<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/x86/entry, branch linux-4.7.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/syscalls/64: Add compat_sys_keyctl for 32-bit userspace</title>
<updated>2016-08-16T07:34:59+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2016-07-27T10:42:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=64494393dff3ce45bfd38b2a382478d8f310c857'/>
<id>64494393dff3ce45bfd38b2a382478d8f310c857</id>
<content type='text'>
commit f7d665627e103e82d34306c7d3f6f46f387c0d8b upstream.

x86_64 needs to use compat_sys_keyctl for 32-bit userspace rather than
calling sys_keyctl(). The latter will work in a lot of cases, thereby
hiding the issue.

Reported-by: Stephan Mueller &lt;smueller@chronox.de&gt;
Tested-by: Stephan Mueller &lt;smueller@chronox.de&gt;
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Josh Poimboeuf &lt;jpoimboe@redhat.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;
Cc: keyrings@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Link: http://lkml.kernel.org/r/146961615805.14395.5581949237156769439.stgit@warthog.procyon.org.uk
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 f7d665627e103e82d34306c7d3f6f46f387c0d8b upstream.

x86_64 needs to use compat_sys_keyctl for 32-bit userspace rather than
calling sys_keyctl(). The latter will work in a lot of cases, thereby
hiding the issue.

Reported-by: Stephan Mueller &lt;smueller@chronox.de&gt;
Tested-by: Stephan Mueller &lt;smueller@chronox.de&gt;
Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Josh Poimboeuf &lt;jpoimboe@redhat.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;
Cc: keyrings@vger.kernel.org
Cc: linux-security-module@vger.kernel.org
Link: http://lkml.kernel.org/r/146961615805.14395.5581949237156769439.stgit@warthog.procyon.org.uk
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>Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild</title>
<updated>2016-05-27T05:01:22+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-05-27T05:01:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5b26fc8824da15a2fe9df89338a5a3cad41ba8ee'/>
<id>5b26fc8824da15a2fe9df89338a5a3cad41ba8ee</id>
<content type='text'>
Pull kbuild updates from Michal Marek:

 - new option CONFIG_TRIM_UNUSED_KSYMS which does a two-pass build and
   unexports symbols which are not used in the current config [Nicolas
   Pitre]

 - several kbuild rule cleanups [Masahiro Yamada]

 - warning option adjustments for gcov etc [Arnd Bergmann]

 - a few more small fixes

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (31 commits)
  kbuild: move -Wunused-const-variable to W=1 warning level
  kbuild: fix if_change and friends to consider argument order
  kbuild: fix adjust_autoksyms.sh for modules that need only one symbol
  kbuild: fix ksym_dep_filter when multiple EXPORT_SYMBOL() on the same line
  gcov: disable -Wmaybe-uninitialized warning
  gcov: disable tree-loop-im to reduce stack usage
  gcov: disable for COMPILE_TEST
  Kbuild: disable 'maybe-uninitialized' warning for CONFIG_PROFILE_ALL_BRANCHES
  Kbuild: change CC_OPTIMIZE_FOR_SIZE definition
  kbuild: forbid kernel directory to contain spaces and colons
  kbuild: adjust ksym_dep_filter for some cmd_* renames
  kbuild: Fix dependencies for final vmlinux link
  kbuild: better abstract vmlinux sequential prerequisites
  kbuild: fix call to adjust_autoksyms.sh when output directory specified
  kbuild: Get rid of KBUILD_STR
  kbuild: rename cmd_as_s_S to cmd_cpp_s_S
  kbuild: rename cmd_cc_i_c to cmd_cpp_i_c
  kbuild: drop redundant "PHONY += FORCE"
  kbuild: delete unnecessary "@:"
  kbuild: mark help target as PHONY
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull kbuild updates from Michal Marek:

 - new option CONFIG_TRIM_UNUSED_KSYMS which does a two-pass build and
   unexports symbols which are not used in the current config [Nicolas
   Pitre]

 - several kbuild rule cleanups [Masahiro Yamada]

 - warning option adjustments for gcov etc [Arnd Bergmann]

 - a few more small fixes

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: (31 commits)
  kbuild: move -Wunused-const-variable to W=1 warning level
  kbuild: fix if_change and friends to consider argument order
  kbuild: fix adjust_autoksyms.sh for modules that need only one symbol
  kbuild: fix ksym_dep_filter when multiple EXPORT_SYMBOL() on the same line
  gcov: disable -Wmaybe-uninitialized warning
  gcov: disable tree-loop-im to reduce stack usage
  gcov: disable for COMPILE_TEST
  Kbuild: disable 'maybe-uninitialized' warning for CONFIG_PROFILE_ALL_BRANCHES
  Kbuild: change CC_OPTIMIZE_FOR_SIZE definition
  kbuild: forbid kernel directory to contain spaces and colons
  kbuild: adjust ksym_dep_filter for some cmd_* renames
  kbuild: Fix dependencies for final vmlinux link
  kbuild: better abstract vmlinux sequential prerequisites
  kbuild: fix call to adjust_autoksyms.sh when output directory specified
  kbuild: Get rid of KBUILD_STR
  kbuild: rename cmd_as_s_S to cmd_cpp_s_S
  kbuild: rename cmd_cc_i_c to cmd_cpp_i_c
  kbuild: drop redundant "PHONY += FORCE"
  kbuild: delete unnecessary "@:"
  kbuild: mark help target as PHONY
  ...
</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>2016-05-26T00:37:33+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-05-26T00:37:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2f7c3a18a2dc79ddf7b83ae199b099a675e1adb2'/>
<id>2f7c3a18a2dc79ddf7b83ae199b099a675e1adb2</id>
<content type='text'>
Pull x86 fixes from Ingo Molnar:
 "Misc fixes: EFI, entry code, pkeys and MPX fixes, TASK_SIZE cleanups
  and a tsc frequency table fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Switch from TASK_SIZE to TASK_SIZE_MAX in the page fault code
  x86/fsgsbase/64: Use TASK_SIZE_MAX for FSBASE/GSBASE upper limits
  x86/mm/mpx: Work around MPX erratum SKD046
  x86/entry/64: Fix stack return address retrieval in thunk
  x86/efi: Fix 7-parameter efi_call()s
  x86/cpufeature, x86/mm/pkeys: Fix broken compile-time disabling of pkeys
  x86/tsc: Add missing Cherrytrail frequency to the table
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 fixes from Ingo Molnar:
 "Misc fixes: EFI, entry code, pkeys and MPX fixes, TASK_SIZE cleanups
  and a tsc frequency table fix"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Switch from TASK_SIZE to TASK_SIZE_MAX in the page fault code
  x86/fsgsbase/64: Use TASK_SIZE_MAX for FSBASE/GSBASE upper limits
  x86/mm/mpx: Work around MPX erratum SKD046
  x86/entry/64: Fix stack return address retrieval in thunk
  x86/efi: Fix 7-parameter efi_call()s
  x86/cpufeature, x86/mm/pkeys: Fix broken compile-time disabling of pkeys
  x86/tsc: Add missing Cherrytrail frequency to the table
</pre>
</div>
</content>
</entry>
<entry>
<title>vdso: make arch_setup_additional_pages wait for mmap_sem for write killable</title>
<updated>2016-05-24T00:04:14+00:00</updated>
<author>
<name>Michal Hocko</name>
<email>mhocko@suse.com</email>
</author>
<published>2016-05-23T23:25:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=69048176078adda4087a648c9b1812ddd800fad1'/>
<id>69048176078adda4087a648c9b1812ddd800fad1</id>
<content type='text'>
most architectures are relying on mmap_sem for write in their
arch_setup_additional_pages.  If the waiting task gets killed by the oom
killer it would block oom_reaper from asynchronous address space reclaim
and reduce the chances of timely OOM resolving.  Wait for the lock in
the killable mode and return with EINTR if the task got killed while
waiting.

Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Andy Lutomirski &lt;luto@amacapital.net&gt;	[x86 vdso]
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&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>
most architectures are relying on mmap_sem for write in their
arch_setup_additional_pages.  If the waiting task gets killed by the oom
killer it would block oom_reaper from asynchronous address space reclaim
and reduce the chances of timely OOM resolving.  Wait for the lock in
the killable mode and return with EINTR if the task got killed while
waiting.

Signed-off-by: Michal Hocko &lt;mhocko@suse.com&gt;
Acked-by: Andy Lutomirski &lt;luto@amacapital.net&gt;	[x86 vdso]
Acked-by: Vlastimil Babka &lt;vbabka@suse.cz&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 'linus' into x86/urgent, to refresh the tree</title>
<updated>2016-05-20T07:09:26+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2016-05-20T07:09:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=06cd3d8c14bdd06f49f1c6a06acf219749c5598e'/>
<id>06cd3d8c14bdd06f49f1c6a06acf219749c5598e</id>
<content type='text'>
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/entry/64: Fix stack return address retrieval in thunk</title>
<updated>2016-05-19T07:12:34+00:00</updated>
<author>
<name>Josh Poimboeuf</name>
<email>jpoimboe@redhat.com</email>
</author>
<published>2016-05-17T18:06:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d4bf7078c43e11097e0d6f04d3fb999bf92c4fb0'/>
<id>d4bf7078c43e11097e0d6f04d3fb999bf92c4fb0</id>
<content type='text'>
With CONFIG_FRAME_POINTER enabled, a thunk can pass a bad return address
value to the called function.  '9*8(%rsp)' actually gets the frame
pointer, not the return address.

The only users of the 'put_ret_addr_in_rdi' option are two functions
which trace the enabling and disabling of interrupts, so this bug can
result in bad debug or tracing information with CONFIG_IRQSOFF_TRACER or
CONFIG_PROVE_LOCKING.

Fix this by implementing the suggestion of Linus: explicitly push
the frame pointer all the time and constify the stack offsets that
way. This is both correct and easier to read.

Reported-by: Matt Fleming &lt;matt@codeblueprint.co.uk&gt;
Signed-off-by: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
[ Extended the changelog a bit. ]
Acked-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Alex Thorlton &lt;athorlton@sgi.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Fixes: 058fb73274f9 ("x86/asm/entry: Create stack frames in thunk functions")
Link: http://lkml.kernel.org/r/20160517180606.v5o7wcgdni7443ol@treble
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
With CONFIG_FRAME_POINTER enabled, a thunk can pass a bad return address
value to the called function.  '9*8(%rsp)' actually gets the frame
pointer, not the return address.

The only users of the 'put_ret_addr_in_rdi' option are two functions
which trace the enabling and disabling of interrupts, so this bug can
result in bad debug or tracing information with CONFIG_IRQSOFF_TRACER or
CONFIG_PROVE_LOCKING.

Fix this by implementing the suggestion of Linus: explicitly push
the frame pointer all the time and constify the stack offsets that
way. This is both correct and easier to read.

Reported-by: Matt Fleming &lt;matt@codeblueprint.co.uk&gt;
Signed-off-by: Josh Poimboeuf &lt;jpoimboe@redhat.com&gt;
[ Extended the changelog a bit. ]
Acked-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Alex Thorlton &lt;athorlton@sgi.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Fixes: 058fb73274f9 ("x86/asm/entry: Create stack frames in thunk functions")
Link: http://lkml.kernel.org/r/20160517180606.v5o7wcgdni7443ol@treble
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86: Use compat version for preadv2 and pwritev2</title>
<updated>2016-05-12T12:27:13+00:00</updated>
<author>
<name>Dmitry V. Levin</name>
<email>ldv@altlinux.org</email>
</author>
<published>2016-05-11T08:48:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9a7a076e8e4ffcfec05e3cafe4c4e31d41ddbaa0'/>
<id>9a7a076e8e4ffcfec05e3cafe4c4e31d41ddbaa0</id>
<content type='text'>
Similar to preadv and pwritev, preadv2 and pwritev2 need compat entries
in the 32-bit syscall table.

This bug was found by strace test suite.

Fixes: 4babf2c5efb7 ("x86: wire up preadv2 and pwritev2")
Signed-off-by: Dmitry V. Levin &lt;ldv@altlinux.org&gt;
Acked-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: http://lkml.kernel.org/r/20160511084817.GA29823@altlinux.org
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Similar to preadv and pwritev, preadv2 and pwritev2 need compat entries
in the 32-bit syscall table.

This bug was found by strace test suite.

Fixes: 4babf2c5efb7 ("x86: wire up preadv2 and pwritev2")
Signed-off-by: Dmitry V. Levin &lt;ldv@altlinux.org&gt;
Acked-by: Christoph Hellwig &lt;hch@lst.de&gt;
Link: http://lkml.kernel.org/r/20160511084817.GA29823@altlinux.org
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>x86/entry/32: Remove GET_THREAD_INFO() from entry code</title>
<updated>2016-05-05T06:37:30+00:00</updated>
<author>
<name>Brian Gerst</name>
<email>brgerst@gmail.com</email>
</author>
<published>2016-05-05T02:44:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1e17880371f85d3d866962e04ba3567c0654a125'/>
<id>1e17880371f85d3d866962e04ba3567c0654a125</id>
<content type='text'>
The entry code used to cache the thread_info pointer in the EBP register,
but all the code that used it has been moved to C.  Remove the unused
code to get the pointer.

Signed-off-by: Brian Gerst &lt;brgerst@gmail.com&gt;
Acked-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Borislav Petkov &lt;bp@suse.de&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.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/1462416278-11974-3-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The entry code used to cache the thread_info pointer in the EBP register,
but all the code that used it has been moved to C.  Remove the unused
code to get the pointer.

Signed-off-by: Brian Gerst &lt;brgerst@gmail.com&gt;
Acked-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Borislav Petkov &lt;bp@suse.de&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.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/1462416278-11974-3-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/entry, sched/x86: Don't save/restore EFLAGS on task switch</title>
<updated>2016-05-05T06:37:30+00:00</updated>
<author>
<name>Brian Gerst</name>
<email>brgerst@gmail.com</email>
</author>
<published>2016-05-05T02:44:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=092c74e420952c7cb68141731f2b562245b51eeb'/>
<id>092c74e420952c7cb68141731f2b562245b51eeb</id>
<content type='text'>
Now that NT is filtered by the SYSENTER entry code, it is safe to skip saving and
restoring flags on task switch.  Also remove a leftover reset of flags on 64-bit
fork.

Signed-off-by: Brian Gerst &lt;brgerst@gmail.com&gt;
Acked-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Borislav Petkov &lt;bp@suse.de&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.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/1462416278-11974-2-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Now that NT is filtered by the SYSENTER entry code, it is safe to skip saving and
restoring flags on task switch.  Also remove a leftover reset of flags on 64-bit
fork.

Signed-off-by: Brian Gerst &lt;brgerst@gmail.com&gt;
Acked-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Borislav Petkov &lt;bp@suse.de&gt;
Cc: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.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/1462416278-11974-2-git-send-email-brgerst@gmail.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86/asm/entry/32: Simplify pushes of zeroed pt_regs-&gt;REGs</title>
<updated>2016-05-03T06:19:40+00:00</updated>
<author>
<name>Denys Vlasenko</name>
<email>dvlasenk@redhat.com</email>
</author>
<published>2016-05-02T14:56:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=778843f934e362ed4ed734520f60a44a78a074b4'/>
<id>778843f934e362ed4ed734520f60a44a78a074b4</id>
<content type='text'>
Use of a temporary R8 register here seems to be unnecessary.

"push %r8" is a two-byte insn (it needs REX prefix to specify R8),
"push $0" is two-byte too. It seems just using the latter would be
no worse.

Thus, code had an unnecessary "xorq %r8,%r8" insn.
It probably costs nothing in execution time here since we are probably
limited by store bandwidth at this point, but still.

Run-tested under QEMU: 32-bit calls still work:

 / # ./test_syscall_vdso32
 [RUN]	Executing 6-argument 32-bit syscall via VDSO
 [OK]	Arguments are preserved across syscall
 [NOTE]	R11 has changed:0000000000200ed7 - assuming clobbered by SYSRET insn
 [OK]	R8..R15 did not leak kernel data
 [RUN]	Executing 6-argument 32-bit syscall via INT 80
 [OK]	Arguments are preserved across syscall
 [OK]	R8..R15 did not leak kernel data
 [RUN]	Running tests under ptrace
 [RUN]	Executing 6-argument 32-bit syscall via VDSO
 [OK]	Arguments are preserved across syscall
 [NOTE]	R11 has changed:0000000000200ed7 - assuming clobbered by SYSRET insn
 [OK]	R8..R15 did not leak kernel data
 [RUN]	Executing 6-argument 32-bit syscall via INT 80
 [OK]	Arguments are preserved across syscall
 [OK]	R8..R15 did not leak kernel data

Signed-off-by: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Acked-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Drewry &lt;wad@chromium.org&gt;
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1462201010-16846-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Use of a temporary R8 register here seems to be unnecessary.

"push %r8" is a two-byte insn (it needs REX prefix to specify R8),
"push $0" is two-byte too. It seems just using the latter would be
no worse.

Thus, code had an unnecessary "xorq %r8,%r8" insn.
It probably costs nothing in execution time here since we are probably
limited by store bandwidth at this point, but still.

Run-tested under QEMU: 32-bit calls still work:

 / # ./test_syscall_vdso32
 [RUN]	Executing 6-argument 32-bit syscall via VDSO
 [OK]	Arguments are preserved across syscall
 [NOTE]	R11 has changed:0000000000200ed7 - assuming clobbered by SYSRET insn
 [OK]	R8..R15 did not leak kernel data
 [RUN]	Executing 6-argument 32-bit syscall via INT 80
 [OK]	Arguments are preserved across syscall
 [OK]	R8..R15 did not leak kernel data
 [RUN]	Running tests under ptrace
 [RUN]	Executing 6-argument 32-bit syscall via VDSO
 [OK]	Arguments are preserved across syscall
 [NOTE]	R11 has changed:0000000000200ed7 - assuming clobbered by SYSRET insn
 [OK]	R8..R15 did not leak kernel data
 [RUN]	Executing 6-argument 32-bit syscall via INT 80
 [OK]	Arguments are preserved across syscall
 [OK]	R8..R15 did not leak kernel data

Signed-off-by: Denys Vlasenko &lt;dvlasenk@redhat.com&gt;
Acked-by: Andy Lutomirski &lt;luto@kernel.org&gt;
Cc: Andy Lutomirski &lt;luto@amacapital.net&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Brian Gerst &lt;brgerst@gmail.com&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: H. Peter Anvin &lt;hpa@zytor.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Drewry &lt;wad@chromium.org&gt;
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1462201010-16846-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
