<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch/cris, branch v4.10</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>Replace &lt;asm/uaccess.h&gt; with &lt;linux/uaccess.h&gt; globally</title>
<updated>2016-12-24T19:46:01+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-12-24T19:46:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=7c0f6ba682b9c7632072ffbedf8d328c8f3c42ba'/>
<id>7c0f6ba682b9c7632072ffbedf8d328c8f3c42ba</id>
<content type='text'>
This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*&lt;asm/uaccess.h&gt;'
  sed -i -e "s!$PATT!#include &lt;linux/uaccess.h&gt;!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro &lt;viro@zeniv.linux.org.uk&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>
This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*&lt;asm/uaccess.h&gt;'
  sed -i -e "s!$PATT!#include &lt;linux/uaccess.h&gt;!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace</title>
<updated>2016-12-14T22:09:48+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-12-14T22:09:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=412ac77a9d3ec015524dacea905471d66480b7ac'/>
<id>412ac77a9d3ec015524dacea905471d66480b7ac</id>
<content type='text'>
Pull namespace updates from Eric Biederman:
 "After a lot of discussion and work we have finally reachanged a basic
  understanding of what is necessary to make unprivileged mounts safe in
  the presence of EVM and IMA xattrs which the last commit in this
  series reflects. While technically it is a revert the comments it adds
  are important for people not getting confused in the future. Clearing
  up that confusion allows us to seriously work on unprivileged mounts
  of fuse in the next development cycle.

  The rest of the fixes in this set are in the intersection of user
  namespaces, ptrace, and exec. I started with the first fix which
  started a feedback cycle of finding additional issues during review
  and fixing them. Culiminating in a fix for a bug that has been present
  since at least Linux v1.0.

  Potentially these fixes were candidates for being merged during the rc
  cycle, and are certainly backport candidates but enough little things
  turned up during review and testing that I decided they should be
  handled as part of the normal development process just to be certain
  there were not any great surprises when it came time to backport some
  of these fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  Revert "evm: Translate user/group ids relative to s_user_ns when computing HMAC"
  exec: Ensure mm-&gt;user_ns contains the execed files
  ptrace: Don't allow accessing an undumpable mm
  ptrace: Capture the ptracer's creds not PT_PTRACE_CAP
  mm: Add a user_ns owner to mm_struct and fix ptrace permission checks
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull namespace updates from Eric Biederman:
 "After a lot of discussion and work we have finally reachanged a basic
  understanding of what is necessary to make unprivileged mounts safe in
  the presence of EVM and IMA xattrs which the last commit in this
  series reflects. While technically it is a revert the comments it adds
  are important for people not getting confused in the future. Clearing
  up that confusion allows us to seriously work on unprivileged mounts
  of fuse in the next development cycle.

  The rest of the fixes in this set are in the intersection of user
  namespaces, ptrace, and exec. I started with the first fix which
  started a feedback cycle of finding additional issues during review
  and fixing them. Culiminating in a fix for a bug that has been present
  since at least Linux v1.0.

  Potentially these fixes were candidates for being merged during the rc
  cycle, and are certainly backport candidates but enough little things
  turned up during review and testing that I decided they should be
  handled as part of the normal development process just to be certain
  there were not any great surprises when it came time to backport some
  of these fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  Revert "evm: Translate user/group ids relative to s_user_ns when computing HMAC"
  exec: Ensure mm-&gt;user_ns contains the execed files
  ptrace: Don't allow accessing an undumpable mm
  ptrace: Capture the ptracer's creds not PT_PTRACE_CAP
  mm: Add a user_ns owner to mm_struct and fix ptrace permission checks
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2016-12-12T18:48:02+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-12-12T18:48:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6cdf89b1ca803b2d2d097466516431b1fc5bf985'/>
<id>6cdf89b1ca803b2d2d097466516431b1fc5bf985</id>
<content type='text'>
Pull locking updates from Ingo Molnar:
 "The tree got pretty big in this development cycle, but the net effect
  is pretty good:

    115 files changed, 673 insertions(+), 1522 deletions(-)

  The main changes were:

   - Rework and generalize the mutex code to remove per arch mutex
     primitives. (Peter Zijlstra)

   - Add vCPU preemption support: add an interface to query the
     preemption status of vCPUs and use it in locking primitives - this
     optimizes paravirt performance. (Pan Xinhui, Juergen Gross,
     Christian Borntraeger)

   - Introduce cpu_relax_yield() and remov cpu_relax_lowlatency() to
     clean up and improve the s390 lock yielding machinery and its core
     kernel impact. (Christian Borntraeger)

   - Micro-optimize mutexes some more. (Waiman Long)

   - Reluctantly add the to-be-deprecated mutex_trylock_recursive()
     interface on a temporary basis, to give the DRM code more time to
     get rid of its locking hacks. Any other users will be NAK-ed on
     sight. (We turned off the deprecation warning for the time being to
     not pollute the build log.) (Peter Zijlstra)

   - Improve the rtmutex code a bit, in light of recent long lived
     bugs/races. (Thomas Gleixner)

   - Misc fixes, cleanups"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  x86/paravirt: Fix bool return type for PVOP_CALL()
  x86/paravirt: Fix native_patch()
  locking/ww_mutex: Use relaxed atomics
  locking/rtmutex: Explain locking rules for rt_mutex_proxy_unlock()/init_proxy_locked()
  locking/rtmutex: Get rid of RT_MUTEX_OWNER_MASKALL
  x86/paravirt: Optimize native pv_lock_ops.vcpu_is_preempted()
  locking/mutex: Break out of expensive busy-loop on {mutex,rwsem}_spin_on_owner() when owner vCPU is preempted
  locking/osq: Break out of spin-wait busy waiting loop for a preempted vCPU in osq_lock()
  Documentation/virtual/kvm: Support the vCPU preemption check
  x86/xen: Support the vCPU preemption check
  x86/kvm: Support the vCPU preemption check
  x86/kvm: Support the vCPU preemption check
  kvm: Introduce kvm_write_guest_offset_cached()
  locking/core, x86/paravirt: Implement vcpu_is_preempted(cpu) for KVM and Xen guests
  locking/spinlocks, s390: Implement vcpu_is_preempted(cpu)
  locking/core, powerpc: Implement vcpu_is_preempted(cpu)
  sched/core: Introduce the vcpu_is_preempted(cpu) interface
  sched/wake_q: Rename WAKE_Q to DEFINE_WAKE_Q
  locking/core: Provide common cpu_relax_yield() definition
  locking/mutex: Don't mark mutex_trylock_recursive() as deprecated, temporarily
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull locking updates from Ingo Molnar:
 "The tree got pretty big in this development cycle, but the net effect
  is pretty good:

    115 files changed, 673 insertions(+), 1522 deletions(-)

  The main changes were:

   - Rework and generalize the mutex code to remove per arch mutex
     primitives. (Peter Zijlstra)

   - Add vCPU preemption support: add an interface to query the
     preemption status of vCPUs and use it in locking primitives - this
     optimizes paravirt performance. (Pan Xinhui, Juergen Gross,
     Christian Borntraeger)

   - Introduce cpu_relax_yield() and remov cpu_relax_lowlatency() to
     clean up and improve the s390 lock yielding machinery and its core
     kernel impact. (Christian Borntraeger)

   - Micro-optimize mutexes some more. (Waiman Long)

   - Reluctantly add the to-be-deprecated mutex_trylock_recursive()
     interface on a temporary basis, to give the DRM code more time to
     get rid of its locking hacks. Any other users will be NAK-ed on
     sight. (We turned off the deprecation warning for the time being to
     not pollute the build log.) (Peter Zijlstra)

   - Improve the rtmutex code a bit, in light of recent long lived
     bugs/races. (Thomas Gleixner)

   - Misc fixes, cleanups"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  x86/paravirt: Fix bool return type for PVOP_CALL()
  x86/paravirt: Fix native_patch()
  locking/ww_mutex: Use relaxed atomics
  locking/rtmutex: Explain locking rules for rt_mutex_proxy_unlock()/init_proxy_locked()
  locking/rtmutex: Get rid of RT_MUTEX_OWNER_MASKALL
  x86/paravirt: Optimize native pv_lock_ops.vcpu_is_preempted()
  locking/mutex: Break out of expensive busy-loop on {mutex,rwsem}_spin_on_owner() when owner vCPU is preempted
  locking/osq: Break out of spin-wait busy waiting loop for a preempted vCPU in osq_lock()
  Documentation/virtual/kvm: Support the vCPU preemption check
  x86/xen: Support the vCPU preemption check
  x86/kvm: Support the vCPU preemption check
  x86/kvm: Support the vCPU preemption check
  kvm: Introduce kvm_write_guest_offset_cached()
  locking/core, x86/paravirt: Implement vcpu_is_preempted(cpu) for KVM and Xen guests
  locking/spinlocks, s390: Implement vcpu_is_preempted(cpu)
  locking/core, powerpc: Implement vcpu_is_preempted(cpu)
  sched/core: Introduce the vcpu_is_preempted(cpu) interface
  sched/wake_q: Rename WAKE_Q to DEFINE_WAKE_Q
  locking/core: Provide common cpu_relax_yield() definition
  locking/mutex: Don't mark mutex_trylock_recursive() as deprecated, temporarily
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>cris: No need to append -O2 and $(LINUXINCLUDE)</title>
<updated>2016-12-08T09:56:40+00:00</updated>
<author>
<name>Paul Bolle</name>
<email>pebolle@tiscali.nl</email>
</author>
<published>2016-11-25T12:30:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8f50f2a1b46a11a9a9fb46c5d8325dfc88281a76'/>
<id>8f50f2a1b46a11a9a9fb46c5d8325dfc88281a76</id>
<content type='text'>
The make variables asflags-y and ccflags-y are appended with -O2 and
$(LINUXINCLUDE). But the build already picks up -O2 from the top Makefile
and $(LINUXINCLUDE) from scripts/Makefile.lib. The net effect is that -O2
and the (long) list of include directories are used twice.

This is harmless but pointless. So stop appending to these flags.

Signed-off-by: Paul Bolle &lt;pebolle@tiscali.nl&gt;
Signed-off-by: Jesper Nilsson &lt;jespern@axis.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The make variables asflags-y and ccflags-y are appended with -O2 and
$(LINUXINCLUDE). But the build already picks up -O2 from the top Makefile
and $(LINUXINCLUDE) from scripts/Makefile.lib. The net effect is that -O2
and the (long) list of include directories are used twice.

This is harmless but pointless. So stop appending to these flags.

Signed-off-by: Paul Bolle &lt;pebolle@tiscali.nl&gt;
Signed-off-by: Jesper Nilsson &lt;jespern@axis.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ptrace: Don't allow accessing an undumpable mm</title>
<updated>2016-11-22T18:57:38+00:00</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2016-11-22T18:06:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=84d77d3f06e7e8dea057d10e8ec77ad71f721be3'/>
<id>84d77d3f06e7e8dea057d10e8ec77ad71f721be3</id>
<content type='text'>
It is the reasonable expectation that if an executable file is not
readable there will be no way for a user without special privileges to
read the file.  This is enforced in ptrace_attach but if ptrace
is already attached before exec there is no enforcement for read-only
executables.

As the only way to read such an mm is through access_process_vm
spin a variant called ptrace_access_vm that will fail if the
target process is not being ptraced by the current process, or
the current process did not have sufficient privileges when ptracing
began to read the target processes mm.

In the ptrace implementations replace access_process_vm by
ptrace_access_vm.  There remain several ptrace sites that still use
access_process_vm as they are reading the target executables
instructions (for kernel consumption) or register stacks.  As such it
does not appear necessary to add a permission check to those calls.

This bug has always existed in Linux.

Fixes: v1.0
Cc: stable@vger.kernel.org
Reported-by: Andy Lutomirski &lt;luto@amacapital.net&gt;
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It is the reasonable expectation that if an executable file is not
readable there will be no way for a user without special privileges to
read the file.  This is enforced in ptrace_attach but if ptrace
is already attached before exec there is no enforcement for read-only
executables.

As the only way to read such an mm is through access_process_vm
spin a variant called ptrace_access_vm that will fail if the
target process is not being ptraced by the current process, or
the current process did not have sufficient privileges when ptracing
began to read the target processes mm.

In the ptrace implementations replace access_process_vm by
ptrace_access_vm.  There remain several ptrace sites that still use
access_process_vm as they are reading the target executables
instructions (for kernel consumption) or register stacks.  As such it
does not appear necessary to add a permission check to those calls.

This bug has always existed in Linux.

Fixes: v1.0
Cc: stable@vger.kernel.org
Reported-by: Andy Lutomirski &lt;luto@amacapital.net&gt;
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/core: Provide common cpu_relax_yield() definition</title>
<updated>2016-11-17T07:17:36+00:00</updated>
<author>
<name>Christian Borntraeger</name>
<email>borntraeger@de.ibm.com</email>
</author>
<published>2016-11-16T12:23:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6d0d287891a022ebba572327cbd70b5de69a63a2'/>
<id>6d0d287891a022ebba572327cbd70b5de69a63a2</id>
<content type='text'>
No need to duplicate the same define everywhere. Since
the only user is stop-machine and the only provider is
s390, we can use a default implementation of cpu_relax_yield()
in sched.h.

Suggested-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Signed-off-by: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Reviewed-by: David Hildenbrand &lt;david@redhat.com&gt;
Acked-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Cc: Noam Camus &lt;noamc@ezchip.com&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-s390 &lt;linux-s390@vger.kernel.org&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1479298985-191589-1-git-send-email-borntraeger@de.ibm.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
No need to duplicate the same define everywhere. Since
the only user is stop-machine and the only provider is
s390, we can use a default implementation of cpu_relax_yield()
in sched.h.

Suggested-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Signed-off-by: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Reviewed-by: David Hildenbrand &lt;david@redhat.com&gt;
Acked-by: Russell King &lt;rmk+kernel@armlinux.org.uk&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Cc: Noam Camus &lt;noamc@ezchip.com&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-s390 &lt;linux-s390@vger.kernel.org&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Cc: sparclinux@vger.kernel.org
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1479298985-191589-1-git-send-email-borntraeger@de.ibm.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/core, arch: Remove cpu_relax_lowlatency()</title>
<updated>2016-11-16T09:15:11+00:00</updated>
<author>
<name>Christian Borntraeger</name>
<email>borntraeger@de.ibm.com</email>
</author>
<published>2016-10-25T09:03:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5bd0b85ba8bb9de6f61f33f3752fc85f4c87fc22'/>
<id>5bd0b85ba8bb9de6f61f33f3752fc85f4c87fc22</id>
<content type='text'>
As there are no users left, we can remove cpu_relax_lowlatency()
implementations from every architecture.

Signed-off-by: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Cc: Noam Camus &lt;noamc@ezchip.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Cc: &lt;linux-arch@vger.kernel.org&gt;
Link: http://lkml.kernel.org/r/1477386195-32736-6-git-send-email-borntraeger@de.ibm.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
As there are no users left, we can remove cpu_relax_lowlatency()
implementations from every architecture.

Signed-off-by: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Cc: Noam Camus &lt;noamc@ezchip.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Cc: &lt;linux-arch@vger.kernel.org&gt;
Link: http://lkml.kernel.org/r/1477386195-32736-6-git-send-email-borntraeger@de.ibm.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>locking/core: Introduce cpu_relax_yield()</title>
<updated>2016-11-16T09:15:09+00:00</updated>
<author>
<name>Christian Borntraeger</name>
<email>borntraeger@de.ibm.com</email>
</author>
<published>2016-10-25T09:03:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=79ab11cdb90d8536817ab7357ecb6b1ff76be26c'/>
<id>79ab11cdb90d8536817ab7357ecb6b1ff76be26c</id>
<content type='text'>
For spinning loops people do often use barrier() or cpu_relax().
For most architectures cpu_relax and barrier are the same, but on
some architectures cpu_relax can add some latency.
For example on power,sparc64 and arc, cpu_relax can shift the CPU
towards other hardware threads in an SMT environment.
On s390 cpu_relax does even more, it uses an hypercall to the
hypervisor to give up the timeslice.
In contrast to the SMT yielding this can result in larger latencies.
In some places this latency is unwanted, so another variant
"cpu_relax_lowlatency" was introduced. Before this is used in more
and more places, lets revert the logic and provide a cpu_relax_yield
that can be called in places where yielding is more important than
latency. By default this is the same as cpu_relax on all architectures.

Signed-off-by: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Cc: Noam Camus &lt;noamc@ezchip.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1477386195-32736-2-git-send-email-borntraeger@de.ibm.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
For spinning loops people do often use barrier() or cpu_relax().
For most architectures cpu_relax and barrier are the same, but on
some architectures cpu_relax can add some latency.
For example on power,sparc64 and arc, cpu_relax can shift the CPU
towards other hardware threads in an SMT environment.
On s390 cpu_relax does even more, it uses an hypercall to the
hypervisor to give up the timeslice.
In contrast to the SMT yielding this can result in larger latencies.
In some places this latency is unwanted, so another variant
"cpu_relax_lowlatency" was introduced. Before this is used in more
and more places, lets revert the logic and provide a cpu_relax_yield
that can be called in places where yielding is more important than
latency. By default this is the same as cpu_relax on all architectures.

Signed-off-by: Christian Borntraeger &lt;borntraeger@de.ibm.com&gt;
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Cc: Noam Camus &lt;noamc@ezchip.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: linuxppc-dev@lists.ozlabs.org
Cc: virtualization@lists.linux-foundation.org
Cc: xen-devel@lists.xenproject.org
Link: http://lkml.kernel.org/r/1477386195-32736-2-git-send-email-borntraeger@de.ibm.com
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'linus' into locking/core, to pick up fixes</title>
<updated>2016-11-11T07:25:07+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2016-11-11T07:25:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4c8ee71620d734c8ad129fad085167f56f9ce351'/>
<id>4c8ee71620d734c8ad129fad085167f56f9ce351</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>cris: Only build flash rescue image if CONFIG_ETRAX_AXISFLASHMAP is selected</title>
<updated>2016-11-07T10:41:37+00:00</updated>
<author>
<name>Guenter Roeck</name>
<email>linux@roeck-us.net</email>
</author>
<published>2016-10-30T16:09:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=328cf6927bb72cadefddebbc9a23c793108147a2'/>
<id>328cf6927bb72cadefddebbc9a23c793108147a2</id>
<content type='text'>
If CONFIG_ETRAX_AXISFLASHMAP is not configured, the flash rescue image
object file is empty. With recent versions of binutils, this results
in the following build error.

cris-linux-objcopy: error:
	the input file 'arch/cris/boot/rescue/rescue.o' has no sections

This is seen, for example, when trying to build cris:allnoconfig
with recently generated toolchains.

Since it does not make sense to build a flash rescue image if there is
no flash, only build it if CONFIG_ETRAX_AXISFLASHMAP is enabled.

Reported-by: kbuild test robot &lt;fengguang.wu@intel.com&gt;
Fixes: 66ab3a74c5ce ("CRIS: Merge machine dependent boot/compressed ..")
Signed-off-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Jesper Nilsson &lt;jesper.nilsson@axis.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If CONFIG_ETRAX_AXISFLASHMAP is not configured, the flash rescue image
object file is empty. With recent versions of binutils, this results
in the following build error.

cris-linux-objcopy: error:
	the input file 'arch/cris/boot/rescue/rescue.o' has no sections

This is seen, for example, when trying to build cris:allnoconfig
with recently generated toolchains.

Since it does not make sense to build a flash rescue image if there is
no flash, only build it if CONFIG_ETRAX_AXISFLASHMAP is enabled.

Reported-by: kbuild test robot &lt;fengguang.wu@intel.com&gt;
Fixes: 66ab3a74c5ce ("CRIS: Merge machine dependent boot/compressed ..")
Signed-off-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Jesper Nilsson &lt;jesper.nilsson@axis.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
