1. 22 Feb, 2011 1 commit
  2. 21 Feb, 2011 1 commit
  3. 17 Feb, 2011 14 commits
  4. 16 Feb, 2011 5 commits
  5. 15 Feb, 2011 7 commits
  6. 14 Feb, 2011 8 commits
  7. 12 Feb, 2011 1 commit
  8. 11 Feb, 2011 3 commits
    • Peter Zijlstra's avatar
      x86: Fix text_poke_smp_batch() deadlock · d91309f6
      Peter Zijlstra authored
      
      
      Fix this deadlock - we are already holding the mutex:
      
      =======================================================
      [ INFO: possible circular locking dependency detected ] 2.6.38-rc4-test+ #1
      -------------------------------------------------------
      bash/1850 is trying to acquire lock:
       (text_mutex){+.+.+.}, at: [<ffffffff8100a9c1>] return_to_handler+0x0/0x2f
      
      but task is already holding lock:
       (smp_alt){+.+...}, at: [<ffffffff8100a9c1>] return_to_handler+0x0/0x2f
      
      which lock already depends on the new lock.
      
      the existing dependency chain (in reverse order) is:
      
      -> #2 (smp_alt){+.+...}:
             [<ffffffff81082d02>] lock_acquire+0xcd/0xf8
             [<ffffffff8192e119>] __mutex_lock_common+0x4c/0x339
             [<ffffffff8192e4ca>] mutex_lock_nested+0x3e/0x43
             [<ffffffff8101050f>] alternatives_smp_switch+0x77/0x1d8
             [<ffffffff81926a6f>] do_boot_cpu+0xd7/0x762
             [<ffffffff819277dd>] native_cpu_up+0xe6/0x16a
             [<ffffffff81928e28>] _cpu_up+0x9d/0xee
             [<ffffffff81928f4c>] cpu_up+0xd3/0xe7
             [<ffffffff82268d4b>] kernel_init+0xe8/0x20a
             [<ffffffff8100ba24>] kernel_thread_helper+0x4/0x10
      
      -> #1 (cpu_hotplug.lock){+.+.+.}:
             [<ffffffff81082d02>] lock_acquire+0xcd/0xf8
             [<ffffffff8192e119>] __mutex_lock_common+0x4c/0x339
             [<ffffffff8192e4ca>] mutex_lock_nested+0x3e/0x43
             [<ffffffff810568cc>] get_online_cpus+0x41/0x55
             [<ffffffff810a1348>] stop_machine+0x1e/0x3e
             [<ffffffff819314c1>] text_poke_smp_batch+0x3a/0x3c
             [<ffffffff81932b6c>] arch_optimize_kprobes+0x10d/0x11c
             [<ffffffff81933a51>] kprobe_optimizer+0x152/0x222
             [<ffffffff8106bb71>] process_one_work+0x1d3/0x335
             [<ffffffff8106cfae>] worker_thread+0x104/0x1a4
             [<ffffffff810707c4>] kthread+0x9d/0xa5
             [<ffffffff8100ba24>] kernel_thread_helper+0x4/0x10
      
      -> #0 (text_mutex){+.+.+.}:
      
      other info that might help us debug this:
      
      6 locks held by bash/1850:
       #0:  (&buffer->mutex){+.+.+.}, at: [<ffffffff8100a9c1>] return_to_handler+0x0/0x2f
       #1:  (s_active#75){.+.+.+}, at: [<ffffffff8100a9c1>] return_to_handler+0x0/0x2f
       #2:  (x86_cpu_hotplug_driver_mutex){+.+.+.}, at: [<ffffffff8100a9c1>] return_to_handler+0x0/0x2f
       #3:  (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff8100a9c1>] return_to_handler+0x0/0x2f
       #4:  (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff8100a9c1>] return_to_handler+0x0/0x2f
       #5:  (smp_alt){+.+...}, at: [<ffffffff8100a9c1>] return_to_handler+0x0/0x2f
      
      stack backtrace:
      Pid: 1850, comm: bash Not tainted 2.6.38-rc4-test+ #1
      Call Trace:
      
       [<ffffffff81080eb2>] print_circular_bug+0xa8/0xb7
       [<ffffffff8192e4ca>] mutex_lock_nested+0x3e/0x43
       [<ffffffff81010302>] alternatives_smp_unlock+0x3d/0x93
       [<ffffffff81010630>] alternatives_smp_switch+0x198/0x1d8
       [<ffffffff8102568a>] native_cpu_die+0x65/0x95
       [<ffffffff818cc4ec>] _cpu_down+0x13e/0x202
       [<ffffffff8117a619>] sysfs_write_file+0x108/0x144
       [<ffffffff8111f5a2>] vfs_write+0xac/0xff
       [<ffffffff8111f7a9>] sys_write+0x4a/0x6e
      Reported-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Tested-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: mathieu.desnoyers@efficios.com
      Cc: rusty@rustcorp.com.au
      Cc: ananth@in.ibm.com
      Cc: masami.hiramatsu.pt@hitachi.com
      Cc: fweisbec@gmail.com
      Cc: jbeulich@novell.com
      Cc: jbaron@redhat.com
      Cc: mhiramat@redhat.com
      LKML-Reference: <1297458466.5226.93.camel@laptop>
      Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
      d91309f6
    • Will Deacon's avatar
      ARM: 6657/1: hw_breakpoint: fix ptrace breakpoint advertising on unsupported arch · 66e1cfe6
      Will Deacon authored
      
      
      The ptrace debug information register was advertising breakpoint and
      watchpoint resources for unsupported debug architectures. This meant
      that setting breakpoints on these architectures would appear to succeed,
      although they would never fire in reality.
      
      This patch fixes the breakpoint slot probing so that it returns 0 when
      running on an unsupported debug architecture.
      Reported-by: default avatarUlrich Weigand <ulrich.weigand@de.ibm.com>
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      66e1cfe6
    • Will Deacon's avatar
      ARM: 6656/1: hw_breakpoint: avoid UNPREDICTABLE behaviour when reading DBGDSCR · ed19b739
      Will Deacon authored
      
      
      Reading baseline CP14 registers, other than DBGDIDR, when the OS Lock
      is set leads to UNPREDICTABLE behaviour.
      
      This patch ensures that we clear the OS lock before accessing anything
      other than the DBGDIDR, thereby avoiding this behaviour.
      Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
      Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
      ed19b739