<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/x86/kernel/cpu/common.c, branch linux-3.19.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2014-12-10T22:24:20+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-12-10T22:24:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3100e448e7d74489a96cb7b45d88fe6962774eaa'/>
<id>3100e448e7d74489a96cb7b45d88fe6962774eaa</id>
<content type='text'>
Pull x86 vdso updates from Ingo Molnar:
 "Various vDSO updates from Andy Lutomirski, mostly cleanups and
  reorganization to improve maintainability, but also some
  micro-optimizations and robustization changes"

* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86_64/vsyscall: Restore orig_ax after vsyscall seccomp
  x86_64: Add a comment explaining the TASK_SIZE_MAX guard page
  x86_64,vsyscall: Make vsyscall emulation configurable
  x86_64, vsyscall: Rewrite comment and clean up headers in vsyscall code
  x86_64, vsyscall: Turn vsyscalls all the way off when vsyscall==none
  x86,vdso: Use LSL unconditionally for vgetcpu
  x86: vdso: Fix build with older gcc
  x86_64/vdso: Clean up vgetcpu init and merge the vdso initcalls
  x86_64/vdso: Remove jiffies from the vvar page
  x86/vdso: Make the PER_CPU segment 32 bits
  x86/vdso: Make the PER_CPU segment start out accessed
  x86/vdso: Change the PER_CPU segment to use struct desc_struct
  x86_64/vdso: Move getcpu code from vsyscall_64.c to vdso/vma.c
  x86_64/vsyscall: Move all of the gate_area code to vsyscall_64.c
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 vdso updates from Ingo Molnar:
 "Various vDSO updates from Andy Lutomirski, mostly cleanups and
  reorganization to improve maintainability, but also some
  micro-optimizations and robustization changes"

* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86_64/vsyscall: Restore orig_ax after vsyscall seccomp
  x86_64: Add a comment explaining the TASK_SIZE_MAX guard page
  x86_64,vsyscall: Make vsyscall emulation configurable
  x86_64, vsyscall: Rewrite comment and clean up headers in vsyscall code
  x86_64, vsyscall: Turn vsyscalls all the way off when vsyscall==none
  x86,vdso: Use LSL unconditionally for vgetcpu
  x86: vdso: Fix build with older gcc
  x86_64/vdso: Clean up vgetcpu init and merge the vdso initcalls
  x86_64/vdso: Remove jiffies from the vvar page
  x86/vdso: Make the PER_CPU segment 32 bits
  x86/vdso: Make the PER_CPU segment start out accessed
  x86/vdso: Change the PER_CPU segment to use struct desc_struct
  x86_64/vdso: Move getcpu code from vsyscall_64.c to vdso/vma.c
  x86_64/vsyscall: Move all of the gate_area code to vsyscall_64.c
</pre>
</div>
</content>
</entry>
<entry>
<title>x86: Require exact match for 'noxsave' command line option</title>
<updated>2014-11-16T11:13:16+00:00</updated>
<author>
<name>Dave Hansen</name>
<email>dave.hansen@linux.intel.com</email>
</author>
<published>2014-11-11T22:01:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2cd3949f702692cf4c5d05b463f19cd706a92dd3'/>
<id>2cd3949f702692cf4c5d05b463f19cd706a92dd3</id>
<content type='text'>
We have some very similarly named command-line options:

arch/x86/kernel/cpu/common.c:__setup("noxsave", x86_xsave_setup);
arch/x86/kernel/cpu/common.c:__setup("noxsaveopt", x86_xsaveopt_setup);
arch/x86/kernel/cpu/common.c:__setup("noxsaves", x86_xsaves_setup);

__setup() is designed to match options that take arguments, like
"foo=bar" where you would have:

	__setup("foo", x86_foo_func...);

The problem is that "noxsave" actually _matches_ "noxsaves" in
the same way that "foo" matches "foo=bar".  If you boot an old
kernel that does not know about "noxsaves" with "noxsaves" on the
command line, it will interpret the argument as "noxsave", which
is not what you want at all.

This makes the "noxsave" handler only return success when it finds
an *exact* match.

[ tglx: We really need to make __setup() more robust. ]

Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Dave Hansen &lt;dave@sr71.net&gt;
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Cc: x86@kernel.org
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20141111220133.FE053984@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We have some very similarly named command-line options:

arch/x86/kernel/cpu/common.c:__setup("noxsave", x86_xsave_setup);
arch/x86/kernel/cpu/common.c:__setup("noxsaveopt", x86_xsaveopt_setup);
arch/x86/kernel/cpu/common.c:__setup("noxsaves", x86_xsaves_setup);

__setup() is designed to match options that take arguments, like
"foo=bar" where you would have:

	__setup("foo", x86_foo_func...);

The problem is that "noxsave" actually _matches_ "noxsaves" in
the same way that "foo" matches "foo=bar".  If you boot an old
kernel that does not know about "noxsaves" with "noxsaves" on the
command line, it will interpret the argument as "noxsave", which
is not what you want at all.

This makes the "noxsave" handler only return success when it finds
an *exact* match.

[ tglx: We really need to make __setup() more robust. ]

Signed-off-by: Dave Hansen &lt;dave.hansen@linux.intel.com&gt;
Cc: Dave Hansen &lt;dave@sr71.net&gt;
Cc: Fenghua Yu &lt;fenghua.yu@intel.com&gt;
Cc: x86@kernel.org
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20141111220133.FE053984@viggo.jf.intel.com
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>x86,vdso: Use LSL unconditionally for vgetcpu</title>
<updated>2014-11-03T12:41:53+00:00</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@amacapital.net</email>
</author>
<published>2014-10-30T21:58:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e76b027e6408f5570dc940b731ec9ae870c6188a'/>
<id>e76b027e6408f5570dc940b731ec9ae870c6188a</id>
<content type='text'>
LSL is faster than RDTSCP and works everywhere; there's no need to
switch between them depending on CPU.

Signed-off-by: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Andi Kleen &lt;andi@firstfloor.org&gt;
Link: http://lkml.kernel.org/r/72f73d5ec4514e02bba345b9759177ef03742efb.1414706021.git.luto@amacapital.net
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
LSL is faster than RDTSCP and works everywhere; there's no need to
switch between them depending on CPU.

Signed-off-by: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Andi Kleen &lt;andi@firstfloor.org&gt;
Link: http://lkml.kernel.org/r/72f73d5ec4514e02bba345b9759177ef03742efb.1414706021.git.luto@amacapital.net
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu</title>
<updated>2014-10-15T05:48:18+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-10-15T05:48:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0429fbc0bdc297d64188483ba029a23773ae07b0'/>
<id>0429fbc0bdc297d64188483ba029a23773ae07b0</id>
<content type='text'>
Pull percpu consistent-ops changes from Tejun Heo:
 "Way back, before the current percpu allocator was implemented, static
  and dynamic percpu memory areas were allocated and handled separately
  and had their own accessors.  The distinction has been gone for many
  years now; however, the now duplicate two sets of accessors remained
  with the pointer based ones - this_cpu_*() - evolving various other
  operations over time.  During the process, we also accumulated other
  inconsistent operations.

  This pull request contains Christoph's patches to clean up the
  duplicate accessor situation.  __get_cpu_var() uses are replaced with
  with this_cpu_ptr() and __this_cpu_ptr() with raw_cpu_ptr().

  Unfortunately, the former sometimes is tricky thanks to C being a bit
  messy with the distinction between lvalues and pointers, which led to
  a rather ugly solution for cpumask_var_t involving the introduction of
  this_cpu_cpumask_var_ptr().

  This converts most of the uses but not all.  Christoph will follow up
  with the remaining conversions in this merge window and hopefully
  remove the obsolete accessors"

* 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (38 commits)
  irqchip: Properly fetch the per cpu offset
  percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t -fix
  ia64: sn_nodepda cannot be assigned to after this_cpu conversion. Use __this_cpu_write.
  percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t
  Revert "powerpc: Replace __get_cpu_var uses"
  percpu: Remove __this_cpu_ptr
  clocksource: Replace __this_cpu_ptr with raw_cpu_ptr
  sparc: Replace __get_cpu_var uses
  avr32: Replace __get_cpu_var with __this_cpu_write
  blackfin: Replace __get_cpu_var uses
  tile: Use this_cpu_ptr() for hardware counters
  tile: Replace __get_cpu_var uses
  powerpc: Replace __get_cpu_var uses
  alpha: Replace __get_cpu_var
  ia64: Replace __get_cpu_var uses
  s390: cio driver &amp;__get_cpu_var replacements
  s390: Replace __get_cpu_var uses
  mips: Replace __get_cpu_var uses
  MIPS: Replace __get_cpu_var uses in FPU emulator.
  arm: Replace __this_cpu_ptr with raw_cpu_ptr
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull percpu consistent-ops changes from Tejun Heo:
 "Way back, before the current percpu allocator was implemented, static
  and dynamic percpu memory areas were allocated and handled separately
  and had their own accessors.  The distinction has been gone for many
  years now; however, the now duplicate two sets of accessors remained
  with the pointer based ones - this_cpu_*() - evolving various other
  operations over time.  During the process, we also accumulated other
  inconsistent operations.

  This pull request contains Christoph's patches to clean up the
  duplicate accessor situation.  __get_cpu_var() uses are replaced with
  with this_cpu_ptr() and __this_cpu_ptr() with raw_cpu_ptr().

  Unfortunately, the former sometimes is tricky thanks to C being a bit
  messy with the distinction between lvalues and pointers, which led to
  a rather ugly solution for cpumask_var_t involving the introduction of
  this_cpu_cpumask_var_ptr().

  This converts most of the uses but not all.  Christoph will follow up
  with the remaining conversions in this merge window and hopefully
  remove the obsolete accessors"

* 'for-3.18-consistent-ops' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: (38 commits)
  irqchip: Properly fetch the per cpu offset
  percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t -fix
  ia64: sn_nodepda cannot be assigned to after this_cpu conversion. Use __this_cpu_write.
  percpu: Resolve ambiguities in __get_cpu_var/cpumask_var_t
  Revert "powerpc: Replace __get_cpu_var uses"
  percpu: Remove __this_cpu_ptr
  clocksource: Replace __this_cpu_ptr with raw_cpu_ptr
  sparc: Replace __get_cpu_var uses
  avr32: Replace __get_cpu_var with __this_cpu_write
  blackfin: Replace __get_cpu_var uses
  tile: Use this_cpu_ptr() for hardware counters
  tile: Replace __get_cpu_var uses
  powerpc: Replace __get_cpu_var uses
  alpha: Replace __get_cpu_var
  ia64: Replace __get_cpu_var uses
  s390: cio driver &amp;__get_cpu_var replacements
  s390: Replace __get_cpu_var uses
  mips: Replace __get_cpu_var uses
  MIPS: Replace __get_cpu_var uses in FPU emulator.
  arm: Replace __this_cpu_ptr with raw_cpu_ptr
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'akpm' (patches from Andrew Morton)</title>
<updated>2014-10-14T01:54:50+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-10-14T01:54:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dfe2c6dcc8ca2cdc662d7c0473e9811b72ef3370'/>
<id>dfe2c6dcc8ca2cdc662d7c0473e9811b72ef3370</id>
<content type='text'>
Merge second patch-bomb from Andrew Morton:
 - a few hotfixes
 - drivers/dma updates
 - MAINTAINERS updates
 - Quite a lot of lib/ updates
 - checkpatch updates
 - binfmt updates
 - autofs4
 - drivers/rtc/
 - various small tweaks to less used filesystems
 - ipc/ updates
 - kernel/watchdog.c changes

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (135 commits)
  mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared
  kernel/param: consolidate __{start,stop}___param[] in &lt;linux/moduleparam.h&gt;
  ia64: remove duplicate declarations of __per_cpu_start[] and __per_cpu_end[]
  frv: remove unused declarations of __start___ex_table and __stop___ex_table
  kvm: ensure hard lockup detection is disabled by default
  kernel/watchdog.c: control hard lockup detection default
  staging: rtl8192u: use %*pEn to escape buffer
  staging: rtl8192e: use %*pEn to escape buffer
  staging: wlan-ng: use %*pEhp to print SN
  lib80211: remove unused print_ssid()
  wireless: hostap: proc: print properly escaped SSID
  wireless: ipw2x00: print SSID via %*pE
  wireless: libertas: print esaped string via %*pE
  lib/vsprintf: add %*pE[achnops] format specifier
  lib / string_helpers: introduce string_escape_mem()
  lib / string_helpers: refactoring the test suite
  lib / string_helpers: move documentation to c-file
  include/linux: remove strict_strto* definitions
  arch/x86/mm/numa.c: fix boot failure when all nodes are hotpluggable
  fs: check bh blocknr earlier when searching lru
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge second patch-bomb from Andrew Morton:
 - a few hotfixes
 - drivers/dma updates
 - MAINTAINERS updates
 - Quite a lot of lib/ updates
 - checkpatch updates
 - binfmt updates
 - autofs4
 - drivers/rtc/
 - various small tweaks to less used filesystems
 - ipc/ updates
 - kernel/watchdog.c changes

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (135 commits)
  mm: softdirty: enable write notifications on VMAs after VM_SOFTDIRTY cleared
  kernel/param: consolidate __{start,stop}___param[] in &lt;linux/moduleparam.h&gt;
  ia64: remove duplicate declarations of __per_cpu_start[] and __per_cpu_end[]
  frv: remove unused declarations of __start___ex_table and __stop___ex_table
  kvm: ensure hard lockup detection is disabled by default
  kernel/watchdog.c: control hard lockup detection default
  staging: rtl8192u: use %*pEn to escape buffer
  staging: rtl8192e: use %*pEn to escape buffer
  staging: wlan-ng: use %*pEhp to print SN
  lib80211: remove unused print_ssid()
  wireless: hostap: proc: print properly escaped SSID
  wireless: ipw2x00: print SSID via %*pE
  wireless: libertas: print esaped string via %*pE
  lib/vsprintf: add %*pE[achnops] format specifier
  lib / string_helpers: introduce string_escape_mem()
  lib / string_helpers: refactoring the test suite
  lib / string_helpers: move documentation to c-file
  include/linux: remove strict_strto* definitions
  arch/x86/mm/numa.c: fix boot failure when all nodes are hotpluggable
  fs: check bh blocknr earlier when searching lru
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2014-10-14T00:28:16+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-10-14T00:28:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2fd7476de999124bbf6830aa59ac092c882280fe'/>
<id>2fd7476de999124bbf6830aa59ac092c882280fe</id>
<content type='text'>
Pull x86 fixes from Ingo Molnar:
 "Misc smaller fixes that missed the v3.17 cycle"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build: Add arch/x86/purgatory/ make generated files to gitignore
  x86: Fix section conflict for numachip
  x86: Reject x32 executables if x32 ABI not supported
  x86_64, entry: Filter RFLAGS.NT on entry from userspace
  x86, boot, kaslr: Fix nuisance warning on 32-bit builds
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 fixes from Ingo Molnar:
 "Misc smaller fixes that missed the v3.17 cycle"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/build: Add arch/x86/purgatory/ make generated files to gitignore
  x86: Fix section conflict for numachip
  x86: Reject x32 executables if x32 ABI not supported
  x86_64, entry: Filter RFLAGS.NT on entry from userspace
  x86, boot, kaslr: Fix nuisance warning on 32-bit builds
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'x86-cpufeature-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2014-10-14T00:19:47+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-10-14T00:19:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=708d0b41a26907ac83cde41dd5a75b5a2f8f1218'/>
<id>708d0b41a26907ac83cde41dd5a75b5a2f8f1218</id>
<content type='text'>
Pull x86 cpufeature updates from Ingo Molnar:
 "This tree includes the following changes:

   - Introduce DISABLED_MASK to list disabled CPU features, to simplify
     CPU feature handling and avoid excessive #ifdefs

   - Remove the lightly used cpu_has_pae() primitive"

* 'x86-cpufeature-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Add more disabled features
  x86: Introduce disabled-features
  x86: Axe the lightly-used cpu_has_pae
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 cpufeature updates from Ingo Molnar:
 "This tree includes the following changes:

   - Introduce DISABLED_MASK to list disabled CPU features, to simplify
     CPU feature handling and avoid excessive #ifdefs

   - Remove the lightly used cpu_has_pae() primitive"

* 'x86-cpufeature-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Add more disabled features
  x86: Introduce disabled-features
  x86: Axe the lightly-used cpu_has_pae
</pre>
</div>
</content>
</entry>
<entry>
<title>arch/x86/kernel/cpu/common.c: fix unused symbol warning</title>
<updated>2014-10-14T00:18:23+00:00</updated>
<author>
<name>Andrew Morton</name>
<email>akpm@linux-foundation.org</email>
</author>
<published>2014-10-13T22:54:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e48510f45107613bf14060eeabd658c49a044242'/>
<id>e48510f45107613bf14060eeabd658c49a044242</id>
<content type='text'>
x86_64 allnoconfig:

arch/x86/kernel/cpu/common.c:968: warning: 'syscall32_cpu_init' defined but not used

Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
x86_64 allnoconfig:

arch/x86/kernel/cpu/common.c:968: warning: 'syscall32_cpu_init' defined but not used

Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2014-10-13T16:16:32+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-10-13T16:16:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=19e00d593e9a273ecbfbe131676ed11c140670ac'/>
<id>19e00d593e9a273ecbfbe131676ed11c140670ac</id>
<content type='text'>
Pull x86 bootup updates from Ingo Molnar:
 "The changes in this cycle were:

   - Fix rare SMP-boot hang (mostly in virtual environments)

   - Fix build warning with certain (rare) toolchains"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/relocs: Make per_cpu_load_addr static
  x86/smpboot: Initialize secondary CPU only if master CPU will wait for it
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 bootup updates from Ingo Molnar:
 "The changes in this cycle were:

   - Fix rare SMP-boot hang (mostly in virtual environments)

   - Fix build warning with certain (rare) toolchains"

* 'x86-boot-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/relocs: Make per_cpu_load_addr static
  x86/smpboot: Initialize secondary CPU only if master CPU will wait for it
</pre>
</div>
</content>
</entry>
<entry>
<title>x86_64, entry: Filter RFLAGS.NT on entry from userspace</title>
<updated>2014-10-06T17:53:26+00:00</updated>
<author>
<name>Andy Lutomirski</name>
<email>luto@amacapital.net</email>
</author>
<published>2014-10-01T18:49:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8c7aa698baca5e8f1ba9edb68081f1e7a1abf455'/>
<id>8c7aa698baca5e8f1ba9edb68081f1e7a1abf455</id>
<content type='text'>
The NT flag doesn't do anything in long mode other than causing IRET
to #GP.  Oddly, CPL3 code can still set NT using popf.

Entry via hardware or software interrupt clears NT automatically, so
the only relevant entries are fast syscalls.

If user code causes kernel code to run with NT set, then there's at
least some (small) chance that it could cause trouble.  For example,
user code could cause a call to EFI code with NT set, and who knows
what would happen?  Apparently some games on Wine sometimes do
this (!), and, if an IRET return happens, they will segfault.  That
segfault cannot be handled, because signal delivery fails, too.

This patch programs the CPU to clear NT on entry via SYSCALL (both
32-bit and 64-bit, by my reading of the AMD APM), and it clears NT
in software on entry via SYSENTER.

To save a few cycles, this borrows a trick from Jan Beulich in Xen:
it checks whether NT is set before trying to clear it.  As a result,
it seems to have very little effect on SYSENTER performance on my
machine.

There's another minor bug fix in here: it looks like the CFI
annotations were wrong if CONFIG_AUDITSYSCALL=n.

Testers beware: on Xen, SYSENTER with NT set turns into a GPF.

I haven't touched anything on 32-bit kernels.

The syscall mask change comes from a variant of this patch by Anish
Bhatt.

Note to stable maintainers: there is no known security issue here.
A misguided program can set NT and cause the kernel to try and fail
to deliver SIGSEGV, crashing the program.  This patch fixes Far Cry
on Wine: https://bugs.winehq.org/show_bug.cgi?id=33275

Cc: &lt;stable@vger.kernel.org&gt;
Reported-by: Anish Bhatt &lt;anish@chelsio.com&gt;
Signed-off-by: Andy Lutomirski &lt;luto@amacapital.net&gt;
Link: http://lkml.kernel.org/r/395749a5d39a29bd3e4b35899cf3a3c1340e5595.1412189265.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The NT flag doesn't do anything in long mode other than causing IRET
to #GP.  Oddly, CPL3 code can still set NT using popf.

Entry via hardware or software interrupt clears NT automatically, so
the only relevant entries are fast syscalls.

If user code causes kernel code to run with NT set, then there's at
least some (small) chance that it could cause trouble.  For example,
user code could cause a call to EFI code with NT set, and who knows
what would happen?  Apparently some games on Wine sometimes do
this (!), and, if an IRET return happens, they will segfault.  That
segfault cannot be handled, because signal delivery fails, too.

This patch programs the CPU to clear NT on entry via SYSCALL (both
32-bit and 64-bit, by my reading of the AMD APM), and it clears NT
in software on entry via SYSENTER.

To save a few cycles, this borrows a trick from Jan Beulich in Xen:
it checks whether NT is set before trying to clear it.  As a result,
it seems to have very little effect on SYSENTER performance on my
machine.

There's another minor bug fix in here: it looks like the CFI
annotations were wrong if CONFIG_AUDITSYSCALL=n.

Testers beware: on Xen, SYSENTER with NT set turns into a GPF.

I haven't touched anything on 32-bit kernels.

The syscall mask change comes from a variant of this patch by Anish
Bhatt.

Note to stable maintainers: there is no known security issue here.
A misguided program can set NT and cause the kernel to try and fail
to deliver SIGSEGV, crashing the program.  This patch fixes Far Cry
on Wine: https://bugs.winehq.org/show_bug.cgi?id=33275

Cc: &lt;stable@vger.kernel.org&gt;
Reported-by: Anish Bhatt &lt;anish@chelsio.com&gt;
Signed-off-by: Andy Lutomirski &lt;luto@amacapital.net&gt;
Link: http://lkml.kernel.org/r/395749a5d39a29bd3e4b35899cf3a3c1340e5595.1412189265.git.luto@amacapital.net
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
