diff options
| -rw-r--r-- | arch/x86/include/asm/traps.h | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mce/core.c | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mce/p5.c | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/cpu/mce/winchip.c | 5 | ||||
| -rw-r--r-- | arch/x86/kernel/traps.c | 71 |
5 files changed, 24 insertions, 65 deletions
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h index fe109fc9a1d2..6f6c417e1e46 100644 --- a/arch/x86/include/asm/traps.h +++ b/arch/x86/include/asm/traps.h @@ -118,9 +118,6 @@ void smp_spurious_interrupt(struct pt_regs *regs); void smp_error_interrupt(struct pt_regs *regs); asmlinkage void smp_irq_move_cleanup_interrupt(void); -extern void ist_enter(struct pt_regs *regs); -extern void ist_exit(struct pt_regs *regs); - #ifdef CONFIG_VMAP_STACK void __noreturn handle_stack_overflow(const char *message, struct pt_regs *regs, diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index 2f0ef95795f3..e9265e2f28c9 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -43,6 +43,7 @@ #include <linux/jump_label.h> #include <linux/set_memory.h> #include <linux/task_work.h> +#include <linux/hardirq.h> #include <asm/intel-family.h> #include <asm/processor.h> @@ -1266,7 +1267,7 @@ void noinstr do_machine_check(struct pt_regs *regs, long error_code) if (__mc_check_crashing_cpu(cpu)) return; - ist_enter(regs); + nmi_enter(); this_cpu_inc(mce_exception_count); @@ -1374,7 +1375,7 @@ void noinstr do_machine_check(struct pt_regs *regs, long error_code) } out_ist: - ist_exit(regs); + nmi_exit(); } EXPORT_SYMBOL_GPL(do_machine_check); diff --git a/arch/x86/kernel/cpu/mce/p5.c b/arch/x86/kernel/cpu/mce/p5.c index 4ae6df556526..5ee94aa1b766 100644 --- a/arch/x86/kernel/cpu/mce/p5.c +++ b/arch/x86/kernel/cpu/mce/p5.c @@ -7,6 +7,7 @@ #include <linux/kernel.h> #include <linux/types.h> #include <linux/smp.h> +#include <linux/hardirq.h> #include <asm/processor.h> #include <asm/traps.h> @@ -24,7 +25,7 @@ static void pentium_machine_check(struct pt_regs *regs, long error_code) { u32 loaddr, hi, lotype; - ist_enter(regs); + nmi_enter(); rdmsr(MSR_IA32_P5_MC_ADDR, loaddr, hi); rdmsr(MSR_IA32_P5_MC_TYPE, lotype, hi); @@ -39,7 +40,7 @@ static void pentium_machine_check(struct pt_regs *regs, long error_code) add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE); - ist_exit(regs); + nmi_exit(); } /* Set up machine check reporting for processors with Intel style MCE: */ diff --git a/arch/x86/kernel/cpu/mce/winchip.c b/arch/x86/kernel/cpu/mce/winchip.c index a30ea13cccc2..b3938c195365 100644 --- a/arch/x86/kernel/cpu/mce/winchip.c +++ b/arch/x86/kernel/cpu/mce/winchip.c @@ -6,6 +6,7 @@ #include <linux/interrupt.h> #include <linux/kernel.h> #include <linux/types.h> +#include <linux/hardirq.h> #include <asm/processor.h> #include <asm/traps.h> @@ -18,12 +19,12 @@ /* Machine check handler for WinChip C6: */ static void winchip_machine_check(struct pt_regs *regs, long error_code) { - ist_enter(regs); + nmi_enter(); pr_emerg("CPU0: Machine Check Exception.\n"); add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE); - ist_exit(regs); + nmi_exit(); } /* 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 8b209fc04749..f9a219b86fdd 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -37,10 +37,12 @@ #include <linux/mm.h> #include <linux/smp.h> #include <linux/io.h> +#include <linux/hardirq.h> +#include <linux/atomic.h> + #include <asm/stacktrace.h> #include <asm/processor.h> #include <asm/debugreg.h> -#include <linux/atomic.h> #include <asm/text-patching.h> #include <asm/ftrace.h> #include <asm/traps.h> @@ -82,41 +84,6 @@ static inline void cond_local_irq_disable(struct pt_regs *regs) local_irq_disable(); } -/* - * In IST context, we explicitly disable preemption. This serves two - * purposes: it makes it much less likely that we would accidentally - * schedule in IST context and it will force a warning if we somehow - * manage to schedule by accident. - */ -void ist_enter(struct pt_regs *regs) -{ - if (user_mode(regs)) { - RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); - } 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(); - } - - preempt_disable(); - - /* This code is a bit fragile. Test it. */ - RCU_LOCKDEP_WARN(!rcu_is_watching(), "ist_enter didn't work"); -} -NOKPROBE_SYMBOL(ist_enter); - -void ist_exit(struct pt_regs *regs) -{ - preempt_enable_no_resched(); - - if (!user_mode(regs)) - rcu_nmi_exit(); -} - int is_valid_bugaddr(unsigned long addr) { unsigned short ud; @@ -326,7 +293,7 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsign * The net result is that our #GP handler will think that we * entered from usermode with the bad user context. * - * No need for ist_enter here because we don't use RCU. + * No need for nmi_enter() here because we don't use RCU. */ if (((long)regs->sp >> P4D_SHIFT) == ESPFIX_PGD_ENTRY && regs->cs == __KERNEL_CS && @@ -366,7 +333,7 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code, unsign } #endif - ist_enter(regs); + nmi_enter(); notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV); tsk->thread.error_code = error_code; @@ -560,19 +527,13 @@ dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code) return; /* - * Unlike any other non-IST entry, we can be called from a kprobe in - * non-CONTEXT_KERNEL kernel mode or even during context tracking - * state changes. Make sure that we wake up RCU even if we're coming - * from kernel code. - * - * This means that we can't schedule even if we came from a - * preemptible kernel context. That's okay. + * Unlike any other non-IST entry, we can be called from pretty much + * any location in the kernel through kprobes -- text_poke() will most + * likely be handled by poke_int3_handler() above. This means this + * handler is effectively NMI-like. */ - if (!user_mode(regs)) { - rcu_nmi_enter(); - preempt_disable(); - } - RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); + if (!user_mode(regs)) + nmi_enter(); #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, @@ -594,10 +555,8 @@ dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code) cond_local_irq_disable(regs); exit: - if (!user_mode(regs)) { - preempt_enable_no_resched(); - rcu_nmi_exit(); - } + if (!user_mode(regs)) + nmi_exit(); } NOKPROBE_SYMBOL(do_int3); @@ -701,7 +660,7 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code) unsigned long dr6; int si_code; - ist_enter(regs); + nmi_enter(); get_debugreg(dr6, 6); /* @@ -794,7 +753,7 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code) debug_stack_usage_dec(); exit: - ist_exit(regs); + nmi_exit(); } NOKPROBE_SYMBOL(do_debug); |