4 files changed, 71 insertions, 84 deletions

diff --git a/arch/x86/include/asm/nmi.h b/arch/x86/include/asm/nmi.h
index fd3f9f18cf3f..0e3793b821ef 100644
--- a/arch/x86/include/asm/nmi.h
+++ b/arch/x86/include/asm/nmi.h
@@ -27,6 +27,8 @@ void arch_trigger_all_cpu_backtrace(void);
 enum {
         NMI_LOCAL=0,
         NMI_UNKNOWN,
+        NMI_SERR,
+        NMI_IO_CHECK,
         NMI_MAX
 };
 
@@ -35,8 +37,24 @@ enum {
 
 typedef int (*nmi_handler_t)(unsigned int, struct pt_regs *);
 
-int register_nmi_handler(unsigned int, nmi_handler_t, unsigned long,
-                         const char *);
+struct nmiaction {
+        struct list_head        list;
+        nmi_handler_t           handler;
+        unsigned long           flags;
+        const char              *name;
+};
+
+#define register_nmi_handler(t, fn, fg, n)              \
+({                                                      \
+        static struct nmiaction fn##_na = {             \
+                .handler = (fn),                        \
+                .name = (n),                            \
+                .flags = (fg),                          \
+        };                                              \
+        __register_nmi_handler((t), &fn##_na);  \
+})
+
+int __register_nmi_handler(unsigned int, struct nmiaction *);
 
 void unregister_nmi_handler(unsigned int, const char *);
 
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 47acaf319165..585be4bd71a5 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -31,14 +31,6 @@
 #include <asm/nmi.h>
 #include <asm/x86_init.h>
 
-#define NMI_MAX_NAMELEN 16
-struct nmiaction {
-        struct list_head list;
-        nmi_handler_t handler;
-        unsigned int flags;
-        char *name;
-};
-
 struct nmi_desc {
         spinlock_t lock;
         struct list_head head;
@@ -54,6 +46,14 @@ static struct nmi_desc nmi_desc[NMI_MAX] =
                 .lock = __SPIN_LOCK_UNLOCKED(&nmi_desc[1].lock),
                 .head = LIST_HEAD_INIT(nmi_desc[1].head),
         },
+        {
+                .lock = __SPIN_LOCK_UNLOCKED(&nmi_desc[2].lock),
+                .head = LIST_HEAD_INIT(nmi_desc[2].head),
+        },
+        {
+                .lock = __SPIN_LOCK_UNLOCKED(&nmi_desc[3].lock),
+                .head = LIST_HEAD_INIT(nmi_desc[3].head),
+        },
 
 };
 
@@ -107,11 +107,14 @@ static int notrace __kprobes nmi_handle(unsigned int type, struct pt_regs *regs,
         return handled;
 }
 
-static int __setup_nmi(unsigned int type, struct nmiaction *action)
+int __register_nmi_handler(unsigned int type, struct nmiaction *action)
 {
         struct nmi_desc *desc = nmi_to_desc(type);
         unsigned long flags;
 
+        if (!action->handler)
+                return -EINVAL;
+
         spin_lock_irqsave(&desc->lock, flags);
 
         /*
@@ -120,6 +123,8 @@ static int __setup_nmi(unsigned int type, struct nmiaction *action)
          * to manage expectations
          */
         WARN_ON_ONCE(type == NMI_UNKNOWN && !list_empty(&desc->head));
+        WARN_ON_ONCE(type == NMI_SERR && !list_empty(&desc->head));
+        WARN_ON_ONCE(type == NMI_IO_CHECK && !list_empty(&desc->head));
 
         /*
          * some handlers need to be executed first otherwise a fake
@@ -133,8 +138,9 @@ static int __setup_nmi(unsigned int type, struct nmiaction *action)
         spin_unlock_irqrestore(&desc->lock, flags);
         return 0;
 }
+EXPORT_SYMBOL(__register_nmi_handler);
 
-static struct nmiaction *__free_nmi(unsigned int type, const char *name)
+void unregister_nmi_handler(unsigned int type, const char *name)
 {
         struct nmi_desc *desc = nmi_to_desc(type);
         struct nmiaction *n;
@@ -157,61 +163,16 @@ static struct nmiaction *__free_nmi(unsigned int type, const char *name)
 
         spin_unlock_irqrestore(&desc->lock, flags);
         synchronize_rcu();
-        return (n);
 }
-
-int register_nmi_handler(unsigned int type, nmi_handler_t handler,
-                        unsigned long nmiflags, const char *devname)
-{
-        struct nmiaction *action;
-        int retval = -ENOMEM;
-
-        if (!handler)
-                return -EINVAL;
-
-        action = kzalloc(sizeof(struct nmiaction), GFP_KERNEL);
-        if (!action)
-                goto fail_action;
-
-        action->handler = handler;
-        action->flags = nmiflags;
-        action->name = kstrndup(devname, NMI_MAX_NAMELEN, GFP_KERNEL);
-        if (!action->name)
-                goto fail_action_name;
-
-        retval = __setup_nmi(type, action);
-
-        if (retval)
-                goto fail_setup_nmi;
-
-        return retval;
-
-fail_setup_nmi:
-        kfree(action->name);
-fail_action_name:
-        kfree(action);
-fail_action:    
-
-        return retval;
-}
-EXPORT_SYMBOL_GPL(register_nmi_handler);
-
-void unregister_nmi_handler(unsigned int type, const char *name)
-{
-        struct nmiaction *a;
-
-        a = __free_nmi(type, name);
-        if (a) {
-                kfree(a->name);
-                kfree(a);
-        }
-}
-
 EXPORT_SYMBOL_GPL(unregister_nmi_handler);
 
 static notrace __kprobes void
 pci_serr_error(unsigned char reason, struct pt_regs *regs)
 {
+        /* check to see if anyone registered against these types of errors */
+        if (nmi_handle(NMI_SERR, regs, false))
+                return;
+
         pr_emerg("NMI: PCI system error (SERR) for reason %02x on CPU %d.\n",
                  reason, smp_processor_id());
 
@@ -241,6 +202,10 @@ io_check_error(unsigned char reason, struct pt_regs *regs)
 {
         unsigned long i;
 
+        /* check to see if anyone registered against these types of errors */
+        if (nmi_handle(NMI_IO_CHECK, regs, false))
+                return;
+
         pr_emerg(
         "NMI: IOCK error (debug interrupt?) for reason %02x on CPU %d.\n",
                  reason, smp_processor_id());
diff --git a/drivers/watchdog/hpwdt.c b/drivers/watchdog/hpwdt.c
index 9f13b897fd64..23885f2d56a0 100644
--- a/drivers/watchdog/hpwdt.c
+++ b/drivers/watchdog/hpwdt.c
@@ -147,7 +147,6 @@ struct cmn_registers {
 
 static unsigned int hpwdt_nmi_decoding;
 static unsigned int allow_kdump;
-static unsigned int priority;           /* hpwdt at end of die_notify list */
 static unsigned int is_icru;
 static DEFINE_SPINLOCK(rom_lock);
 static void *cru_rom_addr;
@@ -723,28 +722,35 @@ static int __devinit hpwdt_init_nmi_decoding(struct pci_dev *dev)
         }
 
         /*
-         * If the priority is set to 1, then we will be put first on the
-         * die notify list to handle a critical NMI. The default is to
-         * be last so other users of the NMI signal can function.
+         * Only one function can register for NMI_UNKNOWN
          */
-        retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout,
-                                        (priority) ? NMI_FLAG_FIRST : 0,
-                                        "hpwdt");
-        if (retval != 0) {
-                dev_warn(&dev->dev,
-                        "Unable to register a die notifier (err=%d).\n",
-                        retval);
-                if (cru_rom_addr)
-                        iounmap(cru_rom_addr);
-        }
+        retval = register_nmi_handler(NMI_UNKNOWN, hpwdt_pretimeout, 0, "hpwdt");
+        if (retval)
+                goto error;
+        retval = register_nmi_handler(NMI_SERR, hpwdt_pretimeout, 0, "hpwdt");
+        if (retval)
+                goto error1;
+        retval = register_nmi_handler(NMI_IO_CHECK, hpwdt_pretimeout, 0, "hpwdt");
+        if (retval)
+                goto error2;
 
         dev_info(&dev->dev,
                         "HP Watchdog Timer Driver: NMI decoding initialized"
-                        ", allow kernel dump: %s (default = 0/OFF)"
-                        ", priority: %s (default = 0/LAST).\n",
-                        (allow_kdump == 0) ? "OFF" : "ON",
-                        (priority == 0) ? "LAST" : "FIRST");
+                        ", allow kernel dump: %s (default = 0/OFF)\n",
+                        (allow_kdump == 0) ? "OFF" : "ON");
         return 0;
+
+error2:
+        unregister_nmi_handler(NMI_SERR, "hpwdt");
+error1:
+        unregister_nmi_handler(NMI_UNKNOWN, "hpwdt");
+error:
+        dev_warn(&dev->dev,
+                "Unable to register a die notifier (err=%d).\n",
+                retval);
+        if (cru_rom_addr)
+                iounmap(cru_rom_addr);
+        return retval;
 }
 
 static void hpwdt_exit_nmi_decoding(void)
@@ -881,10 +887,6 @@ MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 #ifdef CONFIG_HPWDT_NMI_DECODING
 module_param(allow_kdump, int, 0);
 MODULE_PARM_DESC(allow_kdump, "Start a kernel dump after NMI occurs");
-
-module_param(priority, int, 0);
-MODULE_PARM_DESC(priority, "The hpwdt driver handles NMIs first or last"
-                " (default = 0/Last)\n");
 #endif /* !CONFIG_HPWDT_NMI_DECODING */
 
 module_init(hpwdt_init);
diff --git a/kernel/hung_task.c b/kernel/hung_task.c
index c21449f85a2a..6df614912b9d 100644
--- a/kernel/hung_task.c
+++ b/kernel/hung_task.c
@@ -108,8 +108,10 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout)
 
         touch_nmi_watchdog();
 
-        if (sysctl_hung_task_panic)
+        if (sysctl_hung_task_panic) {
+                trigger_all_cpu_backtrace();
                 panic("hung_task: blocked tasks");
+        }
 }
 
 /*