diff options
Diffstat (limited to 'arch/i386')
| -rw-r--r-- | arch/i386/kernel/alternative.c | 15 | ||||
| -rw-r--r-- | arch/i386/kernel/cpu/mcheck/mce.c | 14 | ||||
| -rw-r--r-- | arch/i386/kernel/traps.c | 17 |
3 files changed, 45 insertions, 1 deletions
diff --git a/arch/i386/kernel/alternative.c b/arch/i386/kernel/alternative.c index 206ea2ca63cc..c3750c2c4113 100644 --- a/arch/i386/kernel/alternative.c +++ b/arch/i386/kernel/alternative.c @@ -8,6 +8,8 @@ #include <asm/alternative.h> #include <asm/sections.h> #include <asm/pgtable.h> +#include <asm/mce.h> +#include <asm/nmi.h> #ifdef CONFIG_HOTPLUG_CPU static int smp_alt_once; @@ -373,6 +375,14 @@ void __init alternative_instructions(void) { unsigned long flags; + /* The patching is not fully atomic, so try to avoid local interruptions + that might execute the to be patched code. + Other CPUs are not running. */ + stop_nmi(); +#ifdef CONFIG_MCE + stop_mce(); +#endif + local_irq_save(flags); apply_alternatives(__alt_instructions, __alt_instructions_end); @@ -405,6 +415,11 @@ void __init alternative_instructions(void) #endif apply_paravirt(__parainstructions, __parainstructions_end); local_irq_restore(flags); + + restart_nmi(); +#ifdef CONFIG_MCE + restart_mce(); +#endif } /* diff --git a/arch/i386/kernel/cpu/mcheck/mce.c b/arch/i386/kernel/cpu/mcheck/mce.c index 56cd485b127c..34c781eddee4 100644 --- a/arch/i386/kernel/cpu/mcheck/mce.c +++ b/arch/i386/kernel/cpu/mcheck/mce.c @@ -60,6 +60,20 @@ void mcheck_init(struct cpuinfo_x86 *c) } } +static unsigned long old_cr4 __initdata; + +void __init stop_mce(void) +{ + old_cr4 = read_cr4(); + clear_in_cr4(X86_CR4_MCE); +} + +void __init restart_mce(void) +{ + if (old_cr4 & X86_CR4_MCE) + set_in_cr4(X86_CR4_MCE); +} + static int __init mcheck_disable(char *str) { mce_disabled = 1; diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c index 438949da3b63..cfffe3dd9e83 100644 --- a/arch/i386/kernel/traps.c +++ b/arch/i386/kernel/traps.c @@ -775,6 +775,8 @@ static __kprobes void default_do_nmi(struct pt_regs * regs) reassert_nmi(); } +static int ignore_nmis; + fastcall __kprobes void do_nmi(struct pt_regs * regs, long error_code) { int cpu; @@ -785,11 +787,24 @@ fastcall __kprobes void do_nmi(struct pt_regs * regs, long error_code) ++nmi_count(cpu); - default_do_nmi(regs); + if (!ignore_nmis) + default_do_nmi(regs); nmi_exit(); } +void stop_nmi(void) +{ + acpi_nmi_disable(); + ignore_nmis++; +} + +void restart_nmi(void) +{ + ignore_nmis--; + acpi_nmi_enable(); +} + #ifdef CONFIG_KPROBES fastcall void __kprobes do_int3(struct pt_regs *regs, long error_code) { |
