[PATCH 5/5] x86, NMI: Remove do_nmi_callback logic

Don Zickus
2010-10-16T02:23:57Z

From: Huang Ying <ying.huang@intel.com>

do_nmi_callback related logic is removed, because it is useless, just
adds code complexity.

unknown_nmi_panic sysctl is reserved to keep kernel ABI unchanged.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Don Zickus <dzickus@redhat.com>
---
arch/x86/include/asm/nmi.h | 10 +++++++++-
arch/x86/kernel/apic/hw_nmi.c | 1 -
arch/x86/kernel/apic/nmi.c | 29 +----------------------------
arch/x86/kernel/traps.c | 17 +++++++++++------
4 files changed, 21 insertions(+), 36 deletions(-)

diff --git a/arch/x86/include/asm/nmi.h b/arch/x86/include/asm/nmi.h
index 932f0f8..d5a5793 100644
--- a/arch/x86/include/asm/nmi.h
+++ b/arch/x86/include/asm/nmi.h
@@ -30,9 +30,17 @@ extern void setup_apic_nmi_watchdog(void *);
extern void stop_apic_nmi_watchdog(void *);
extern void disable_timer_nmi_watchdog(void);
extern void enable_timer_nmi_watchdog(void);
-extern int nmi_watchdog_tick(struct pt_regs *regs, unsigned reason);
extern void cpu_nmi_set_wd_enabled(void);

+#if defined(CONFIG_X86_LOCAL_APIC) && !defined(CONFIG_LOCKUP_DETECTOR)
+extern int nmi_watchdog_tick(struct pt_regs *regs);
+#else
+static inline int nmi_watchdog_tick(struct pt_regs *regs)
+{
+ return 0;
+}
+#endif
+
extern atomic_t nmi_active;
extern unsigned int nmi_watchdog;
#define NMI_NONE 0
diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c
index cefd694..e66b16d 100644
--- a/arch/x86/kernel/apic/hw_nmi.c
+++ b/arch/x86/kernel/apic/hw_nmi.c
@@ -100,7 +100,6 @@ void acpi_nmi_disable(void) { return; }
#endif
atomic_t nmi_active = ATOMIC_INIT(0); /* oprofile uses this */
EXPORT_SYMBOL(nmi_active);
-int unknown_nmi_panic;
void cpu_nmi_set_wd_enabled(void) { return; }
void stop_apic_nmi_watchdog(void *unused) { return; }
void setup_apic_nmi_watchdog(void *unused) { return; }
diff --git a/arch/x86/kernel/apic/nmi.c b/arch/x86/kernel/apic/nmi.c
index a43f71c..f407b6b 100644
--- a/arch/x86/kernel/apic/nmi.c
+++ b/arch/x86/kernel/apic/nmi.c
@@ -37,7 +37,6 @@

#include <asm/mach_traps.h>

-int unknown_nmi_panic;
int nmi_watchdog_enabled;

/* For reliability, we're prepared to waste bits here. */
@@ -389,7 +388,7 @@ void touch_nmi_watchdog(void)
EXPORT_SYMBOL(touch_nmi_watchdog);

notrace __kprobes int
-nmi_watchdog_tick(struct pt_regs *regs, unsigned reason)
+nmi_watchdog_tick(struct pt_regs *regs)
{
/*
* Since current_thread_info()-> is always on the stack, and we
@@ -483,23 +482,6 @@ static void disable_ioapic_nmi_watchdog(void)
on_each_cpu(stop_apic_nmi_watchdog, NULL, 1);
}

-static int __init setup_unknown_nmi_panic(char *str)
-{
- unknown_nmi_panic = 1;
- return 1;
-}
-__setup("unknown_nmi_panic", setup_unknown_nmi_panic);
-
-static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu)
-{
- unsigned char reason = get_nmi_reason();
- char buf[64];
-
- sprintf(buf, "NMI received for unknown reason %02x\n", reason);
- die_nmi(buf, regs, 1); /* Always panic here */
- return 0;
-}
-
/*
* proc handler for /proc/sys/kernel/nmi
*/
@@ -540,15 +522,6 @@ int proc_nmi_enabled(struct ctl_table *table, int write,

#endif /* CONFIG_SYSCTL */

-int do_nmi_callback(struct pt_regs *regs, int cpu)
-{
-#ifdef CONFIG_SYSCTL
- if (unknown_nmi_panic)
- return unknown_nmi_panic_callback(regs, cpu);
-#endif
- return 0;
-}
-
void arch_trigger_all_cpu_backtrace(void)
{
int i;
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index accb2f4..9ef8e15 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -83,6 +83,8 @@ EXPORT_SYMBOL_GPL(used_vectors);

static int ignore_nmis;

+int unknown_nmi_panic;
+
/*
* Prevent NMI reason port (0x61) being accessed simultaneously, can
* only be used in NMI handler.
@@ -306,6 +308,13 @@ gp_in_kernel:
die("general protection fault", regs, error_code);
}

+static int __init setup_unknown_nmi_panic(char *str)
+{
+ unknown_nmi_panic = 1;
+ return 1;
+}
+__setup("unknown_nmi_panic", setup_unknown_nmi_panic);
+
static notrace __kprobes void
pci_serr_error(unsigned char reason, struct pt_regs *regs)
{
@@ -380,7 +389,7 @@ unknown_nmi_error(unsigned char reason, struct pt_regs *regs)
reason, smp_processor_id());

pr_emerg("Do you have a strange power saving mode enabled?\n");
- if (panic_on_unrecovered_nmi)
+ if (unknown_nmi_panic || panic_on_unrecovered_nmi)
panic("NMI: Not continuing");

pr_emerg("Dazed and confused, but trying to continue\n");
@@ -431,12 +440,8 @@ unlock_return:
if (notify_die(DIE_NMI, "nmi", regs, 0, 2, SIGINT) == NOTIFY_STOP)
return;

-#if defined(CONFIG_X86_LOCAL_APIC) && !defined(CONFIG_LOCKUP_DETECTOR)
- if (nmi_watchdog_tick(regs, reason))
- return;
- if (do_nmi_callback(regs, cpu))
+ if (nmi_watchdog_tick(regs))
return;
-#endif

unknown_nmi_error(reason, regs);
}
--
1.7.2.3