<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/include/linux, branch v3.2.96</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>cs5536: add support for IDE controller variant</title>
<updated>2017-11-26T13:51:03+00:00</updated>
<author>
<name>Andrey Korolyov</name>
<email>andrey@xdel.ru</email>
</author>
<published>2017-08-10T10:21:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=27c98187446ad56a2911e5c83baf4ebf68492b91'/>
<id>27c98187446ad56a2911e5c83baf4ebf68492b91</id>
<content type='text'>
commit 591b6bb605785c12a21e8b07a08a277065b655a5 upstream.

Several legacy devices such as Geode-based Cisco ASA appliances
and DB800 development board do possess CS5536 IDE controller
with different PCI id than existing one. Using pata_generic is
not always feasible as at least DB800 requires MSR quirk from
pata_cs5536 to be used with vendor firmware.

Signed-off-by: Andrey Korolyov &lt;andrey@xdel.ru&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 591b6bb605785c12a21e8b07a08a277065b655a5 upstream.

Several legacy devices such as Geode-based Cisco ASA appliances
and DB800 development board do possess CS5536 IDE controller
with different PCI id than existing one. Using pata_generic is
not always feasible as at least DB800 requires MSR quirk from
pata_cs5536 to be used with vendor firmware.

Signed-off-by: Andrey Korolyov &lt;andrey@xdel.ru&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>fcntl: Don't use ambiguous SIG_POLL si_codes</title>
<updated>2017-11-26T13:51:01+00:00</updated>
<author>
<name>Eric W. Biederman</name>
<email>ebiederm@xmission.com</email>
</author>
<published>2017-06-29T14:28:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=00e1fb59eddc1de07358dde20ae3aa50e49f043d'/>
<id>00e1fb59eddc1de07358dde20ae3aa50e49f043d</id>
<content type='text'>
commit d08477aa975e97f1dc64c0ae59cebf98520456ce upstream.

We have a weird and problematic intersection of features that when
they all come together result in ambiguous siginfo values, that
we can not support properly.

- Supporting fcntl(F_SETSIG,...) with arbitrary valid signals.

- Using positive values for POLL_IN, POLL_OUT, POLL_MSG, ..., etc
  that imply they are signal specific si_codes and using the
  aforementioned arbitrary signal to deliver them.

- Supporting injection of arbitrary siginfo values for debugging and
  checkpoint/restore.

The result is that just looking at siginfo si_codes of 1 to 6 are
ambigious.  It could either be a signal specific si_code or it could
be a generic si_code.

For most of the kernel this is a non-issue but for sending signals
with siginfo it is impossible to play back the kernel signals and
get the same result.

Strictly speaking when the si_code was changed from SI_SIGIO to
POLL_IN and friends between 2.2 and 2.4 this functionality was not
ambiguous, as only real time signals were supported.  Before 2.4 was
released the kernel began supporting siginfo with non realtime signals
so they could give details of why the signal was sent.

The result is that if F_SETSIG is set to one of the signals with signal
specific si_codes then user space can not know why the signal was sent.

I grepped through a bunch of userspace programs using debian code
search to get a feel for how often people choose a signal that results
in an ambiguous si_code.  I only found one program doing so and it was
using SIGCHLD to test the F_SETSIG functionality, and did not appear
to be a real world usage.

Therefore the ambiguity does not appears to be a real world problem in
practice.  Remove the ambiguity while introducing the smallest chance
of breakage by changing the si_code to SI_SIGIO when signals with
signal specific si_codes are targeted.

Fixes: v2.3.40 -- Added support for queueing non-rt signals
Fixes: v2.3.21 -- Changed the si_code from SI_SIGIO
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit d08477aa975e97f1dc64c0ae59cebf98520456ce upstream.

We have a weird and problematic intersection of features that when
they all come together result in ambiguous siginfo values, that
we can not support properly.

- Supporting fcntl(F_SETSIG,...) with arbitrary valid signals.

- Using positive values for POLL_IN, POLL_OUT, POLL_MSG, ..., etc
  that imply they are signal specific si_codes and using the
  aforementioned arbitrary signal to deliver them.

- Supporting injection of arbitrary siginfo values for debugging and
  checkpoint/restore.

The result is that just looking at siginfo si_codes of 1 to 6 are
ambigious.  It could either be a signal specific si_code or it could
be a generic si_code.

For most of the kernel this is a non-issue but for sending signals
with siginfo it is impossible to play back the kernel signals and
get the same result.

Strictly speaking when the si_code was changed from SI_SIGIO to
POLL_IN and friends between 2.2 and 2.4 this functionality was not
ambiguous, as only real time signals were supported.  Before 2.4 was
released the kernel began supporting siginfo with non realtime signals
so they could give details of why the signal was sent.

The result is that if F_SETSIG is set to one of the signals with signal
specific si_codes then user space can not know why the signal was sent.

I grepped through a bunch of userspace programs using debian code
search to get a feel for how often people choose a signal that results
in an ambiguous si_code.  I only found one program doing so and it was
using SIGCHLD to test the F_SETSIG functionality, and did not appear
to be a real world usage.

Therefore the ambiguity does not appears to be a real world problem in
practice.  Remove the ambiguity while introducing the smallest chance
of breakage by changing the si_code to SI_SIGIO when signals with
signal specific si_codes are targeted.

Fixes: v2.3.40 -- Added support for queueing non-rt signals
Fixes: v2.3.21 -- Changed the si_code from SI_SIGIO
Signed-off-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>signal: move the "sig &lt; SIGRTMIN" check into siginmask(sig)</title>
<updated>2017-11-26T13:51:01+00:00</updated>
<author>
<name>Oleg Nesterov</name>
<email>oleg@redhat.com</email>
</author>
<published>2016-05-23T23:24:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b88cd8f4f1dd0b64e12eb0a944270380f88a4755'/>
<id>b88cd8f4f1dd0b64e12eb0a944270380f88a4755</id>
<content type='text'>
commit 5c8ccefdf46c5f87d87b694c7fbc04941c2c99a5 upstream.

All the users of siginmask() must ensure that sig &lt; SIGRTMIN.  sig_fatal()
doesn't and this is wrong:

	UBSAN: Undefined behaviour in kernel/signal.c:911:6
	shift exponent 32 is too large for 32-bit type 'long unsigned int'

the patch doesn't add the neccesary check to sig_fatal(), it moves the
check into siginmask() and updates other callers.

Link: http://lkml.kernel.org/r/20160517195052.GA15187@redhat.com
Reported-by: Meelis Roos &lt;mroos@linux.ee&gt;
Signed-off-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 5c8ccefdf46c5f87d87b694c7fbc04941c2c99a5 upstream.

All the users of siginmask() must ensure that sig &lt; SIGRTMIN.  sig_fatal()
doesn't and this is wrong:

	UBSAN: Undefined behaviour in kernel/signal.c:911:6
	shift exponent 32 is too large for 32-bit type 'long unsigned int'

the patch doesn't add the neccesary check to sig_fatal(), it moves the
check into siginmask() and updates other callers.

Link: http://lkml.kernel.org/r/20160517195052.GA15187@redhat.com
Reported-by: Meelis Roos &lt;mroos@linux.ee&gt;
Signed-off-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mtd: map: Fix compilation warning</title>
<updated>2017-11-11T13:34:46+00:00</updated>
<author>
<name>Viresh Kumar</name>
<email>viresh.kumar@linaro.org</email>
</author>
<published>2012-10-29T17:17:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e09bdbeef9cef82cf5bb11d9b576731db4abdc4c'/>
<id>e09bdbeef9cef82cf5bb11d9b576731db4abdc4c</id>
<content type='text'>
commit 3e9ce49e0ef95e22790a74720f0068696b2477c9 upstream.

This patch is an attempt to fix following compilation warning.

In file included from drivers/mtd/chips/cfi_cmdset_0001.c:35:0:
drivers/mtd/chips/cfi_cmdset_0001.c: In function 'cfi_intelext_write_words':
include/linux/mtd/map.h:331:11: warning: 'r.x[0]' may be used uninitialized in this function [-Wmaybe-uninitialized]

I could have used uninitialized_var() too, but didn't used it as the final else
part of map_word_load() is missing. So there is a chance that it might be passed
uninitialized. Better initialize to zero.

Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Artem Bityutskiy &lt;artem.bityutskiy@linux.intel.com&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 3e9ce49e0ef95e22790a74720f0068696b2477c9 upstream.

This patch is an attempt to fix following compilation warning.

In file included from drivers/mtd/chips/cfi_cmdset_0001.c:35:0:
drivers/mtd/chips/cfi_cmdset_0001.c: In function 'cfi_intelext_write_words':
include/linux/mtd/map.h:331:11: warning: 'r.x[0]' may be used uninitialized in this function [-Wmaybe-uninitialized]

I could have used uninitialized_var() too, but didn't used it as the final else
part of map_word_load() is missing. So there is a chance that it might be passed
uninitialized. Better initialize to zero.

Signed-off-by: Viresh Kumar &lt;viresh.kumar@linaro.org&gt;
Signed-off-by: Artem Bityutskiy &lt;artem.bityutskiy@linux.intel.com&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>USB: fix out-of-bounds in usb_set_configuration</title>
<updated>2017-11-11T13:34:40+00:00</updated>
<author>
<name>Greg Kroah-Hartman</name>
<email>gregkh@linuxfoundation.org</email>
</author>
<published>2017-09-19T13:07:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a0e0a5850211dd09725c819a8915c2cbe9067317'/>
<id>a0e0a5850211dd09725c819a8915c2cbe9067317</id>
<content type='text'>
commit bd7a3fe770ebd8391d1c7d072ff88e9e76d063eb upstream.

Andrey Konovalov reported a possible out-of-bounds problem for a USB interface
association descriptor.  He writes:
	It seems there's no proper size check of a USB_DT_INTERFACE_ASSOCIATION
	descriptor. It's only checked that the size is &gt;= 2 in
	usb_parse_configuration(), so find_iad() might do out-of-bounds access
	to intf_assoc-&gt;bInterfaceCount.

And he's right, we don't check for crazy descriptors of this type very well, so
resolve this problem.  Yet another issue found by syzkaller...

Reported-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Tested-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit bd7a3fe770ebd8391d1c7d072ff88e9e76d063eb upstream.

Andrey Konovalov reported a possible out-of-bounds problem for a USB interface
association descriptor.  He writes:
	It seems there's no proper size check of a USB_DT_INTERFACE_ASSOCIATION
	descriptor. It's only checked that the size is &gt;= 2 in
	usb_parse_configuration(), so find_iad() might do out-of-bounds access
	to intf_assoc-&gt;bInterfaceCount.

And he's right, we don't check for crazy descriptors of this type very well, so
resolve this problem.  Yet another issue found by syzkaller...

Reported-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Tested-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm: fix printk() rate limiting code</title>
<updated>2017-11-11T13:34:33+00:00</updated>
<author>
<name>Bart Van Assche</name>
<email>bart.vanassche@wdc.com</email>
</author>
<published>2017-08-09T18:32:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=62b3046afa78f34d1e05997ce86e4ce6f2f060d1'/>
<id>62b3046afa78f34d1e05997ce86e4ce6f2f060d1</id>
<content type='text'>
commit 604407890ecf624c2fb41013c82b22aade59b455 upstream.

Using the same rate limiting state for different kinds of messages
is wrong because this can cause a high frequency message to suppress
a report of a low frequency message. Hence use a unique rate limiting
state per message type.

Fixes: 71a16736a15e ("dm: use local printk ratelimit")
Signed-off-by: Bart Van Assche &lt;bart.vanassche@wdc.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 604407890ecf624c2fb41013c82b22aade59b455 upstream.

Using the same rate limiting state for different kinds of messages
is wrong because this can cause a high frequency message to suppress
a report of a low frequency message. Hence use a unique rate limiting
state per message type.

Fixes: 71a16736a15e ("dm: use local printk ratelimit")
Signed-off-by: Bart Van Assche &lt;bart.vanassche@wdc.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>dm: convert DM printk macros to pr_&lt;level&gt; macros</title>
<updated>2017-11-11T13:34:33+00:00</updated>
<author>
<name>Joe Perches</name>
<email>joe@perches.com</email>
</author>
<published>2017-04-20T17:46:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b3a6804d1ad844ec55aa96e81cae1825313daf11'/>
<id>b3a6804d1ad844ec55aa96e81cae1825313daf11</id>
<content type='text'>
commit d2c3c8dcb5987b8352e82089c79a41b6e17e28d2 upstream.

Using pr_&lt;level&gt; is the more common logging style.

Standardize style and use new macro DM_FMT.
Use no_printk in DMDEBUG macros when CONFIG_DM_DEBUG is not #defined.

Signed-off-by: Joe Perches &lt;joe@perches.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit d2c3c8dcb5987b8352e82089c79a41b6e17e28d2 upstream.

Using pr_&lt;level&gt; is the more common logging style.

Standardize style and use new macro DM_FMT.
Use no_printk in DMDEBUG macros when CONFIG_DM_DEBUG is not #defined.

Signed-off-by: Joe Perches &lt;joe@perches.com&gt;
Signed-off-by: Mike Snitzer &lt;snitzer@redhat.com&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf: Tighten (and fix) the grouping condition</title>
<updated>2017-11-11T13:34:31+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2015-01-23T10:19:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5f542f7740bc8db862b8078e6a621ee7a13427b8'/>
<id>5f542f7740bc8db862b8078e6a621ee7a13427b8</id>
<content type='text'>
commit c3c87e770458aa004bd7ed3f29945ff436fd6511 upstream.

The fix from 9fc81d87420d ("perf: Fix events installation during
moving group") was incomplete in that it failed to recognise that
creating a group with events for different CPUs is semantically
broken -- they cannot be co-scheduled.

Furthermore, it leads to real breakage where, when we create an event
for CPU Y and then migrate it to form a group on CPU X, the code gets
confused where the counter is programmed -- triggered in practice
as well by me via the perf fuzzer.

Fix this by tightening the rules for creating groups. Only allow
grouping of counters that can be co-scheduled in the same context.
This means for the same task and/or the same cpu.

Fixes: 9fc81d87420d ("perf: Fix events installation during moving group")
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Link: http://lkml.kernel.org/r/20150123125834.090683288@infradead.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c3c87e770458aa004bd7ed3f29945ff436fd6511 upstream.

The fix from 9fc81d87420d ("perf: Fix events installation during
moving group") was incomplete in that it failed to recognise that
creating a group with events for different CPUs is semantically
broken -- they cannot be co-scheduled.

Furthermore, it leads to real breakage where, when we create an event
for CPU Y and then migrate it to form a group on CPU X, the code gets
confused where the counter is programmed -- triggered in practice
as well by me via the perf fuzzer.

Fix this by tightening the rules for creating groups. Only allow
grouping of counters that can be co-scheduled in the same context.
This means for the same task and/or the same cpu.

Fixes: 9fc81d87420d ("perf: Fix events installation during moving group")
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Cc: Arnaldo Carvalho de Melo &lt;acme@kernel.org&gt;
Cc: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Link: http://lkml.kernel.org/r/20150123125834.090683288@infradead.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net/mlx4_en: Fix wrong indication of Wake-on-LAN (WoL) support</title>
<updated>2017-11-11T13:34:28+00:00</updated>
<author>
<name>Inbar Karmy</name>
<email>inbark@mellanox.com</email>
</author>
<published>2017-08-01T13:43:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=967d0125c4f681921cf805d0121b9f72f00e03f8'/>
<id>967d0125c4f681921cf805d0121b9f72f00e03f8</id>
<content type='text'>
commit c994f778bb1cca8ebe7a4e528cefec233e93b5cc upstream.

Currently when WoL is supported but disabled, ethtool reports:
"Supports Wake-on: d".
Fix the indication of Wol support, so that the indication
remains "g" all the time if the NIC supports WoL.

Tested:
As accepted, when NIC supports WoL- ethtool reports:
	Supports Wake-on: g
	Wake-on: d
when NIC doesn't support WoL- ethtool reports:
        Supports Wake-on: d
        Wake-on: d

Fixes: 14c07b1358ed ("mlx4: Wake on LAN support")
Signed-off-by: Inbar Karmy &lt;inbark@mellanox.com&gt;
Signed-off-by: Tariq Toukan &lt;tariqt@mellanox.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c994f778bb1cca8ebe7a4e528cefec233e93b5cc upstream.

Currently when WoL is supported but disabled, ethtool reports:
"Supports Wake-on: d".
Fix the indication of Wol support, so that the indication
remains "g" all the time if the NIC supports WoL.

Tested:
As accepted, when NIC supports WoL- ethtool reports:
	Supports Wake-on: g
	Wake-on: d
when NIC doesn't support WoL- ethtool reports:
        Supports Wake-on: d
        Wake-on: d

Fixes: 14c07b1358ed ("mlx4: Wake on LAN support")
Signed-off-by: Inbar Karmy &lt;inbark@mellanox.com&gt;
Signed-off-by: Tariq Toukan &lt;tariqt@mellanox.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>cpuset: PF_SPREAD_PAGE and PF_SPREAD_SLAB should be atomic flags</title>
<updated>2017-10-12T14:27:22+00:00</updated>
<author>
<name>Zefan Li</name>
<email>lizefan@huawei.com</email>
</author>
<published>2014-09-25T01:41:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=eb33a02fddad907cea8b2c4ec3b49835b12d0107'/>
<id>eb33a02fddad907cea8b2c4ec3b49835b12d0107</id>
<content type='text'>
commit 2ad654bc5e2b211e92f66da1d819e47d79a866f0 upstream.

When we change cpuset.memory_spread_{page,slab}, cpuset will flip
PF_SPREAD_{PAGE,SLAB} bit of tsk-&gt;flags for each task in that cpuset.
This should be done using atomic bitops, but currently we don't,
which is broken.

Tetsuo reported a hard-to-reproduce kernel crash on RHEL6, which happened
when one thread tried to clear PF_USED_MATH while at the same time another
thread tried to flip PF_SPREAD_PAGE/PF_SPREAD_SLAB. They both operate on
the same task.

Here's the full report:
https://lkml.org/lkml/2014/9/19/230

To fix this, we make PF_SPREAD_PAGE and PF_SPREAD_SLAB atomic flags.

v4:
- updated mm/slab.c. (Fengguang Wu)
- updated Documentation.

Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Miao Xie &lt;miaox@cn.fujitsu.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Fixes: 950592f7b991 ("cpusets: update tasks' page/slab spread flags in time")
Reported-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Signed-off-by: Zefan Li &lt;lizefan@huawei.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
[lizf: Backported to 3.4:
 - adjust context
 - check current-&gt;flags &amp; PF_MEMPOLICY rather than current-&gt;mempolicy]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
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<pre>
commit 2ad654bc5e2b211e92f66da1d819e47d79a866f0 upstream.

When we change cpuset.memory_spread_{page,slab}, cpuset will flip
PF_SPREAD_{PAGE,SLAB} bit of tsk-&gt;flags for each task in that cpuset.
This should be done using atomic bitops, but currently we don't,
which is broken.

Tetsuo reported a hard-to-reproduce kernel crash on RHEL6, which happened
when one thread tried to clear PF_USED_MATH while at the same time another
thread tried to flip PF_SPREAD_PAGE/PF_SPREAD_SLAB. They both operate on
the same task.

Here's the full report:
https://lkml.org/lkml/2014/9/19/230

To fix this, we make PF_SPREAD_PAGE and PF_SPREAD_SLAB atomic flags.

v4:
- updated mm/slab.c. (Fengguang Wu)
- updated Documentation.

Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Ingo Molnar &lt;mingo@kernel.org&gt;
Cc: Miao Xie &lt;miaox@cn.fujitsu.com&gt;
Cc: Kees Cook &lt;keescook@chromium.org&gt;
Fixes: 950592f7b991 ("cpusets: update tasks' page/slab spread flags in time")
Reported-by: Tetsuo Handa &lt;penguin-kernel@I-love.SAKURA.ne.jp&gt;
Signed-off-by: Zefan Li &lt;lizefan@huawei.com&gt;
Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
[lizf: Backported to 3.4:
 - adjust context
 - check current-&gt;flags &amp; PF_MEMPOLICY rather than current-&gt;mempolicy]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
</pre>
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