Skip to content

K
Kernel

openeuler / Kernel
大约 1 年 前同步成功

通知 5
Star 0
Fork 0
K
Kernel

体验新版 GitCode，发现更多精彩内容 >>

切换分支/标签
  1. 08 4月, 2014 3 次提交
  3. 20 3月, 2014 1 次提交
  5. 11 3月, 2014 1 次提交
  7. 24 1月, 2014 4 次提交
    • O
      proc: fix ->f_pos overflows in first_tid() · 9f6e963f
      由 Oleg Nesterov 提交于 
      1. proc_task_readdir()->first_tid() path truncates f_pos to int, this
   is wrong even on 64bit.

   We could check that f_pos < PID_MAX or even INT_MAX in
   proc_task_readdir(), but this patch simply checks the potential
   overflow in first_tid(), this check is nop on 64bit.  We do not care if
   it was negative and the new unsigned value is huge, all we need to
   ensure is that we never wrongly return !NULL.

2. Remove the 2nd "nr != 0" check before get_nr_threads(),
   nr_threads == 0 is not distinguishable from !pid_task() above.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Sameer Nanda <snanda@chromium.org>
Cc: Sergey Dyasly <dserrg@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9f6e963f
    • O
      proc: don't (ab)use ->group_leader in proc_task_readdir() paths · d855a4b7
      由 Oleg Nesterov 提交于 
      proc_task_readdir() does not really need "leader", first_tid() has to
revalidate it anyway.  Just pass proc_pid(inode) to first_tid() instead,
it can do pid_task(PIDTYPE_PID) itself and read ->group_leader only if
necessary.

The patch also extracts the "inode is dead" code from
pid_delete_dentry(dentry) into the new trivial helper,
proc_inode_is_dead(inode), proc_task_readdir() uses it to return -ENOENT
if this dir was removed.

This is a bit racy, but the race is very inlikely and the getdents() after
openndir() can see the empty "." + ".." dir only once.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Sameer Nanda <snanda@chromium.org>
Cc: Sergey Dyasly <dserrg@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d855a4b7
    • O
      proc: change first_tid() to use while_each_thread() rather than next_thread() · c986c14a
      由 Oleg Nesterov 提交于 
      Rerwrite the main loop to use while_each_thread() instead of
next_thread().  We are going to fix or replace while_each_thread(),
next_thread() should be avoided whenever possible.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Sameer Nanda <snanda@chromium.org>
Cc: Sergey Dyasly <dserrg@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c986c14a
    • O
      proc: fix the potential use-after-free in first_tid() · 940fe479
      由 Oleg Nesterov 提交于 
      proc_task_readdir() verifies that the result of get_proc_task() is
pid_alive() and thus its ->group_leader is fine too.  However this is not
necessarily true after rcu_read_unlock(), we need to recheck this again
after first_tid() does rcu_read_lock().  Otherwise
leader->thread_group.next (used by next_thread()) can be invalid if the
rcu grace period expires in between.

The race is subtle and unlikely, but still it is possible afaics.  To
simplify lets ignore the "likely" case when tid != 0, f_version can be
cleared by proc_task_operations->llseek().

Suppose we have a main thread M and its subthread T.  Suppose that f_pos
== 3, iow first_tid() should return T.  Now suppose that the following
happens between rcu_read_unlock() and rcu_read_lock():

	1. T execs and becomes the new leader. This removes M from
	    ->thread_group but next_thread(M) is still T.

	2. T creates another thread X which does exec as well, T
	   goes away.

	3. X creates another subthread, this increments nr_threads.

	4. first_tid() does next_thread(M) and returns the already
	   dead T.

Note also that we need 2.  and 3.  only because of get_nr_threads() check,
and this check was supposed to be optimization only.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Sameer Nanda <snanda@chromium.org>
Cc: Sergey Dyasly <dserrg@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      940fe479
  9. 06 11月, 2013 1 次提交
  11. 29 6月, 2013 5 次提交
  13. 28 5月, 2013 1 次提交
  15. 02 5月, 2013 2 次提交
  17. 01 5月, 2013 1 次提交
  19. 18 4月, 2013 2 次提交
    • P
      posix-timers: Show sigevent info in proc file · 57b8015e
      由 Pavel Emelyanov 提交于 
      Previous patch added proc file to list posix timers created by task.
Expand the information provided in this file by adding info about
notification method, with which timers were created. I.e. after
the "ID:" line there go

1. "signal:" line, that shows signal number and sigval bits;
2. "notify:" line, that shows the timer notification method.

Thus the timer entry would looke like this:

ID: 123
signal: 14/0000000000b005d0
notify: signal/pid.732

This information is enough to understand how timer_create() was called
for each particular timer.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Link: http://lkml.kernel.org/r/513DA024.80404@parallels.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      57b8015e
    • P
      posix-timers: Introduce /proc/PID/timers file · 48f6a7a5
      由 Pavel Emelyanov 提交于 
      Currently kernel doesn't provide any API for getting info about what
posix timers are configured by processes. It's implied, that a process
which configured some timers, knows what it did. However, for external
tools it's impossible to get this information. In particular, this is
critical for checkpoint-restore project to have this info.

Introduce a per-pid proc file with information about posix
timers. Since these timers are shared between threads, this file is
present on tgid level only, no such thing in tid subdirs.

The file format is expected to be the "/proc/<pid>/smaps"-like,
i.e. each timer will occupy seveal lines to allow for future
extending.

Each new timer entry starts with the

ID: <number>

line which is added by this patch.
Signed-off-by: NPavel Emelyanov <xemul@parallels.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Matthew Helsley <matt.helsley@gmail.com>
Link: http://lkml.kernel.org/r/513DA00D.6070009@parallels.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
      48f6a7a5
  21. 10 4月, 2013 1 次提交
  23. 28 2月, 2013 1 次提交
  25. 26 2月, 2013 2 次提交
  27. 23 2月, 2013 1 次提交
  29. 21 12月, 2012 1 次提交
  31. 12 12月, 2012 1 次提交
  33. 11 12月, 2012 1 次提交
  35. 27 11月, 2012 1 次提交
  37. 19 11月, 2012 3 次提交
    • E
      pidns: Make the pidns proc mount/umount logic obvious. · 0a01f2cc
      由 Eric W. Biederman 提交于 
      Track the number of pids in the proc hash table.  When the number of
pids goes to 0 schedule work to unmount the kernel mount of proc.

Move the mount of proc into alloc_pid when we allocate the pid for
init.

Remove the surprising calls of pid_ns_release proc in fork and
proc_flush_task.  Those code paths really shouldn't know about proc
namespace implementation details and people have demonstrated several
times that finding and understanding those code paths is difficult and
non-obvious.

Because of the call path detach pid is alwasy called with the
rtnl_lock held free_pid is not allowed to sleep, so the work to
unmounting proc is moved to a work queue.  This has the side benefit
of not blocking the entire world waiting for the unnecessary
rcu_barrier in deactivate_locked_super.

In the process of making the code clear and obvious this fixes a bug
reported by Gao feng <gaofeng@cn.fujitsu.com> where we would leak a
mount of proc during clone(CLONE_NEWPID|CLONE_NEWNET) if copy_pid_ns
succeeded and copy_net_ns failed.
Acked-by: N"Serge E. Hallyn" <serge@hallyn.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      0a01f2cc
    • E
      procfs: Don't cache a pid in the root inode. · ae06c7c8
      由 Eric W. Biederman 提交于 
      Now that we have s_fs_info pointing to our pid namespace
the original reason for the proc root inode having a struct
pid is gone.

Caching a pid in the root inode has led to some complicated
code.  Now that we don't need the struct pid, just remove it.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
      ae06c7c8
    • E
      procfs: Use the proc generic infrastructure for proc/self. · e656d8a6
      由 Eric W. Biederman 提交于 
      I had visions at one point of splitting proc into two filesystems.  If
that had happened proc/self being the the part of proc that actually deals
with pids would have been a nice cleanup.  As it is proc/self requires
a lot of unnecessary infrastructure for a single file.

The only user visible change is that a mounted /proc for a pid namespace
that is dead now shows a broken proc symlink, instead of being completely
invisible.  I don't think anyone will notice or care.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
      e656d8a6
  39. 17 11月, 2012 1 次提交
  41. 30 10月, 2012 1 次提交
    • M
      sched/autogroup: Fix crash on reboot when autogroup is disabled · 5258f386
      由 Mike Galbraith 提交于 
      Due to these two commits:

  8323f26c sched: Fix race in task_group()
  800d4d30 sched, autogroup: Stop going ahead if autogroup is disabled

... autogroup scheduling's dynamic knobs are wrecked.

With both patches applied, all you have to do to crash a box is
disable autogroup during boot up, then reboot.. boom, NULL pointer
dereference due to 800d4d30 not allowing autogroup to move things,
and 8323f26c making that the only way to switch runqueues.

Remove most of the (dysfunctional) knobs and turn the remaining
sched_autogroup_enabled knob readonly.

If the user fiddles with cgroups hereafter, once tasks
are moved, autogroup won't mess with them again unless
they call setsid().

No knobs, no glitz, nada, just a cute little thing folks can
turn on if they don't want to muck about with cgroups and/or
systemd.
Signed-off-by: NMike Galbraith <efault@gmx.de>
Cc: Xiaotian Feng <xtfeng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Xiaotian Feng <dannyfeng@tencent.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: <stable@vger.kernel.org> # v3.6
Link: http://lkml.kernel.org/r/1351451963.4999.8.camel@maggy.simpson.netSigned-off-by: NIngo Molnar <mingo@kernel.org>
      5258f386
  43. 13 10月, 2012 1 次提交
  45. 09 10月, 2012 1 次提交
  47. 27 9月, 2012 3 次提交