1. 18 Sep, 2009 2 commits
  2. 07 Sep, 2009 2 commits
  3. 05 Sep, 2009 2 commits
    • Oleg Nesterov's avatar
      exec: do not sleep in TASK_TRACED under ->cred_guard_mutex · a2a8474c
      Oleg Nesterov authored
      
      
      Tom Horsley reports that his debugger hangs when it tries to read
      /proc/pid_of_tracee/maps, this happens since
      
      	"mm_for_maps: take ->cred_guard_mutex to fix the race with exec"
      	04b836cbf19e885f8366bccb2e4b0474346c02d
      
      commit in 2.6.31.
      
      But the root of the problem lies in the fact that do_execve() path calls
      tracehook_report_exec() which can stop if the tracer sets PT_TRACE_EXEC.
      
      The tracee must not sleep in TASK_TRACED holding this mutex.  Even if we
      remove ->cred_guard_mutex from mm_for_maps() and proc_pid_attr_write(),
      another task doing PTRACE_ATTACH should not hang until it is killed or the
      tracee resumes.
      
      With this patch do_execve() does not use ->cred_guard_mutex directly and
      we do not hold it throughout, instead:
      
      	- introduce prepare_bprm_creds() helper, it locks the mutex
      	  and calls prepare_exec_creds() to initialize bprm->cred.
      
      	- install_exec_creds() drops the mutex after commit_creds(),
      	  and thus before tracehook_report_exec()->ptrace_stop().
      
      	  or, if exec fails,
      
      	  free_bprm() drops this mutex when bprm->cred != NULL which
      	  indicates install_exec_creds() was not called.
      Reported-by: default avatarTom Horsley <tom.horsley@att.net>
      Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
      Acked-by: default avatarDavid Howells <dhowells@redhat.com>
      Cc: Roland McGrath <roland@redhat.com>
      Cc: James Morris <jmorris@namei.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      a2a8474c
    • Oleg Nesterov's avatar
      workqueues: introduce __cancel_delayed_work() · 4e49627b
      Oleg Nesterov authored
      cancel_delayed_work() has to use del_timer_sync() to guarantee the timer
      function is not running after return.  But most users doesn't actually
      need this, and del_timer_sync() has problems: it is not useable from
      interrupt, and it depends on every lock which could be taken from irq.
      
      Introduce __cancel_delayed_work() which calls del_timer() instead.
      
      The immediate reason for this patch is
      http://bugzilla.kernel.org/show_bug.cgi?id=13757
      
      
      but hopefully this helper makes sense anyway.
      
      As for 13757 bug, actually we need requeue_delayed_work(), but its
      semantics are not yet clear.
      
      Merge this patch early to resolves cross-tree interdependencies between
      input and infiniband.
      Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
      Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
      Cc: Roland Dreier <rdreier@cisco.com>
      Cc: Stefan Richter <stefanr@s5r6.in-berlin.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      4e49627b
  4. 04 Sep, 2009 2 commits
    • Jonathan Brassow's avatar
      dm log: userspace add luid to distinguish between concurrent log instances · 7ec23d50
      Jonathan Brassow authored
      
      
      Device-mapper userspace logs (like the clustered log) are
      identified by a universally unique identifier (UUID).  This
      identifier is used to associate requests from the kernel to
      a specific log in userspace.  The UUID must be unique everywhere,
      since multiple machines may use this identifier when communicating
      about a particular log, as is the case for cluster logs.
      
      Sometimes, device-mapper/LVM may re-use a UUID.  This is the
      case during pvmoves, when moving from one segment of an LV
      to another, or when resizing a mirror, etc.  In these cases,
      a new log is created with the same UUID and loaded in the
      "inactive" slot.  When a device-mapper "resume" is issued,
      the "live" table is deactivated and the new "inactive" table
      becomes "live".  (The "inactive" table can also be removed
      via a device-mapper 'clear' command.)
      
      The above two issues were colliding.  More than one log was being
      created with the same UUID, and there was no way to distinguish
      between them.  So, sometimes the wrong log would be swapped
      out during the exchange.
      
      The solution is to create a locally unique identifier,
      'luid', to go along with the UUID.  This new identifier is used
      to determine exactly which log is being referenced by the kernel
      when the log exchange is made.  The identifier is not
      universally safe, but it does not need to be, since
      create/destroy/suspend/resume operations are bound to a specific
      machine; and these are the operations that make up the exchange.
      Signed-off-by: default avatarJonathan Brassow <jbrassow@redhat.com>
      Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
      7ec23d50
    • Mike Snitzer's avatar
      dm stripe: expose correct io hints · 40bea431
      Mike Snitzer authored
      
      
      Set sensible I/O hints for striped DM devices in the topology
      infrastructure added for 2.6.31 for userspace tools to
      obtain via sysfs.
      
      Add .io_hints to 'struct target_type' to allow the I/O hints portion
      (io_min and io_opt) of the 'struct queue_limits' to be set by each
      target and implement this for dm-stripe.
      Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
      Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
      40bea431
  5. 01 Sep, 2009 3 commits
    • David S. Miller's avatar
      pkt_sched: Revert tasklet_hrtimer changes. · 2fbd3da3
      David S. Miller authored
      These are full of unresolved problems, mainly that conversions don't
      work 1-1 from hrtimers to tasklet_hrtimers because unlike hrtimers
      tasklets can't be killed from softirq context.
      
      And when a qdisc gets reset, that's exactly what we need to do here.
      
      We'll work this out in the net-next-2.6 tree and if warranted we'll
      backport that work to -stable.
      
      This reverts the following 3 changesets:
      
      a2cb6a4d
      ("pkt_sched: Fix bogon in tasklet_hrtimer changes.")
      
      38acce2d
      ("pkt_sched: Convert CBQ to tasklet_hrtimer.")
      
      ee5f9757
      
      
      ("pkt_sched: Convert qdisc_watchdog to tasklet_hrtimer")
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      2fbd3da3
    • Dave Airlie's avatar
      drm/kms: add explicit encoder disable function and detach harder. · a3a0544b
      Dave Airlie authored
      
      
      For shared tv-out and VGA encoders, we really need to know if
      the encoder is just being switched off temporarily in blanking
      or if we are really disabling it hard.
      
      Also we need to try harder to disconnect encoders from unused
      connectors so we can share more efficently.
      
      (shared encoders stuff is coming in radeon tv-out support)
      Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
      a3a0544b
    • Dave Airlie's avatar
      drm/mm: add ability to dump mm lists via debugfs · fa8a1238
      Dave Airlie authored
      
      
      This adds code to the drm_mm to talk to debugfs, and adds
      support to radeon to add the VRAM and GTT mm lists to debugfs.
      
      I tested with spinlock debugging and it doesn't give out.
      Signed-off-by: default avatarDave Airlie <airlied@redhat.com>
      fa8a1238
  6. 31 Aug, 2009 1 commit
  7. 30 Aug, 2009 2 commits
  8. 29 Aug, 2009 1 commit
  9. 26 Aug, 2009 5 commits
  10. 24 Aug, 2009 1 commit
    • Hugh Dickins's avatar
      mm: fix hugetlb bug due to user_shm_unlock call · 353d5c30
      Hugh Dickins authored
      2.6.30's commit 8a0bdec1
      
       removed
      user_shm_lock() calls in hugetlb_file_setup() but left the
      user_shm_unlock call in shm_destroy().
      
      In detail:
      Assume that can_do_hugetlb_shm() returns true and hence user_shm_lock()
      is not called in hugetlb_file_setup(). However, user_shm_unlock() is
      called in any case in shm_destroy() and in the following
      atomic_dec_and_lock(&up->__count) in free_uid() is executed and if
      up->__count gets zero, also cleanup_user_struct() is scheduled.
      
      Note that sched_destroy_user() is empty if CONFIG_USER_SCHED is not set.
      However, the ref counter up->__count gets unexpectedly non-positive and
      the corresponding structs are freed even though there are live
      references to them, resulting in a kernel oops after a lots of
      shmget(SHM_HUGETLB)/shmctl(IPC_RMID) cycles and CONFIG_USER_SCHED set.
      
      Hugh changed Stefan's suggested patch: can_do_hugetlb_shm() at the
      time of shm_destroy() may give a different answer from at the time
      of hugetlb_file_setup().  And fixed newseg()'s no_id error path,
      which has missed user_shm_unlock() ever since it came in 2.6.9.
      Reported-by: default avatarStefan Huber <shuber2@gmail.com>
      Signed-off-by: default avatarHugh Dickins <hugh.dickins@tiscali.co.uk>
      Tested-by: default avatarStefan Huber <shuber2@gmail.com>
      Cc: stable@kernel.org
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      353d5c30
  11. 23 Aug, 2009 1 commit
  12. 22 Aug, 2009 1 commit
  13. 21 Aug, 2009 3 commits
  14. 20 Aug, 2009 1 commit
  15. 19 Aug, 2009 6 commits
  16. 18 Aug, 2009 2 commits
    • Dave Airlie's avatar
      776f3360
    • KOSAKI Motohiro's avatar
      mm: revert "oom: move oom_adj value" · 0753ba01
      KOSAKI Motohiro authored
      The commit 2ff05b2b (oom: move oom_adj value) moveed the oom_adj value to
      the mm_struct.  It was a very good first step for sanitize OOM.
      
      However Paul Menage reported the commit makes regression to his job
      scheduler.  Current OOM logic can kill OOM_DISABLED process.
      
      Why? His program has the code of similar to the following.
      
      	...
      	set_oom_adj(OOM_DISABLE); /* The job scheduler never killed by oom */
      	...
      	if (vfork() == 0) {
      		set_oom_adj(0); /* Invoked child can be killed */
      		execve("foo-bar-cmd");
      	}
      	....
      
      vfork() parent and child are shared the same mm_struct.  then above
      set_oom_adj(0) doesn't only change oom_adj for vfork() child, it's also
      change oom_adj for vfork() parent.  Then, vfork() parent (job scheduler)
      lost OOM immune and it was killed.
      
      Actually, fork-setting-exec idiom is very frequently used in userland program.
      We must not break this assumption.
      
      Then, this patch revert commit 2ff05b2b and related commit.
      
      Reverted commit list
      ---------------------
      - commit 2ff05b2b (oom: move oom_adj value from task_struct to mm_struct)
      - commit 4d8b9135 (oom: avoid unnecessary mm locking and scanning for OOM_DISABLE)
      - commit 81236810 (oom: only oom kill exiting tasks with attached memory)
      - commit 933b787b
      
       (mm: copy over oom_adj value at fork time)
      Signed-off-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Cc: Paul Menage <menage@google.com>
      Cc: David Rientjes <rientjes@google.com>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Nick Piggin <npiggin@suse.de>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      0753ba01
  17. 17 Aug, 2009 1 commit
  18. 16 Aug, 2009 4 commits