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authorLinus Torvalds <torvalds@linux-foundation.org>2012-05-22 06:25:14 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-22 06:25:14 +0400
commit5ec29e3149d800e6db83c1b6ff441daf319cbbe2 (patch)
treeb23ecaff7078590215e91b2b6aa4c90c2d923e10 /arch/x86
parentabd209b7083b2f3a2a19e522f688e7569f284e5d (diff)
parent6ff968cca1dfebd4b6fcade87c11658dbfc96932 (diff)
downloadlinux-5ec29e3149d800e6db83c1b6ff441daf319cbbe2.tar.xz
Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core locking updates from Ingo Molnar: "This update: - extends and simplifies x86 NMI callback handling code to enhance and fix the HP hw-watchdog driver - simplifies the x86 NMI callback handling code to fix a kmemcheck bug. - enhances the hung-task debugger" * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/nmi: Fix the type of the nmiaction.flags field x86/nmi: Fix page faults by nmiaction if kmemcheck is enabled x86/nmi: Add new NMI queues to deal with IO_CHK and SERR watchdog, hpwdt: Remove priority option for NMI callback hung task debugging: Inject NMI when hung and going to panic
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/include/asm/nmi.h22
-rw-r--r--arch/x86/kernel/nmi.c83
2 files changed, 44 insertions, 61 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());