diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/include/asm/traps.h | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce.c | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/p5.c | 6 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/winchip.c | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/traps.c | 47 |
5 files changed, 61 insertions, 6 deletions
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index 707adc6549d8..3cf525ec762d 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -1,6 +1,7 @@ #ifndef _ASM_X86_TRAPS_H #define _ASM_X86_TRAPS_H +#include <linux/context_tracking_state.h> #include <linux/kprobes.h> #include <asm/debugreg.h> @@ -110,6 +111,9 @@ asmlinkage void smp_thermal_interrupt(void); asmlinkage void mce_threshold_interrupt(void); #endif +extern enum ctx_state ist_enter(struct pt_regs *regs); +extern void ist_exit(struct pt_regs *regs, enum ctx_state prev_state); + /* Interrupts/Exceptions */ enum { X86_TRAP_DE = 0, /* 0, Divide-by-zero */ diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index d2c611699cd9..800d423f1e92 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -43,6 +43,7 @@ #include <linux/export.h> #include <asm/processor.h> +#include <asm/traps.h> #include <asm/mce.h> #include <asm/msr.h> @@ -1063,6 +1064,7 @@ void do_machine_check(struct pt_regs *regs, long error_code) { struct mca_config *cfg = &mca_cfg; struct mce m, *final; + enum ctx_state prev_state; int i; int worst = 0; int severity; @@ -1085,6 +1087,8 @@ void do_machine_check(struct pt_regs *regs, long error_code) DECLARE_BITMAP(valid_banks, MAX_NR_BANKS); char *msg = "Unknown"; + prev_state = ist_enter(regs); + this_cpu_inc(mce_exception_count); if (!cfg->banks) @@ -1216,6 +1220,7 @@ void do_machine_check(struct pt_regs *regs, long error_code) mce_wrmsrl(MSR_IA32_MCG_STATUS, 0); out: sync_core(); + ist_exit(regs, prev_state); } EXPORT_SYMBOL_GPL(do_machine_check); diff --git a/arch/x86/kernel/cpu/mcheck/p5.c b/arch/x86/kernel/cpu/mcheck/p5.c index a3042989398c..ec2663a708e4 100644 --- a/arch/x86/kernel/cpu/mcheck/p5.c +++ b/arch/x86/kernel/cpu/mcheck/p5.c @@ -8,6 +8,7 @@ #include <linux/smp.h> #include <asm/processor.h> +#include <asm/traps.h> #include <asm/mce.h> #include <asm/msr.h> @@ -17,8 +18,11 @@ int mce_p5_enabled __read_mostly; /* Machine check handler for Pentium class Intel CPUs: */ static void pentium_machine_check(struct pt_regs *regs, long error_code) { + enum ctx_state prev_state; u32 loaddr, hi, lotype; + prev_state = ist_enter(regs); + rdmsr(MSR_IA32_P5_MC_ADDR, loaddr, hi); rdmsr(MSR_IA32_P5_MC_TYPE, lotype, hi); @@ -33,6 +37,8 @@ static void pentium_machine_check(struct pt_regs *regs, long error_code) } add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE); + + ist_exit(regs, prev_state); } /* Set up machine check reporting for processors with Intel style MCE: */ diff --git a/arch/x86/kernel/cpu/mcheck/winchip.c b/arch/x86/kernel/cpu/mcheck/winchip.c index 7dc5564d0cdf..bd5d46a32210 100644 --- a/arch/x86/kernel/cpu/mcheck/winchip.c +++ b/arch/x86/kernel/cpu/mcheck/winchip.c @@ -7,14 +7,19 @@ #include <linux/types.h> #include <asm/processor.h> +#include <asm/traps.h> #include <asm/mce.h> #include <asm/msr.h> /* Machine check handler for WinChip C6: */ static void winchip_machine_check(struct pt_regs *regs, long error_code) { + enum ctx_state prev_state = ist_enter(regs); + printk(KERN_EMERG "CPU0: Machine Check Exception.\n"); add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE); + + ist_exit(regs, prev_state); } /* Set up machine check reporting on the Winchip C6 series */ diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 28f3e5ffc55d..b3a9d24dba25 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -108,6 +108,39 @@ static inline void preempt_conditional_cli(struct pt_regs *regs) preempt_count_dec(); } +enum ctx_state ist_enter(struct pt_regs *regs) +{ + /* + * We are atomic because we're on the IST stack (or we're on x86_32, + * in which case we still shouldn't schedule. + */ + preempt_count_add(HARDIRQ_OFFSET); + + if (user_mode_vm(regs)) { + /* Other than that, we're just an exception. */ + return exception_enter(); + } else { + /* + * We might have interrupted pretty much anything. In + * fact, if we're a machine check, we can even interrupt + * NMI processing. We don't want in_nmi() to return true, + * but we need to notify RCU. + */ + rcu_nmi_enter(); + return IN_KERNEL; /* the value is irrelevant. */ + } +} + +void ist_exit(struct pt_regs *regs, enum ctx_state prev_state) +{ + preempt_count_sub(HARDIRQ_OFFSET); + + if (user_mode_vm(regs)) + return exception_exit(prev_state); + else + rcu_nmi_exit(); +} + static nokprobe_inline int do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str, struct pt_regs *regs, long error_code) @@ -251,6 +284,8 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) * end up promoting it to a doublefault. In that case, modify * the stack to make it look like we just entered the #GP * handler from user space, similar to bad_iret. + * + * No need for ist_enter here because we don't use RCU. */ if (((long)regs->sp >> PGDIR_SHIFT) == ESPFIX_PGD_ENTRY && regs->cs == __KERNEL_CS && @@ -263,12 +298,12 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) normal_regs->orig_ax = 0; /* Missing (lost) #GP error code */ regs->ip = (unsigned long)general_protection; regs->sp = (unsigned long)&normal_regs->orig_ax; + return; } #endif - exception_enter(); - /* Return not checked because double check cannot be ignored */ + ist_enter(regs); /* Discard prev_state because we won't return. */ notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV); tsk->thread.error_code = error_code; @@ -434,7 +469,7 @@ dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code) if (poke_int3_handler(regs)) return; - prev_state = exception_enter(); + prev_state = ist_enter(regs); #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, SIGTRAP) == NOTIFY_STOP) @@ -460,7 +495,7 @@ dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code) preempt_conditional_cli(regs); debug_stack_usage_dec(); exit: - exception_exit(prev_state); + ist_exit(regs, prev_state); } NOKPROBE_SYMBOL(do_int3); @@ -541,7 +576,7 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code) unsigned long dr6; int si_code; - prev_state = exception_enter(); + prev_state = ist_enter(regs); get_debugreg(dr6, 6); @@ -616,7 +651,7 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code) debug_stack_usage_dec(); exit: - exception_exit(prev_state); + ist_exit(regs, prev_state); } NOKPROBE_SYMBOL(do_debug); |