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-rw-r--r--arch/x86/include/asm/nmi.h22
-rw-r--r--arch/x86/kernel/nmi.c83
-rw-r--r--drivers/watchdog/hpwdt.c46
-rw-r--r--kernel/hung_task.c4
4 files changed, 71 insertions, 84 deletions
diff --git a/arch/x86/include/asm/nmi.h b/arch/x86/include/asm/nmi.h
index fd3f9f18cf3..0e3793b821e 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 47acaf31916..585be4bd71a 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 9f13b897fd6..23885f2d56a 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 c21449f85a2..6df614912b9 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");
+ }
}
/*