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
b7471c6da94d30d3deadc55986cc38d1ff57f9ca.
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: Daniel Gollub <dgollub@suse.de>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
index f9fff29..3d67ae1 100644
--- a/arch/i386/kernel/apic.c
+++ b/arch/i386/kernel/apic.c
@@ -1085,7 +1085,7 @@
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");
diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c
index 99beac7..8c1c965 100644
--- a/arch/i386/kernel/nmi.c
+++ b/arch/i386/kernel/nmi.c
@@ -77,7 +77,7 @@
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 @@
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;
}
diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c
index cb8ee9d0..0ec6d2d 100644
--- a/arch/x86_64/kernel/nmi.c
+++ b/arch/x86_64/kernel/nmi.c
@@ -85,7 +85,7 @@
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 @@
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;
}
diff --git a/include/asm-i386/nmi.h b/include/asm-i386/nmi.h
index ff30c98..70a958a 100644
--- a/include/asm-i386/nmi.h
+++ b/include/asm-i386/nmi.h
@@ -33,11 +33,12 @@
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;
diff --git a/include/asm-x86_64/nmi.h b/include/asm-x86_64/nmi.h
index 5fb3c0d..65b6acf 100644
--- a/include/asm-x86_64/nmi.h
+++ b/include/asm-x86_64/nmi.h
@@ -64,11 +64,12 @@
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;