<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/x86, branch linux-3.6.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>x86: hpet: Fix masking of MSI interrupts</title>
<updated>2012-12-17T17:26:53+00:00</updated>
<author>
<name>Jan Beulich</name>
<email>JBeulich@suse.com</email>
</author>
<published>2012-11-02T14:02:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=519b4022e803a6d983a895a30845adfc368fbfdf'/>
<id>519b4022e803a6d983a895a30845adfc368fbfdf</id>
<content type='text'>
commit 6acf5a8c931da9d26c8dd77d784daaf07fa2bff0 upstream.

HPET_TN_FSB is not a proper mask bit; it merely toggles between MSI and
legacy interrupt delivery. The proper mask bit is HPET_TN_ENABLE, so
use both bits when (un)masking the interrupt.

Signed-off-by: Jan Beulich &lt;jbeulich@suse.com&gt;
Link: http://lkml.kernel.org/r/5093E09002000078000A60E6@nat28.tlf.novell.com
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.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 6acf5a8c931da9d26c8dd77d784daaf07fa2bff0 upstream.

HPET_TN_FSB is not a proper mask bit; it merely toggles between MSI and
legacy interrupt delivery. The proper mask bit is HPET_TN_ENABLE, so
use both bits when (un)masking the interrupt.

Signed-off-by: Jan Beulich &lt;jbeulich@suse.com&gt;
Link: http://lkml.kernel.org/r/5093E09002000078000A60E6@nat28.tlf.novell.com
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>x86, amd: Disable way access filter on Piledriver CPUs</title>
<updated>2012-12-10T19:13:12+00:00</updated>
<author>
<name>Andre Przywara</name>
<email>andre.przywara@amd.com</email>
</author>
<published>2012-10-31T16:20:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5916348fdb27dbc3adc176a82573878d3f2b6456'/>
<id>5916348fdb27dbc3adc176a82573878d3f2b6456</id>
<content type='text'>
commit 2bbf0a1427c377350f001fbc6260995334739ad7 upstream.

The Way Access Filter in recent AMD CPUs may hurt the performance of
some workloads, caused by aliasing issues in the L1 cache.
This patch disables it on the affected CPUs.

The issue is similar to that one of last year:
http://lkml.indiana.edu/hypermail/linux/kernel/1107.3/00041.html
This new patch does not replace the old one, we just need another
quirk for newer CPUs.

The performance penalty without the patch depends on the
circumstances, but is a bit less than the last year's 3%.

The workloads affected would be those that access code from the same
physical page under different virtual addresses, so different
processes using the same libraries with ASLR or multiple instances of
PIE-binaries. The code needs to be accessed simultaneously from both
cores of the same compute unit.

More details can be found here:
http://developer.amd.com/Assets/SharedL1InstructionCacheonAMD15hCPU.pdf

CPUs affected are anything with the core known as Piledriver.
That includes the new parts of the AMD A-Series (aka Trinity) and the
just released new CPUs of the FX-Series (aka Vishera).
The model numbering is a bit odd here: FX CPUs have model 2,
A-Series has model 10h, with possible extensions to 1Fh. Hence the
range of model ids.

Signed-off-by: Andre Przywara &lt;osp@andrep.de&gt;
Link: http://lkml.kernel.org/r/1351700450-9277-1-git-send-email-osp@andrep.de
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
Signed-off-by: CAI Qian &lt;caiqian@redhat.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 2bbf0a1427c377350f001fbc6260995334739ad7 upstream.

The Way Access Filter in recent AMD CPUs may hurt the performance of
some workloads, caused by aliasing issues in the L1 cache.
This patch disables it on the affected CPUs.

The issue is similar to that one of last year:
http://lkml.indiana.edu/hypermail/linux/kernel/1107.3/00041.html
This new patch does not replace the old one, we just need another
quirk for newer CPUs.

The performance penalty without the patch depends on the
circumstances, but is a bit less than the last year's 3%.

The workloads affected would be those that access code from the same
physical page under different virtual addresses, so different
processes using the same libraries with ASLR or multiple instances of
PIE-binaries. The code needs to be accessed simultaneously from both
cores of the same compute unit.

More details can be found here:
http://developer.amd.com/Assets/SharedL1InstructionCacheonAMD15hCPU.pdf

CPUs affected are anything with the core known as Piledriver.
That includes the new parts of the AMD A-Series (aka Trinity) and the
just released new CPUs of the FX-Series (aka Vishera).
The model numbering is a bit odd here: FX CPUs have model 2,
A-Series has model 10h, with possible extensions to 1Fh. Hence the
range of model ids.

Signed-off-by: Andre Przywara &lt;osp@andrep.de&gt;
Link: http://lkml.kernel.org/r/1351700450-9277-1-git-send-email-osp@andrep.de
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
Signed-off-by: CAI Qian &lt;caiqian@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>x86, fpu: Avoid FPU lazy restore after suspend</title>
<updated>2012-12-10T19:13:10+00:00</updated>
<author>
<name>Vincent Palatin</name>
<email>vpalatin@chromium.org</email>
</author>
<published>2012-11-30T20:15:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bc7dba85cff59313fe1c01f6026c763a18a0b2b1'/>
<id>bc7dba85cff59313fe1c01f6026c763a18a0b2b1</id>
<content type='text'>
commit 644c154186386bb1fa6446bc5e037b9ed098db46 upstream.

When a cpu enters S3 state, the FPU state is lost.
After resuming for S3, if we try to lazy restore the FPU for a process running
on the same CPU, this will result in a corrupted FPU context.

Ensure that "fpu_owner_task" is properly invalided when (re-)initializing a CPU,
so nobody will try to lazy restore a state which doesn't exist in the hardware.

Tested with a 64-bit kernel on a 4-core Ivybridge CPU with eagerfpu=off,
by doing thousands of suspend/resume cycles with 4 processes doing FPU
operations running. Without the patch, a process is killed after a
few hundreds cycles by a SIGFPE.

Signed-off-by: Vincent Palatin &lt;vpalatin@chromium.org&gt;
Cc: Duncan Laurie &lt;dlaurie@chromium.org&gt;
Cc: Olof Johansson &lt;olofj@chromium.org&gt;
Link: http://lkml.kernel.org/r/1354306532-1014-1-git-send-email-vpalatin@chromium.org
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.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 644c154186386bb1fa6446bc5e037b9ed098db46 upstream.

When a cpu enters S3 state, the FPU state is lost.
After resuming for S3, if we try to lazy restore the FPU for a process running
on the same CPU, this will result in a corrupted FPU context.

Ensure that "fpu_owner_task" is properly invalided when (re-)initializing a CPU,
so nobody will try to lazy restore a state which doesn't exist in the hardware.

Tested with a 64-bit kernel on a 4-core Ivybridge CPU with eagerfpu=off,
by doing thousands of suspend/resume cycles with 4 processes doing FPU
operations running. Without the patch, a process is killed after a
few hundreds cycles by a SIGFPE.

Signed-off-by: Vincent Palatin &lt;vpalatin@chromium.org&gt;
Cc: Duncan Laurie &lt;dlaurie@chromium.org&gt;
Cc: Olof Johansson &lt;olofj@chromium.org&gt;
Link: http://lkml.kernel.org/r/1354306532-1014-1-git-send-email-vpalatin@chromium.org
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: x86: invalid opcode oops on SET_SREGS with OSXSAVE bit set (CVE-2012-4461)</title>
<updated>2012-12-03T19:38:13+00:00</updated>
<author>
<name>Petr Matousek</name>
<email>pmatouse@redhat.com</email>
</author>
<published>2012-11-06T18:24:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e467125d3c2cd80d100e7d3c12547621a5eb8e2f'/>
<id>e467125d3c2cd80d100e7d3c12547621a5eb8e2f</id>
<content type='text'>
commit 6d1068b3a98519247d8ba4ec85cd40ac136dbdf9 upstream.

On hosts without the XSAVE support unprivileged local user can trigger
oops similar to the one below by setting X86_CR4_OSXSAVE bit in guest
cr4 register using KVM_SET_SREGS ioctl and later issuing KVM_RUN
ioctl.

invalid opcode: 0000 [#2] SMP
Modules linked in: tun ip6table_filter ip6_tables ebtable_nat ebtables
...
Pid: 24935, comm: zoog_kvm_monito Tainted: G      D      3.2.0-3-686-pae
EIP: 0060:[&lt;f8b9550c&gt;] EFLAGS: 00210246 CPU: 0
EIP is at kvm_arch_vcpu_ioctl_run+0x92a/0xd13 [kvm]
EAX: 00000001 EBX: 000f387e ECX: 00000000 EDX: 00000000
ESI: 00000000 EDI: 00000000 EBP: ef5a0060 ESP: d7c63e70
 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process zoog_kvm_monito (pid: 24935, ti=d7c62000 task=ed84a0c0
task.ti=d7c62000)
Stack:
 00000001 f70a1200 f8b940a9 ef5a0060 00000000 00200202 f8769009 00000000
 ef5a0060 000f387e eda5c020 8722f9c8 00015bae 00000000 ed84a0c0 ed84a0c0
 c12bf02d 0000ae80 ef7f8740 fffffffb f359b740 ef5a0060 f8b85dc1 0000ae80
Call Trace:
 [&lt;f8b940a9&gt;] ? kvm_arch_vcpu_ioctl_set_sregs+0x2fe/0x308 [kvm]
...
 [&lt;c12bfb44&gt;] ? syscall_call+0x7/0xb
Code: 89 e8 e8 14 ee ff ff ba 00 00 04 00 89 e8 e8 98 48 ff ff 85 c0 74
1e 83 7d 48 00 75 18 8b 85 08 07 00 00 31 c9 8b 95 0c 07 00 00 &lt;0f&gt; 01
d1 c7 45 48 01 00 00 00 c7 45 1c 01 00 00 00 0f ae f0 89
EIP: [&lt;f8b9550c&gt;] kvm_arch_vcpu_ioctl_run+0x92a/0xd13 [kvm] SS:ESP
0068:d7c63e70

QEMU first retrieves the supported features via KVM_GET_SUPPORTED_CPUID
and then sets them later. So guest's X86_FEATURE_XSAVE should be masked
out on hosts without X86_FEATURE_XSAVE, making kvm_set_cr4 with
X86_CR4_OSXSAVE fail. Userspaces that allow specifying guest cpuid with
X86_FEATURE_XSAVE even on hosts that do not support it, might be
susceptible to this attack from inside the guest as well.

Allow setting X86_CR4_OSXSAVE bit only if host has XSAVE support.

Signed-off-by: Petr Matousek &lt;pmatouse@redhat.com&gt;
Signed-off-by: Marcelo Tosatti &lt;mtosatti@redhat.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 6d1068b3a98519247d8ba4ec85cd40ac136dbdf9 upstream.

On hosts without the XSAVE support unprivileged local user can trigger
oops similar to the one below by setting X86_CR4_OSXSAVE bit in guest
cr4 register using KVM_SET_SREGS ioctl and later issuing KVM_RUN
ioctl.

invalid opcode: 0000 [#2] SMP
Modules linked in: tun ip6table_filter ip6_tables ebtable_nat ebtables
...
Pid: 24935, comm: zoog_kvm_monito Tainted: G      D      3.2.0-3-686-pae
EIP: 0060:[&lt;f8b9550c&gt;] EFLAGS: 00210246 CPU: 0
EIP is at kvm_arch_vcpu_ioctl_run+0x92a/0xd13 [kvm]
EAX: 00000001 EBX: 000f387e ECX: 00000000 EDX: 00000000
ESI: 00000000 EDI: 00000000 EBP: ef5a0060 ESP: d7c63e70
 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
Process zoog_kvm_monito (pid: 24935, ti=d7c62000 task=ed84a0c0
task.ti=d7c62000)
Stack:
 00000001 f70a1200 f8b940a9 ef5a0060 00000000 00200202 f8769009 00000000
 ef5a0060 000f387e eda5c020 8722f9c8 00015bae 00000000 ed84a0c0 ed84a0c0
 c12bf02d 0000ae80 ef7f8740 fffffffb f359b740 ef5a0060 f8b85dc1 0000ae80
Call Trace:
 [&lt;f8b940a9&gt;] ? kvm_arch_vcpu_ioctl_set_sregs+0x2fe/0x308 [kvm]
...
 [&lt;c12bfb44&gt;] ? syscall_call+0x7/0xb
Code: 89 e8 e8 14 ee ff ff ba 00 00 04 00 89 e8 e8 98 48 ff ff 85 c0 74
1e 83 7d 48 00 75 18 8b 85 08 07 00 00 31 c9 8b 95 0c 07 00 00 &lt;0f&gt; 01
d1 c7 45 48 01 00 00 00 c7 45 1c 01 00 00 00 0f ae f0 89
EIP: [&lt;f8b9550c&gt;] kvm_arch_vcpu_ioctl_run+0x92a/0xd13 [kvm] SS:ESP
0068:d7c63e70

QEMU first retrieves the supported features via KVM_GET_SUPPORTED_CPUID
and then sets them later. So guest's X86_FEATURE_XSAVE should be masked
out on hosts without X86_FEATURE_XSAVE, making kvm_set_cr4 with
X86_CR4_OSXSAVE fail. Userspaces that allow specifying guest cpuid with
X86_FEATURE_XSAVE even on hosts that do not support it, might be
susceptible to this attack from inside the guest as well.

Allow setting X86_CR4_OSXSAVE bit only if host has XSAVE support.

Signed-off-by: Petr Matousek &lt;pmatouse@redhat.com&gt;
Signed-off-by: Marcelo Tosatti &lt;mtosatti@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>x86-32: Export kernel_stack_pointer() for modules</title>
<updated>2012-12-03T19:37:56+00:00</updated>
<author>
<name>H. Peter Anvin</name>
<email>hpa@linux.intel.com</email>
</author>
<published>2012-11-21T06:21:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=051d62f6f239a9427fcab244a310610ed8bedb43'/>
<id>051d62f6f239a9427fcab244a310610ed8bedb43</id>
<content type='text'>
commit cb57a2b4cff7edf2a4e32c0163200e9434807e0a upstream.

Modules, in particular oprofile (and possibly other similar tools)
need kernel_stack_pointer(), so export it using EXPORT_SYMBOL_GPL().

Link: http://lkml.kernel.org/r/20120912135059.GZ8285@erda.amd.com
Cc: Yang Wei &lt;wei.yang@windriver.com&gt;
Cc: Robert Richter &lt;robert.richter@amd.com&gt;
Cc: Jun Zhang &lt;jun.zhang@intel.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.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 cb57a2b4cff7edf2a4e32c0163200e9434807e0a upstream.

Modules, in particular oprofile (and possibly other similar tools)
need kernel_stack_pointer(), so export it using EXPORT_SYMBOL_GPL().

Link: http://lkml.kernel.org/r/20120912135059.GZ8285@erda.amd.com
Cc: Yang Wei &lt;wei.yang@windriver.com&gt;
Cc: Robert Richter &lt;robert.richter@amd.com&gt;
Cc: Jun Zhang &lt;jun.zhang@intel.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>x86, microcode, AMD: Add support for family 16h processors</title>
<updated>2012-12-03T19:37:56+00:00</updated>
<author>
<name>Boris Ostrovsky</name>
<email>boris.ostrovsky@amd.com</email>
</author>
<published>2012-11-15T18:41:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1ea87b1fa98cfa76a2aad6f182367b0ba2296015'/>
<id>1ea87b1fa98cfa76a2aad6f182367b0ba2296015</id>
<content type='text'>
commit 36c46ca4f322a7bf89aad5462a3a1f61713edce7 upstream.

Add valid patch size for family 16h processors.

[ hpa: promoting to urgent/stable since it is hw enabling and trivial ]

Signed-off-by: Boris Ostrovsky &lt;boris.ostrovsky@amd.com&gt;
Acked-by: Andreas Herrmann &lt;herrmann.der.user@googlemail.com&gt;
Link: http://lkml.kernel.org/r/1353004910-2204-1-git-send-email-boris.ostrovsky@amd.com
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.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 36c46ca4f322a7bf89aad5462a3a1f61713edce7 upstream.

Add valid patch size for family 16h processors.

[ hpa: promoting to urgent/stable since it is hw enabling and trivial ]

Signed-off-by: Boris Ostrovsky &lt;boris.ostrovsky@amd.com&gt;
Acked-by: Andreas Herrmann &lt;herrmann.der.user@googlemail.com&gt;
Link: http://lkml.kernel.org/r/1353004910-2204-1-git-send-email-boris.ostrovsky@amd.com
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>x86, efi: Fix processor-specific memcpy() build error</title>
<updated>2012-12-03T19:37:55+00:00</updated>
<author>
<name>Matt Fleming</name>
<email>matt.fleming@intel.com</email>
</author>
<published>2012-11-20T13:07:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5e0edcfdac8ef57ef873f75de0780860745942ed'/>
<id>5e0edcfdac8ef57ef873f75de0780860745942ed</id>
<content type='text'>
commit 0f905a43ce955b638139bd84486194770a6a2c08 upstream.

Building for Athlon/Duron/K7 results in the following build error,

arch/x86/boot/compressed/eboot.o: In function `__constant_memcpy3d':
eboot.c:(.text+0x385): undefined reference to `_mmx_memcpy'
arch/x86/boot/compressed/eboot.o: In function `efi_main':
eboot.c:(.text+0x1a22): undefined reference to `_mmx_memcpy'

because the boot stub code doesn't link with the kernel proper, and
therefore doesn't have access to the 3DNow version of memcpy. So,
follow the example of misc.c and #undef memcpy so that we use the
version provided by misc.c.

See https://bugzilla.kernel.org/show_bug.cgi?id=50391

Reported-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Reported-by: Ryan Underwood &lt;nemesis@icequake.net&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Signed-off-by: Matt Fleming &lt;matt.fleming@intel.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 0f905a43ce955b638139bd84486194770a6a2c08 upstream.

Building for Athlon/Duron/K7 results in the following build error,

arch/x86/boot/compressed/eboot.o: In function `__constant_memcpy3d':
eboot.c:(.text+0x385): undefined reference to `_mmx_memcpy'
arch/x86/boot/compressed/eboot.o: In function `efi_main':
eboot.c:(.text+0x1a22): undefined reference to `_mmx_memcpy'

because the boot stub code doesn't link with the kernel proper, and
therefore doesn't have access to the 3DNow version of memcpy. So,
follow the example of misc.c and #undef memcpy so that we use the
version provided by misc.c.

See https://bugzilla.kernel.org/show_bug.cgi?id=50391

Reported-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Reported-by: Ryan Underwood &lt;nemesis@icequake.net&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Signed-off-by: Matt Fleming &lt;matt.fleming@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>x86-32: Fix invalid stack address while in softirq</title>
<updated>2012-12-03T19:37:55+00:00</updated>
<author>
<name>Robert Richter</name>
<email>robert.richter@amd.com</email>
</author>
<published>2012-09-03T18:54:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e7a733a0c023a9f32c6bf3d34c2f954085ebc322'/>
<id>e7a733a0c023a9f32c6bf3d34c2f954085ebc322</id>
<content type='text'>
commit 1022623842cb72ee4d0dbf02f6937f38c92c3f41 upstream.

In 32 bit the stack address provided by kernel_stack_pointer() may
point to an invalid range causing NULL pointer access or page faults
while in NMI (see trace below). This happens if called in softirq
context and if the stack is empty. The address at &amp;regs-&gt;sp is then
out of range.

Fixing this by checking if regs and &amp;regs-&gt;sp are in the same stack
context. Otherwise return the previous stack pointer stored in struct
thread_info. If that address is invalid too, return address of regs.

 BUG: unable to handle kernel NULL pointer dereference at 0000000a
 IP: [&lt;c1004237&gt;] print_context_stack+0x6e/0x8d
 *pde = 00000000
 Oops: 0000 [#1] SMP
 Modules linked in:
 Pid: 4434, comm: perl Not tainted 3.6.0-rc3-oprofile-i386-standard-g4411a05 #4 Hewlett-Packard HP xw9400 Workstation/0A1Ch
 EIP: 0060:[&lt;c1004237&gt;] EFLAGS: 00010093 CPU: 0
 EIP is at print_context_stack+0x6e/0x8d
 EAX: ffffe000 EBX: 0000000a ECX: f4435f94 EDX: 0000000a
 ESI: f4435f94 EDI: f4435f94 EBP: f5409ec0 ESP: f5409ea0
  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
 CR0: 8005003b CR2: 0000000a CR3: 34ac9000 CR4: 000007d0
 DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
 DR6: ffff0ff0 DR7: 00000400
 Process perl (pid: 4434, ti=f5408000 task=f5637850 task.ti=f4434000)
 Stack:
  000003e8 ffffe000 00001ffc f4e39b00 00000000 0000000a f4435f94 c155198c
  f5409ef0 c1003723 c155198c f5409f04 00000000 f5409edc 00000000 00000000
  f5409ee8 f4435f94 f5409fc4 00000001 f5409f1c c12dce1c 00000000 c155198c
 Call Trace:
  [&lt;c1003723&gt;] dump_trace+0x7b/0xa1
  [&lt;c12dce1c&gt;] x86_backtrace+0x40/0x88
  [&lt;c12db712&gt;] ? oprofile_add_sample+0x56/0x84
  [&lt;c12db731&gt;] oprofile_add_sample+0x75/0x84
  [&lt;c12ddb5b&gt;] op_amd_check_ctrs+0x46/0x260
  [&lt;c12dd40d&gt;] profile_exceptions_notify+0x23/0x4c
  [&lt;c1395034&gt;] nmi_handle+0x31/0x4a
  [&lt;c1029dc5&gt;] ? ftrace_define_fields_irq_handler_entry+0x45/0x45
  [&lt;c13950ed&gt;] do_nmi+0xa0/0x2ff
  [&lt;c1029dc5&gt;] ? ftrace_define_fields_irq_handler_entry+0x45/0x45
  [&lt;c13949e5&gt;] nmi_stack_correct+0x28/0x2d
  [&lt;c1029dc5&gt;] ? ftrace_define_fields_irq_handler_entry+0x45/0x45
  [&lt;c1003603&gt;] ? do_softirq+0x4b/0x7f
  &lt;IRQ&gt;
  [&lt;c102a06f&gt;] irq_exit+0x35/0x5b
  [&lt;c1018f56&gt;] smp_apic_timer_interrupt+0x6c/0x7a
  [&lt;c1394746&gt;] apic_timer_interrupt+0x2a/0x30
 Code: 89 fe eb 08 31 c9 8b 45 0c ff 55 ec 83 c3 04 83 7d 10 00 74 0c 3b 5d 10 73 26 3b 5d e4 73 0c eb 1f 3b 5d f0 76 1a 3b 5d e8 73 15 &lt;8b&gt; 13 89 d0 89 55 e0 e8 ad 42 03 00 85 c0 8b 55 e0 75 a6 eb cc
 EIP: [&lt;c1004237&gt;] print_context_stack+0x6e/0x8d SS:ESP 0068:f5409ea0
 CR2: 000000000000000a
 ---[ end trace 62afee3481b00012 ]---
 Kernel panic - not syncing: Fatal exception in interrupt

V2:
* add comments to kernel_stack_pointer()
* always return a valid stack address by falling back to the address
  of regs

Reported-by: Yang Wei &lt;wei.yang@windriver.com&gt;
Signed-off-by: Robert Richter &lt;robert.richter@amd.com&gt;
Link: http://lkml.kernel.org/r/20120912135059.GZ8285@erda.amd.com
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
Cc: Jun Zhang &lt;jun.zhang@intel.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 1022623842cb72ee4d0dbf02f6937f38c92c3f41 upstream.

In 32 bit the stack address provided by kernel_stack_pointer() may
point to an invalid range causing NULL pointer access or page faults
while in NMI (see trace below). This happens if called in softirq
context and if the stack is empty. The address at &amp;regs-&gt;sp is then
out of range.

Fixing this by checking if regs and &amp;regs-&gt;sp are in the same stack
context. Otherwise return the previous stack pointer stored in struct
thread_info. If that address is invalid too, return address of regs.

 BUG: unable to handle kernel NULL pointer dereference at 0000000a
 IP: [&lt;c1004237&gt;] print_context_stack+0x6e/0x8d
 *pde = 00000000
 Oops: 0000 [#1] SMP
 Modules linked in:
 Pid: 4434, comm: perl Not tainted 3.6.0-rc3-oprofile-i386-standard-g4411a05 #4 Hewlett-Packard HP xw9400 Workstation/0A1Ch
 EIP: 0060:[&lt;c1004237&gt;] EFLAGS: 00010093 CPU: 0
 EIP is at print_context_stack+0x6e/0x8d
 EAX: ffffe000 EBX: 0000000a ECX: f4435f94 EDX: 0000000a
 ESI: f4435f94 EDI: f4435f94 EBP: f5409ec0 ESP: f5409ea0
  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
 CR0: 8005003b CR2: 0000000a CR3: 34ac9000 CR4: 000007d0
 DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
 DR6: ffff0ff0 DR7: 00000400
 Process perl (pid: 4434, ti=f5408000 task=f5637850 task.ti=f4434000)
 Stack:
  000003e8 ffffe000 00001ffc f4e39b00 00000000 0000000a f4435f94 c155198c
  f5409ef0 c1003723 c155198c f5409f04 00000000 f5409edc 00000000 00000000
  f5409ee8 f4435f94 f5409fc4 00000001 f5409f1c c12dce1c 00000000 c155198c
 Call Trace:
  [&lt;c1003723&gt;] dump_trace+0x7b/0xa1
  [&lt;c12dce1c&gt;] x86_backtrace+0x40/0x88
  [&lt;c12db712&gt;] ? oprofile_add_sample+0x56/0x84
  [&lt;c12db731&gt;] oprofile_add_sample+0x75/0x84
  [&lt;c12ddb5b&gt;] op_amd_check_ctrs+0x46/0x260
  [&lt;c12dd40d&gt;] profile_exceptions_notify+0x23/0x4c
  [&lt;c1395034&gt;] nmi_handle+0x31/0x4a
  [&lt;c1029dc5&gt;] ? ftrace_define_fields_irq_handler_entry+0x45/0x45
  [&lt;c13950ed&gt;] do_nmi+0xa0/0x2ff
  [&lt;c1029dc5&gt;] ? ftrace_define_fields_irq_handler_entry+0x45/0x45
  [&lt;c13949e5&gt;] nmi_stack_correct+0x28/0x2d
  [&lt;c1029dc5&gt;] ? ftrace_define_fields_irq_handler_entry+0x45/0x45
  [&lt;c1003603&gt;] ? do_softirq+0x4b/0x7f
  &lt;IRQ&gt;
  [&lt;c102a06f&gt;] irq_exit+0x35/0x5b
  [&lt;c1018f56&gt;] smp_apic_timer_interrupt+0x6c/0x7a
  [&lt;c1394746&gt;] apic_timer_interrupt+0x2a/0x30
 Code: 89 fe eb 08 31 c9 8b 45 0c ff 55 ec 83 c3 04 83 7d 10 00 74 0c 3b 5d 10 73 26 3b 5d e4 73 0c eb 1f 3b 5d f0 76 1a 3b 5d e8 73 15 &lt;8b&gt; 13 89 d0 89 55 e0 e8 ad 42 03 00 85 c0 8b 55 e0 75 a6 eb cc
 EIP: [&lt;c1004237&gt;] print_context_stack+0x6e/0x8d SS:ESP 0068:f5409ea0
 CR2: 000000000000000a
 ---[ end trace 62afee3481b00012 ]---
 Kernel panic - not syncing: Fatal exception in interrupt

V2:
* add comments to kernel_stack_pointer()
* always return a valid stack address by falling back to the address
  of regs

Reported-by: Yang Wei &lt;wei.yang@windriver.com&gt;
Signed-off-by: Robert Richter &lt;robert.richter@amd.com&gt;
Link: http://lkml.kernel.org/r/20120912135059.GZ8285@erda.amd.com
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
Cc: Jun Zhang &lt;jun.zhang@intel.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: x86: Fix invalid secondary exec controls in vmx_cpuid_update()</title>
<updated>2012-11-26T20:14:17+00:00</updated>
<author>
<name>Takashi Iwai</name>
<email>tiwai@suse.de</email>
</author>
<published>2012-11-09T14:20:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=05e7fb4f1ab1840c84ebb3e840d8bcce90b283cd'/>
<id>05e7fb4f1ab1840c84ebb3e840d8bcce90b283cd</id>
<content type='text'>
commit 29282fde80d44e587f8c152b10049a56e61659f0 upstream.

The commit [ad756a16: KVM: VMX: Implement PCID/INVPCID for guests with
EPT] introduced the unconditional access to SECONDARY_VM_EXEC_CONTROL,
and this triggers kernel warnings like below on old CPUs:

    vmwrite error: reg 401e value a0568000 (err 12)
    Pid: 13649, comm: qemu-kvm Not tainted 3.7.0-rc4-test2+ #154
    Call Trace:
     [&lt;ffffffffa0558d86&gt;] vmwrite_error+0x27/0x29 [kvm_intel]
     [&lt;ffffffffa054e8cb&gt;] vmcs_writel+0x1b/0x20 [kvm_intel]
     [&lt;ffffffffa054f114&gt;] vmx_cpuid_update+0x74/0x170 [kvm_intel]
     [&lt;ffffffffa03629b6&gt;] kvm_vcpu_ioctl_set_cpuid2+0x76/0x90 [kvm]
     [&lt;ffffffffa0341c67&gt;] kvm_arch_vcpu_ioctl+0xc37/0xed0 [kvm]
     [&lt;ffffffff81143f7c&gt;] ? __vunmap+0x9c/0x110
     [&lt;ffffffffa0551489&gt;] ? vmx_vcpu_load+0x39/0x1a0 [kvm_intel]
     [&lt;ffffffffa0340ee2&gt;] ? kvm_arch_vcpu_load+0x52/0x1a0 [kvm]
     [&lt;ffffffffa032dcd4&gt;] ? vcpu_load+0x74/0xd0 [kvm]
     [&lt;ffffffffa032deb0&gt;] kvm_vcpu_ioctl+0x110/0x5e0 [kvm]
     [&lt;ffffffffa032e93d&gt;] ? kvm_dev_ioctl+0x4d/0x4a0 [kvm]
     [&lt;ffffffff8117dc6f&gt;] do_vfs_ioctl+0x8f/0x530
     [&lt;ffffffff81139d76&gt;] ? remove_vma+0x56/0x60
     [&lt;ffffffff8113b708&gt;] ? do_munmap+0x328/0x400
     [&lt;ffffffff81187c8c&gt;] ? fget_light+0x4c/0x100
     [&lt;ffffffff8117e1a1&gt;] sys_ioctl+0x91/0xb0
     [&lt;ffffffff815a942d&gt;] system_call_fastpath+0x1a/0x1f

This patch adds a check for the availability of secondary exec
control to avoid these warnings.

Signed-off-by: Takashi Iwai &lt;tiwai@suse.de&gt;
Signed-off-by: Marcelo Tosatti &lt;mtosatti@redhat.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 29282fde80d44e587f8c152b10049a56e61659f0 upstream.

The commit [ad756a16: KVM: VMX: Implement PCID/INVPCID for guests with
EPT] introduced the unconditional access to SECONDARY_VM_EXEC_CONTROL,
and this triggers kernel warnings like below on old CPUs:

    vmwrite error: reg 401e value a0568000 (err 12)
    Pid: 13649, comm: qemu-kvm Not tainted 3.7.0-rc4-test2+ #154
    Call Trace:
     [&lt;ffffffffa0558d86&gt;] vmwrite_error+0x27/0x29 [kvm_intel]
     [&lt;ffffffffa054e8cb&gt;] vmcs_writel+0x1b/0x20 [kvm_intel]
     [&lt;ffffffffa054f114&gt;] vmx_cpuid_update+0x74/0x170 [kvm_intel]
     [&lt;ffffffffa03629b6&gt;] kvm_vcpu_ioctl_set_cpuid2+0x76/0x90 [kvm]
     [&lt;ffffffffa0341c67&gt;] kvm_arch_vcpu_ioctl+0xc37/0xed0 [kvm]
     [&lt;ffffffff81143f7c&gt;] ? __vunmap+0x9c/0x110
     [&lt;ffffffffa0551489&gt;] ? vmx_vcpu_load+0x39/0x1a0 [kvm_intel]
     [&lt;ffffffffa0340ee2&gt;] ? kvm_arch_vcpu_load+0x52/0x1a0 [kvm]
     [&lt;ffffffffa032dcd4&gt;] ? vcpu_load+0x74/0xd0 [kvm]
     [&lt;ffffffffa032deb0&gt;] kvm_vcpu_ioctl+0x110/0x5e0 [kvm]
     [&lt;ffffffffa032e93d&gt;] ? kvm_dev_ioctl+0x4d/0x4a0 [kvm]
     [&lt;ffffffff8117dc6f&gt;] do_vfs_ioctl+0x8f/0x530
     [&lt;ffffffff81139d76&gt;] ? remove_vma+0x56/0x60
     [&lt;ffffffff8113b708&gt;] ? do_munmap+0x328/0x400
     [&lt;ffffffff81187c8c&gt;] ? fget_light+0x4c/0x100
     [&lt;ffffffff8117e1a1&gt;] sys_ioctl+0x91/0xb0
     [&lt;ffffffff815a942d&gt;] system_call_fastpath+0x1a/0x1f

This patch adds a check for the availability of secondary exec
control to avoid these warnings.

Signed-off-by: Takashi Iwai &lt;tiwai@suse.de&gt;
Signed-off-by: Marcelo Tosatti &lt;mtosatti@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>xen/mmu: Use Xen specific TLB flush instead of the generic one.</title>
<updated>2012-11-17T21:18:28+00:00</updated>
<author>
<name>Konrad Rzeszutek Wilk</name>
<email>konrad.wilk@oracle.com</email>
</author>
<published>2012-10-31T16:38:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3f7a06d68337171fef9f8e7621a6d73777385619'/>
<id>3f7a06d68337171fef9f8e7621a6d73777385619</id>
<content type='text'>
commit 95a7d76897c1e7243d4137037c66d15cbf2cce76 upstream.

As Mukesh explained it, the MMUEXT_TLB_FLUSH_ALL allows the
hypervisor to do a TLB flush on all active vCPUs. If instead
we were using the generic one (which ends up being xen_flush_tlb)
we end up making the MMUEXT_TLB_FLUSH_LOCAL hypercall. But
before we make that hypercall the kernel will IPI all of the
vCPUs (even those that were asleep from the hypervisor
perspective). The end result is that we needlessly wake them
up and do a TLB flush when we can just let the hypervisor
do it correctly.

This patch gives around 50% speed improvement when migrating
idle guest's from one host to another.

Oracle-bug: 14630170

Tested-by:  Jingjie Jiang &lt;jingjie.jiang@oracle.com&gt;
Suggested-by:  Mukesh Rathor &lt;mukesh.rathor@oracle.com&gt;
Signed-off-by: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.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 95a7d76897c1e7243d4137037c66d15cbf2cce76 upstream.

As Mukesh explained it, the MMUEXT_TLB_FLUSH_ALL allows the
hypervisor to do a TLB flush on all active vCPUs. If instead
we were using the generic one (which ends up being xen_flush_tlb)
we end up making the MMUEXT_TLB_FLUSH_LOCAL hypercall. But
before we make that hypercall the kernel will IPI all of the
vCPUs (even those that were asleep from the hypervisor
perspective). The end result is that we needlessly wake them
up and do a TLB flush when we can just let the hypervisor
do it correctly.

This patch gives around 50% speed improvement when migrating
idle guest's from one host to another.

Oracle-bug: 14630170

Tested-by:  Jingjie Jiang &lt;jingjie.jiang@oracle.com&gt;
Suggested-by:  Mukesh Rathor &lt;mukesh.rathor@oracle.com&gt;
Signed-off-by: Konrad Rzeszutek Wilk &lt;konrad.wilk@oracle.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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