From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758438Ab2EUUOp (ORCPT ); Mon, 21 May 2012 16:14:45 -0400 Received: from mail-wg0-f44.google.com ([74.125.82.44]:60984 "EHLO mail-wg0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758297Ab2EUUOn (ORCPT ); Mon, 21 May 2012 16:14:43 -0400 Date: Mon, 21 May 2012 22:14:38 +0200 From: Ingo Molnar To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, Thomas Gleixner , Peter Zijlstra , Andrew Morton Subject: [GIT PULL] core/locking changes for v3.5 Message-ID: <20120521201438.GA9270@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus, Please pull the latest core-locking-for-linus git tree from: git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core-locking-for-linus HEAD: 6ff968cca1dfebd4b6fcade87c11658dbfc96932 x86/nmi: Fix the type of the nmiaction.flags field 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 Thanks, Ingo ------------------> Betty Dall (1): x86/nmi: Fix the type of the nmiaction.flags field Don Zickus (2): watchdog, hpwdt: Remove priority option for NMI callback x86/nmi: Add new NMI queues to deal with IO_CHK and SERR Li Zhong (1): x86/nmi: Fix page faults by nmiaction if kmemcheck is enabled Sasha Levin (1): hung task debugging: Inject NMI when hung and going to panic arch/x86/include/asm/nmi.h | 22 ++++++++++- arch/x86/kernel/nmi.c | 83 +++++++++++++------------------------------- drivers/watchdog/hpwdt.c | 46 +++++++++++++------------ kernel/hung_task.c | 4 ++- 4 files changed, 71 insertions(+), 84 deletions(-) diff --git a/arch/x86/include/asm/nmi.h b/arch/x86/include/asm/nmi.h index fd3f9f1..0e3793b 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 47acaf3..585be4b 100644 --- a/arch/x86/kernel/nmi.c +++ b/arch/x86/kernel/nmi.c @@ -31,14 +31,6 @@ #include #include -#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 cbc7cee..6e414b5 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 c21449f..6df6149 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"); + } } /*