1. 05 Aug, 2010 1 commit
  2. 04 Aug, 2010 2 commits
  3. 03 Aug, 2010 8 commits
  4. 02 Aug, 2010 1 commit
  5. 01 Aug, 2010 2 commits
  6. 31 Jul, 2010 5 commits
  7. 30 Jul, 2010 16 commits
  8. 29 Jul, 2010 5 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
    • 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