<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/include/linux, branch v3.13-rc3</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge tag 'pm-3.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm</title>
<updated>2013-12-06T02:26:40+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-12-06T02:26:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=002acf1fc16cf60e60345bd68e03734628505b83'/>
<id>002acf1fc16cf60e60345bd68e03734628505b83</id>
<content type='text'>
Pull power management fixes from Rafael Wysocki:

 - cpufreq regression fix from Bjørn Mork restoring the pre-3.12
   behavior of the framework during system suspend/hibernation to avoid
   garbage sysfs files from being left behind in case of a suspend error

 - PNP regression fix to restore the correct states of devices after
   resume from hibernation broken in 3.12.  From Dmitry Torokhov.

 - cpuidle fix to prevent cpuidle device unregistration from crashing
   due to a NULL pointer dereference if cpuidle has been disabled from
   the kernel command line.  From Konrad Rzeszutek Wilk.

 - intel_idle fix for the C6 state definition on Intel Avoton/Rangeley
   processors from Arne Bockholdt.

 - Power capping framework fix to make the energy_uj sysfs attribute
   work in accordance with the documentation.  From Srinivas Pandruvada.

 - epoll fix to make it ignore the EPOLLWAKEUP flag if the kernel has
   been compiled with CONFIG_PM_SLEEP unset (in which case that flag
   should not have any effect).  From Amit Pundir.

 - cpufreq fix to prevent governor sysfs files from being lost over
   system suspend/resume in some (arguably unusual) situations.  From
   Viresh Kumar.

* tag 'pm-3.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PowerCap: Fix mode for energy counter
  PNP: fix restoring devices after hibernation
  cpuidle: Check for dev before deregistering it.
  epoll: drop EPOLLWAKEUP if PM_SLEEP is disabled
  cpufreq: fix garbage kobjects on errors during suspend/resume
  cpufreq: suspend governors on system suspend/hibernate
  intel_idle: Fixed C6 state on Avoton/Rangeley processors
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull power management fixes from Rafael Wysocki:

 - cpufreq regression fix from Bjørn Mork restoring the pre-3.12
   behavior of the framework during system suspend/hibernation to avoid
   garbage sysfs files from being left behind in case of a suspend error

 - PNP regression fix to restore the correct states of devices after
   resume from hibernation broken in 3.12.  From Dmitry Torokhov.

 - cpuidle fix to prevent cpuidle device unregistration from crashing
   due to a NULL pointer dereference if cpuidle has been disabled from
   the kernel command line.  From Konrad Rzeszutek Wilk.

 - intel_idle fix for the C6 state definition on Intel Avoton/Rangeley
   processors from Arne Bockholdt.

 - Power capping framework fix to make the energy_uj sysfs attribute
   work in accordance with the documentation.  From Srinivas Pandruvada.

 - epoll fix to make it ignore the EPOLLWAKEUP flag if the kernel has
   been compiled with CONFIG_PM_SLEEP unset (in which case that flag
   should not have any effect).  From Amit Pundir.

 - cpufreq fix to prevent governor sysfs files from being lost over
   system suspend/resume in some (arguably unusual) situations.  From
   Viresh Kumar.

* tag 'pm-3.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PowerCap: Fix mode for energy counter
  PNP: fix restoring devices after hibernation
  cpuidle: Check for dev before deregistering it.
  epoll: drop EPOLLWAKEUP if PM_SLEEP is disabled
  cpufreq: fix garbage kobjects on errors during suspend/resume
  cpufreq: suspend governors on system suspend/hibernate
  intel_idle: Fixed C6 state on Avoton/Rangeley processors
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branches 'pm-cpuidle' and 'pm-cpufreq'</title>
<updated>2013-12-06T01:17:59+00:00</updated>
<author>
<name>Rafael J. Wysocki</name>
<email>rafael.j.wysocki@intel.com</email>
</author>
<published>2013-12-06T01:17:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7cdcec991c06cd6d792b304851cc245cfec507a7'/>
<id>7cdcec991c06cd6d792b304851cc245cfec507a7</id>
<content type='text'>
* pm-cpuidle:
  cpuidle: Check for dev before deregistering it.
  intel_idle: Fixed C6 state on Avoton/Rangeley processors

* pm-cpufreq:
  cpufreq: fix garbage kobjects on errors during suspend/resume
  cpufreq: suspend governors on system suspend/hibernate
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* pm-cpuidle:
  cpuidle: Check for dev before deregistering it.
  intel_idle: Fixed C6 state on Avoton/Rangeley processors

* pm-cpufreq:
  cpufreq: fix garbage kobjects on errors during suspend/resume
  cpufreq: suspend governors on system suspend/hibernate
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'nfs-for-3.13-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs</title>
<updated>2013-12-05T21:05:48+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-12-05T21:05:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=29be6345bbaec8502a70c4e2204d5818b48c4e8f'/>
<id>29be6345bbaec8502a70c4e2204d5818b48c4e8f</id>
<content type='text'>
Pull NFS client bugfixes from Trond Myklebust:
 - Stable fix for a NFSv4.1 delegation and state recovery deadlock
 - Stable fix for a loop on irrecoverable errors when returning
   delegations
 - Fix a 3-way deadlock between layoutreturn, open, and state recovery
 - Update the MAINTAINERS file with contact information for Trond
   Myklebust
 - Close needs to handle NFS4ERR_ADMIN_REVOKED
 - Enabling v4.2 should not recompile nfsd and lockd
 - Fix a couple of compile warnings

* tag 'nfs-for-3.13-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  nfs: fix do_div() warning by instead using sector_div()
  MAINTAINERS: Update contact information for Trond Myklebust
  NFSv4.1: Prevent a 3-way deadlock between layoutreturn, open and state recovery
  SUNRPC: do not fail gss proc NULL calls with EACCES
  NFSv4: close needs to handle NFS4ERR_ADMIN_REVOKED
  NFSv4: Update list of irrecoverable errors on DELEGRETURN
  NFSv4 wait on recovery for async session errors
  NFS: Fix a warning in nfs_setsecurity
  NFS: Enabling v4.2 should not recompile nfsd and lockd
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull NFS client bugfixes from Trond Myklebust:
 - Stable fix for a NFSv4.1 delegation and state recovery deadlock
 - Stable fix for a loop on irrecoverable errors when returning
   delegations
 - Fix a 3-way deadlock between layoutreturn, open, and state recovery
 - Update the MAINTAINERS file with contact information for Trond
   Myklebust
 - Close needs to handle NFS4ERR_ADMIN_REVOKED
 - Enabling v4.2 should not recompile nfsd and lockd
 - Fix a couple of compile warnings

* tag 'nfs-for-3.13-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  nfs: fix do_div() warning by instead using sector_div()
  MAINTAINERS: Update contact information for Trond Myklebust
  NFSv4.1: Prevent a 3-way deadlock between layoutreturn, open and state recovery
  SUNRPC: do not fail gss proc NULL calls with EACCES
  NFSv4: close needs to handle NFS4ERR_ADMIN_REVOKED
  NFSv4: Update list of irrecoverable errors on DELEGRETURN
  NFSv4 wait on recovery for async session errors
  NFS: Fix a warning in nfs_setsecurity
  NFS: Enabling v4.2 should not recompile nfsd and lockd
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2013-12-05T05:45:21+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-12-05T05:45:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=53c6de50262a8edd6932bb59a32db7b9d92f8d67'/>
<id>53c6de50262a8edd6932bb59a32db7b9d92f8d67</id>
<content type='text'>
Pull x86 and EFI fixes from Peter Anvin:
 "Half of these are EFI-related:

  The by far biggest change is the change to hold off the deletion of a
  sysfs entry while a backend scan is in progress.  This is to avoid
  calling kmemdup() while under a spinlock.

  The other major change is for each entry in the EFI pstore backend to
  get a unique identifier, as required by the pstore filesystem proper.

  The other changes are:

  A fix to the recent consolidation and optimization of using "asm goto"
  with read-modify-write operation, which broke the bitops; specifically
  in such a way that we could end up generating invalid code.

  A build hack to make sure we compile with -mno-sse.  icc, and most
  likely future versions of gcc, can generate SSE instructions unless we
  tell it not to.

  A comment-only patch to a change the was due in part to an unpublished
  erratum; now when the erratum is published we want to add a comment
  explaining why"

* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic, doc: Justification for disabling IO APIC before Local APIC
  x86, bitops: Correct the assembly constraints to testing bitops
  x86-64, build: Always pass in -mno-sse
  efi-pstore: Make efi-pstore return a unique id
  x86/efi: Fix earlyprintk off-by-one bug
  efivars, efi-pstore: Hold off deletion of sysfs entry until the scan is completed
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull x86 and EFI fixes from Peter Anvin:
 "Half of these are EFI-related:

  The by far biggest change is the change to hold off the deletion of a
  sysfs entry while a backend scan is in progress.  This is to avoid
  calling kmemdup() while under a spinlock.

  The other major change is for each entry in the EFI pstore backend to
  get a unique identifier, as required by the pstore filesystem proper.

  The other changes are:

  A fix to the recent consolidation and optimization of using "asm goto"
  with read-modify-write operation, which broke the bitops; specifically
  in such a way that we could end up generating invalid code.

  A build hack to make sure we compile with -mno-sse.  icc, and most
  likely future versions of gcc, can generate SSE instructions unless we
  tell it not to.

  A comment-only patch to a change the was due in part to an unpublished
  erratum; now when the erratum is published we want to add a comment
  explaining why"

* 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/apic, doc: Justification for disabling IO APIC before Local APIC
  x86, bitops: Correct the assembly constraints to testing bitops
  x86-64, build: Always pass in -mno-sse
  efi-pstore: Make efi-pstore return a unique id
  x86/efi: Fix earlyprintk off-by-one bug
  efivars, efi-pstore: Hold off deletion of sysfs entry until the scan is completed
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'gpio-v3.13-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio</title>
<updated>2013-12-04T16:59:33+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-12-04T16:59:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=8ecffd7914484b728799dd31968f1339fae91593'/>
<id>8ecffd7914484b728799dd31968f1339fae91593</id>
<content type='text'>
Pull GPIO fixes from Linus Walleij:
 "Here are a few more GPIO patches, we're a bit noisy for being the GPIO
  subsystem, mostly due to the new descriptor API, but all is getting
  into shape.

   - Fix compile warnings

   - Fix overly talkative diagnostic messages from usual use cases wrt
     GPIO descriptors

   - Add a documentation 00-INDEX

   - Use platform GPIOs as fallback when ACPI or device tree is used as
     the primary means to get GPIO lines

   - A bug fix for the MPC8572/MPC8536 fixing erroneous input data"

* tag 'gpio-v3.13-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpiolib: change a warning to debug message when failing to get gpio
  powerpc/gpio: Fix the wrong GPIO input data on MPC8572/MPC8536
  gpiolib: use platform GPIO mappings as fallback
  Documentation: gpiolib: add 00-INDEX file
  gpiolib: fix lookup of platform-mapped GPIOs
  gpiolib: add missing declarations
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull GPIO fixes from Linus Walleij:
 "Here are a few more GPIO patches, we're a bit noisy for being the GPIO
  subsystem, mostly due to the new descriptor API, but all is getting
  into shape.

   - Fix compile warnings

   - Fix overly talkative diagnostic messages from usual use cases wrt
     GPIO descriptors

   - Add a documentation 00-INDEX

   - Use platform GPIOs as fallback when ACPI or device tree is used as
     the primary means to get GPIO lines

   - A bug fix for the MPC8572/MPC8536 fixing erroneous input data"

* tag 'gpio-v3.13-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpiolib: change a warning to debug message when failing to get gpio
  powerpc/gpio: Fix the wrong GPIO input data on MPC8572/MPC8536
  gpiolib: use platform GPIO mappings as fallback
  Documentation: gpiolib: add 00-INDEX file
  gpiolib: fix lookup of platform-mapped GPIOs
  gpiolib: add missing declarations
</pre>
</div>
</content>
</entry>
<entry>
<title>gpiolib: add missing declarations</title>
<updated>2013-12-03T12:10:47+00:00</updated>
<author>
<name>Alexandre Courbot</name>
<email>acourbot@nvidia.com</email>
</author>
<published>2013-11-25T09:34:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c9a9972b6f093e4e2f81f58892a7523df894144d'/>
<id>c9a9972b6f093e4e2f81f58892a7523df894144d</id>
<content type='text'>
Add declaration of 'struct of_phandle_args' to avoid the following
warning:

  In file included from arch/arm/mach-tegra/board-paz00.c:21:0:
  include/linux/gpio/driver.h:102:17: warning: 'struct of_phandle_args' declared inside parameter list
  include/linux/gpio/driver.h:102:17: warning: its scope is only this definition or declaration, which is probably not what you want

Also proactively add other definitions/includes that could be missing
in other contexts.

Signed-off-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Reported-by: Stephen Warren &lt;swarren@wwwdotorg.org&gt;
Reviewed-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add declaration of 'struct of_phandle_args' to avoid the following
warning:

  In file included from arch/arm/mach-tegra/board-paz00.c:21:0:
  include/linux/gpio/driver.h:102:17: warning: 'struct of_phandle_args' declared inside parameter list
  include/linux/gpio/driver.h:102:17: warning: its scope is only this definition or declaration, which is probably not what you want

Also proactively add other definitions/includes that could be missing
in other contexts.

Signed-off-by: Alexandre Courbot &lt;acourbot@nvidia.com&gt;
Reported-by: Stephen Warren &lt;swarren@wwwdotorg.org&gt;
Reviewed-by: Mika Westerberg &lt;mika.westerberg@linux.intel.com&gt;
Signed-off-by: Linus Walleij &lt;linus.walleij@linaro.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2013-12-02T18:15:39+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-12-02T18:15:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a45299e72737c528975546a0680cace5d7364d27'/>
<id>a45299e72737c528975546a0680cace5d7364d27</id>
<content type='text'>
Pull irq fixes from Thomas Gleixner:
 - Correction of fuzzy and fragile IRQ_RETVAL macro
 - IRQ related resume fix affecting only XEN
 - ARM/GIC fix for chained GIC controllers

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip: Gic: fix boot for chained gics
  irq: Enable all irqs unconditionally in irq_resume
  genirq: Correct fuzzy and fragile IRQ_RETVAL() definition
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull irq fixes from Thomas Gleixner:
 - Correction of fuzzy and fragile IRQ_RETVAL macro
 - IRQ related resume fix affecting only XEN
 - ARM/GIC fix for chained GIC controllers

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip: Gic: fix boot for chained gics
  irq: Enable all irqs unconditionally in irq_resume
  genirq: Correct fuzzy and fragile IRQ_RETVAL() definition
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2013-12-02T18:13:44+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-12-02T18:13:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a0b57ca33ec1cd915ba49051512b3463fa44b4e3'/>
<id>a0b57ca33ec1cd915ba49051512b3463fa44b4e3</id>
<content type='text'>
Pull scheduler fixes from Ingo Molnar:
 "Various smaller fixlets, all over the place"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/doc: Fix generation of device-drivers
  sched: Expose preempt_schedule_irq()
  sched: Fix a trivial typo in comments
  sched: Remove unused variable in 'struct sched_domain'
  sched: Avoid NULL dereference on sd_busy
  sched: Check sched_domain before computing group power
  MAINTAINERS: Update file patterns in the lockdep and scheduler entries
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull scheduler fixes from Ingo Molnar:
 "Various smaller fixlets, all over the place"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/doc: Fix generation of device-drivers
  sched: Expose preempt_schedule_irq()
  sched: Fix a trivial typo in comments
  sched: Remove unused variable in 'struct sched_domain'
  sched: Avoid NULL dereference on sd_busy
  sched: Check sched_domain before computing group power
  MAINTAINERS: Update file patterns in the lockdep and scheduler entries
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip</title>
<updated>2013-12-02T18:13:09+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2013-12-02T18:13:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e321ae4c207ce4c6c6812fc65e666efc325cc65e'/>
<id>e321ae4c207ce4c6c6812fc65e666efc325cc65e</id>
<content type='text'>
Pull perf fixes from Ingo Molnar:
 "Misc kernel and tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tools lib traceevent: Fix conversion of pointer to integer of different size
  perf/trace: Properly use u64 to hold event_id
  perf: Remove fragile swevent hlist optimization
  ftrace, perf: Avoid infinite event generation loop
  tools lib traceevent: Fix use of multiple options in processing field
  perf header: Fix possible memory leaks in process_group_desc()
  perf header: Fix bogus group name
  perf tools: Tag thread comm as overriden
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull perf fixes from Ingo Molnar:
 "Misc kernel and tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tools lib traceevent: Fix conversion of pointer to integer of different size
  perf/trace: Properly use u64 to hold event_id
  perf: Remove fragile swevent hlist optimization
  ftrace, perf: Avoid infinite event generation loop
  tools lib traceevent: Fix use of multiple options in processing field
  perf header: Fix possible memory leaks in process_group_desc()
  perf header: Fix bogus group name
  perf tools: Tag thread comm as overriden
</pre>
</div>
</content>
</entry>
<entry>
<title>efivars, efi-pstore: Hold off deletion of sysfs entry until the scan is completed</title>
<updated>2013-11-28T20:16:55+00:00</updated>
<author>
<name>Seiji Aguchi</name>
<email>seiji.aguchi@hds.com</email>
</author>
<published>2013-10-30T19:27:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e0d59733f6b1796b8d6692642c87d7dd862c3e3a'/>
<id>e0d59733f6b1796b8d6692642c87d7dd862c3e3a</id>
<content type='text'>
Currently, when mounting pstore file system, a read callback of
efi_pstore driver runs mutiple times as below.

- In the first read callback, scan efivar_sysfs_list from head and pass
  a kmsg buffer of a entry to an upper pstore layer.
- In the second read callback, rescan efivar_sysfs_list from the entry
  and pass another kmsg buffer to it.
- Repeat the scan and pass until the end of efivar_sysfs_list.

In this process, an entry is read across the multiple read function
calls. To avoid race between the read and erasion, the whole process
above is protected by a spinlock, holding in open() and releasing in
close().

At the same time, kmemdup() is called to pass the buffer to pstore
filesystem during it. And then, it causes a following lockdep warning.

To make the dynamic memory allocation runnable without taking spinlock,
holding off a deletion of sysfs entry if it happens while scanning it
via efi_pstore, and deleting it after the scan is completed.

To implement it, this patch introduces two flags, scanning and deleting,
to efivar_entry.

On the code basis, it seems that all the scanning and deleting logic is
not needed because __efivars-&gt;lock are not dropped when reading from the
EFI variable store.

But, the scanning and deleting logic is still needed because an
efi-pstore and a pstore filesystem works as follows.

In case an entry(A) is found, the pointer is saved to psi-&gt;data.  And
efi_pstore_read() passes the entry(A) to a pstore filesystem by
releasing  __efivars-&gt;lock.

And then, the pstore filesystem calls efi_pstore_read() again and the
same entry(A), which is saved to psi-&gt;data, is used for resuming to scan
a sysfs-list.

So, to protect the entry(A), the logic is needed.

[    1.143710] ------------[ cut here ]------------
[    1.144058] WARNING: CPU: 1 PID: 1 at kernel/lockdep.c:2740 lockdep_trace_alloc+0x104/0x110()
[    1.144058] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))
[    1.144058] Modules linked in:
[    1.144058] CPU: 1 PID: 1 Comm: systemd Not tainted 3.11.0-rc5 #2
[    1.144058]  0000000000000009 ffff8800797e9ae0 ffffffff816614a5 ffff8800797e9b28
[    1.144058]  ffff8800797e9b18 ffffffff8105510d 0000000000000080 0000000000000046
[    1.144058]  00000000000000d0 00000000000003af ffffffff81ccd0c0 ffff8800797e9b78
[    1.144058] Call Trace:
[    1.144058]  [&lt;ffffffff816614a5&gt;] dump_stack+0x54/0x74
[    1.144058]  [&lt;ffffffff8105510d&gt;] warn_slowpath_common+0x7d/0xa0
[    1.144058]  [&lt;ffffffff8105517c&gt;] warn_slowpath_fmt+0x4c/0x50
[    1.144058]  [&lt;ffffffff8131290f&gt;] ? vsscanf+0x57f/0x7b0
[    1.144058]  [&lt;ffffffff810bbd74&gt;] lockdep_trace_alloc+0x104/0x110
[    1.144058]  [&lt;ffffffff81192da0&gt;] __kmalloc_track_caller+0x50/0x280
[    1.144058]  [&lt;ffffffff815147bb&gt;] ? efi_pstore_read_func.part.1+0x12b/0x170
[    1.144058]  [&lt;ffffffff8115b260&gt;] kmemdup+0x20/0x50
[    1.144058]  [&lt;ffffffff815147bb&gt;] efi_pstore_read_func.part.1+0x12b/0x170
[    1.144058]  [&lt;ffffffff81514800&gt;] ? efi_pstore_read_func.part.1+0x170/0x170
[    1.144058]  [&lt;ffffffff815148b4&gt;] efi_pstore_read_func+0xb4/0xe0
[    1.144058]  [&lt;ffffffff81512b7b&gt;] __efivar_entry_iter+0xfb/0x120
[    1.144058]  [&lt;ffffffff8151428f&gt;] efi_pstore_read+0x3f/0x50
[    1.144058]  [&lt;ffffffff8128d7ba&gt;] pstore_get_records+0x9a/0x150
[    1.158207]  [&lt;ffffffff812af25c&gt;] ? selinux_d_instantiate+0x1c/0x20
[    1.158207]  [&lt;ffffffff8128ce30&gt;] ? parse_options+0x80/0x80
[    1.158207]  [&lt;ffffffff8128ced5&gt;] pstore_fill_super+0xa5/0xc0
[    1.158207]  [&lt;ffffffff811ae7d2&gt;] mount_single+0xa2/0xd0
[    1.158207]  [&lt;ffffffff8128ccf8&gt;] pstore_mount+0x18/0x20
[    1.158207]  [&lt;ffffffff811ae8b9&gt;] mount_fs+0x39/0x1b0
[    1.158207]  [&lt;ffffffff81160550&gt;] ? __alloc_percpu+0x10/0x20
[    1.158207]  [&lt;ffffffff811c9493&gt;] vfs_kern_mount+0x63/0xf0
[    1.158207]  [&lt;ffffffff811cbb0e&gt;] do_mount+0x23e/0xa20
[    1.158207]  [&lt;ffffffff8115b51b&gt;] ? strndup_user+0x4b/0xf0
[    1.158207]  [&lt;ffffffff811cc373&gt;] SyS_mount+0x83/0xc0
[    1.158207]  [&lt;ffffffff81673cc2&gt;] system_call_fastpath+0x16/0x1b
[    1.158207] ---[ end trace 61981bc62de9f6f4 ]---

Signed-off-by: Seiji Aguchi &lt;seiji.aguchi@hds.com&gt;
Tested-by: Madper Xie &lt;cxie@redhat.com&gt;
Cc: stable@kernel.org
Signed-off-by: Matt Fleming &lt;matt.fleming@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Currently, when mounting pstore file system, a read callback of
efi_pstore driver runs mutiple times as below.

- In the first read callback, scan efivar_sysfs_list from head and pass
  a kmsg buffer of a entry to an upper pstore layer.
- In the second read callback, rescan efivar_sysfs_list from the entry
  and pass another kmsg buffer to it.
- Repeat the scan and pass until the end of efivar_sysfs_list.

In this process, an entry is read across the multiple read function
calls. To avoid race between the read and erasion, the whole process
above is protected by a spinlock, holding in open() and releasing in
close().

At the same time, kmemdup() is called to pass the buffer to pstore
filesystem during it. And then, it causes a following lockdep warning.

To make the dynamic memory allocation runnable without taking spinlock,
holding off a deletion of sysfs entry if it happens while scanning it
via efi_pstore, and deleting it after the scan is completed.

To implement it, this patch introduces two flags, scanning and deleting,
to efivar_entry.

On the code basis, it seems that all the scanning and deleting logic is
not needed because __efivars-&gt;lock are not dropped when reading from the
EFI variable store.

But, the scanning and deleting logic is still needed because an
efi-pstore and a pstore filesystem works as follows.

In case an entry(A) is found, the pointer is saved to psi-&gt;data.  And
efi_pstore_read() passes the entry(A) to a pstore filesystem by
releasing  __efivars-&gt;lock.

And then, the pstore filesystem calls efi_pstore_read() again and the
same entry(A), which is saved to psi-&gt;data, is used for resuming to scan
a sysfs-list.

So, to protect the entry(A), the logic is needed.

[    1.143710] ------------[ cut here ]------------
[    1.144058] WARNING: CPU: 1 PID: 1 at kernel/lockdep.c:2740 lockdep_trace_alloc+0x104/0x110()
[    1.144058] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))
[    1.144058] Modules linked in:
[    1.144058] CPU: 1 PID: 1 Comm: systemd Not tainted 3.11.0-rc5 #2
[    1.144058]  0000000000000009 ffff8800797e9ae0 ffffffff816614a5 ffff8800797e9b28
[    1.144058]  ffff8800797e9b18 ffffffff8105510d 0000000000000080 0000000000000046
[    1.144058]  00000000000000d0 00000000000003af ffffffff81ccd0c0 ffff8800797e9b78
[    1.144058] Call Trace:
[    1.144058]  [&lt;ffffffff816614a5&gt;] dump_stack+0x54/0x74
[    1.144058]  [&lt;ffffffff8105510d&gt;] warn_slowpath_common+0x7d/0xa0
[    1.144058]  [&lt;ffffffff8105517c&gt;] warn_slowpath_fmt+0x4c/0x50
[    1.144058]  [&lt;ffffffff8131290f&gt;] ? vsscanf+0x57f/0x7b0
[    1.144058]  [&lt;ffffffff810bbd74&gt;] lockdep_trace_alloc+0x104/0x110
[    1.144058]  [&lt;ffffffff81192da0&gt;] __kmalloc_track_caller+0x50/0x280
[    1.144058]  [&lt;ffffffff815147bb&gt;] ? efi_pstore_read_func.part.1+0x12b/0x170
[    1.144058]  [&lt;ffffffff8115b260&gt;] kmemdup+0x20/0x50
[    1.144058]  [&lt;ffffffff815147bb&gt;] efi_pstore_read_func.part.1+0x12b/0x170
[    1.144058]  [&lt;ffffffff81514800&gt;] ? efi_pstore_read_func.part.1+0x170/0x170
[    1.144058]  [&lt;ffffffff815148b4&gt;] efi_pstore_read_func+0xb4/0xe0
[    1.144058]  [&lt;ffffffff81512b7b&gt;] __efivar_entry_iter+0xfb/0x120
[    1.144058]  [&lt;ffffffff8151428f&gt;] efi_pstore_read+0x3f/0x50
[    1.144058]  [&lt;ffffffff8128d7ba&gt;] pstore_get_records+0x9a/0x150
[    1.158207]  [&lt;ffffffff812af25c&gt;] ? selinux_d_instantiate+0x1c/0x20
[    1.158207]  [&lt;ffffffff8128ce30&gt;] ? parse_options+0x80/0x80
[    1.158207]  [&lt;ffffffff8128ced5&gt;] pstore_fill_super+0xa5/0xc0
[    1.158207]  [&lt;ffffffff811ae7d2&gt;] mount_single+0xa2/0xd0
[    1.158207]  [&lt;ffffffff8128ccf8&gt;] pstore_mount+0x18/0x20
[    1.158207]  [&lt;ffffffff811ae8b9&gt;] mount_fs+0x39/0x1b0
[    1.158207]  [&lt;ffffffff81160550&gt;] ? __alloc_percpu+0x10/0x20
[    1.158207]  [&lt;ffffffff811c9493&gt;] vfs_kern_mount+0x63/0xf0
[    1.158207]  [&lt;ffffffff811cbb0e&gt;] do_mount+0x23e/0xa20
[    1.158207]  [&lt;ffffffff8115b51b&gt;] ? strndup_user+0x4b/0xf0
[    1.158207]  [&lt;ffffffff811cc373&gt;] SyS_mount+0x83/0xc0
[    1.158207]  [&lt;ffffffff81673cc2&gt;] system_call_fastpath+0x16/0x1b
[    1.158207] ---[ end trace 61981bc62de9f6f4 ]---

Signed-off-by: Seiji Aguchi &lt;seiji.aguchi@hds.com&gt;
Tested-by: Madper Xie &lt;cxie@redhat.com&gt;
Cc: stable@kernel.org
Signed-off-by: Matt Fleming &lt;matt.fleming@intel.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
