1. 13 Feb, 2017 1 commit
    • Mike Galbraith's avatar
      tick/broadcast: Prevent deadlock on tick_broadcast_lock · 202461e2
      Mike Galbraith authored
      tick_broadcast_lock is taken from interrupt context, but the following call
      chain takes the lock without disabling interrupts:
      
      [   12.703736]  _raw_spin_lock+0x3b/0x50
      [   12.703738]  tick_broadcast_control+0x5a/0x1a0
      [   12.703742]  intel_idle_cpu_online+0x22/0x100
      [   12.703744]  cpuhp_invoke_callback+0x245/0x9d0
      [   12.703752]  cpuhp_thread_fun+0x52/0x110
      [   12.703754]  smpboot_thread_fn+0x276/0x320
      
      So the following deadlock can happen:
      
         lock(tick_broadcast_lock);
         <Interrupt>
            lock(tick_broadcast_lock);
      
      intel_idle_cpu_online() is the only place which violates the calling
      convention of tick_broadcast_control(). This was caused by the removal of
      the smp function call in course of the cpu hotplug rework.
      
      Instead of slapping local_irq_disable/enable() at the call site, we can
      relax the calling convention and handle it in the core code, which makes
      the whole machinery more robust.
      
      Fixes: 29d7bbad ("intel_idle: Remove superfluous SMP fuction call")
      Reported-by: default avatarGabriel C <nix.or.die@gmail.com>
      Signed-off-by: default avatarMike Galbraith <efault@gmx.de>
      Cc: Ruslan Ruslichenko <rruslich@cisco.com>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Greg KH <gregkh@linuxfoundation.org>
      Cc: Borislav Petkov <bp@alien8.de>
      Cc: lwn@lwn.net
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
      Cc: Sebastian Siewior <bigeasy@linutronix.de>
      Cc: stable <stable@vger.kernel.org>
      Link: http://lkml.kernel.org/r/1486953115.5912.4.camel@gmx.deSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      202461e2
  2. 12 Feb, 2017 1 commit
  3. 11 Feb, 2017 8 commits
  4. 10 Feb, 2017 25 commits
  5. 09 Feb, 2017 5 commits