• Vishal Verma's avatar
    x86/mce: Make the MCE notifier a blocking one · 0dc9c639
    Vishal Verma authored
    The NFIT MCE handler callback (for handling media errors on NVDIMMs)
    takes a mutex to add the location of a memory error to a list. But since
    the notifier call chain for machine checks (x86_mce_decoder_chain) is
    atomic, we get a lockdep splat like:
    
      BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
      in_atomic(): 1, irqs_disabled(): 0, pid: 4, name: kworker/0:0
      [..]
      Call Trace:
       dump_stack
       ___might_sleep
       __might_sleep
       mutex_lock_nested
       ? __lock_acquire
       nfit_handle_mce
       notifier_call_chain
       atomic_notifier_call_chain
       ? atomic_notifier_call_chain
       mce_gen_pool_process
    
    Convert the notifier to a blocking one which gets to run only in process
    context.
    
    Boris: remove the notifier call in atomic context in print_mce(). For
    now, let's print the MCE on the atomic path so that we can make sure
    they go out and get logged at least.
    
    Fixes: 6839a6d9 ("nfit: do an ARS scrub on hitting a latent media error")
    Reported-by: default avatarRoss Zwisler <ross.zwisler@linux.intel.com>
    Signed-off-by: default avatarVishal Verma <vishal.l.verma@intel.com>
    Acked-by: default avatarTony Luck <tony.luck@intel.com>
    Cc: Dan Williams <dan.j.williams@intel.com>
    Cc: linux-edac <linux-edac@vger.kernel.org>
    Cc: x86-ml <x86@kernel.org>
    Cc: <stable@vger.kernel.org>
    Link: http://lkml.kernel.org/r/20170411224457.24777-1-vishal.l.verma@intel.comSigned-off-by: default avatarBorislav Petkov <bp@suse.de>
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    0dc9c639
mce-genpool.c 3.28 KB