<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/include/linux/cred.h, branch Colibri_T30_LinuxImageV2.1Beta2_20140206</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>cred: use 'const' in get_current_{user,groups}</title>
<updated>2011-08-08T18:33:23+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2011-08-08T18:33:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=638a8439096c582bdb523fcea9d875d3e1fed38a'/>
<id>638a8439096c582bdb523fcea9d875d3e1fed38a</id>
<content type='text'>
Avoid annoying warnings from these functions ("discards qualifiers")
because they assign 'current_cred()' to a non-const pointer.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Avoid annoying warnings from these functions ("discards qualifiers")
because they assign 'current_cred()' to a non-const pointer.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>CRED: Restore const to current_cred()</title>
<updated>2011-08-08T16:03:16+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2011-08-08T14:54:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=27e4e4362756a78b15e83ef104c8bbe257f40f90'/>
<id>27e4e4362756a78b15e83ef104c8bbe257f40f90</id>
<content type='text'>
Commit 3295514841c2 ("fix rcu annotations noise in cred.h") accidentally
dropped the const of current-&gt;cred inside current_cred() by the
insertion of a cast to deal with an RCU annotation loss warning from
sparce.

Use an appropriate RCU wrapper instead so as not to lose the const.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Reviewed-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
cc: 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>
Commit 3295514841c2 ("fix rcu annotations noise in cred.h") accidentally
dropped the const of current-&gt;cred inside current_cred() by the
insertion of a cast to deal with an RCU annotation loss warning from
sparce.

Use an appropriate RCU wrapper instead so as not to lose the const.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Reviewed-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
cc: 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>fix rcu annotations noise in cred.h</title>
<updated>2011-08-07T20:42:35+00:00</updated>
<author>
<name>Al Viro</name>
<email>viro@ZenIV.linux.org.uk</email>
</author>
<published>2011-08-07T17:55:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3295514841c2112d94451ba5deaf54f5afb78ea9'/>
<id>3295514841c2112d94451ba5deaf54f5afb78ea9</id>
<content type='text'>
task-&gt;cred is declared as __rcu, and access to other tasks' -&gt;cred is,
indeed, protected.  Access to current-&gt;cred does not need rcu_dereference()
at all, since only the task itself can change its -&gt;cred.  sparse, of
course, has no way of knowing that...

Add force-cast in current_cred(), make current_fsuid() et.al. use it.

Signed-off-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>
task-&gt;cred is declared as __rcu, and access to other tasks' -&gt;cred is,
indeed, protected.  Access to current-&gt;cred does not need rcu_dereference()
at all, since only the task itself can change its -&gt;cred.  sparse, of
course, has no way of knowing that...

Add force-cast in current_cred(), make current_fsuid() et.al. use it.

Signed-off-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>atomic: use &lt;linux/atomic.h&gt;</title>
<updated>2011-07-26T23:49:47+00:00</updated>
<author>
<name>Arun Sharma</name>
<email>asharma@fb.com</email>
</author>
<published>2011-07-26T23:09:06+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=60063497a95e716c9a689af3be2687d261f115b4'/>
<id>60063497a95e716c9a689af3be2687d261f115b4</id>
<content type='text'>
This allows us to move duplicated code in &lt;asm/atomic.h&gt;
(atomic_inc_not_zero() for now) to &lt;linux/atomic.h&gt;

Signed-off-by: Arun Sharma &lt;asharma@fb.com&gt;
Reviewed-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Cc: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Acked-by: Mike Frysinger &lt;vapier@gentoo.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This allows us to move duplicated code in &lt;asm/atomic.h&gt;
(atomic_inc_not_zero() for now) to &lt;linux/atomic.h&gt;

Signed-off-by: Arun Sharma &lt;asharma@fb.com&gt;
Reviewed-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: David Miller &lt;davem@davemloft.net&gt;
Cc: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Acked-by: Mike Frysinger &lt;vapier@gentoo.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rcu: treewide: Do not use rcu_read_lock_held when calling rcu_dereference_check</title>
<updated>2011-07-08T20:21:58+00:00</updated>
<author>
<name>Michal Hocko</name>
<email>mhocko@suse.cz</email>
</author>
<published>2011-07-08T12:39:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d8bf4ca9ca9576548628344c9725edd3786e90b1'/>
<id>d8bf4ca9ca9576548628344c9725edd3786e90b1</id>
<content type='text'>
Since ca5ecddf (rcu: define __rcu address space modifier for sparse)
rcu_dereference_check use rcu_read_lock_held as a part of condition
automatically so callers do not have to do that as well.

Signed-off-by: Michal Hocko &lt;mhocko@suse.cz&gt;
Acked-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Since ca5ecddf (rcu: define __rcu address space modifier for sparse)
rcu_dereference_check use rcu_read_lock_held as a part of condition
automatically so callers do not have to do that as well.

Signed-off-by: Michal Hocko &lt;mhocko@suse.cz&gt;
Acked-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Create Documentation/security/,</title>
<updated>2011-05-19T22:59:38+00:00</updated>
<author>
<name>Randy Dunlap</name>
<email>randy.dunlap@oracle.com</email>
</author>
<published>2011-05-19T22:59:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=d410fa4ef99112386de5f218dd7df7b4fca910b4'/>
<id>d410fa4ef99112386de5f218dd7df7b4fca910b4</id>
<content type='text'>
move LSM-, credentials-, and keys-related files from Documentation/
  to Documentation/security/,
add Documentation/security/00-INDEX, and
update all occurrences of Documentation/&lt;moved_file&gt;
  to Documentation/security/&lt;moved_file&gt;.
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
move LSM-, credentials-, and keys-related files from Documentation/
  to Documentation/security/,
add Documentation/security/00-INDEX, and
update all occurrences of Documentation/&lt;moved_file&gt;
  to Documentation/security/&lt;moved_file&gt;.
</pre>
</div>
</content>
</entry>
<entry>
<title>Cache user_ns in struct cred</title>
<updated>2011-05-13T18:45:33+00:00</updated>
<author>
<name>Serge E. Hallyn</name>
<email>serge.hallyn@canonical.com</email>
</author>
<published>2011-05-13T03:27:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=47a150edc2ae734c0f4bf50aa19499e23b9a46f8'/>
<id>47a150edc2ae734c0f4bf50aa19499e23b9a46f8</id>
<content type='text'>
If !CONFIG_USERNS, have current_user_ns() defined to (&amp;init_user_ns).

Get rid of _current_user_ns.  This requires nsown_capable() to be
defined in capability.c rather than as static inline in capability.h,
so do that.

Request_key needs init_user_ns defined at current_user_ns if
!CONFIG_USERNS, so forward-declare that in cred.h if !CONFIG_USERNS
at current_user_ns() define.

Compile-tested with and without CONFIG_USERNS.

Signed-off-by: Serge E. Hallyn &lt;serge.hallyn@canonical.com&gt;
[ This makes a huge performance difference for acl_permission_check(),
  up to 30%.  And that is one of the hottest kernel functions for loads
  that are pathname-lookup heavy.  ]
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If !CONFIG_USERNS, have current_user_ns() defined to (&amp;init_user_ns).

Get rid of _current_user_ns.  This requires nsown_capable() to be
defined in capability.c rather than as static inline in capability.h,
so do that.

Request_key needs init_user_ns defined at current_user_ns if
!CONFIG_USERNS, so forward-declare that in cred.h if !CONFIG_USERNS
at current_user_ns() define.

Compile-tested with and without CONFIG_USERNS.

Signed-off-by: Serge E. Hallyn &lt;serge.hallyn@canonical.com&gt;
[ This makes a huge performance difference for acl_permission_check(),
  up to 30%.  And that is one of the hottest kernel functions for loads
  that are pathname-lookup heavy.  ]
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>userns: security: make capabilities relative to the user namespace</title>
<updated>2011-03-24T02:47:02+00:00</updated>
<author>
<name>Serge E. Hallyn</name>
<email>serge@hallyn.com</email>
</author>
<published>2011-03-23T23:43:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3486740a4f32a6a466f5ac931654d154790ba648'/>
<id>3486740a4f32a6a466f5ac931654d154790ba648</id>
<content type='text'>
- Introduce ns_capable to test for a capability in a non-default
  user namespace.
- Teach cap_capable to handle capabilities in a non-default
  user namespace.

The motivation is to get to the unprivileged creation of new
namespaces.  It looks like this gets us 90% of the way there, with
only potential uid confusion issues left.

I still need to handle getting all caps after creation but otherwise I
think I have a good starter patch that achieves all of your goals.

Changelog:
	11/05/2010: [serge] add apparmor
	12/14/2010: [serge] fix capabilities to created user namespaces
	Without this, if user serge creates a user_ns, he won't have
	capabilities to the user_ns he created.  THis is because we
	were first checking whether his effective caps had the caps
	he needed and returning -EPERM if not, and THEN checking whether
	he was the creator.  Reverse those checks.
	12/16/2010: [serge] security_real_capable needs ns argument in !security case
	01/11/2011: [serge] add task_ns_capable helper
	01/11/2011: [serge] add nsown_capable() helper per Bastian Blank suggestion
	02/16/2011: [serge] fix a logic bug: the root user is always creator of
		    init_user_ns, but should not always have capabilities to
		    it!  Fix the check in cap_capable().
	02/21/2011: Add the required user_ns parameter to security_capable,
		    fixing a compile failure.
	02/23/2011: Convert some macros to functions as per akpm comments.  Some
		    couldn't be converted because we can't easily forward-declare
		    them (they are inline if !SECURITY, extern if SECURITY).  Add
		    a current_user_ns function so we can use it in capability.h
		    without #including cred.h.  Move all forward declarations
		    together to the top of the #ifdef __KERNEL__ section, and use
		    kernel-doc format.
	02/23/2011: Per dhowells, clean up comment in cap_capable().
	02/23/2011: Per akpm, remove unreachable 'return -EPERM' in cap_capable.

(Original written and signed off by Eric;  latest, modified version
acked by him)

[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: export current_user_ns() for ecryptfs]
[serge.hallyn@canonical.com: remove unneeded extra argument in selinux's task_has_capability]
Signed-off-by: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
Signed-off-by: Serge E. Hallyn &lt;serge.hallyn@canonical.com&gt;
Acked-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Acked-by: Daniel Lezcano &lt;daniel.lezcano@free.fr&gt;
Acked-by: David Howells &lt;dhowells@redhat.com&gt;
Cc: James Morris &lt;jmorris@namei.org&gt;
Signed-off-by: Serge E. Hallyn &lt;serge.hallyn@canonical.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
- Introduce ns_capable to test for a capability in a non-default
  user namespace.
- Teach cap_capable to handle capabilities in a non-default
  user namespace.

The motivation is to get to the unprivileged creation of new
namespaces.  It looks like this gets us 90% of the way there, with
only potential uid confusion issues left.

I still need to handle getting all caps after creation but otherwise I
think I have a good starter patch that achieves all of your goals.

Changelog:
	11/05/2010: [serge] add apparmor
	12/14/2010: [serge] fix capabilities to created user namespaces
	Without this, if user serge creates a user_ns, he won't have
	capabilities to the user_ns he created.  THis is because we
	were first checking whether his effective caps had the caps
	he needed and returning -EPERM if not, and THEN checking whether
	he was the creator.  Reverse those checks.
	12/16/2010: [serge] security_real_capable needs ns argument in !security case
	01/11/2011: [serge] add task_ns_capable helper
	01/11/2011: [serge] add nsown_capable() helper per Bastian Blank suggestion
	02/16/2011: [serge] fix a logic bug: the root user is always creator of
		    init_user_ns, but should not always have capabilities to
		    it!  Fix the check in cap_capable().
	02/21/2011: Add the required user_ns parameter to security_capable,
		    fixing a compile failure.
	02/23/2011: Convert some macros to functions as per akpm comments.  Some
		    couldn't be converted because we can't easily forward-declare
		    them (they are inline if !SECURITY, extern if SECURITY).  Add
		    a current_user_ns function so we can use it in capability.h
		    without #including cred.h.  Move all forward declarations
		    together to the top of the #ifdef __KERNEL__ section, and use
		    kernel-doc format.
	02/23/2011: Per dhowells, clean up comment in cap_capable().
	02/23/2011: Per akpm, remove unreachable 'return -EPERM' in cap_capable.

(Original written and signed off by Eric;  latest, modified version
acked by him)

[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: export current_user_ns() for ecryptfs]
[serge.hallyn@canonical.com: remove unneeded extra argument in selinux's task_has_capability]
Signed-off-by: Eric W. Biederman &lt;ebiederm@xmission.com&gt;
Signed-off-by: Serge E. Hallyn &lt;serge.hallyn@canonical.com&gt;
Acked-by: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Acked-by: Daniel Lezcano &lt;daniel.lezcano@free.fr&gt;
Acked-by: David Howells &lt;dhowells@redhat.com&gt;
Cc: James Morris &lt;jmorris@namei.org&gt;
Signed-off-by: Serge E. Hallyn &lt;serge.hallyn@canonical.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>keys: __rcu annotations</title>
<updated>2010-08-20T00:18:00+00:00</updated>
<author>
<name>Arnd Bergmann</name>
<email>arnd@arndb.de</email>
</author>
<published>2010-02-26T17:01:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e63ba744a64d234c8a07c469ab1806443cb0a6ff'/>
<id>e63ba744a64d234c8a07c469ab1806443cb0a6ff</id>
<content type='text'>
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Acked-by: David Howells &lt;dhowells@redhat.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Signed-off-by: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Acked-by: David Howells &lt;dhowells@redhat.com&gt;
Reviewed-by: Josh Triplett &lt;josh@joshtriplett.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>CRED: Fix __task_cred()'s lockdep check and banner comment</title>
<updated>2010-07-29T22:16:18+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2010-07-29T11:45:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=8f92054e7ca1d3a3ae50fb42d2253ac8730d9b2a'/>
<id>8f92054e7ca1d3a3ae50fb42d2253ac8730d9b2a</id>
<content type='text'>
Fix __task_cred()'s lockdep check by removing the following validation
condition:

	lockdep_tasklist_lock_is_held()

as commit_creds() does not take the tasklist_lock, and nor do most of the
functions that call it, so this check is pointless and it can prevent
detection of the RCU lock not being held if the tasklist_lock is held.

Instead, add the following validation condition:

	task-&gt;exit_state &gt;= 0

to permit the access if the target task is dead and therefore unable to change
its own credentials.

Fix __task_cred()'s comment to:

 (1) discard the bit that says that the caller must prevent the target task
     from being deleted.  That shouldn't need saying.

 (2) Add a comment indicating the result of __task_cred() should not be passed
     directly to get_cred(), but rather than get_task_cred() should be used
     instead.

Also put a note into the documentation to enforce this point there too.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&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>
Fix __task_cred()'s lockdep check by removing the following validation
condition:

	lockdep_tasklist_lock_is_held()

as commit_creds() does not take the tasklist_lock, and nor do most of the
functions that call it, so this check is pointless and it can prevent
detection of the RCU lock not being held if the tasklist_lock is held.

Instead, add the following validation condition:

	task-&gt;exit_state &gt;= 0

to permit the access if the target task is dead and therefore unable to change
its own credentials.

Fix __task_cred()'s comment to:

 (1) discard the bit that says that the caller must prevent the target task
     from being deleted.  That shouldn't need saying.

 (2) Add a comment indicating the result of __task_cred() should not be passed
     directly to get_cred(), but rather than get_task_cred() should be used
     instead.

Also put a note into the documentation to enforce this point there too.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Acked-by: Jiri Olsa &lt;jolsa@redhat.com&gt;
Cc: Paul E. McKenney &lt;paulmck@linux.vnet.ibm.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
