Commit 0328ecef authored by Daniel Gollub's avatar Daniel Gollub Committed by Linus Torvalds
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x86_64: Fix to keep watchdog disabled by default for i386/x86_64 

Fixed wrong expression which enabled watchdogs even if nmi_watchdog kernel
parameter wasn't set. This regression got slightly introduced with commit
b7471c6d.

Introduced NMI_DISABLED (-1) which allows to switch the value of NMI_DEFAULT
without breaking the APIC NMI watchdog code (again).

Fixes:
   https://bugzilla.novell.com/show_bug.cgi?id=298084
   http://bugzilla.kernel.org/show_bug.cgi?id=7839


And likely some more nmi_watchdog=0 related issues.

Signed-off-by: default avatarDaniel Gollub <dgollub@suse.de>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8154549c

arch/i386/kernel/apic.c

+1 −1
Original line number Diff line number Diff line
@@ -1085,7 +1085,7 @@ static int __init detect_init_APIC (void) 
	if (l & MSR_IA32_APICBASE_ENABLE)

		mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;



	if (nmi_watchdog != NMI_NONE)

	if (nmi_watchdog != NMI_NONE && nmi_watchdog != NMI_DISABLED)

		nmi_watchdog = NMI_LOCAL_APIC;



	printk(KERN_INFO "Found and enabled local APIC!\n");

arch/i386/kernel/nmi.c

+2 −2
Original line number Diff line number Diff line
@@ -77,7 +77,7 @@ static int __init check_nmi_watchdog(void) 
	unsigned int *prev_nmi_count;

	int cpu;



	if ((nmi_watchdog == NMI_NONE) || (nmi_watchdog == NMI_DEFAULT))

	if ((nmi_watchdog == NMI_NONE) || (nmi_watchdog == NMI_DISABLED))

		return 0;



	if (!atomic_read(&nmi_active))
@@ -424,7 +424,7 @@ int proc_nmi_enabled(struct ctl_table *table, int write, struct file *file, 
	if (!!old_state == !!nmi_watchdog_enabled)

		return 0;



	if (atomic_read(&nmi_active) < 0) {

	if (atomic_read(&nmi_active) < 0 || nmi_watchdog == NMI_DISABLED) {

		printk( KERN_WARNING "NMI watchdog is permanently disabled\n");

		return -EIO;

	}

arch/x86_64/kernel/nmi.c

+2 −2
Original line number Diff line number Diff line
@@ -85,7 +85,7 @@ int __init check_nmi_watchdog (void) 
	int *counts;

	int cpu;



	if ((nmi_watchdog == NMI_NONE) || (nmi_watchdog == NMI_DEFAULT))

	if ((nmi_watchdog == NMI_NONE) || (nmi_watchdog == NMI_DISABLED)) 

		return 0;



	if (!atomic_read(&nmi_active))
@@ -442,7 +442,7 @@ int proc_nmi_enabled(struct ctl_table *table, int write, struct file *file, 
	if (!!old_state == !!nmi_watchdog_enabled)

		return 0;



	if (atomic_read(&nmi_active) < 0) {

	if (atomic_read(&nmi_active) < 0 || nmi_watchdog == NMI_DISABLED) {

		printk( KERN_WARNING "NMI watchdog is permanently disabled\n");

		return -EIO;

	}

include/asm-i386/nmi.h

+2 −1
Original line number Diff line number Diff line
@@ -33,11 +33,12 @@ extern int nmi_watchdog_tick (struct pt_regs * regs, unsigned reason); 


extern atomic_t nmi_active;

extern unsigned int nmi_watchdog;

#define NMI_DEFAULT     -1

#define NMI_DISABLED    -1

#define NMI_NONE	0

#define NMI_IO_APIC	1

#define NMI_LOCAL_APIC	2

#define NMI_INVALID	3

#define NMI_DEFAULT	NMI_DISABLED



struct ctl_table;

struct file;

include/asm-x86_64/nmi.h

+2 −1
Original line number Diff line number Diff line
@@ -64,11 +64,12 @@ extern int setup_nmi_watchdog(char *); 


extern atomic_t nmi_active;

extern unsigned int nmi_watchdog;

#define NMI_DEFAULT	-1

#define NMI_DISABLED    -1

#define NMI_NONE	0

#define NMI_IO_APIC	1

#define NMI_LOCAL_APIC	2

#define NMI_INVALID	3

#define NMI_DEFAULT	NMI_DISABLED



struct ctl_table;

struct file;

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