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  1. 15 Aug, 2010 15 commits
  3. 08 Aug, 2010 3 commits
  5. 07 Aug, 2010 1 commit
    • Rafael J. Wysocki's avatar
      ACPI / ACPICA: Fix reference counting problems with GPE handlers · 28f4f8a9
      Rafael J. Wysocki authored 
      If a handler is installed for a GPE associated with an AML method and
such that it cannot wake up the system from sleep states, the GPE
remains enabled after the handler has been installed, although it
should be disabled in that case to avoid spurious execution of the
handler.

Fix this issue by making acpi_install_gpe_handler() disable GPEs
that were previously associated with AML methods and cannot wake up
the system from sleep states.

Analogously, make acpi_remove_gpe_handler() enable the GPEs that
are associated with AML methods after their handlers have been
removed and cannot wake up the system from sleep states.  In addition
to that, fix a code ordering issue in acpi_remove_gpe_handler() that
renders the locking ineffective (ACPI_MTX_EVENTS is released
temporarily in the middle of the routine to wait for the completion
of events already in progress).

For this purpose introduce acpi_raw_disable_gpe() and
acpi_raw_enable_gpe() to be called with acpi_gbl_gpe_lock held
and rework acpi_disable_gpe() and acpi_enable_gpe(), respectively, to
use them.  Also rework acpi_gpe_can_wake() to use
acpi_raw_disable_gpe() instead of calling acpi_disable_gpe() after
releasing the lock to avoid the possible theoretical race with
acpi_install_gpe_handler().
Signed-off-by: default avatarRafael J. Wysocki <rjw@sisk.pl>
Cc: "Moore, Robert" <robert.moore@intel.com>
Cc: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: default avatarLen Brown <len.brown@intel.com>
      28f4f8a9
  7. 01 Aug, 2010 2 commits
  9. 31 Jul, 2010 5 commits
  11. 30 Jul, 2010 8 commits
  13. 29 Jul, 2010 6 commits
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6 · a2dccdb2
      Linus Torvalds authored 
      * 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
  [S390] etr: fix clock synchronization race
  [S390] Fix IRQ tracing in case of PER
      a2dccdb2
    • Linus Torvalds's avatar
      Merge git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog · 7d5fcdc3
      Linus Torvalds authored 
      * git://git.kernel.org/pub/scm/linux/kernel/git/wim/linux-2.6-watchdog:
  watchdog: update MAINTAINERS entry
      7d5fcdc3
    • Linus Torvalds's avatar
      Merge branch 'fix/hda' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6 · e271e872
      Linus Torvalds authored 
      * 'fix/hda' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  ALSA: hda - Add a PC-beep workaround for ASUS P5-V
  ALSA: hda - Assume PC-beep as default for Realtek
  ALSA: hda - Don't register beep input device when no beep is available
  ALSA: hda - Fix pin-detection of Nvidia HDMI
      e271e872
    • David Howells's avatar
      CRED: Fix __task_cred()'s lockdep check and banner comment · 8f92054e
      David Howells authored 
      Fix __task_cred()'s lockdep check by removing the following validation
condition:

	lockdep_tasklist_lock_is_held()

as commit_creds() does not take the tasklist_lock, and nor do most of the
functions that call it, so this check is pointless and it can prevent
detection of the RCU lock not being held if the tasklist_lock is held.

Instead, add the following validation condition:

	task->exit_state >= 0

to permit the access if the target task is dead and therefore unable to change
its own credentials.

Fix __task_cred()'s comment to:

 (1) discard the bit that says that the caller must prevent the target task
     from being deleted.  That shouldn't need saying.

 (2) Add a comment indicating the result of __task_cred() should not be passed
     directly to get_cred(), but rather than get_task_cred() should be used
     instead.

Also put a note into the documentation to enforce this point there too.
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarJiri Olsa <jolsa@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      8f92054e
    • David Howells's avatar
      CRED: Fix get_task_cred() and task_state() to not resurrect dead credentials · de09a977
      David Howells authored 
      It's possible for get_task_cred() as it currently stands to 'corrupt' a set of
credentials by incrementing their usage count after their replacement by the
task being accessed.

What happens is that get_task_cred() can race with commit_creds():

	TASK_1			TASK_2			RCU_CLEANER
	-->get_task_cred(TASK_2)
	rcu_read_lock()
	__cred = __task_cred(TASK_2)
				-->commit_creds()
				old_cred = TASK_2->real_cred
				TASK_2->real_cred = ...
				put_cred(old_cred)
				  call_rcu(old_cred)
		[__cred->usage == 0]
	get_cred(__cred)
		[__cred->usage == 1]
	rcu_read_unlock()
							-->put_cred_rcu()
							[__cred->usage == 1]
							panic()

However, since a tasks credentials are generally not changed very often, we can
reasonably make use of a loop involving reading the creds pointer and using
atomic_inc_not_zero() to attempt to increment it if it hasn't already hit zero.

If successful, we can safely return the credentials in the knowledge that, even
if the task we're accessing has released them, they haven't gone to the RCU
cleanup code.

We then change task_state() in procfs to use get_task_cred() rather than
calling get_cred() on the result of __task_cred(), as that suffers from the
same problem.

Without this change, a BUG_ON in __put_cred() or in put_cred_rcu() can be
tripped when it is noticed that the usage count is not zero as it ought to be,
for example:

kernel BUG at kernel/cred.c:168!
invalid opcode: 0000 [#1] SMP
last sysfs file: /sys/kernel/mm/ksm/run
CPU 0
Pid: 2436, comm: master Not tainted 2.6.33.3-85.fc13.x86_64 #1 0HR330/OptiPlex
745
RIP: 0010:[<ffffffff81069881>]  [<ffffffff81069881>] __put_cred+0xc/0x45
RSP: 0018:ffff88019e7e9eb8  EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffff880161514480 RCX: 00000000ffffffff
RDX: 00000000ffffffff RSI: ffff880140c690c0 RDI: ffff880140c690c0
RBP: ffff88019e7e9eb8 R08: 00000000000000d0 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000040 R12: ffff880140c690c0
R13: ffff88019e77aea0 R14: 00007fff336b0a5c R15: 0000000000000001
FS:  00007f12f50d97c0(0000) GS:ffff880007400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8f461bc000 CR3: 00000001b26ce000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process master (pid: 2436, threadinfo ffff88019e7e8000, task ffff88019e77aea0)
Stack:
 ffff88019e7e9ec8 ffffffff810698cd ffff88019e7e9ef8 ffffffff81069b45
<0> ffff880161514180 ffff880161514480 ffff880161514180 0000000000000000
<0> ffff88019e7e9f28 ffffffff8106aace 0000000000000001 0000000000000246
Call Trace:
 [<ffffffff810698cd>] put_cred+0x13/0x15
 [<ffffffff81069b45>] commit_creds+0x16b/0x175
 [<ffffffff8106aace>] set_current_groups+0x47/0x4e
 [<ffffffff8106ac89>] sys_setgroups+0xf6/0x105
 [<ffffffff81009b02>] system_call_fastpath+0x16/0x1b
Code: 48 8d 71 ff e8 7e 4e 15 00 85 c0 78 0b 8b 75 ec 48 89 df e8 ef 4a 15 00
48 83 c4 18 5b c9 c3 55 8b 07 8b 07 48 89 e5 85 c0 74 04 <0f> 0b eb fe 65 48 8b
04 25 00 cc 00 00 48 3b b8 58 04 00 00 75
RIP  [<ffffffff81069881>] __put_cred+0xc/0x45
 RSP <ffff88019e7e9eb8>
---[ end trace df391256a100ebdd ]---
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Acked-by: default avatarJiri Olsa <jolsa@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      de09a977
    • Wim Van Sebroeck's avatar
      watchdog: update MAINTAINERS entry · 230a5cef
      Wim Van Sebroeck authored 
      Add Mailing-list and website to watchdog MAINTAINERS entry.
Signed-off-by: default avatarWim Van Sebroeck <wim@iguana.be>
      230a5cef
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