linux.git/kernel/fork.c, branch v3.3-rc3 Linux kernel source tree Fix race in process_vm_rw_core 2012-02-02T20:55:17+00:00 Christopher Yeoh cyeoh@au1.ibm.com 2012-02-02T01:04:09+00:00 8cdb878dcb359fd1137e9abdee9322f5e9bcfdf8 This fixes the race in process_vm_core found by Oleg (see http://article.gmane.org/gmane.linux.kernel/1235667/ for details). This has been updated since I last sent it as the creation of the new mm_access() function did almost exactly the same thing as parts of the previous version of this patch did. In order to use mm_access() even when /proc isn't enabled, we move it to kernel/fork.c where other related process mm access functions already are. Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
This fixes the race in process_vm_core found by Oleg (see

  http://article.gmane.org/gmane.linux.kernel/1235667/

for details).

This has been updated since I last sent it as the creation of the new
mm_access() function did almost exactly the same thing as parts of the
previous version of this patch did.

In order to use mm_access() even when /proc isn't enabled, we move it to
kernel/fork.c where other related process mm access functions already
are.

Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit 2012-01-18T00:41:31+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-01-18T00:06:51+00:00 f429ee3b808118591d1f3cdf3c0d0793911a5677 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit: (29 commits) audit: no leading space in audit_log_d_path prefix audit: treat s_id as an untrusted string audit: fix signedness bug in audit_log_execve_info() audit: comparison on interprocess fields audit: implement all object interfield comparisons audit: allow interfield comparison between gid and ogid audit: complex interfield comparison helper audit: allow interfield comparison in audit rules Kernel: Audit Support For The ARM Platform audit: do not call audit_getname on error audit: only allow tasks to set their loginuid if it is -1 audit: remove task argument to audit_set_loginuid audit: allow audit matching on inode gid audit: allow matching on obj_uid audit: remove audit_finish_fork as it can't be called audit: reject entry,always rules audit: inline audit_free to simplify the look of generic code audit: drop audit_set_macxattr as it doesn't do anything audit: inline checks for not needing to collect aux records audit: drop some potentially inadvisable likely notations ... Use evil merge to fix up grammar mistakes in Kconfig file. Bad speling and horrible grammar (and copious swearing) is to be expected, but let's keep it to commit messages and comments, rather than expose it to users in config help texts or printouts. 
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit: (29 commits)
  audit: no leading space in audit_log_d_path prefix
  audit: treat s_id as an untrusted string
  audit: fix signedness bug in audit_log_execve_info()
  audit: comparison on interprocess fields
  audit: implement all object interfield comparisons
  audit: allow interfield comparison between gid and ogid
  audit: complex interfield comparison helper
  audit: allow interfield comparison in audit rules
  Kernel: Audit Support For The ARM Platform
  audit: do not call audit_getname on error
  audit: only allow tasks to set their loginuid if it is -1
  audit: remove task argument to audit_set_loginuid
  audit: allow audit matching on inode gid
  audit: allow matching on obj_uid
  audit: remove audit_finish_fork as it can't be called
  audit: reject entry,always rules
  audit: inline audit_free to simplify the look of generic code
  audit: drop audit_set_macxattr as it doesn't do anything
  audit: inline checks for not needing to collect aux records
  audit: drop some potentially inadvisable likely notations
  ...

Use evil merge to fix up grammar mistakes in Kconfig file.

Bad speling and horrible grammar (and copious swearing) is to be
expected, but let's keep it to commit messages and comments, rather than
expose it to users in config help texts or printouts.
audit: remove audit_finish_fork as it can't be called 2012-01-17T21:16:59+00:00 Eric Paris eparis@redhat.com 2012-01-03T19:23:07+00:00 6422e78de6880c66a82af512d9bd0c85eb62e661 Audit entry,always rules are not allowed and are automatically changed in exit,always rules in userspace. The kernel refuses to load such rules. Thus a task in the middle of a syscall (and thus in audit_finish_fork()) can only be in one of two states: AUDIT_BUILD_CONTEXT or AUDIT_DISABLED. Since the current task cannot be in AUDIT_RECORD_CONTEXT we aren't every going to actually use the code in audit_finish_fork() since it will return without doing anything. Thus drop the code. Signed-off-by: Eric Paris <eparis@redhat.com> 
Audit entry,always rules are not allowed and are automatically changed in
exit,always rules in userspace.  The kernel refuses to load such rules.

Thus a task in the middle of a syscall (and thus in audit_finish_fork())
can only be in one of two states: AUDIT_BUILD_CONTEXT or AUDIT_DISABLED.
Since the current task cannot be in AUDIT_RECORD_CONTEXT we aren't every
going to actually use the code in audit_finish_fork() since it will
return without doing anything.  Thus drop the code.

Signed-off-by: Eric Paris <eparis@redhat.com>
Merge branch 'for-3.3/core' of git://git.kernel.dk/linux-block 2012-01-15T20:24:45+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-01-15T20:24:45+00:00 b3c9dd182ed3bdcdaf0e42625a35924b0497afdc * 'for-3.3/core' of git://git.kernel.dk/linux-block: (37 commits) Revert "block: recursive merge requests" block: Stop using macro stubs for the bio data integrity calls blockdev: convert some macros to static inlines fs: remove unneeded plug in mpage_readpages() block: Add BLKROTATIONAL ioctl block: Introduce blk_set_stacking_limits function block: remove WARN_ON_ONCE() in exit_io_context() block: an exiting task should be allowed to create io_context block: ioc_cgroup_changed() needs to be exported block: recursive merge requests block, cfq: fix empty queue crash caused by request merge block, cfq: move icq creation and rq->elv.icq association to block core block, cfq: restructure io_cq creation path for io_context interface cleanup block, cfq: move io_cq exit/release to blk-ioc.c block, cfq: move icq cache management to block core block, cfq: move io_cq lookup to blk-ioc.c block, cfq: move cfqd->icq_list to request_queue and add request->elv.icq block, cfq: reorganize cfq_io_context into generic and cfq specific parts block: remove elevator_queue->ops block: reorder elevator switch sequence ... Fix up conflicts in: - block/blk-cgroup.c Switch from can_attach_task to can_attach - block/cfq-iosched.c conflict with now removed cic index changes (we now use q->id instead) 
* 'for-3.3/core' of git://git.kernel.dk/linux-block: (37 commits)
  Revert "block: recursive merge requests"
  block: Stop using macro stubs for the bio data integrity calls
  blockdev: convert some macros to static inlines
  fs: remove unneeded plug in mpage_readpages()
  block: Add BLKROTATIONAL ioctl
  block: Introduce blk_set_stacking_limits function
  block: remove WARN_ON_ONCE() in exit_io_context()
  block: an exiting task should be allowed to create io_context
  block: ioc_cgroup_changed() needs to be exported
  block: recursive merge requests
  block, cfq: fix empty queue crash caused by request merge
  block, cfq: move icq creation and rq->elv.icq association to block core
  block, cfq: restructure io_cq creation path for io_context interface cleanup
  block, cfq: move io_cq exit/release to blk-ioc.c
  block, cfq: move icq cache management to block core
  block, cfq: move io_cq lookup to blk-ioc.c
  block, cfq: move cfqd->icq_list to request_queue and add request->elv.icq
  block, cfq: reorganize cfq_io_context into generic and cfq specific parts
  block: remove elevator_queue->ops
  block: reorder elevator switch sequence
  ...

Fix up conflicts in:
 - block/blk-cgroup.c
	Switch from can_attach_task to can_attach
 - block/cfq-iosched.c
	conflict with now removed cic index changes (we now use q->id instead)
Merge branch 'writeback-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux 2012-01-11T00:59:59+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-01-11T00:59:59+00:00 001a541ea9163ace5e8243ee0e907ad80a4c0ec2 * 'writeback-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux: writeback: move MIN_WRITEBACK_PAGES to fs-writeback.c writeback: balanced_rate cannot exceed write bandwidth writeback: do strict bdi dirty_exceeded writeback: avoid tiny dirty poll intervals writeback: max, min and target dirty pause time writeback: dirty ratelimit - think time compensation btrfs: fix dirtied pages accounting on sub-page writes writeback: fix dirtied pages accounting on redirty writeback: fix dirtied pages accounting on sub-page writes writeback: charge leaked page dirties to active tasks writeback: Include all dirty inodes in background writeback 
* 'writeback-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux:
  writeback: move MIN_WRITEBACK_PAGES to fs-writeback.c
  writeback: balanced_rate cannot exceed write bandwidth
  writeback: do strict bdi dirty_exceeded
  writeback: avoid tiny dirty poll intervals
  writeback: max, min and target dirty pause time
  writeback: dirty ratelimit - think time compensation
  btrfs: fix dirtied pages accounting on sub-page writes
  writeback: fix dirtied pages accounting on redirty
  writeback: fix dirtied pages accounting on sub-page writes
  writeback: charge leaked page dirties to active tasks
  writeback: Include all dirty inodes in background writeback
tracepoint: add tracepoints for debugging oom_score_adj 2012-01-11T00:30:44+00:00 KAMEZAWA Hiroyuki kamezawa.hiroyu@jp.fujitsu.com 2012-01-10T23:08:09+00:00 43d2b113241d6797b890318767e0af78e313414b oom_score_adj is used for guarding processes from OOM-Killer. One of problem is that it's inherited at fork(). When a daemon set oom_score_adj and make children, it's hard to know where the value is set. This patch adds some tracepoints useful for debugging. This patch adds 3 trace points. - creating new task - renaming a task (exec) - set oom_score_adj To debug, users need to enable some trace pointer. Maybe filtering is useful as # EVENT=/sys/kernel/debug/tracing/events/task/ # echo "oom_score_adj != 0" > $EVENT/task_newtask/filter # echo "oom_score_adj != 0" > $EVENT/task_rename/filter # echo 1 > $EVENT/enable # EVENT=/sys/kernel/debug/tracing/events/oom/ # echo 1 > $EVENT/enable output will be like this. # grep oom /sys/kernel/debug/tracing/trace bash-7699 [007] d..3 5140.744510: oom_score_adj_update: pid=7699 comm=bash oom_score_adj=-1000 bash-7699 [007] ...1 5151.818022: task_newtask: pid=7729 comm=bash clone_flags=1200011 oom_score_adj=-1000 ls-7729 [003] ...2 5151.818504: task_rename: pid=7729 oldcomm=bash newcomm=ls oom_score_adj=-1000 bash-7699 [002] ...1 5175.701468: task_newtask: pid=7730 comm=bash clone_flags=1200011 oom_score_adj=-1000 grep-7730 [007] ...2 5175.701993: task_rename: pid=7730 oldcomm=bash newcomm=grep oom_score_adj=-1000 Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
oom_score_adj is used for guarding processes from OOM-Killer.  One of
problem is that it's inherited at fork().  When a daemon set oom_score_adj
and make children, it's hard to know where the value is set.

This patch adds some tracepoints useful for debugging. This patch adds
3 trace points.
  - creating new task
  - renaming a task (exec)
  - set oom_score_adj

To debug, users need to enable some trace pointer. Maybe filtering is useful as

# EVENT=/sys/kernel/debug/tracing/events/task/
# echo "oom_score_adj != 0" > $EVENT/task_newtask/filter
# echo "oom_score_adj != 0" > $EVENT/task_rename/filter
# echo 1 > $EVENT/enable
# EVENT=/sys/kernel/debug/tracing/events/oom/
# echo 1 > $EVENT/enable

output will be like this.
# grep oom /sys/kernel/debug/tracing/trace
bash-7699  [007] d..3  5140.744510: oom_score_adj_update: pid=7699 comm=bash oom_score_adj=-1000
bash-7699  [007] ...1  5151.818022: task_newtask: pid=7729 comm=bash clone_flags=1200011 oom_score_adj=-1000
ls-7729  [003] ...2  5151.818504: task_rename: pid=7729 oldcomm=bash newcomm=ls oom_score_adj=-1000
bash-7699  [002] ...1  5175.701468: task_newtask: pid=7730 comm=bash clone_flags=1200011 oom_score_adj=-1000
grep-7730  [007] ...2  5175.701993: task_rename: pid=7730 oldcomm=bash newcomm=grep oom_score_adj=-1000

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge branch 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2012-01-09T20:59:24+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-01-09T20:59:24+00:00 db0c2bf69aa095d4a6de7b1145f29fe9a7c0f6a3 * 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits) cgroup: fix to allow mounting a hierarchy by name cgroup: move assignement out of condition in cgroup_attach_proc() cgroup: Remove task_lock() from cgroup_post_fork() cgroup: add sparse annotation to cgroup_iter_start() and cgroup_iter_end() cgroup: mark cgroup_rmdir_waitq and cgroup_attach_proc() as static cgroup: only need to check oldcgrp==newgrp once cgroup: remove redundant get/put of task struct cgroup: remove redundant get/put of old css_set from migrate cgroup: Remove unnecessary task_lock before fetching css_set on migration cgroup: Drop task_lock(parent) on cgroup_fork() cgroups: remove redundant get/put of css_set from css_set_check_fetched() resource cgroups: remove bogus cast cgroup: kill subsys->can_attach_task(), pre_attach() and attach_task() cgroup, cpuset: don't use ss->pre_attach() cgroup: don't use subsys->can_attach_task() or ->attach_task() cgroup: introduce cgroup_taskset and use it in subsys->can_attach(), cancel_attach() and attach() cgroup: improve old cgroup handling in cgroup_attach_proc() cgroup: always lock threadgroup during migration threadgroup: extend threadgroup_lock() to cover exit and exec threadgroup: rename signal->threadgroup_fork_lock to ->group_rwsem ... Fix up conflict in kernel/cgroup.c due to commit e0197aae59e5: "cgroups: fix a css_set not found bug in cgroup_attach_proc" that already mentioned that the bug is fixed (differently) in Tejun's cgroup patchset. This one, in other words. 
* 'for-3.3' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (21 commits)
  cgroup: fix to allow mounting a hierarchy by name
  cgroup: move assignement out of condition in cgroup_attach_proc()
  cgroup: Remove task_lock() from cgroup_post_fork()
  cgroup: add sparse annotation to cgroup_iter_start() and cgroup_iter_end()
  cgroup: mark cgroup_rmdir_waitq and cgroup_attach_proc() as static
  cgroup: only need to check oldcgrp==newgrp once
  cgroup: remove redundant get/put of task struct
  cgroup: remove redundant get/put of old css_set from migrate
  cgroup: Remove unnecessary task_lock before fetching css_set on migration
  cgroup: Drop task_lock(parent) on cgroup_fork()
  cgroups: remove redundant get/put of css_set from css_set_check_fetched()
  resource cgroups: remove bogus cast
  cgroup: kill subsys->can_attach_task(), pre_attach() and attach_task()
  cgroup, cpuset: don't use ss->pre_attach()
  cgroup: don't use subsys->can_attach_task() or ->attach_task()
  cgroup: introduce cgroup_taskset and use it in subsys->can_attach(), cancel_attach() and attach()
  cgroup: improve old cgroup handling in cgroup_attach_proc()
  cgroup: always lock threadgroup during migration
  threadgroup: extend threadgroup_lock() to cover exit and exec
  threadgroup: rename signal->threadgroup_fork_lock to ->group_rwsem
  ...

Fix up conflict in kernel/cgroup.c due to commit e0197aae59e5: "cgroups:
fix a css_set not found bug in cgroup_attach_proc" that already
mentioned that the bug is fixed (differently) in Tejun's cgroup
patchset. This one, in other words.
Merge branch 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm 2012-01-08T21:10:57+00:00 Linus Torvalds torvalds@linux-foundation.org 2012-01-08T21:10:57+00:00 eb59c505f8a5906ad2e053d14fab50eb8574fd6f * 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (76 commits) PM / Hibernate: Implement compat_ioctl for /dev/snapshot PM / Freezer: fix return value of freezable_schedule_timeout_killable() PM / shmobile: Allow the A4R domain to be turned off at run time PM / input / touchscreen: Make st1232 use device PM QoS constraints PM / QoS: Introduce dev_pm_qos_add_ancestor_request() PM / shmobile: Remove the stay_on flag from SH7372's PM domains PM / shmobile: Don't include SH7372's INTCS in syscore suspend/resume PM / shmobile: Add support for the sh7372 A4S power domain / sleep mode PM: Drop generic_subsys_pm_ops PM / Sleep: Remove forward-only callbacks from AMBA bus type PM / Sleep: Remove forward-only callbacks from platform bus type PM: Run the driver callback directly if the subsystem one is not there PM / Sleep: Make pm_op() and pm_noirq_op() return callback pointers PM/Devfreq: Add Exynos4-bus device DVFS driver for Exynos4210/4212/4412. PM / Sleep: Merge internal functions in generic_ops.c PM / Sleep: Simplify generic system suspend callbacks PM / Hibernate: Remove deprecated hibernation snapshot ioctls PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled() ARM: S3C64XX: Implement basic power domain support PM / shmobile: Use common always on power domain governor ... Fix up trivial conflict in fs/xfs/xfs_buf.c due to removal of unused XBT_FORCE_SLEEP bit 
* 'pm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (76 commits)
  PM / Hibernate: Implement compat_ioctl for /dev/snapshot
  PM / Freezer: fix return value of freezable_schedule_timeout_killable()
  PM / shmobile: Allow the A4R domain to be turned off at run time
  PM / input / touchscreen: Make st1232 use device PM QoS constraints
  PM / QoS: Introduce dev_pm_qos_add_ancestor_request()
  PM / shmobile: Remove the stay_on flag from SH7372's PM domains
  PM / shmobile: Don't include SH7372's INTCS in syscore suspend/resume
  PM / shmobile: Add support for the sh7372 A4S power domain / sleep mode
  PM: Drop generic_subsys_pm_ops
  PM / Sleep: Remove forward-only callbacks from AMBA bus type
  PM / Sleep: Remove forward-only callbacks from platform bus type
  PM: Run the driver callback directly if the subsystem one is not there
  PM / Sleep: Make pm_op() and pm_noirq_op() return callback pointers
  PM/Devfreq: Add Exynos4-bus device DVFS driver for Exynos4210/4212/4412.
  PM / Sleep: Merge internal functions in generic_ops.c
  PM / Sleep: Simplify generic system suspend callbacks
  PM / Hibernate: Remove deprecated hibernation snapshot ioctls
  PM / Sleep: Fix freezer failures due to racy usermodehelper_is_disabled()
  ARM: S3C64XX: Implement basic power domain support
  PM / shmobile: Use common always on power domain governor
  ...

Fix up trivial conflict in fs/xfs/xfs_buf.c due to removal of unused
XBT_FORCE_SLEEP bit
writeback: dirty ratelimit - think time compensation 2011-12-18T06:20:27+00:00 Wu Fengguang fengguang.wu@intel.com 2011-06-12T01:25:42+00:00 83712358ba0a1497ce59a4f84ce4dd0f803fe6fc Compensate the task's think time when computing the final pause time, so that ->dirty_ratelimit can be executed accurately. think time := time spend outside of balance_dirty_pages() In the rare case that the task slept longer than the 200ms period time (result in negative pause time), the sleep time will be compensated in the following periods, too, if it's less than 1 second. Accumulated errors are carefully avoided as long as the max pause area is not hitted. Pseudo code: period = pages_dirtied / task_ratelimit; think = jiffies - dirty_paused_when; pause = period - think; 1) normal case: period > think pause = period - think dirty_paused_when = jiffies + pause nr_dirtied = 0 period time |===============================>| think time pause time |===============>|==============>| ------|----------------|---------------|------------------------ dirty_paused_when jiffies 2) no pause case: period <= think don't pause; reduce future pause time by: dirty_paused_when += period nr_dirtied = 0 period time |===============================>| think time |===================================================>| ------|--------------------------------+-------------------|---- dirty_paused_when jiffies Acked-by: Jan Kara <jack@suse.cz> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> 
Compensate the task's think time when computing the final pause time,
so that ->dirty_ratelimit can be executed accurately.

        think time := time spend outside of balance_dirty_pages()

In the rare case that the task slept longer than the 200ms period time
(result in negative pause time), the sleep time will be compensated in
the following periods, too, if it's less than 1 second.

Accumulated errors are carefully avoided as long as the max pause area
is not hitted.

Pseudo code:

        period = pages_dirtied / task_ratelimit;
        think = jiffies - dirty_paused_when;
        pause = period - think;

1) normal case: period > think

        pause = period - think
        dirty_paused_when = jiffies + pause
        nr_dirtied = 0

                             period time
              |===============================>|
                  think time      pause time
              |===============>|==============>|
        ------|----------------|---------------|------------------------
        dirty_paused_when   jiffies

2) no pause case: period <= think

        don't pause; reduce future pause time by:
        dirty_paused_when += period
        nr_dirtied = 0

                           period time
              |===============================>|
                                  think time
              |===================================================>|
        ------|--------------------------------+-------------------|----
        dirty_paused_when                                       jiffies

Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
[S390] cputime: add sparse checking and cleanup 2011-12-15T13:56:19+00:00 Martin Schwidefsky schwidefsky@de.ibm.com 2011-12-15T13:56:09+00:00 648616343cdbe904c585a6c12e323d3b3c72e46f Make cputime_t and cputime64_t nocast to enable sparse checking to detect incorrect use of cputime. Drop the cputime macros for simple scalar operations. The conversion macros are still needed. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> 
Make cputime_t and cputime64_t nocast to enable sparse checking to
detect incorrect use of cputime. Drop the cputime macros for simple
scalar operations. The conversion macros are still needed.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>