diff options
Diffstat (limited to 'arch/x86/kernel/traps.c')
| -rw-r--r-- | arch/x86/kernel/traps.c | 65 |
1 files changed, 56 insertions, 9 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 6ef00eb6fbb9..d54cffdc7cac 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -46,6 +46,7 @@ #include <asm/traps.h> #include <asm/desc.h> #include <asm/fpu/internal.h> +#include <asm/cpu.h> #include <asm/cpu_entry_area.h> #include <asm/mce.h> #include <asm/fixmap.h> @@ -242,7 +243,6 @@ do_trap(int trapnr, int signr, char *str, struct pt_regs *regs, { struct task_struct *tsk = current; - if (!do_trap_no_signal(tsk, trapnr, str, regs, error_code)) return; @@ -288,9 +288,29 @@ DO_ERROR(X86_TRAP_OLD_MF, SIGFPE, 0, NULL, "coprocessor segment overru DO_ERROR(X86_TRAP_TS, SIGSEGV, 0, NULL, "invalid TSS", invalid_TSS) DO_ERROR(X86_TRAP_NP, SIGBUS, 0, NULL, "segment not present", segment_not_present) DO_ERROR(X86_TRAP_SS, SIGBUS, 0, NULL, "stack segment", stack_segment) -DO_ERROR(X86_TRAP_AC, SIGBUS, BUS_ADRALN, NULL, "alignment check", alignment_check) #undef IP +dotraplinkage void do_alignment_check(struct pt_regs *regs, long error_code) +{ + char *str = "alignment check"; + + RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); + + if (notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_AC, SIGBUS) == NOTIFY_STOP) + return; + + if (!user_mode(regs)) + die("Split lock detected\n", regs, error_code); + + local_irq_enable(); + + if (handle_user_split_lock(regs, error_code)) + return; + + do_trap(X86_TRAP_AC, SIGBUS, "alignment check", regs, + error_code, BUS_ADRALN, NULL); +} + #ifdef CONFIG_VMAP_STACK __visible void __noreturn handle_stack_overflow(const char *message, struct pt_regs *regs, @@ -572,14 +592,20 @@ dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code) return; /* - * Use ist_enter despite the fact that we don't use an IST stack. - * We can be called from a kprobe in non-CONTEXT_KERNEL kernel - * mode or even during context tracking state changes. + * 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. That's okay. + * This means that we can't schedule even if we came from a + * preemptible kernel context. That's okay. */ - ist_enter(regs); + if (!user_mode(regs)) { + rcu_nmi_enter(); + preempt_disable(); + } RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU"); + #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, SIGTRAP) == NOTIFY_STOP) @@ -600,7 +626,10 @@ dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code) cond_local_irq_disable(regs); exit: - ist_exit(regs); + if (!user_mode(regs)) { + preempt_enable_no_resched(); + rcu_nmi_exit(); + } } NOKPROBE_SYMBOL(do_int3); @@ -862,7 +891,25 @@ do_simd_coprocessor_error(struct pt_regs *regs, long error_code) dotraplinkage void do_spurious_interrupt_bug(struct pt_regs *regs, long error_code) { - cond_local_irq_enable(regs); + /* + * This addresses a Pentium Pro Erratum: + * + * PROBLEM: If the APIC subsystem is configured in mixed mode with + * Virtual Wire mode implemented through the local APIC, an + * interrupt vector of 0Fh (Intel reserved encoding) may be + * generated by the local APIC (Int 15). This vector may be + * generated upon receipt of a spurious interrupt (an interrupt + * which is removed before the system receives the INTA sequence) + * instead of the programmed 8259 spurious interrupt vector. + * + * IMPLICATION: The spurious interrupt vector programmed in the + * 8259 is normally handled by an operating system's spurious + * interrupt handler. However, a vector of 0Fh is unknown to some + * operating systems, which would crash if this erratum occurred. + * + * In theory this could be limited to 32bit, but the handler is not + * hurting and who knows which other CPUs suffer from this. + */ } dotraplinkage void |