<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/include/linux, branch v2.6.34.11</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>gro: Only reset frag0 when skb can be pulled</title>
<updated>2012-03-14T14:58:03+00:00</updated>
<author>
<name>Herbert Xu</name>
<email>herbert@gondor.apana.org.au</email>
</author>
<published>2011-07-27T13:16:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d17256d40e2f123145f12a38018f235a351da95f'/>
<id>d17256d40e2f123145f12a38018f235a351da95f</id>
<content type='text'>
commit 17dd759c67f21e34f2156abcf415e1f60605a188 upstream.

Currently skb_gro_header_slow unconditionally resets frag0 and
frag0_len.  However, when we can't pull on the skb this leaves
the GRO fields in an inconsistent state.

This patch fixes this by only resetting those fields after the
pskb_may_pull test.

Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 17dd759c67f21e34f2156abcf415e1f60605a188 upstream.

Currently skb_gro_header_slow unconditionally resets frag0 and
frag0_len.  However, when we can't pull on the skb this leaves
the GRO fields in an inconsistent state.

This patch fixes this by only resetting those fields after the
pskb_may_pull test.

Signed-off-by: Herbert Xu &lt;herbert@gondor.apana.org.au&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mmc: fix all hangs related to mmc/sd card insert/removal during suspend/resume</title>
<updated>2012-03-14T14:57:45+00:00</updated>
<author>
<name>Maxim Levitsky</name>
<email>maximlevitsky@gmail.com</email>
</author>
<published>2010-08-11T01:01:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1f477eb7ec34c5522caebbdeb49f96868169b4fa'/>
<id>1f477eb7ec34c5522caebbdeb49f96868169b4fa</id>
<content type='text'>
commit 4c2ef25fe0b847d2ae818f74758ddb0be1c27d8e upstream.

If you don't use CONFIG_MMC_UNSAFE_RESUME, as soon as you attempt to
suspend, the card will be removed, therefore this patch doesn't change the
behavior of this option.

However the removal will be done by pm notifier, which runs while
userspace is still not frozen and thus can freely use del_gendisk, without
the risk of deadlock which would happen otherwise.

Card detect workqueue is now disabled while userspace is frozen, Therefore
if you do use CONFIG_MMC_UNSAFE_RESUME, and remove the card during
suspend, the removal will be detected as soon as userspace is unfrozen,
again at the moment it is safe to call del_gendisk.

Tested with and without CONFIG_MMC_UNSAFE_RESUME with suspend and hibernate.

[akpm@linux-foundation.org: clean up function prototype]
[akpm@linux-foundation.org: fix CONFIG_PM-n linkage, small cleanups]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Maxim Levitsky &lt;maximlevitsky@gmail.com&gt;
Cc: David Brownell &lt;david-b@pacbell.net&gt;
Cc: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Cc: &lt;linux-mmc@vger.kernel.org&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: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 4c2ef25fe0b847d2ae818f74758ddb0be1c27d8e upstream.

If you don't use CONFIG_MMC_UNSAFE_RESUME, as soon as you attempt to
suspend, the card will be removed, therefore this patch doesn't change the
behavior of this option.

However the removal will be done by pm notifier, which runs while
userspace is still not frozen and thus can freely use del_gendisk, without
the risk of deadlock which would happen otherwise.

Card detect workqueue is now disabled while userspace is frozen, Therefore
if you do use CONFIG_MMC_UNSAFE_RESUME, and remove the card during
suspend, the removal will be detected as soon as userspace is unfrozen,
again at the moment it is safe to call del_gendisk.

Tested with and without CONFIG_MMC_UNSAFE_RESUME with suspend and hibernate.

[akpm@linux-foundation.org: clean up function prototype]
[akpm@linux-foundation.org: fix CONFIG_PM-n linkage, small cleanups]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Maxim Levitsky &lt;maximlevitsky@gmail.com&gt;
Cc: David Brownell &lt;david-b@pacbell.net&gt;
Cc: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Cc: &lt;linux-mmc@vger.kernel.org&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: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>next_pidmap: fix overflow condition</title>
<updated>2012-03-14T14:57:19+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2011-04-18T17:35:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1e6b4f8971e43ea40fba523bc98ef30a17e8acc7'/>
<id>1e6b4f8971e43ea40fba523bc98ef30a17e8acc7</id>
<content type='text'>
commit c78193e9c7bcbf25b8237ad0dec82f805c4ea69b upstream.

next_pidmap() just quietly accepted whatever 'last' pid that was passed
in, which is not all that safe when one of the users is /proc.

Admittedly the proc code should do some sanity checking on the range
(and that will be the next commit), but that doesn't mean that the
helper functions should just do that pidmap pointer arithmetic without
checking the range of its arguments.

So clamp 'last' to PID_MAX_LIMIT.  The fact that we then do "last+1"
doesn't really matter, the for-loop does check against the end of the
pidmap array properly (it's only the actual pointer arithmetic overflow
case we need to worry about, and going one bit beyond isn't going to
overflow).

[ Use PID_MAX_LIMIT rather than pid_max as per Eric Biederman ]

Reported-by: Tavis Ormandy &lt;taviso@cmpxchg8b.com&gt;
Analyzed-by: Robert Święcki &lt;robert@swiecki.net&gt;
Cc: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
Cc: Pavel Emelyanov &lt;xemul@openvz.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit c78193e9c7bcbf25b8237ad0dec82f805c4ea69b upstream.

next_pidmap() just quietly accepted whatever 'last' pid that was passed
in, which is not all that safe when one of the users is /proc.

Admittedly the proc code should do some sanity checking on the range
(and that will be the next commit), but that doesn't mean that the
helper functions should just do that pidmap pointer arithmetic without
checking the range of its arguments.

So clamp 'last' to PID_MAX_LIMIT.  The fact that we then do "last+1"
doesn't really matter, the for-loop does check against the end of the
pidmap array properly (it's only the actual pointer arithmetic overflow
case we need to worry about, and going one bit beyond isn't going to
overflow).

[ Use PID_MAX_LIMIT rather than pid_max as per Eric Biederman ]

Reported-by: Tavis Ormandy &lt;taviso@cmpxchg8b.com&gt;
Analyzed-by: Robert Święcki &lt;robert@swiecki.net&gt;
Cc: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
Cc: Pavel Emelyanov &lt;xemul@openvz.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>exec: copy-and-paste the fixes into compat_do_execve() paths</title>
<updated>2012-03-14T14:57:09+00:00</updated>
<author>
<name>Oleg Nesterov</name>
<email>oleg@redhat.com</email>
</author>
<published>2010-11-30T19:56:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=27aa0fdd1252e7e541487dd3b70870733735df29'/>
<id>27aa0fdd1252e7e541487dd3b70870733735df29</id>
<content type='text'>
commit 114279be2120a916e8a04feeb2ac976a10016f2f upstream.

Note: this patch targets 2.6.37 and tries to be as simple as possible.
That is why it adds more copy-and-paste horror into fs/compat.c and
uglifies fs/exec.c, this will be cleanuped later.

compat_copy_strings() plays with bprm-&gt;vma/mm directly and thus has
two problems: it lacks the RLIMIT_STACK check and argv/envp memory
is not visible to oom killer.

Export acct_arg_size() and get_arg_page(), change compat_copy_strings()
to use get_arg_page(), change compat_do_execve() to do acct_arg_size(0)
as do_execve() does.

Add the fatal_signal_pending/cond_resched checks into compat_count() and
compat_copy_strings(), this matches the code in fs/exec.c and certainly
makes sense.

Signed-off-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: KOSAKI Motohiro &lt;kosaki.motohiro@jp.fujitsu.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 114279be2120a916e8a04feeb2ac976a10016f2f upstream.

Note: this patch targets 2.6.37 and tries to be as simple as possible.
That is why it adds more copy-and-paste horror into fs/compat.c and
uglifies fs/exec.c, this will be cleanuped later.

compat_copy_strings() plays with bprm-&gt;vma/mm directly and thus has
two problems: it lacks the RLIMIT_STACK check and argv/envp memory
is not visible to oom killer.

Export acct_arg_size() and get_arg_page(), change compat_copy_strings()
to use get_arg_page(), change compat_do_execve() to do acct_arg_size(0)
as do_execve() does.

Add the fatal_signal_pending/cond_resched checks into compat_count() and
compat_copy_strings(), this matches the code in fs/exec.c and certainly
makes sense.

Signed-off-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: KOSAKI Motohiro &lt;kosaki.motohiro@jp.fujitsu.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>epoll: convert max_user_watches to long</title>
<updated>2011-06-26T16:47:17+00:00</updated>
<author>
<name>Robin Holt</name>
<email>holt@sgi.com</email>
</author>
<published>2011-01-13T01:00:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=0ec63bc8c16763ab565ab97d39f10eb9a6ab9125'/>
<id>0ec63bc8c16763ab565ab97d39f10eb9a6ab9125</id>
<content type='text'>
commit 52bd19f7691b2ea6433aef0ef94c08c57efd7e79 upstream.

On a 16TB machine, max_user_watches has an integer overflow.  Convert it
to use a long and handle the associated fallout.

Signed-off-by: Robin Holt &lt;holt@sgi.com&gt;
Cc: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Acked-by: Davide Libenzi &lt;davidel@xmailserver.org&gt;
Cc: Pekka Enberg &lt;penberg@cs.helsinki.fi&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: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 52bd19f7691b2ea6433aef0ef94c08c57efd7e79 upstream.

On a 16TB machine, max_user_watches has an integer overflow.  Convert it
to use a long and handle the associated fallout.

Signed-off-by: Robin Holt &lt;holt@sgi.com&gt;
Cc: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Acked-by: Davide Libenzi &lt;davidel@xmailserver.org&gt;
Cc: Pekka Enberg &lt;penberg@cs.helsinki.fi&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: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ftrace: Fix memory leak with function graph and cpu hotplug</title>
<updated>2011-06-26T16:47:01+00:00</updated>
<author>
<name>Steven Rostedt</name>
<email>srostedt@redhat.com</email>
</author>
<published>2011-02-11T02:26:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=1237d7b76c365f5026e9c55534dcd7126fa014ed'/>
<id>1237d7b76c365f5026e9c55534dcd7126fa014ed</id>
<content type='text'>
commit 868baf07b1a259f5f3803c1dc2777b6c358f83cf upstream.

When the fuction graph tracer starts, it needs to make a special
stack for each task to save the real return values of the tasks.
All running tasks have this stack created, as well as any new
tasks.

On CPU hot plug, the new idle task will allocate a stack as well
when init_idle() is called. The problem is that cpu hotplug does
not create a new idle_task. Instead it uses the idle task that
existed when the cpu went down.

ftrace_graph_init_task() will add a new ret_stack to the task
that is given to it. Because a clone will make the task
have a stack of its parent it does not check if the task's
ret_stack is already NULL or not. When the CPU hotplug code
starts a CPU up again, it will allocate a new stack even
though one already existed for it.

The solution is to treat the idle_task specially. In fact, the
function_graph code already does, just not at init_idle().
Instead of using the ftrace_graph_init_task() for the idle task,
which that function expects the task to be a clone, have a
separate ftrace_graph_init_idle_task(). Also, we will create a
per_cpu ret_stack that is used by the idle task. When we call
ftrace_graph_init_idle_task() it will check if the idle task's
ret_stack is NULL, if it is, then it will assign it the per_cpu
ret_stack.

Reported-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Suggested-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 868baf07b1a259f5f3803c1dc2777b6c358f83cf upstream.

When the fuction graph tracer starts, it needs to make a special
stack for each task to save the real return values of the tasks.
All running tasks have this stack created, as well as any new
tasks.

On CPU hot plug, the new idle task will allocate a stack as well
when init_idle() is called. The problem is that cpu hotplug does
not create a new idle_task. Instead it uses the idle task that
existed when the cpu went down.

ftrace_graph_init_task() will add a new ret_stack to the task
that is given to it. Because a clone will make the task
have a stack of its parent it does not check if the task's
ret_stack is already NULL or not. When the CPU hotplug code
starts a CPU up again, it will allocate a new stack even
though one already existed for it.

The solution is to treat the idle_task specially. In fact, the
function_graph code already does, just not at init_idle().
Instead of using the ftrace_graph_init_task() for the idle task,
which that function expects the task to be a clone, have a
separate ftrace_graph_init_idle_task(). Also, we will create a
per_cpu ret_stack that is used by the idle task. When we call
ftrace_graph_init_idle_task() it will check if the idle task's
ret_stack is NULL, if it is, then it will assign it the per_cpu
ret_stack.

Reported-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Suggested-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Signed-off-by: Steven Rostedt &lt;rostedt@goodmis.org&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>CRED: Fix get_task_cred() and task_state() to not resurrect dead credentials</title>
<updated>2011-06-26T16:46:42+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2010-07-29T11:45:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=803caa34f9b51f4f0e513bc9a216f738af7bb488'/>
<id>803caa34f9b51f4f0e513bc9a216f738af7bb488</id>
<content type='text'>
commit de09a9771a5346029f4d11e4ac886be7f9bfdd75 upstream.

It's possible for get_task_cred() as it currently stands to 'corrupt' a set of
credentials by incrementing their usage count after their replacement by the
task being accessed.

What happens is that get_task_cred() can race with commit_creds():

	TASK_1			TASK_2			RCU_CLEANER
	--&gt;get_task_cred(TASK_2)
	rcu_read_lock()
	__cred = __task_cred(TASK_2)
				--&gt;commit_creds()
				old_cred = TASK_2-&gt;real_cred
				TASK_2-&gt;real_cred = ...
				put_cred(old_cred)
				  call_rcu(old_cred)
		[__cred-&gt;usage == 0]
	get_cred(__cred)
		[__cred-&gt;usage == 1]
	rcu_read_unlock()
							--&gt;put_cred_rcu()
							[__cred-&gt;usage == 1]
							panic()

However, since a tasks credentials are generally not changed very often, we can
reasonably make use of a loop involving reading the creds pointer and using
atomic_inc_not_zero() to attempt to increment it if it hasn't already hit zero.

If successful, we can safely return the credentials in the knowledge that, even
if the task we're accessing has released them, they haven't gone to the RCU
cleanup code.

We then change task_state() in procfs to use get_task_cred() rather than
calling get_cred() on the result of __task_cred(), as that suffers from the
same problem.

Without this change, a BUG_ON in __put_cred() or in put_cred_rcu() can be
tripped when it is noticed that the usage count is not zero as it ought to be,
for example:

kernel BUG at kernel/cred.c:168!
invalid opcode: 0000 [#1] SMP
last sysfs file: /sys/kernel/mm/ksm/run
CPU 0
Pid: 2436, comm: master Not tainted 2.6.33.3-85.fc13.x86_64 #1 0HR330/OptiPlex
745
RIP: 0010:[&lt;ffffffff81069881&gt;]  [&lt;ffffffff81069881&gt;] __put_cred+0xc/0x45
RSP: 0018:ffff88019e7e9eb8  EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffff880161514480 RCX: 00000000ffffffff
RDX: 00000000ffffffff RSI: ffff880140c690c0 RDI: ffff880140c690c0
RBP: ffff88019e7e9eb8 R08: 00000000000000d0 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000040 R12: ffff880140c690c0
R13: ffff88019e77aea0 R14: 00007fff336b0a5c R15: 0000000000000001
FS:  00007f12f50d97c0(0000) GS:ffff880007400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8f461bc000 CR3: 00000001b26ce000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process master (pid: 2436, threadinfo ffff88019e7e8000, task ffff88019e77aea0)
Stack:
 ffff88019e7e9ec8 ffffffff810698cd ffff88019e7e9ef8 ffffffff81069b45
&lt;0&gt; ffff880161514180 ffff880161514480 ffff880161514180 0000000000000000
&lt;0&gt; ffff88019e7e9f28 ffffffff8106aace 0000000000000001 0000000000000246
Call Trace:
 [&lt;ffffffff810698cd&gt;] put_cred+0x13/0x15
 [&lt;ffffffff81069b45&gt;] commit_creds+0x16b/0x175
 [&lt;ffffffff8106aace&gt;] set_current_groups+0x47/0x4e
 [&lt;ffffffff8106ac89&gt;] sys_setgroups+0xf6/0x105
 [&lt;ffffffff81009b02&gt;] system_call_fastpath+0x16/0x1b
Code: 48 8d 71 ff e8 7e 4e 15 00 85 c0 78 0b 8b 75 ec 48 89 df e8 ef 4a 15 00
48 83 c4 18 5b c9 c3 55 8b 07 8b 07 48 89 e5 85 c0 74 04 &lt;0f&gt; 0b eb fe 65 48 8b
04 25 00 cc 00 00 48 3b b8 58 04 00 00 75
RIP  [&lt;ffffffff81069881&gt;] __put_cred+0xc/0x45
 RSP &lt;ffff88019e7e9eb8&gt;
---[ end trace df391256a100ebdd ]---

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit de09a9771a5346029f4d11e4ac886be7f9bfdd75 upstream.

It's possible for get_task_cred() as it currently stands to 'corrupt' a set of
credentials by incrementing their usage count after their replacement by the
task being accessed.

What happens is that get_task_cred() can race with commit_creds():

	TASK_1			TASK_2			RCU_CLEANER
	--&gt;get_task_cred(TASK_2)
	rcu_read_lock()
	__cred = __task_cred(TASK_2)
				--&gt;commit_creds()
				old_cred = TASK_2-&gt;real_cred
				TASK_2-&gt;real_cred = ...
				put_cred(old_cred)
				  call_rcu(old_cred)
		[__cred-&gt;usage == 0]
	get_cred(__cred)
		[__cred-&gt;usage == 1]
	rcu_read_unlock()
							--&gt;put_cred_rcu()
							[__cred-&gt;usage == 1]
							panic()

However, since a tasks credentials are generally not changed very often, we can
reasonably make use of a loop involving reading the creds pointer and using
atomic_inc_not_zero() to attempt to increment it if it hasn't already hit zero.

If successful, we can safely return the credentials in the knowledge that, even
if the task we're accessing has released them, they haven't gone to the RCU
cleanup code.

We then change task_state() in procfs to use get_task_cred() rather than
calling get_cred() on the result of __task_cred(), as that suffers from the
same problem.

Without this change, a BUG_ON in __put_cred() or in put_cred_rcu() can be
tripped when it is noticed that the usage count is not zero as it ought to be,
for example:

kernel BUG at kernel/cred.c:168!
invalid opcode: 0000 [#1] SMP
last sysfs file: /sys/kernel/mm/ksm/run
CPU 0
Pid: 2436, comm: master Not tainted 2.6.33.3-85.fc13.x86_64 #1 0HR330/OptiPlex
745
RIP: 0010:[&lt;ffffffff81069881&gt;]  [&lt;ffffffff81069881&gt;] __put_cred+0xc/0x45
RSP: 0018:ffff88019e7e9eb8  EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffff880161514480 RCX: 00000000ffffffff
RDX: 00000000ffffffff RSI: ffff880140c690c0 RDI: ffff880140c690c0
RBP: ffff88019e7e9eb8 R08: 00000000000000d0 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000040 R12: ffff880140c690c0
R13: ffff88019e77aea0 R14: 00007fff336b0a5c R15: 0000000000000001
FS:  00007f12f50d97c0(0000) GS:ffff880007400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8f461bc000 CR3: 00000001b26ce000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process master (pid: 2436, threadinfo ffff88019e7e8000, task ffff88019e77aea0)
Stack:
 ffff88019e7e9ec8 ffffffff810698cd ffff88019e7e9ef8 ffffffff81069b45
&lt;0&gt; ffff880161514180 ffff880161514480 ffff880161514180 0000000000000000
&lt;0&gt; ffff88019e7e9f28 ffffffff8106aace 0000000000000001 0000000000000246
Call Trace:
 [&lt;ffffffff810698cd&gt;] put_cred+0x13/0x15
 [&lt;ffffffff81069b45&gt;] commit_creds+0x16b/0x175
 [&lt;ffffffff8106aace&gt;] set_current_groups+0x47/0x4e
 [&lt;ffffffff8106ac89&gt;] sys_setgroups+0xf6/0x105
 [&lt;ffffffff81009b02&gt;] system_call_fastpath+0x16/0x1b
Code: 48 8d 71 ff e8 7e 4e 15 00 85 c0 78 0b 8b 75 ec 48 89 df e8 ef 4a 15 00
48 83 c4 18 5b c9 c3 55 8b 07 8b 07 48 89 e5 85 c0 74 04 &lt;0f&gt; 0b eb fe 65 48 8b
04 25 00 cc 00 00 48 3b b8 58 04 00 00 75
RIP  [&lt;ffffffff81069881&gt;] __put_cred+0xc/0x45
 RSP &lt;ffff88019e7e9eb8&gt;
---[ end trace df391256a100ebdd ]---

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>sched, cgroup: Fixup broken cgroup movement</title>
<updated>2011-06-26T16:46:39+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>a.p.zijlstra@chello.nl</email>
</author>
<published>2010-10-15T13:24:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d4d67e0abb92d7237a2e95dd9106bdc69723ade7'/>
<id>d4d67e0abb92d7237a2e95dd9106bdc69723ade7</id>
<content type='text'>
commit b2b5ce022acf5e9f52f7b78c5579994fdde191d4 upstream.

Dima noticed that we fail to correct the -&gt;vruntime of sleeping tasks
when we move them between cgroups.

Reported-by: Dima Zavin &lt;dima@android.com&gt;
Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Tested-by: Mike Galbraith &lt;efault@gmx.de&gt;
LKML-Reference: &lt;1287150604.29097.1513.camel@twins&gt;
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit b2b5ce022acf5e9f52f7b78c5579994fdde191d4 upstream.

Dima noticed that we fail to correct the -&gt;vruntime of sleeping tasks
when we move them between cgroups.

Reported-by: Dima Zavin &lt;dima@android.com&gt;
Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Tested-by: Mike Galbraith &lt;efault@gmx.de&gt;
LKML-Reference: &lt;1287150604.29097.1513.camel@twins&gt;
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ieee80211: correct IEEE80211_ADDBA_PARAM_BUF_SIZE_MASK macro</title>
<updated>2011-06-26T16:46:34+00:00</updated>
<author>
<name>Amitkumar Karwar</name>
<email>akarwar@marvell.com</email>
</author>
<published>2011-01-12T00:14:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=693394c0404b8a4e34e4486797437779db0cac51'/>
<id>693394c0404b8a4e34e4486797437779db0cac51</id>
<content type='text'>
commit 8d661f1e462d50bd83de87ee628aaf820ce3c66c upstream.

It is defined in include/linux/ieee80211.h. As per IEEE spec.
bit6 to bit15 in block ack parameter represents buffer size.
So the bitmask should be 0xFFC0.

Signed-off-by: Amitkumar Karwar &lt;akarwar@marvell.com&gt;
Signed-off-by: Bing Zhao &lt;bzhao@marvell.com&gt;
Reviewed-by: Johannes Berg &lt;johannes@sipsolutions.net&gt;
Signed-off-by: John W. Linville &lt;linville@tuxdriver.com&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 8d661f1e462d50bd83de87ee628aaf820ce3c66c upstream.

It is defined in include/linux/ieee80211.h. As per IEEE spec.
bit6 to bit15 in block ack parameter represents buffer size.
So the bitmask should be 0xFFC0.

Signed-off-by: Amitkumar Karwar &lt;akarwar@marvell.com&gt;
Signed-off-by: Bing Zhao &lt;bzhao@marvell.com&gt;
Reviewed-by: Johannes Berg &lt;johannes@sipsolutions.net&gt;
Signed-off-by: John W. Linville &lt;linville@tuxdriver.com&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>klist: Fix object alignment on 64-bit.</title>
<updated>2011-06-26T16:46:32+00:00</updated>
<author>
<name>David Miller</name>
<email>davem@davemloft.net</email>
</author>
<published>2011-02-14T00:37:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=93b75f6331e290a50e2905e8b15e51afba6a9549'/>
<id>93b75f6331e290a50e2905e8b15e51afba6a9549</id>
<content type='text'>
commit 795abaf1e4e188c4171e3cd3dbb11a9fcacaf505 upstream.

Commit c0e69a5bbc6f ("klist.c: bit 0 in pointer can't be used as flag")
intended to make sure that all klist objects were at least pointer size
aligned, but used the constant "4" which only works on 32-bit.

Use "sizeof(void *)" which is correct in all cases.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Acked-by: Jesper Nilsson &lt;jesper.nilsson@axis.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 795abaf1e4e188c4171e3cd3dbb11a9fcacaf505 upstream.

Commit c0e69a5bbc6f ("klist.c: bit 0 in pointer can't be used as flag")
intended to make sure that all klist objects were at least pointer size
aligned, but used the constant "4" which only works on 32-bit.

Use "sizeof(void *)" which is correct in all cases.

Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
Acked-by: Jesper Nilsson &lt;jesper.nilsson@axis.com&gt;
Cc: Greg Kroah-Hartman &lt;gregkh@suse.de&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</pre>
</div>
</content>
</entry>
</feed>
