linux-toradex.git/kernel/cgroup.c, branch T20_LinuxImageV2.0Beta1_20121218

Merge branch 'linux-3.1.y' into android-tegra-nv-3.1

2012-01-16T10:02:21+00:00

Linux 3.1.9

Conflicts:
	Makefile

Change-Id: I22227ab33ba7ddaba8e6fe049393c58a83d73648
Signed-off-by: Varun Wadekar

cgroup: fix to allow mounting a hierarchy by name

2012-01-12T19:33:24+00:00

commit 0d19ea866562e46989412a0676412fa0983c9ce7 upstream.

If we mount a hierarchy with a specified name, the name is unique,
and we can use it to mount the hierarchy without specifying its
set of subsystem names. This feature is documented is
Documentation/cgroups/cgroups.txt section 2.3

Here's an example:

	# mount -t cgroup -o cpuset,name=myhier xxx /cgroup1
	# mount -t cgroup -o name=myhier xxx /cgroup2

But it was broken by commit 32a8cf235e2f192eb002755076994525cdbaa35a
(cgroup: make the mount options parsing more accurate)

This fixes the regression.

Signed-off-by: Li Zefan 
Signed-off-by: Tejun Heo 
Signed-off-by: Greg Kroah-Hartman

cgroups: fix a css_set not found bug in cgroup_attach_proc

2012-01-11T17:52:46+00:00

commit e0197aae59e55c06db172bfbe1a1cdb8c0e1cab3 upstream.

There is a BUG when migrating a PF_EXITING proc. Since css_set_prefetch()
is not called for the PF_EXITING case, find_existing_css_set() will return
NULL inside cgroup_task_migrate() causing a BUG.

This bug is easy to reproduce. Create a zombie and echo its pid to
cgroup.procs.

$ cat zombie.c
\#include 

int main()
{
  if (fork())
      pause();
  return 0;
}
$

We are hitting this bug pretty regularly on ChromeOS.

This bug is already fixed by Tejun Heo's cgroup patchset which is
targetted for the next merge window:

https://lkml.org/lkml/2011/11/1/356

I've create a smaller patch here which just fixes this bug so that a
fix can be merged into the current release and stable.

Signed-off-by: Mandeep Singh Baines 
Downstream-Bug-Report: http://crosbug.com/23953
Reviewed-by: Li Zefan 
Signed-off-by: Tejun Heo 
Cc: containers@lists.linux-foundation.org
Cc: cgroups@vger.kernel.org
Cc: KAMEZAWA Hiroyuki 
Cc: Frederic Weisbecker 
Cc: Oleg Nesterov 
Cc: Andrew Morton 
Cc: Paul Menage 
Cc: Olof Johansson 
Signed-off-by: Greg Kroah-Hartman 
Change-Id: I61bf2d48574d6ce5418b988e9547937c2efdd084
Reviewed-on: http://git-master/r/74185
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Rohan Somvanshi 
Tested-by: Rohan Somvanshi

cgroups: fix a css_set not found bug in cgroup_attach_proc

2012-01-06T22:17:11+00:00

commit e0197aae59e55c06db172bfbe1a1cdb8c0e1cab3 upstream.

There is a BUG when migrating a PF_EXITING proc. Since css_set_prefetch()
is not called for the PF_EXITING case, find_existing_css_set() will return
NULL inside cgroup_task_migrate() causing a BUG.

This bug is easy to reproduce. Create a zombie and echo its pid to
cgroup.procs.

$ cat zombie.c
\#include 

int main()
{
  if (fork())
      pause();
  return 0;
}
$

We are hitting this bug pretty regularly on ChromeOS.

This bug is already fixed by Tejun Heo's cgroup patchset which is
targetted for the next merge window:

https://lkml.org/lkml/2011/11/1/356

I've create a smaller patch here which just fixes this bug so that a
fix can be merged into the current release and stable.

Signed-off-by: Mandeep Singh Baines 
Downstream-Bug-Report: http://crosbug.com/23953
Reviewed-by: Li Zefan 
Signed-off-by: Tejun Heo 
Cc: containers@lists.linux-foundation.org
Cc: cgroups@vger.kernel.org
Cc: KAMEZAWA Hiroyuki 
Cc: Frederic Weisbecker 
Cc: Oleg Nesterov 
Cc: Andrew Morton 
Cc: Paul Menage 
Cc: Olof Johansson 
Signed-off-by: Greg Kroah-Hartman

cgroup: Add generic cgroup subsystem permission checks

2011-12-01T05:38:49+00:00

Rather than using explicit euid == 0 checks when trying to move
tasks into a cgroup via CFS, move permission checks into each
specific cgroup subsystem. If a subsystem does not specify a
'allow_attach' handler, then we fall back to doing our checks
the old way.

Use the 'allow_attach' handler for the 'cpu' cgroup to allow
non-root processes to add arbitrary processes to a 'cpu' cgroup
if it has the CAP_SYS_NICE capability set.

This version of the patch adds a 'allow_attach' handler instead
of reusing the 'can_attach' handler.  If the 'can_attach' handler
is reused, a new cgroup that implements 'can_attach' but not
the permission checks could end up with no permission checks
at all.

Change-Id: Icfa950aa9321d1ceba362061d32dc7dfa2c64f0c
Original-Author: San Mehat 
Signed-off-by: Colin Cross

Revert "cgroup: Add generic cgroup subsystem permission checks."

2011-12-01T05:38:49+00:00

This reverts commit 1d38bc7d0523af2233b4280e2aeab34c6a076665.

Change-Id: I2c5066b696cbdd5ca117ed74718bcb7e70e878e7
Signed-off-by: Colin Cross

cgroup: Remove call to synchronize_rcu in cgroup_attach_task

2011-12-01T05:38:25+00:00

synchronize_rcu can be very expensive, averaging 100 ms in
some cases.  In cgroup_attach_task, it is used to prevent
a task->cgroups pointer dereferenced in an RCU read side
critical section from being invalidated, by delaying the
call to put_css_set until after an RCU grace period.

To avoid the call to synchronize_rcu, make the put_css_set
call rcu-safe by moving the deletion of the css_set links
into free_css_set_work, scheduled by the rcu callback
free_css_set_rcu.

The decrement of the cgroup refcount is no longer
synchronous with the call to put_css_set, which can result
in the cgroup refcount staying positive after the last call
to cgroup_attach_task returns.  To allow the cgroup to be
deleted with cgroup_rmdir synchronously after
cgroup_attach_task, have rmdir check the refcount of all
associated css_sets.  If cgroup_rmdir is called on a cgroup
for which the css_sets all have refcount zero but the
cgroup refcount is nonzero, reuse the rmdir waitqueue to
block the rmdir until free_css_set_work is called.

Signed-off-by: Colin Cross

cgroup: Set CGRP_RELEASABLE when adding to a cgroup

2011-12-01T05:38:25+00:00

Changes the meaning of CGRP_RELEASABLE to be set on any cgroup
that has ever had a task or cgroup in it, or had css_get called
on it.  The bit is set in cgroup_attach_task, cgroup_create,
and __css_get.  It is not necessary to set the bit in
cgroup_fork, as the task is either in the root cgroup, in
which can never be released, or the task it was forked from
already set the bit in croup_attach_task.

Signed-off-by: Colin Cross

cgroup: Add generic cgroup subsystem permission checks.

2011-12-01T05:38:10+00:00

    Rather than using explicit euid == 0 checks when trying to move
tasks into a cgroup via CFS, move permission checks into each
specific cgroup subsystem. If a subsystem does not specify a
'can_attach' handler, then we fall back to doing our checks the old way.

    This way non-root processes can add arbitrary processes to
a cgroup if all the registered subsystems on that cgroup agree.

    Also change explicit euid == 0 check to CAP_SYS_ADMIN

Signed-off-by: San Mehat

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6

2011-07-28T02:26:38+00:00

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (54 commits)
  tpm_nsc: Fix bug when loading multiple TPM drivers
  tpm: Move tpm_tis_reenable_interrupts out of CONFIG_PNP block
  tpm: Fix compilation warning when CONFIG_PNP is not defined
  TOMOYO: Update kernel-doc.
  tpm: Fix a typo
  tpm_tis: Probing function for Intel iTPM bug
  tpm_tis: Fix the probing for interrupts
  tpm_tis: Delay ACPI S3 suspend while the TPM is busy
  tpm_tis: Re-enable interrupts upon (S3) resume
  tpm: Fix display of data in pubek sysfs entry
  tpm_tis: Add timeouts sysfs entry
  tpm: Adjust interface timeouts if they are too small
  tpm: Use interface timeouts returned from the TPM
  tpm_tis: Introduce durations sysfs entry
  tpm: Adjust the durations if they are too small
  tpm: Use durations returned from TPM
  TOMOYO: Enable conditional ACL.
  TOMOYO: Allow using argv[]/envp[] of execve() as conditions.
  TOMOYO: Allow using executable's realpath and symlink's target as conditions.
  TOMOYO: Allow using owner/group etc. of file objects as conditions.
  ...

Fix up trivial conflict in security/tomoyo/realpath.c