<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch, branch v4.4.97</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>ARM: pxa: Don't rely on public mmc header to include leds.h</title>
<updated>2017-11-08T09:06:29+00:00</updated>
<author>
<name>Ulf Hansson</name>
<email>ulf.hansson@linaro.org</email>
</author>
<published>2017-10-07T22:37:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ed414aeb5291ae1e1733bb24d8801b0167a454f0'/>
<id>ed414aeb5291ae1e1733bb24d8801b0167a454f0</id>
<content type='text'>
[ Upstream commit 40d727a2defa176b78159d445bcf7afcc2ed9021 ]

Some of the pxa platforms, balloon3, colibri-pxa270-income, corgi,
trizeps4, vpac270, zeus and zylonite depends on leds.h. Explicitly include
it instead of relying on the public mmc header host.h.

Cc: Daniel Mack &lt;daniel@zonque.org&gt;
Cc: Haojian Zhuang &lt;haojian.zhuang@gmail.com&gt;
Cc: Robert Jarzmik &lt;robert.jarzmik@free.fr&gt;
Cc: &lt;linux-arm-kernel@lists.infradead.org&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Acked-by: Robert Jarzmik &lt;robert.jarzmik@free.fr&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 40d727a2defa176b78159d445bcf7afcc2ed9021 ]

Some of the pxa platforms, balloon3, colibri-pxa270-income, corgi,
trizeps4, vpac270, zeus and zylonite depends on leds.h. Explicitly include
it instead of relying on the public mmc header host.h.

Cc: Daniel Mack &lt;daniel@zonque.org&gt;
Cc: Haojian Zhuang &lt;haojian.zhuang@gmail.com&gt;
Cc: Robert Jarzmik &lt;robert.jarzmik@free.fr&gt;
Cc: &lt;linux-arm-kernel@lists.infradead.org&gt;
Signed-off-by: Ulf Hansson &lt;ulf.hansson@linaro.org&gt;
Acked-by: Robert Jarzmik &lt;robert.jarzmik@free.fr&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: 8715/1: add a private asm/unaligned.h</title>
<updated>2017-11-08T09:06:28+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2017-10-20T20:17:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=cc7d9933400f9b7f16e4d36cb6974395c3116695'/>
<id>cc7d9933400f9b7f16e4d36cb6974395c3116695</id>
<content type='text'>
commit 1cce91dfc8f7990ca3aea896bfb148f240b12860 upstream.

The asm-generic/unaligned.h header provides two different implementations
for accessing unaligned variables: the access_ok.h version used when
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is set pretends that all pointers
are in fact aligned, while the le_struct.h version convinces gcc that the
alignment of a pointer is '1', to make it issue the correct load/store
instructions depending on the architecture flags.

On ARMv5 and older, we always use the second version, to let the compiler
use byte accesses. On ARMv6 and newer, we currently use the access_ok.h
version, so the compiler can use any instruction including stm/ldm and
ldrd/strd that will cause an alignment trap. This trap can significantly
impact performance when we have to do a lot of fixups and, worse, has
led to crashes in the LZ4 decompressor code that does not have a trap
handler.

This adds an ARM specific version of asm/unaligned.h that uses the
le_struct.h/be_struct.h implementation unconditionally. This should lead
to essentially the same code on ARMv6+ as before, with the exception of
using regular load/store instructions instead of the trapping instructions
multi-register variants.

The crash in the LZ4 decompressor code was probably introduced by the
patch replacing the LZ4 implementation, commit 4e1a33b105dd ("lib: update
LZ4 compressor module"), so linux-4.11 and higher would be affected most.
However, we probably want to have this backported to all older stable
kernels as well, to help with the performance issues.

There are two follow-ups that I think we should also work on, but not
backport to stable kernels, first to change the asm-generic version of
the header to remove the ARM special case, and second to review all
other uses of CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to see if they
might be affected by the same problem on ARM.

Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 1cce91dfc8f7990ca3aea896bfb148f240b12860 upstream.

The asm-generic/unaligned.h header provides two different implementations
for accessing unaligned variables: the access_ok.h version used when
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS is set pretends that all pointers
are in fact aligned, while the le_struct.h version convinces gcc that the
alignment of a pointer is '1', to make it issue the correct load/store
instructions depending on the architecture flags.

On ARMv5 and older, we always use the second version, to let the compiler
use byte accesses. On ARMv6 and newer, we currently use the access_ok.h
version, so the compiler can use any instruction including stm/ldm and
ldrd/strd that will cause an alignment trap. This trap can significantly
impact performance when we have to do a lot of fixups and, worse, has
led to crashes in the LZ4 decompressor code that does not have a trap
handler.

This adds an ARM specific version of asm/unaligned.h that uses the
le_struct.h/be_struct.h implementation unconditionally. This should lead
to essentially the same code on ARMv6+ as before, with the exception of
using regular load/store instructions instead of the trapping instructions
multi-register variants.

The crash in the LZ4 decompressor code was probably introduced by the
patch replacing the LZ4 implementation, commit 4e1a33b105dd ("lib: update
LZ4 compressor module"), so linux-4.11 and higher would be affected most.
However, we probably want to have this backported to all older stable
kernels as well, to help with the performance issues.

There are two follow-ups that I think we should also work on, but not
backport to stable kernels, first to change the asm-generic version of
the header to remove the ARM special case, and second to review all
other uses of CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS to see if they
might be affected by the same problem on ARM.

Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>ARM: dts: mvebu: pl310-cache disable double-linefill</title>
<updated>2017-11-08T09:06:27+00:00</updated>
<author>
<name>Yan Markman</name>
<email>ymarkman@marvell.com</email>
</author>
<published>2016-10-15T21:22:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4e351b8dd8b773669c3f0c5e50e4e61031f9e43e'/>
<id>4e351b8dd8b773669c3f0c5e50e4e61031f9e43e</id>
<content type='text'>
commit cda80a82ac3e89309706c027ada6ab232be1d640 upstream.

Under heavy system stress mvebu SoC using Cortex A9 sporadically
encountered instability issues.

The "double linefill" feature of L2 cache was identified as causing
dependency between read and write which lead to the deadlock.

Especially, it was the cause of deadlock seen under heavy PCIe traffic,
as this dependency violates PCIE overtaking rule.

Fixes: c8f5a878e554 ("ARM: mvebu: use DT properties to fine-tune the L2 configuration")
Signed-off-by: Yan Markman &lt;ymarkman@marvell.com&gt;
Signed-off-by: Igal Liberman &lt;igall@marvell.com&gt;
Signed-off-by: Nadav Haklai &lt;nadavh@marvell.com&gt;
[gregory.clement@free-electrons.com: reformulate commit log, add Armada
375 and add Fixes tag]
Signed-off-by: Gregory CLEMENT &lt;gregory.clement@free-electrons.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit cda80a82ac3e89309706c027ada6ab232be1d640 upstream.

Under heavy system stress mvebu SoC using Cortex A9 sporadically
encountered instability issues.

The "double linefill" feature of L2 cache was identified as causing
dependency between read and write which lead to the deadlock.

Especially, it was the cause of deadlock seen under heavy PCIe traffic,
as this dependency violates PCIE overtaking rule.

Fixes: c8f5a878e554 ("ARM: mvebu: use DT properties to fine-tune the L2 configuration")
Signed-off-by: Yan Markman &lt;ymarkman@marvell.com&gt;
Signed-off-by: Igal Liberman &lt;igall@marvell.com&gt;
Signed-off-by: Nadav Haklai &lt;nadavh@marvell.com&gt;
[gregory.clement@free-electrons.com: reformulate commit log, add Armada
375 and add Fixes tag]
Signed-off-by: Gregory CLEMENT &lt;gregory.clement@free-electrons.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: ensure __dump_instr() checks addr_limit</title>
<updated>2017-11-08T09:06:27+00:00</updated>
<author>
<name>Mark Rutland</name>
<email>mark.rutland@arm.com</email>
</author>
<published>2017-11-02T16:12:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=581ac5f431c9b01a820ee10581b042328d870230'/>
<id>581ac5f431c9b01a820ee10581b042328d870230</id>
<content type='text'>
commit 7a7003b1da010d2b0d1dc8bf21c10f5c73b389f1 upstream.

It's possible for a user to deliberately trigger __dump_instr with a
chosen kernel address.

Let's avoid problems resulting from this by using get_user() rather than
__get_user(), ensuring that we don't erroneously access kernel memory.

Where we use __dump_instr() on kernel text, we already switch to
KERNEL_DS, so this shouldn't adversely affect those cases.

Fixes: 60ffc30d5652810d ("arm64: Exception handling")
Acked-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 7a7003b1da010d2b0d1dc8bf21c10f5c73b389f1 upstream.

It's possible for a user to deliberately trigger __dump_instr with a
chosen kernel address.

Let's avoid problems resulting from this by using get_user() rather than
__get_user(), ensuring that we don't erroneously access kernel memory.

Where we use __dump_instr() on kernel text, we already switch to
KERNEL_DS, so this shouldn't adversely affect those cases.

Fixes: 60ffc30d5652810d ("arm64: Exception handling")
Acked-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>x86/microcode/intel: Disable late loading on model 79</title>
<updated>2017-11-02T08:40:50+00:00</updated>
<author>
<name>Borislav Petkov</name>
<email>bp@suse.de</email>
</author>
<published>2017-10-18T11:12:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=da0933ceec963ee0e9d477535901cd9a696362b1'/>
<id>da0933ceec963ee0e9d477535901cd9a696362b1</id>
<content type='text'>
commit 723f2828a98c8ca19842042f418fb30dd8cfc0f7 upstream.

Blacklist Broadwell X model 79 for late loading due to an erratum.

Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Acked-by: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: http://lkml.kernel.org/r/20171018111225.25635-1-bp@alien8.de
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;


</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 723f2828a98c8ca19842042f418fb30dd8cfc0f7 upstream.

Blacklist Broadwell X model 79 for late loading due to an erratum.

Signed-off-by: Borislav Petkov &lt;bp@suse.de&gt;
Acked-by: Tony Luck &lt;tony.luck@intel.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Link: http://lkml.kernel.org/r/20171018111225.25635-1-bp@alien8.de
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;


</pre>
</div>
</content>
</entry>
<entry>
<title>parisc: Fix double-word compare and exchange in LWS code on 32-bit kernels</title>
<updated>2017-10-27T08:23:17+00:00</updated>
<author>
<name>John David Anglin</name>
<email>dave.anglin@bell.net</email>
</author>
<published>2017-09-30T21:24:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fcc65ab173ebf797472b046f2d84663fbbe443a7'/>
<id>fcc65ab173ebf797472b046f2d84663fbbe443a7</id>
<content type='text'>
commit 374b3bf8e8b519f61eb9775888074c6e46b3bf0c upstream.

As discussed on the debian-hppa list, double-wordcompare and exchange
operations fail on 32-bit kernels.  Looking at the code, I realized that
the ",ma" completer does the wrong thing in the  "ldw,ma  4(%r26), %r29"
instruction.  This increments %r26 and causes the following store to
write to the wrong location.

Note by Helge Deller:
The patch applies cleanly to stable kernel series if this upstream
commit is merged in advance:
f4125cfdb300 ("parisc: Avoid trashing sr2 and sr3 in LWS code").

Signed-off-by: John David Anglin &lt;dave.anglin@bell.net&gt;
Tested-by: Christoph Biedl &lt;debian.axhn@manchmal.in-ulm.de&gt;
Fixes: 89206491201c ("parisc: Implement new LWS CAS supporting 64 bit operations.")
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 374b3bf8e8b519f61eb9775888074c6e46b3bf0c upstream.

As discussed on the debian-hppa list, double-wordcompare and exchange
operations fail on 32-bit kernels.  Looking at the code, I realized that
the ",ma" completer does the wrong thing in the  "ldw,ma  4(%r26), %r29"
instruction.  This increments %r26 and causes the following store to
write to the wrong location.

Note by Helge Deller:
The patch applies cleanly to stable kernel series if this upstream
commit is merged in advance:
f4125cfdb300 ("parisc: Avoid trashing sr2 and sr3 in LWS code").

Signed-off-by: John David Anglin &lt;dave.anglin@bell.net&gt;
Tested-by: Christoph Biedl &lt;debian.axhn@manchmal.in-ulm.de&gt;
Fixes: 89206491201c ("parisc: Implement new LWS CAS supporting 64 bit operations.")
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>parisc: Avoid trashing sr2 and sr3 in LWS code</title>
<updated>2017-10-27T08:23:17+00:00</updated>
<author>
<name>John David Anglin</name>
<email>dave.anglin@bell.net</email>
</author>
<published>2016-10-28T20:13:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=558ca24dc296a859af75edf495a0972a00e9200d'/>
<id>558ca24dc296a859af75edf495a0972a00e9200d</id>
<content type='text'>
commit f4125cfdb3008363137f744c101e5d76ead760ba upstream.

There is no need to trash sr2 and sr3 in the Light-weight syscall (LWS).  sr2
already points to kernel space (it's zero in userspace, otherwise syscalls
wouldn't work), and since the LWS code is executed in userspace, we can simply
ignore to preload sr3.

Signed-off-by: John David Anglin &lt;dave.anglin@bell.net&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit f4125cfdb3008363137f744c101e5d76ead760ba upstream.

There is no need to trash sr2 and sr3 in the Light-weight syscall (LWS).  sr2
already points to kernel space (it's zero in userspace, otherwise syscalls
wouldn't work), and since the LWS code is executed in userspace, we can simply
ignore to preload sr3.

Signed-off-by: John David Anglin &lt;dave.anglin@bell.net&gt;
Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>sparc64: Migrate hvcons irq to panicked cpu</title>
<updated>2017-10-21T15:09:05+00:00</updated>
<author>
<name>Vijay Kumar</name>
<email>vijay.ac.kumar@oracle.com</email>
</author>
<published>2017-02-01T19:34:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7bf94b9595cc8a561b1baf1046f9933785934a71'/>
<id>7bf94b9595cc8a561b1baf1046f9933785934a71</id>
<content type='text'>
[ Upstream commit 7dd4fcf5b70694dc961eb6b954673e4fc9730dbd ]

On panic, all other CPUs are stopped except the one which had
hit panic. To keep console alive, we need to migrate hvcons irq
to panicked CPU.

Signed-off-by: Vijay Kumar &lt;vijay.ac.kumar@oracle.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 7dd4fcf5b70694dc961eb6b954673e4fc9730dbd ]

On panic, all other CPUs are stopped except the one which had
hit panic. To keep console alive, we need to migrate hvcons irq
to panicked CPU.

Signed-off-by: Vijay Kumar &lt;vijay.ac.kumar@oracle.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Sasha Levin &lt;alexander.levin@verizon.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>MIPS: Fix minimum alignment requirement of IRQ stack</title>
<updated>2017-10-21T15:09:01+00:00</updated>
<author>
<name>Matt Redfearn</name>
<email>matt.redfearn@imgtec.com</email>
</author>
<published>2017-07-10T08:43:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=9f5bbe694df14d56860ffd8c1e121e2cda1aa076'/>
<id>9f5bbe694df14d56860ffd8c1e121e2cda1aa076</id>
<content type='text'>
commit 5fdc66e046206306bf61ff2d626bfa52ca087f7b upstream.

Commit db8466c581cc ("MIPS: IRQ Stack: Unwind IRQ stack onto task
stack") erroneously set the initial stack pointer of the IRQ stack to a
value with a 4 byte alignment. The MIPS32 ABI requires that the minimum
stack alignment is 8 byte, and the MIPS64 ABIs(n32/n64) require 16 byte
minimum alignment. Fix IRQ_STACK_START such that it leaves space for the
dummy stack frame (containing interrupted task kernel stack pointer)
while also meeting minimum alignment requirements.

Fixes: db8466c581cc ("MIPS: IRQ Stack: Unwind IRQ stack onto task stack")
Reported-by: Darius Ivanauskas &lt;dasilt@yahoo.com&gt;
Signed-off-by: Matt Redfearn &lt;matt.redfearn@imgtec.com&gt;
Cc: Chris Metcalf &lt;cmetcalf@mellanox.com&gt;
Cc: Petr Mladek &lt;pmladek@suse.com&gt;
Cc: Aaron Tomlin &lt;atomlin@redhat.com&gt;
Cc: Jason A. Donenfeld &lt;jason@zx2c4.com&gt;
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16760/
Signed-off-by: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 5fdc66e046206306bf61ff2d626bfa52ca087f7b upstream.

Commit db8466c581cc ("MIPS: IRQ Stack: Unwind IRQ stack onto task
stack") erroneously set the initial stack pointer of the IRQ stack to a
value with a 4 byte alignment. The MIPS32 ABI requires that the minimum
stack alignment is 8 byte, and the MIPS64 ABIs(n32/n64) require 16 byte
minimum alignment. Fix IRQ_STACK_START such that it leaves space for the
dummy stack frame (containing interrupted task kernel stack pointer)
while also meeting minimum alignment requirements.

Fixes: db8466c581cc ("MIPS: IRQ Stack: Unwind IRQ stack onto task stack")
Reported-by: Darius Ivanauskas &lt;dasilt@yahoo.com&gt;
Signed-off-by: Matt Redfearn &lt;matt.redfearn@imgtec.com&gt;
Cc: Chris Metcalf &lt;cmetcalf@mellanox.com&gt;
Cc: Petr Mladek &lt;pmladek@suse.com&gt;
Cc: Aaron Tomlin &lt;atomlin@redhat.com&gt;
Cc: Jason A. Donenfeld &lt;jason@zx2c4.com&gt;
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/16760/
Signed-off-by: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>x86/alternatives: Fix alt_max_short macro to really be a max()</title>
<updated>2017-10-18T07:20:43+00:00</updated>
<author>
<name>Mathias Krause</name>
<email>minipli@googlemail.com</email>
</author>
<published>2017-10-05T18:30:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ad505a7b4fb0fd8d533f78083df203d88cdf1a27'/>
<id>ad505a7b4fb0fd8d533f78083df203d88cdf1a27</id>
<content type='text'>
commit 6b32c126d33d5cb379bca280ab8acedc1ca978ff upstream.

The alt_max_short() macro in asm/alternative.h does not work as
intended, leading to nasty bugs. E.g. alt_max_short("1", "3")
evaluates to 3, but alt_max_short("3", "1") evaluates to 1 -- not
exactly the maximum of 1 and 3.

In fact, I had to learn it the hard way by crashing my kernel in not
so funny ways by attempting to make use of the ALTENATIVE_2 macro
with alternatives where the first one was larger than the second
one.

According to [1] and commit dbe4058a6a44 ("x86/alternatives: Fix
ALTERNATIVE_2 padding generation properly") the right handed side
should read "-(-(a &lt; b))" not "-(-(a - b))". Fix that, to make the
macro work as intended.

While at it, fix up the comments regarding the additional "-", too.
It's not about gas' usage of s32 but brain dead logic of having a
"true" value of -1 for the &lt; operator ... *sigh*

Btw., the one in asm/alternative-asm.h is correct. And, apparently,
all current users of ALTERNATIVE_2() pass same sized alternatives,
avoiding to hit the bug.

[1] http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax

Reviewed-and-tested-by: Borislav Petkov &lt;bp@suse.de&gt;
Fixes: dbe4058a6a44 ("x86/alternatives: Fix ALTERNATIVE_2 padding generation properly")
Signed-off-by: Mathias Krause &lt;minipli@googlemail.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Borislav Petkov &lt;bp@suse.de&gt;
Link: https://lkml.kernel.org/r/1507228213-13095-1-git-send-email-minipli@googlemail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 6b32c126d33d5cb379bca280ab8acedc1ca978ff upstream.

The alt_max_short() macro in asm/alternative.h does not work as
intended, leading to nasty bugs. E.g. alt_max_short("1", "3")
evaluates to 3, but alt_max_short("3", "1") evaluates to 1 -- not
exactly the maximum of 1 and 3.

In fact, I had to learn it the hard way by crashing my kernel in not
so funny ways by attempting to make use of the ALTENATIVE_2 macro
with alternatives where the first one was larger than the second
one.

According to [1] and commit dbe4058a6a44 ("x86/alternatives: Fix
ALTERNATIVE_2 padding generation properly") the right handed side
should read "-(-(a &lt; b))" not "-(-(a - b))". Fix that, to make the
macro work as intended.

While at it, fix up the comments regarding the additional "-", too.
It's not about gas' usage of s32 but brain dead logic of having a
"true" value of -1 for the &lt; operator ... *sigh*

Btw., the one in asm/alternative-asm.h is correct. And, apparently,
all current users of ALTERNATIVE_2() pass same sized alternatives,
avoiding to hit the bug.

[1] http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax

Reviewed-and-tested-by: Borislav Petkov &lt;bp@suse.de&gt;
Fixes: dbe4058a6a44 ("x86/alternatives: Fix ALTERNATIVE_2 padding generation properly")
Signed-off-by: Mathias Krause &lt;minipli@googlemail.com&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Borislav Petkov &lt;bp@suse.de&gt;
Link: https://lkml.kernel.org/r/1507228213-13095-1-git-send-email-minipli@googlemail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
</feed>
