Commit ab531878 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull core debug changes from Ingo Molnar:
 "This contains mostly kernel debugging related updates:

   - make hung_task detection more configurable to distros
   - add final bits for x86 UV NMI debugging, with related KGDB changes
   - update the mailing-list of MAINTAINERS entries I'm involved with"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hung_task: Display every hung task warning
  sysctl: Add neg_one as a standard constraint
  x86/uv/nmi, kgdb/kdb: Fix UV NMI handler when KDB not configured
  x86/uv/nmi: Fix Sparse warnings
  kgdb/kdb: Fix no KDB config problem
  MAINTAINERS: Restore "L: linux-kernel@vger.kernel.org" entries
parents 14164b46 270750db

Documentation/sysctl/kernel.txt

+42 −0
Original line number Diff line number Diff line
@@ -33,6 +33,10 @@ show up in /proc/sys/kernel: 
- domainname

- hostname

- hotplug

- hung_task_panic

- hung_task_check_count

- hung_task_timeout_secs

- hung_task_warnings

- kexec_load_disabled

- kptr_restrict

- kstack_depth_to_print       [ X86 only ]
@@ -288,6 +292,44 @@ Default value is "/sbin/hotplug". 


==============================================================



hung_task_panic:



Controls the kernel's behavior when a hung task is detected.

This file shows up if CONFIG_DETECT_HUNG_TASK is enabled.



0: continue operation. This is the default behavior.



1: panic immediately.



==============================================================



hung_task_check_count:



The upper bound on the number of tasks that are checked.

This file shows up if CONFIG_DETECT_HUNG_TASK is enabled.



==============================================================



hung_task_timeout_secs:



Check interval. When a task in D state did not get scheduled

for more than this value report a warning.

This file shows up if CONFIG_DETECT_HUNG_TASK is enabled.



0: means infinite timeout - no checking done.



==============================================================



hung_task_warning:



The maximum number of warnings to report. During a check interval

When this value is reached, no more the warnings will be reported.

This file shows up if CONFIG_DETECT_HUNG_TASK is enabled.



-1: report an infinite number of warnings.



==============================================================



kexec_load_disabled:



A toggle indicating if the kexec_load syscall has been disabled. This

MAINTAINERS

+13 −0
Original line number Diff line number Diff line
@@ -2222,6 +2222,7 @@ F: include/linux/clk.h 
CLOCKSOURCE, CLOCKEVENT DRIVERS

M:	Daniel Lezcano <daniel.lezcano@linaro.org>

M:	Thomas Gleixner <tglx@linutronix.de>

L:	linux-kernel@vger.kernel.org

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/core

S:	Supported

F:	drivers/clocksource
@@ -4023,6 +4024,7 @@ F: include/uapi/linux/hid* 


HIGH-RESOLUTION TIMERS, CLOCKEVENTS, DYNTICKS

M:	Thomas Gleixner <tglx@linutronix.de>

L:	linux-kernel@vger.kernel.org

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/core

S:	Maintained

F:	Documentation/timers/
@@ -4694,6 +4696,7 @@ F: net/irda/ 


IRQ SUBSYSTEM

M:	Thomas Gleixner <tglx@linutronix.de>

L:	linux-kernel@vger.kernel.org

S:	Maintained

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git irq/core

F:	kernel/irq/
@@ -5325,6 +5328,7 @@ F: drivers/media/usb/dvb-usb-v2/lmedm04* 
LOCKDEP AND LOCKSTAT

M:	Peter Zijlstra <peterz@infradead.org>

M:	Ingo Molnar <mingo@redhat.com>

L:	linux-kernel@vger.kernel.org

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git core/locking

S:	Maintained

F:	Documentation/lockdep*.txt
@@ -6622,6 +6626,7 @@ M: Peter Zijlstra <a.p.zijlstra@chello.nl> 
M:	Paul Mackerras <paulus@samba.org>

M:	Ingo Molnar <mingo@redhat.com>

M:	Arnaldo Carvalho de Melo <acme@ghostprotocols.net>

L:	linux-kernel@vger.kernel.org

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git perf/core

S:	Supported

F:	kernel/events/*
@@ -6745,6 +6750,7 @@ F: drivers/scsi/pm8001/ 


POSIX CLOCKS and TIMERS

M:	Thomas Gleixner <tglx@linutronix.de>

L:	linux-kernel@vger.kernel.org

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/core

S:	Supported

F:	fs/timerfd.c
@@ -7153,6 +7159,7 @@ F: drivers/net/wireless/ray* 
RCUTORTURE MODULE

M:	Josh Triplett <josh@freedesktop.org>

M:	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

L:	linux-kernel@vger.kernel.org

S:	Supported

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git

F:	Documentation/RCU/torture.txt
@@ -7160,6 +7167,7 @@ F: kernel/rcu/torture.c 


RCUTORTURE TEST FRAMEWORK

M:	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

L:	linux-kernel@vger.kernel.org

S:	Supported

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git

F:	tools/testing/selftests/rcutorture
@@ -7183,6 +7191,7 @@ F: net/rds/ 
READ-COPY UPDATE (RCU)

M:	Dipankar Sarma <dipankar@in.ibm.com>

M:	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

L:	linux-kernel@vger.kernel.org

W:	http://www.rdrop.com/users/paulmck/RCU/

S:	Supported

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
@@ -7492,6 +7501,7 @@ F: drivers/mmc/host/dw_mmc* 
TIMEKEEPING, CLOCKSOURCE CORE, NTP

M:	John Stultz <john.stultz@linaro.org>

M:	Thomas Gleixner <tglx@linutronix.de>

L:	linux-kernel@vger.kernel.org

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/core

S:	Supported

F:	include/linux/clocksource.h
@@ -7517,6 +7527,7 @@ F: drivers/watchdog/sc1200wdt.c 
SCHEDULER

M:	Ingo Molnar <mingo@redhat.com>

M:	Peter Zijlstra <peterz@infradead.org>

L:	linux-kernel@vger.kernel.org

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched/core

S:	Maintained

F:	kernel/sched/
@@ -7884,6 +7895,7 @@ F: mm/sl?b.c 
SLEEPABLE READ-COPY UPDATE (SRCU)

M:	Lai Jiangshan <laijs@cn.fujitsu.com>

M:	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

L:	linux-kernel@vger.kernel.org

W:	http://www.rdrop.com/users/paulmck/RCU/

S:	Supported

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
@@ -9587,6 +9599,7 @@ M: Thomas Gleixner <tglx@linutronix.de> 
M:	Ingo Molnar <mingo@redhat.com>

M:	"H. Peter Anvin" <hpa@zytor.com>

M:	x86@kernel.org

L:	linux-kernel@vger.kernel.org

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/core

S:	Maintained

F:	Documentation/x86/

arch/x86/include/asm/uv/uv.h

+0 −2
Original line number Diff line number Diff line
@@ -12,7 +12,6 @@ extern enum uv_system_type get_uv_system_type(void); 
extern int is_uv_system(void);

extern void uv_cpu_init(void);

extern void uv_nmi_init(void);

extern void uv_register_nmi_notifier(void);

extern void uv_system_init(void);

extern const struct cpumask *uv_flush_tlb_others(const struct cpumask *cpumask,

						 struct mm_struct *mm,
@@ -26,7 +25,6 @@ static inline enum uv_system_type get_uv_system_type(void) { return UV_NONE; } 
static inline int is_uv_system(void)	{ return 0; }

static inline void uv_cpu_init(void)	{ }

static inline void uv_system_init(void)	{ }

static inline void uv_register_nmi_notifier(void) { }

static inline const struct cpumask *

uv_flush_tlb_others(const struct cpumask *cpumask, struct mm_struct *mm,

		    unsigned long start, unsigned long end, unsigned int cpu)

arch/x86/kernel/apic/x2apic_uv_x.c

+0 −1
Original line number Diff line number Diff line
@@ -980,7 +980,6 @@ void __init uv_system_init(void) 
	uv_nmi_setup();

	uv_cpu_init();

	uv_scir_register_cpu_notifier();

	uv_register_nmi_notifier();

	proc_mkdir("sgi_uv", NULL);



	/* register Legacy VGA I/O redirection handler */

arch/x86/platform/uv/uv_nmi.c

+46 −19
Original line number Diff line number Diff line
@@ -74,7 +74,6 @@ static atomic_t uv_in_nmi; 
static atomic_t uv_nmi_cpu = ATOMIC_INIT(-1);

static atomic_t uv_nmi_cpus_in_nmi = ATOMIC_INIT(-1);

static atomic_t uv_nmi_slave_continue;

static atomic_t uv_nmi_kexec_failed;

static cpumask_var_t uv_nmi_cpu_mask;



/* Values for uv_nmi_slave_continue */
@@ -149,7 +148,8 @@ module_param_named(retry_count, uv_nmi_retry_count, int, 0644); 
 *  "dump"	- dump process stack for each cpu

 *  "ips"	- dump IP info for each cpu

 *  "kdump"	- do crash dump

 *  "kdb"	- enter KDB/KGDB (default)

 *  "kdb"	- enter KDB (default)

 *  "kgdb"	- enter KGDB

 */

static char uv_nmi_action[8] = "kdb";

module_param_string(action, uv_nmi_action, sizeof(uv_nmi_action), 0644);
@@ -504,6 +504,7 @@ static void uv_nmi_touch_watchdogs(void) 
}



#if defined(CONFIG_KEXEC)

static atomic_t uv_nmi_kexec_failed;

static void uv_nmi_kdump(int cpu, int master, struct pt_regs *regs)

{

	/* Call crash to dump system state */
@@ -537,18 +538,45 @@ static inline void uv_nmi_kdump(int cpu, int master, struct pt_regs *regs) 
}

#endif /* !CONFIG_KEXEC */



#ifdef CONFIG_KGDB

#ifdef CONFIG_KGDB_KDB

/* Call KDB from NMI handler */

static void uv_call_kdb(int cpu, struct pt_regs *regs, int master)

static inline int uv_nmi_kdb_reason(void)

{

	int ret;

	return KDB_REASON_SYSTEM_NMI;

}

#else /* !CONFIG_KGDB_KDB */

static inline int uv_nmi_kdb_reason(void)

{

	/* Insure user is expecting to attach gdb remote */

	if (uv_nmi_action_is("kgdb"))

		return 0;



	pr_err("UV: NMI error: KDB is not enabled in this kernel\n");

	return -1;

}

#endif /* CONFIG_KGDB_KDB */



/*

 * Call KGDB/KDB from NMI handler

 *

 * Note that if both KGDB and KDB are configured, then the action of 'kgdb' or

 * 'kdb' has no affect on which is used.  See the KGDB documention for further

 * information.

 */

static void uv_call_kgdb_kdb(int cpu, struct pt_regs *regs, int master)

{

	if (master) {

		int reason = uv_nmi_kdb_reason();

		int ret;



		if (reason < 0)

			return;



		/* call KGDB NMI handler as MASTER */

		ret = kgdb_nmicallin(cpu, X86_TRAP_NMI, regs,

		ret = kgdb_nmicallin(cpu, X86_TRAP_NMI, regs, reason,

				&uv_nmi_slave_continue);

		if (ret) {

			pr_alert("KDB returned error, is kgdboc set?\n");

			pr_alert("KGDB returned error, is kgdboc set?\n");

			atomic_set(&uv_nmi_slave_continue, SLAVE_EXIT);

		}

	} else {
@@ -567,12 +595,12 @@ static void uv_call_kdb(int cpu, struct pt_regs *regs, int master) 
	uv_nmi_sync_exit(master);

}



#else /* !CONFIG_KGDB_KDB */

static inline void uv_call_kdb(int cpu, struct pt_regs *regs, int master)

#else /* !CONFIG_KGDB */

static inline void uv_call_kgdb_kdb(int cpu, struct pt_regs *regs, int master)

{

	pr_err("UV: NMI error: KGDB/KDB is not enabled in this kernel\n");

	pr_err("UV: NMI error: KGDB is not enabled in this kernel\n");

}

#endif /* !CONFIG_KGDB_KDB */

#endif /* !CONFIG_KGDB */



/*

 * UV NMI handler
@@ -606,9 +634,9 @@ int uv_handle_nmi(unsigned int reason, struct pt_regs *regs) 
	if (uv_nmi_action_is("ips") || uv_nmi_action_is("dump"))

		uv_nmi_dump_state(cpu, regs, master);



	/* Call KDB if enabled */

	else if (uv_nmi_action_is("kdb"))

		uv_call_kdb(cpu, regs, master);

	/* Call KGDB/KDB if enabled */

	else if (uv_nmi_action_is("kdb") || uv_nmi_action_is("kgdb"))

		uv_call_kgdb_kdb(cpu, regs, master);



	/* Clear per_cpu "in nmi" flag */

	atomic_set(&uv_cpu_nmi.state, UV_NMI_STATE_OUT);
@@ -634,7 +662,7 @@ int uv_handle_nmi(unsigned int reason, struct pt_regs *regs) 
/*

 * NMI handler for pulling in CPUs when perf events are grabbing our NMI

 */

int uv_handle_nmi_ping(unsigned int reason, struct pt_regs *regs)

static int uv_handle_nmi_ping(unsigned int reason, struct pt_regs *regs)

{

	int ret;
@@ -651,7 +679,7 @@ int uv_handle_nmi_ping(unsigned int reason, struct pt_regs *regs) 
	return ret;

}



void uv_register_nmi_notifier(void)

static void uv_register_nmi_notifier(void)

{

	if (register_nmi_handler(NMI_UNKNOWN, uv_handle_nmi, 0, "uv"))

		pr_warn("UV: NMI handler failed to register\n");
@@ -695,6 +723,5 @@ void uv_nmi_setup(void) 
		uv_hub_nmi_per(cpu) = uv_hub_nmi_list[nid];

	}

	BUG_ON(!alloc_cpumask_var(&uv_nmi_cpu_mask, GFP_KERNEL));

	uv_register_nmi_notifier();

}

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