[GIT pull] ras fix for 4.11

[Thomas Gleixner]

Linus,

please pull the latest ras-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 
ras-urgent-for-linus

The MCE atomic notifier callchain invokes callbacks which might
sleep. Convert it to a blocking notifier and prevent calls from atomic
context.

Thanks,

        tglx

------------------>
Vishal Verma (1):
      x86/mce: Make the MCE notifier a blocking one


 arch/x86/kernel/cpu/mcheck/mce-genpool.c  |  2 +-
 arch/x86/kernel/cpu/mcheck/mce-internal.h |  2 +-
 arch/x86/kernel/cpu/mcheck/mce.c          | 17 +++--------------
 3 files changed, 5 insertions(+), 16 deletions(-)

diff --git a/arch/x86/kernel/cpu/mcheck/mce-genpool.c 
b/arch/x86/kernel/cpu/mcheck/mce-genpool.c
index 1e5a50c11d3c..217cd4449bc9 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-genpool.c
+++ b/arch/x86/kernel/cpu/mcheck/mce-genpool.c
@@ -85,7 +85,7 @@ void mce_gen_pool_process(struct work_struct *__unused)
        head = llist_reverse_order(head);
        llist_for_each_entry_safe(node, tmp, head, llnode) {
                mce = &node->mce;
-               atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, mce);
+               blocking_notifier_call_chain(&x86_mce_decoder_chain, 0, mce);
                gen_pool_free(mce_evt_pool, (unsigned long)node, sizeof(*node));
        }
 }
diff --git a/arch/x86/kernel/cpu/mcheck/mce-internal.h 
b/arch/x86/kernel/cpu/mcheck/mce-internal.h
index 903043e6a62b..19592ba1a320 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-internal.h
+++ b/arch/x86/kernel/cpu/mcheck/mce-internal.h
@@ -13,7 +13,7 @@ enum severity_level {
        MCE_PANIC_SEVERITY,
 };
 
-extern struct atomic_notifier_head x86_mce_decoder_chain;
+extern struct blocking_notifier_head x86_mce_decoder_chain;
 
 #define ATTR_LEN               16
 #define INITIAL_CHECK_INTERVAL 5 * 60 /* 5 minutes */
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 5accfbdee3f0..af44ebeb593f 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -123,7 +123,7 @@ static void (*quirk_no_way_out)(int bank, struct mce *m, 
struct pt_regs *regs);
  * CPU/chipset specific EDAC code can register a notifier call here to print
  * MCE errors in a human-readable form.
  */
-ATOMIC_NOTIFIER_HEAD(x86_mce_decoder_chain);
+BLOCKING_NOTIFIER_HEAD(x86_mce_decoder_chain);
 
 /* Do initial initialization of a struct mce */
 void mce_setup(struct mce *m)
@@ -220,7 +220,7 @@ void mce_register_decode_chain(struct notifier_block *nb)
 
        WARN_ON(nb->priority > MCE_PRIO_LOWEST && nb->priority < MCE_PRIO_EDAC);
 
-       atomic_notifier_chain_register(&x86_mce_decoder_chain, nb);
+       blocking_notifier_chain_register(&x86_mce_decoder_chain, nb);
 }
 EXPORT_SYMBOL_GPL(mce_register_decode_chain);
 
@@ -228,7 +228,7 @@ void mce_unregister_decode_chain(struct notifier_block *nb)
 {
        atomic_dec(&num_notifiers);
 
-       atomic_notifier_chain_unregister(&x86_mce_decoder_chain, nb);
+       blocking_notifier_chain_unregister(&x86_mce_decoder_chain, nb);
 }
 EXPORT_SYMBOL_GPL(mce_unregister_decode_chain);
 
@@ -321,18 +321,7 @@ static void __print_mce(struct mce *m)
 
 static void print_mce(struct mce *m)
 {
-       int ret = 0;
-
        __print_mce(m);
-
-       /*
-        * Print out human-readable details about the MCE error,
-        * (if the CPU has an implementation for that)
-        */
-       ret = atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, m);
-       if (ret == NOTIFY_STOP)
-               return;
-
        pr_emerg_ratelimited(HW_ERR "Run the above through 'mcelog --ascii'\n");
 }