Previously selinux_skb_peerlbl_sid() would only check for labeled
IPsec security labels on inbound packets, this patch enables it to
check both inbound and outbound traffic for labeled IPsec security
labels.
Reported-by: NJanak Desai <Janak.Desai@gtri.gatech.edu>
Cc: stable@vger.kernel.org
Signed-off-by: NPaul Moore <pmoore@redhat.com>

In selinux_ip_postroute() we perform access checks based on the
packet's security label.  For locally generated traffic we get the
packet's security label from the associated socket; this works in all
cases except for TCP SYN-ACK packets.  In the case of SYN-ACK packet's
the correct security label is stored in the connection's request_sock,
not the server's socket.  Unfortunately, at the point in time when
selinux_ip_postroute() is called we can't query the request_sock
directly, we need to recreate the label using the same logic that
originally labeled the associated request_sock.

See the inline comments for more explanation.
Reported-by: NJanak Desai <Janak.Desai@gtri.gatech.edu>
Tested-by: NJanak Desai <Janak.Desai@gtri.gatech.edu>
Cc: stable@vger.kernel.org
Signed-off-by: NPaul Moore <pmoore@redhat.com>

In selinux_ip_output() we always label packets based on the parent
socket.  While this approach works in almost all cases, it doesn't
work in the case of TCP SYN-ACK packets when the correct label is not
the label of the parent socket, but rather the label of the larval
socket represented by the request_sock struct.

Unfortunately, since the request_sock isn't queued on the parent
socket until *after* the SYN-ACK packet is sent, we can't lookup the
request_sock to determine the correct label for the packet; at this
point in time the best we can do is simply pass/NF_ACCEPT the packet.
It must be said that simply passing the packet without any explicit
labeling action, while far from ideal, is not terrible as the SYN-ACK
packet will inherit any IP option based labeling from the initial
connection request so the label *should* be correct and all our
access controls remain in place so we shouldn't have to worry about
information leaks.
Reported-by: NJanak Desai <Janak.Desai@gtri.gatech.edu>
Tested-by: NJanak Desai <Janak.Desai@gtri.gatech.edu>
Cc: stable@vger.kernel.org
Signed-off-by: NPaul Moore <pmoore@redhat.com>

Free 'ctx_str' when necessary.
Signed-off-by: NGeyslan G. Bem <geyslan@gmail.com>
Signed-off-by: NPaul Moore <pmoore@redhat.com>

BugLink: http://bugs.launchpad.net/bugs/1235977

The profile introspection seq file has a locking bug when policy is viewed
from a virtual root (task in a policy namespace), introspection from the
real root is not affected.

The test for root
    while (parent) {
is correct for the real root, but incorrect for tasks in a policy namespace.
This allows the task to walk backup the policy tree past its virtual root
causing it to be unlocked before the virtual root should be in the p_stop
fn.

This results in the following lockdep back trace:
[   78.479744] [ BUG: bad unlock balance detected! ]
[   78.479792] 3.11.0-11-generic #17 Not tainted
[   78.479838] -------------------------------------
[   78.479885] grep/2223 is trying to release lock (&ns->lock) at:
[   78.479952] [<ffffffff817bf3be>] mutex_unlock+0xe/0x10
[   78.480002] but there are no more locks to release!
[   78.480037]
[   78.480037] other info that might help us debug this:
[   78.480037] 1 lock held by grep/2223:
[   78.480037]  #0:  (&p->lock){+.+.+.}, at: [<ffffffff812111bd>] seq_read+0x3d/0x3d0
[   78.480037]
[   78.480037] stack backtrace:
[   78.480037] CPU: 0 PID: 2223 Comm: grep Not tainted 3.11.0-11-generic #17
[   78.480037] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   78.480037]  ffffffff817bf3be ffff880007763d60 ffffffff817b97ef ffff8800189d2190
[   78.480037]  ffff880007763d88 ffffffff810e1c6e ffff88001f044730 ffff8800189d2190
[   78.480037]  ffffffff817bf3be ffff880007763e00 ffffffff810e5bd6 0000000724fe56b7
[   78.480037] Call Trace:
[   78.480037]  [<ffffffff817bf3be>] ? mutex_unlock+0xe/0x10
[   78.480037]  [<ffffffff817b97ef>] dump_stack+0x54/0x74
[   78.480037]  [<ffffffff810e1c6e>] print_unlock_imbalance_bug+0xee/0x100
[   78.480037]  [<ffffffff817bf3be>] ? mutex_unlock+0xe/0x10
[   78.480037]  [<ffffffff810e5bd6>] lock_release_non_nested+0x226/0x300
[   78.480037]  [<ffffffff817bf2fe>] ? __mutex_unlock_slowpath+0xce/0x180
[   78.480037]  [<ffffffff817bf3be>] ? mutex_unlock+0xe/0x10
[   78.480037]  [<ffffffff810e5d5c>] lock_release+0xac/0x310
[   78.480037]  [<ffffffff817bf2b3>] __mutex_unlock_slowpath+0x83/0x180
[   78.480037]  [<ffffffff817bf3be>] mutex_unlock+0xe/0x10
[   78.480037]  [<ffffffff81376c91>] p_stop+0x51/0x90
[   78.480037]  [<ffffffff81211408>] seq_read+0x288/0x3d0
[   78.480037]  [<ffffffff811e9d9e>] vfs_read+0x9e/0x170
[   78.480037]  [<ffffffff811ea8cc>] SyS_read+0x4c/0xa0
[   78.480037]  [<ffffffff817ccc9d>] system_call_fastpath+0x1a/0x1f
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>

BugLink: http://bugs.launchpad.net/bugs/1235523

This fixes the following kmemleak trace:
unreferenced object 0xffff8801e8c35680 (size 32):
  comm "apparmor_parser", pid 691, jiffies 4294895667 (age 13230.876s)
  hex dump (first 32 bytes):
    e0 d3 4e b5 ac 6d f4 ed 3f cb ee 48 1c fd 40 cf  ..N..m..?..H..@.
    5b cc e9 93 00 00 00 00 00 00 00 00 00 00 00 00  [...............
  backtrace:
    [<ffffffff817a97ee>] kmemleak_alloc+0x4e/0xb0
    [<ffffffff811ca9f3>] __kmalloc+0x103/0x290
    [<ffffffff8138acbc>] aa_calc_profile_hash+0x6c/0x150
    [<ffffffff8138074d>] aa_unpack+0x39d/0xd50
    [<ffffffff8137eced>] aa_replace_profiles+0x3d/0xd80
    [<ffffffff81376937>] profile_replace+0x37/0x50
    [<ffffffff811e9f2d>] vfs_write+0xbd/0x1e0
    [<ffffffff811ea96c>] SyS_write+0x4c/0xa0
    [<ffffffff817ccb1d>] system_call_fastpath+0x1a/0x1f
    [<ffffffffffffffff>] 0xffffffffffffffff
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>

Now avc_audit() has no more users with that parameter. Remove it.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

.. so get rid of it.  The only indirect users were all the
avc_has_perm() callers which just expanded to have a zero flags
argument.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Every single user passes in '0'.  I think we had non-zero users back in
some stone age when selinux_inode_permission() was implemented in terms
of inode_has_perm(), but that complicated case got split up into a
totally separate code-path so that we could optimize the much simpler
special cases.

See commit 2e334057 ("SELinux: delay initialization of audit data in
selinux_inode_permission") for example.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The recent 3.12 pull request for apparmor was missing a couple rcu _protected
access modifiers. Resulting in the follow suspicious RCU usage

 [   29.804534] [ INFO: suspicious RCU usage. ]
 [   29.804539] 3.11.0+ #5 Not tainted
 [   29.804541] -------------------------------
 [   29.804545] security/apparmor/include/policy.h:363 suspicious rcu_dereference_check() usage!
 [   29.804548]
 [   29.804548] other info that might help us debug this:
 [   29.804548]
 [   29.804553]
 [   29.804553] rcu_scheduler_active = 1, debug_locks = 1
 [   29.804558] 2 locks held by apparmor_parser/1268:
 [   29.804560]  #0:  (sb_writers#9){.+.+.+}, at: [<ffffffff81120a4c>] file_start_write+0x27/0x29
 [   29.804576]  #1:  (&ns->lock){+.+.+.}, at: [<ffffffff811f5d88>] aa_replace_profiles+0x166/0x57c
 [   29.804589]
 [   29.804589] stack backtrace:
 [   29.804595] CPU: 0 PID: 1268 Comm: apparmor_parser Not tainted 3.11.0+ #5
 [   29.804599] Hardware name: ASUSTeK Computer Inc.         UL50VT          /UL50VT    , BIOS 217     03/01/2010
 [   29.804602]  0000000000000000 ffff8800b95a1d90 ffffffff8144eb9b ffff8800b94db540
 [   29.804611]  ffff8800b95a1dc0 ffffffff81087439 ffff880138cc3a18 ffff880138cc3a18
 [   29.804619]  ffff8800b9464a90 ffff880138cc3a38 ffff8800b95a1df0 ffffffff811f5084
 [   29.804628] Call Trace:
 [   29.804636]  [<ffffffff8144eb9b>] dump_stack+0x4e/0x82
 [   29.804642]  [<ffffffff81087439>] lockdep_rcu_suspicious+0xfc/0x105
 [   29.804649]  [<ffffffff811f5084>] __aa_update_replacedby+0x53/0x7f
 [   29.804655]  [<ffffffff811f5408>] __replace_profile+0x11f/0x1ed
 [   29.804661]  [<ffffffff811f6032>] aa_replace_profiles+0x410/0x57c
 [   29.804668]  [<ffffffff811f16d4>] profile_replace+0x35/0x4c
 [   29.804674]  [<ffffffff81120fa3>] vfs_write+0xad/0x113
 [   29.804680]  [<ffffffff81121609>] SyS_write+0x44/0x7a
 [   29.804687]  [<ffffffff8145bfd2>] system_call_fastpath+0x16/0x1b
 [   29.804691]
 [   29.804694] ===============================
 [   29.804697] [ INFO: suspicious RCU usage. ]
 [   29.804700] 3.11.0+ #5 Not tainted
 [   29.804703] -------------------------------
 [   29.804706] security/apparmor/policy.c:566 suspicious rcu_dereference_check() usage!
 [   29.804709]
 [   29.804709] other info that might help us debug this:
 [   29.804709]
 [   29.804714]
 [   29.804714] rcu_scheduler_active = 1, debug_locks = 1
 [   29.804718] 2 locks held by apparmor_parser/1268:
 [   29.804721]  #0:  (sb_writers#9){.+.+.+}, at: [<ffffffff81120a4c>] file_start_write+0x27/0x29
 [   29.804733]  #1:  (&ns->lock){+.+.+.}, at: [<ffffffff811f5d88>] aa_replace_profiles+0x166/0x57c
 [   29.804744]
 [   29.804744] stack backtrace:
 [   29.804750] CPU: 0 PID: 1268 Comm: apparmor_parser Not tainted 3.11.0+ #5
 [   29.804753] Hardware name: ASUSTeK Computer Inc.         UL50VT          /UL50VT    , BIOS 217     03/01/2010
 [   29.804756]  0000000000000000 ffff8800b95a1d80 ffffffff8144eb9b ffff8800b94db540
 [   29.804764]  ffff8800b95a1db0 ffffffff81087439 ffff8800b95b02b0 0000000000000000
 [   29.804772]  ffff8800b9efba08 ffff880138cc3a38 ffff8800b95a1dd0 ffffffff811f4f94
 [   29.804779] Call Trace:
 [   29.804786]  [<ffffffff8144eb9b>] dump_stack+0x4e/0x82
 [   29.804791]  [<ffffffff81087439>] lockdep_rcu_suspicious+0xfc/0x105
 [   29.804798]  [<ffffffff811f4f94>] aa_free_replacedby_kref+0x4d/0x62
 [   29.804804]  [<ffffffff811f4f47>] ? aa_put_namespace+0x17/0x17
 [   29.804810]  [<ffffffff811f4f0b>] kref_put+0x36/0x40
 [   29.804816]  [<ffffffff811f5423>] __replace_profile+0x13a/0x1ed
 [   29.804822]  [<ffffffff811f6032>] aa_replace_profiles+0x410/0x57c
 [   29.804829]  [<ffffffff811f16d4>] profile_replace+0x35/0x4c
 [   29.804835]  [<ffffffff81120fa3>] vfs_write+0xad/0x113
 [   29.804840]  [<ffffffff81121609>] SyS_write+0x44/0x7a
 [   29.804847]  [<ffffffff8145bfd2>] system_call_fastpath+0x16/0x1b

Reported-by: miles.lane@gmail.com
CC: paulmck@linux.vnet.ibm.com
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>

Use the shash interface, rather than the hash interface, when hashing
AppArmor profiles. The shash interface does not use scatterlists and it
is a better fit for what AppArmor needs.

This fixes a kernel paging BUG when aa_calc_profile_hash() is passed a
buffer from vmalloc(). The hash interface requires callers to handle
vmalloc() buffers differently than what AppArmor was doing. Due to
vmalloc() memory not being physically contiguous, each individual page
behind the buffer must be assigned to a scatterlist with sg_set_page()
and then the scatterlist passed to crypto_hash_update().

The shash interface does not have that limitation and allows vmalloc()
and kmalloc() buffers to be handled in the same manner.

BugLink: https://launchpad.net/bugs/1216294/
BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=62261Signed-off-by: NTyler Hicks <tyhicks@canonical.com>
Acked-by: NSeth Arnold <seth.arnold@canonical.com>
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>

The SELinux/NetLabel glue code has a locking bug that affects systems
with NetLabel enabled, see the kernel error message below.  This patch
corrects this problem by converting the bottom half socket lock to a
more conventional, and correct for this call-path, lock_sock() call.

 ===============================
 [ INFO: suspicious RCU usage. ]
 3.11.0-rc3+ #19 Not tainted
 -------------------------------
 net/ipv4/cipso_ipv4.c:1928 suspicious rcu_dereference_protected() usage!

 other info that might help us debug this:

 rcu_scheduler_active = 1, debug_locks = 0
 2 locks held by ping/731:
  #0:  (slock-AF_INET/1){+.-...}, at: [...] selinux_netlbl_socket_connect
  #1:  (rcu_read_lock){.+.+..}, at: [<...>] netlbl_conn_setattr

 stack backtrace:
 CPU: 1 PID: 731 Comm: ping Not tainted 3.11.0-rc3+ #19
 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
  0000000000000001 ffff88006f659d28 ffffffff81726b6a ffff88003732c500
  ffff88006f659d58 ffffffff810e4457 ffff88006b845a00 0000000000000000
  000000000000000c ffff880075aa2f50 ffff88006f659d90 ffffffff8169bec7
 Call Trace:
  [<ffffffff81726b6a>] dump_stack+0x54/0x74
  [<ffffffff810e4457>] lockdep_rcu_suspicious+0xe7/0x120
  [<ffffffff8169bec7>] cipso_v4_sock_setattr+0x187/0x1a0
  [<ffffffff8170f317>] netlbl_conn_setattr+0x187/0x190
  [<ffffffff8170f195>] ? netlbl_conn_setattr+0x5/0x190
  [<ffffffff8131ac9e>] selinux_netlbl_socket_connect+0xae/0xc0
  [<ffffffff81303025>] selinux_socket_connect+0x135/0x170
  [<ffffffff8119d127>] ? might_fault+0x57/0xb0
  [<ffffffff812fb146>] security_socket_connect+0x16/0x20
  [<ffffffff815d3ad3>] SYSC_connect+0x73/0x130
  [<ffffffff81739a85>] ? sysret_check+0x22/0x5d
  [<ffffffff810e5e2d>] ? trace_hardirqs_on_caller+0xfd/0x1c0
  [<ffffffff81373d4e>] ? trace_hardirqs_on_thunk+0x3a/0x3f
  [<ffffffff815d52be>] SyS_connect+0xe/0x10
  [<ffffffff81739a59>] system_call_fastpath+0x16/0x1b

Cc: stable@vger.kernel.org
Signed-off-by: NPaul Moore <pmoore@redhat.com>

Signed-off-by: NDuan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: NPaul Moore <paul@paul-moore.com>

We allow task A to change B's nice level if it has a supserset of
B's privileges, or of it has CAP_SYS_NICE.  Also allow it if A has
CAP_SYS_NICE with respect to B - meaning it is root in the same
namespace, or it created B's namespace.
Signed-off-by: NSerge Hallyn <serge.hallyn@canonical.com>
Reviewed-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>

As the capabilites and capability bounding set are per user namespace
properties it is safe to allow changing them with just CAP_SETPCAP
permission in the user namespace.
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Tested-by: NRichard Weinberger <richard@nod.at>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

This reverts commit 308ab70c.

It breaks my FC6 test box.  /dev/pts is not mounted.  dmesg says

SELinux: mount invalid.  Same superblock, different security settings
for (dev devpts, type devpts)

Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NEric Paris <eparis@redhat.com>

Not considering sub filesystem has the following limitation. Support
for SELinux in FUSE is dependent on the particular userspace
filesystem, which is identified by the subtype. For e.g, GlusterFS,
a FUSE based filesystem supports SELinux (by mounting and processing
FUSE requests in different threads, avoiding the mount time
deadlock), whereas other FUSE based filesystems (identified by a
different subtype) have the mount time deadlock.

By considering the subtype of the filesytem in the SELinux policies,
allows us to specify a filesystem subtype, in the following way:

fs_use_xattr fuse.glusterfs gen_context(system_u:object_r:fs_t,s0);

This way not all FUSE filesystems are put in the same bucket and
subjected to the limitations of the other subtypes.
Signed-off-by: NAnand Avati <avati@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

The apparmor module parameters for param_ops_aabool and
param_ops_aalockpolicy are both based off of the param_ops_bool,
and can handle a NULL value passed in as val. Have it enable the
new KERNEL_PARAM_FL_NOARGS flag to allow the parameters to be set
without having to state "=y" or "=1".

Cc: John Johansen <john.johansen@canonical.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Provide userspace the ability to introspect a sha1 hash value for each
profile currently loaded.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NSeth Arnold <seth.arnold@canonical.com>

Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NSeth Arnold <seth.arnold@canonical.com>

Add the dynamic namespace relative profiles file to the interace, to allow
introspection of loaded profiles and their modes.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NKees Cook <kees@ubuntu.com>

Add the ability to take in and report a human readable profile attachment
string for profiles so that attachment specifications can be easily
inspected.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NSeth Arnold <seth.arnold@canonical.com>

Add basic interface files to access namespace and profile information.
The interface files are created when a profile is loaded and removed
when the profile or namespace is removed.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>

Allow emulating the default profile behavior from boot, by allowing
loading of a profile in the unconfined state into a new NS.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NSeth Arnold <seth.arnold@canonical.com>

Signed-off-by: NJohn Johansen <john.johansen@canonical.com>

namespaces now completely use the unconfined profile to track the
refcount and rcu freeing cycle. So rework the code to simplify (track
everything through the profile path right up to the end), and move the
rcu_head from policy base to profile as the namespace no longer needs
it.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NSeth Arnold <seth.arnold@canonical.com>

ns->unconfined is being used read side without locking, nor rcu but is
being updated when a namespace is removed. This works for the root ns
which is never removed but has a race window and can cause failures when
children namespaces are removed.

Also ns and ns->unconfined have a circular refcounting dependency that
is problematic and must be broken. Currently this is done incorrectly
when the namespace is destroyed.

Fix this by forward referencing unconfined via the replacedby infrastructure
instead of directly updating the ns->unconfined pointer.

Remove the circular refcount dependency by making the ns and its unconfined
profile share the same refcount.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NSeth Arnold <seth.arnold@canonical.com>

remove the use of replaced by chaining and move to profile invalidation
and lookup to handle task replacement.

Replacement chaining can result in large chains of profiles being pinned
in memory when one profile in the chain is use. With implicit labeling
this will be even more of a problem, so move to a direct lookup method.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>

Signed-off-by: NJohn Johansen <john.johansen@canonical.com>

previously profiles had to be loaded one at a time, which could result
in cases where a replacement of a set would partially succeed, and then fail
resulting in inconsistent policy.

Allow multiple profiles to replaced "atomically" so that the replacement
either succeeds or fails for the entire set of profiles.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>

Add a policy directory to features to contain features that can affect
policy compilation but do not affect mediation. Eg of such features would
be types of dfa compression supported, etc.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NKees Cook <kees@ubuntu.com>

Signed-off-by: NJohn Johansen <john.johansen@canonical.com>

This is a follow-up to commit b5b3ee6c "apparmor: no need to delay vfree()".

Since vmalloc() will do "size = PAGE_ALIGN(size);",
we don't need to check for "size >= sizeof(struct work_struct)".
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>

Smack interface for loading rules has always parsed only single rule from
data written to it. This requires user program to call one write() per
each rule it wants to load.
This change makes it possible to write multiple rules, separated by new
line character. Smack will load at most PAGE_SIZE-1 characters and properly
return number of processed bytes. In case when user buffer is larger, it
will be additionally truncated. All characters after last \n will not get
parsed to avoid partial rule near input buffer boundary.
Signed-off-by: NRafal Krypa <r.krypa@samsung.com>

Previously, all css descendant iterators didn't include the origin
(root of subtree) css in the iteration.  The reasons were maintaining
consistency with css_for_each_child() and that at the time of
introduction more use cases needed skipping the origin anyway;
however, given that css_is_descendant() considers self to be a
descendant, omitting the origin css has become more confusing and
looking at the accumulated use cases rather clearly indicates that
including origin would result in simpler code overall.

While this is a change which can easily lead to subtle bugs, cgroup
API including the iterators has recently gone through major
restructuring and no out-of-tree changes will be applicable without
adjustments making this a relatively acceptable opportunity for this
type of change.

The conversions are mostly straight-forward.  If the iteration block
had explicit origin handling before or after, it's moved inside the
iteration.  If not, if (pos == origin) continue; is added.  Some
conversions add extra reference get/put around origin handling by
consolidating origin handling and the rest.  While the extra ref
operations aren't strictly necessary, this shouldn't cause any
noticeable difference.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NLi Zefan <lizefan@huawei.com>
Acked-by: NVivek Goyal <vgoyal@redhat.com>
Acked-by: NAristeu Rozanski <aris@redhat.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>

cgroup is currently in the process of transitioning to using css
(cgroup_subsys_state) as the primary handle instead of cgroup in
subsystem API.  For hierarchy iterators, this is beneficial because

* In most cases, css is the only thing subsystems care about anyway.

* On the planned unified hierarchy, iterations for different
  subsystems will need to skip over different subtrees of the
  hierarchy depending on which subsystems are enabled on each cgroup.
  Passing around css makes it unnecessary to explicitly specify the
  subsystem in question as css is intersection between cgroup and
  subsystem

* For the planned unified hierarchy, css's would need to be created
  and destroyed dynamically independent from cgroup hierarchy.  Having
  cgroup core manage css iteration makes enforcing deref rules a lot
  easier.

Most subsystem conversions are straight-forward.  Noteworthy changes
are

* blkio: cgroup_to_blkcg() is no longer used.  Removed.

* freezer: cgroup_freezer() is no longer used.  Removed.

* devices: cgroup_to_devcgroup() is no longer used.  Removed.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NLi Zefan <lizefan@huawei.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NVivek Goyal <vgoyal@redhat.com>
Acked-by: NAristeu Rozanski <aris@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>

cgroup is currently in the process of transitioning to using struct
cgroup_subsys_state * as the primary handle instead of struct cgroup.
Please see the previous commit which converts the subsystem methods
for rationale.

This patch converts all cftype file operations to take @css instead of
@cgroup.  cftypes for the cgroup core files don't have their subsytem
pointer set.  These will automatically use the dummy_css added by the
previous patch and can be converted the same way.

Most subsystem conversions are straight forwards but there are some
interesting ones.

* freezer: update_if_frozen() is also converted to take @css instead
  of @cgroup for consistency.  This will make the code look simpler
  too once iterators are converted to use css.

* memory/vmpressure: mem_cgroup_from_css() needs to be exported to
  vmpressure while mem_cgroup_from_cont() can be made static.
  Updated accordingly.

* cpu: cgroup_tg() doesn't have any user left.  Removed.

* cpuacct: cgroup_ca() doesn't have any user left.  Removed.

* hugetlb: hugetlb_cgroup_form_cgroup() doesn't have any user left.
  Removed.

* net_cls: cgrp_cls_state() doesn't have any user left.  Removed.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NLi Zefan <lizefan@huawei.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NVivek Goyal <vgoyal@redhat.com>
Acked-by: NAristeu Rozanski <aris@redhat.com>
Acked-by: NDaniel Wagner <daniel.wagner@bmw-carit.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Steven Rostedt <rostedt@goodmis.org>

cgroup is currently in the process of transitioning to using struct
cgroup_subsys_state * as the primary handle instead of struct cgroup *
in subsystem implementations for the following reasons.

* With unified hierarchy, subsystems will be dynamically bound and
  unbound from cgroups and thus css's (cgroup_subsys_state) may be
  created and destroyed dynamically over the lifetime of a cgroup,
  which is different from the current state where all css's are
  allocated and destroyed together with the associated cgroup.  This
  in turn means that cgroup_css() should be synchronized and may
  return NULL, making it more cumbersome to use.

* Differing levels of per-subsystem granularity in the unified
  hierarchy means that the task and descendant iterators should behave
  differently depending on the specific subsystem the iteration is
  being performed for.

* In majority of the cases, subsystems only care about its part in the
  cgroup hierarchy - ie. the hierarchy of css's.  Subsystem methods
  often obtain the matching css pointer from the cgroup and don't
  bother with the cgroup pointer itself.  Passing around css fits
  much better.

This patch converts all cgroup_subsys methods to take @css instead of
@cgroup.  The conversions are mostly straight-forward.  A few
noteworthy changes are

* ->css_alloc() now takes css of the parent cgroup rather than the
  pointer to the new cgroup as the css for the new cgroup doesn't
  exist yet.  Knowing the parent css is enough for all the existing
  subsystems.

* In kernel/cgroup.c::offline_css(), unnecessary open coded css
  dereference is replaced with local variable access.

This patch shouldn't cause any behavior differences.

v2: Unnecessary explicit cgrp->subsys[] deref in css_online() replaced
    with local variable @css as suggested by Li Zefan.

    Rebased on top of new for-3.12 which includes for-3.11-fixes so
    that ->css_free() invocation added by da0a12ca ("cgroup: fix a
    leak when percpu_ref_init() fails") is converted too.  Suggested
    by Li Zefan.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NLi Zefan <lizefan@huawei.com>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Acked-by: NVivek Goyal <vgoyal@redhat.com>
Acked-by: NAristeu Rozanski <aris@redhat.com>
Acked-by: NDaniel Wagner <daniel.wagner@bmw-carit.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Steven Rostedt <rostedt@goodmis.org>

Currently, controllers have to explicitly follow the cgroup hierarchy
to find the parent of a given css.  cgroup is moving towards using
cgroup_subsys_state as the main controller interface construct, so
let's provide a way to climb the hierarchy using just csses.

This patch implements css_parent() which, given a css, returns its
parent.  The function is guarnateed to valid non-NULL parent css as
long as the target css is not at the top of the hierarchy.

freezer, cpuset, cpu, cpuacct, hugetlb, memory, net_cls and devices
are converted to use css_parent() instead of accessing cgroup->parent
directly.

* __parent_ca() is dropped from cpuacct and its usage is replaced with
  parent_ca().  The only difference between the two was NULL test on
  cgroup->parent which is now embedded in css_parent() making the
  distinction moot.  Note that eventually a css->parent field will be
  added to css and the NULL check in css_parent() will go away.

This patch shouldn't cause any behavior differences.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NLi Zefan <lizefan@huawei.com>

css (cgroup_subsys_state) is usually embedded in a subsys specific
data structure.  Subsystems either use container_of() directly to cast
from css to such data structure or has an accessor function wrapping
such cast.  As cgroup as whole is moving towards using css as the main
interface handle, add and update such accessors to ease dealing with
css's.

All accessors explicitly handle NULL input and return NULL in those
cases.  While this looks like an extra branch in the code, as all
controllers specific data structures have css as the first field, the
casting doesn't involve any offsetting and the compiler can trivially
optimize out the branch.

* blkio, freezer, cpuset, cpu, cpuacct and net_cls didn't have such
  accessor.  Added.

* memory, hugetlb and devices already had one but didn't explicitly
  handle NULL input.  Updated.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NLi Zefan <lizefan@huawei.com>