-m68k.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 8fe9c93e7453e67b8bd09f263ec1bb0783c733fc upstream.

GCC 4.8 now generates out-of-line vr save/restore functions when
optimizing for size.  They are needed for the raid6 altivec support.

Signed-off-by: Andreas Schwab &lt;schwab@linux-m68k.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Align p_dyn, p_rela and p_st symbols</title>
<updated>2014-04-01T23:58:58+00:00</updated>
<author>
<name>Anton Blanchard</name>
<email>anton@samba.org</email>
</author>
<published>2014-03-03T21:31:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0c97b887e8125a445ac220dbb3d81adb2690ccba'/>
<id>0c97b887e8125a445ac220dbb3d81adb2690ccba</id>
<content type='text'>
commit a5b2cf5b1af424ee3dd9e3ce6d5cea18cb927e67 upstream.

The 64bit relocation code places a few symbols in the text segment.
These symbols are only 4 byte aligned where they need to be 8 byte
aligned. Add an explicit alignment.

Signed-off-by: Anton Blanchard &lt;anton@samba.org&gt;
Tested-by: Laurent Dufour &lt;ldufour@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a5b2cf5b1af424ee3dd9e3ce6d5cea18cb927e67 upstream.

The 64bit relocation code places a few symbols in the text segment.
These symbols are only 4 byte aligned where they need to be 8 byte
aligned. Add an explicit alignment.

Signed-off-by: Anton Blanchard &lt;anton@samba.org&gt;
Tested-by: Laurent Dufour &lt;ldufour@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/crashdump : Fix page frame number check in copy_oldmem_page</title>
<updated>2014-04-01T23:58:57+00:00</updated>
<author>
<name>Laurent Dufour</name>
<email>ldufour@linux.vnet.ibm.com</email>
</author>
<published>2014-02-24T16:30:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=955f8acb2df06b1e28c88dc653293f51b42eb8f0'/>
<id>955f8acb2df06b1e28c88dc653293f51b42eb8f0</id>
<content type='text'>
commit f5295bd8ea8a65dc5eac608b151386314cb978f1 upstream.

In copy_oldmem_page, the current check using max_pfn and min_low_pfn to
decide if the page is backed or not, is not valid when the memory layout is
not continuous.

This happens when running as a QEMU/KVM guest, where RTAS is mapped higher
in the memory. In that case max_pfn points to the end of RTAS, and a hole
between the end of the kdump kernel and RTAS is not backed by PTEs. As a
consequence, the kdump kernel is crashing in copy_oldmem_page when accessing
in a direct way the pages in that hole.

This fix relies on the memblock's service memblock_is_region_memory to
check if the read page is part or not of the directly accessible memory.

Signed-off-by: Laurent Dufour &lt;ldufour@linux.vnet.ibm.com&gt;
Tested-by: Mahesh Salgaonkar &lt;mahesh@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
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<pre>
commit f5295bd8ea8a65dc5eac608b151386314cb978f1 upstream.

In copy_oldmem_page, the current check using max_pfn and min_low_pfn to
decide if the page is backed or not, is not valid when the memory layout is
not continuous.

This happens when running as a QEMU/KVM guest, where RTAS is mapped higher
in the memory. In that case max_pfn points to the end of RTAS, and a hole
between the end of the kdump kernel and RTAS is not backed by PTEs. As a
consequence, the kdump kernel is crashing in copy_oldmem_page when accessing
in a direct way the pages in that hole.

This fix relies on the memblock's service memblock_is_region_memory to
check if the read page is part or not of the directly accessible memory.

Signed-off-by: Laurent Dufour &lt;ldufour@linux.vnet.ibm.com&gt;
Tested-by: Mahesh Salgaonkar &lt;mahesh@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
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