diff options
Diffstat (limited to 'arch/x86/kernel/traps.c')
| -rw-r--r-- | arch/x86/kernel/traps.c | 62 |
1 files changed, 40 insertions, 22 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 4ff5d162ff9f..324ab5247687 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -112,7 +112,7 @@ enum ctx_state ist_enter(struct pt_regs *regs) { enum ctx_state prev_state; - if (user_mode_vm(regs)) { + if (user_mode(regs)) { /* Other than that, we're just an exception. */ prev_state = exception_enter(); } else { @@ -123,7 +123,7 @@ enum ctx_state ist_enter(struct pt_regs *regs) * but we need to notify RCU. */ rcu_nmi_enter(); - prev_state = IN_KERNEL; /* the value is irrelevant. */ + prev_state = CONTEXT_KERNEL; /* the value is irrelevant. */ } /* @@ -146,7 +146,7 @@ void ist_exit(struct pt_regs *regs, enum ctx_state prev_state) /* Must be before exception_exit. */ preempt_count_sub(HARDIRQ_OFFSET); - if (user_mode_vm(regs)) + if (user_mode(regs)) return exception_exit(prev_state); else rcu_nmi_exit(); @@ -158,7 +158,7 @@ void ist_exit(struct pt_regs *regs, enum ctx_state prev_state) * * IST exception handlers normally cannot schedule. As a special * exception, if the exception interrupted userspace code (i.e. - * user_mode_vm(regs) would return true) and the exception was not + * user_mode(regs) would return true) and the exception was not * a double fault, it can be safe to schedule. ist_begin_non_atomic() * begins a non-atomic section within an ist_enter()/ist_exit() region. * Callers are responsible for enabling interrupts themselves inside @@ -167,15 +167,15 @@ void ist_exit(struct pt_regs *regs, enum ctx_state prev_state) */ void ist_begin_non_atomic(struct pt_regs *regs) { - BUG_ON(!user_mode_vm(regs)); + BUG_ON(!user_mode(regs)); /* * Sanity check: we need to be on the normal thread stack. This * will catch asm bugs and any attempt to use ist_preempt_enable * from double_fault. */ - BUG_ON(((current_stack_pointer() ^ this_cpu_read_stable(kernel_stack)) - & ~(THREAD_SIZE - 1)) != 0); + BUG_ON((unsigned long)(current_top_of_stack() - + current_stack_pointer()) >= THREAD_SIZE); preempt_count_sub(HARDIRQ_OFFSET); } @@ -194,8 +194,7 @@ static nokprobe_inline int do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str, struct pt_regs *regs, long error_code) { -#ifdef CONFIG_X86_32 - if (regs->flags & X86_VM_MASK) { + if (v8086_mode(regs)) { /* * Traps 0, 1, 3, 4, and 5 should be forwarded to vm86. * On nmi (interrupt 2), do_trap should not be called. @@ -207,7 +206,7 @@ do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str, } return -1; } -#endif + if (!user_mode(regs)) { if (!fixup_exception(regs)) { tsk->thread.error_code = error_code; @@ -384,7 +383,7 @@ dotraplinkage void do_bounds(struct pt_regs *regs, long error_code) goto exit; conditional_sti(regs); - if (!user_mode_vm(regs)) + if (!user_mode(regs)) die("bounds", regs, error_code); if (!cpu_feature_enabled(X86_FEATURE_MPX)) { @@ -462,13 +461,11 @@ do_general_protection(struct pt_regs *regs, long error_code) prev_state = exception_enter(); conditional_sti(regs); -#ifdef CONFIG_X86_32 - if (regs->flags & X86_VM_MASK) { + if (v8086_mode(regs)) { local_irq_enable(); handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code); goto exit; } -#endif tsk = current; if (!user_mode(regs)) { @@ -587,7 +584,7 @@ struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s) /* Copy the remainder of the stack from the current stack. */ memmove(new_stack, s, offsetof(struct bad_iret_stack, regs.ip)); - BUG_ON(!user_mode_vm(&new_stack->regs)); + BUG_ON(!user_mode(&new_stack->regs)); return new_stack; } NOKPROBE_SYMBOL(fixup_bad_iret); @@ -637,7 +634,7 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code) * then it's very likely the result of an icebp/int01 trap. * User wants a sigtrap for that. */ - if (!dr6 && user_mode_vm(regs)) + if (!dr6 && user_mode(regs)) user_icebp = 1; /* Catch kmemcheck conditions first of all! */ @@ -673,7 +670,7 @@ dotraplinkage void do_debug(struct pt_regs *regs, long error_code) /* It's safe to allow irq's after DR6 has been saved */ preempt_conditional_sti(regs); - if (regs->flags & X86_VM_MASK) { + if (v8086_mode(regs)) { handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, X86_TRAP_DB); preempt_conditional_cli(regs); @@ -721,7 +718,7 @@ static void math_error(struct pt_regs *regs, int error_code, int trapnr) return; conditional_sti(regs); - if (!user_mode_vm(regs)) + if (!user_mode(regs)) { if (!fixup_exception(regs)) { task->thread.error_code = error_code; @@ -734,7 +731,7 @@ static void math_error(struct pt_regs *regs, int error_code, int trapnr) /* * Save the info for the exception handler and clear the error. */ - save_init_fpu(task); + unlazy_fpu(task); task->thread.trap_nr = trapnr; task->thread.error_code = error_code; info.si_signo = SIGFPE; @@ -863,7 +860,7 @@ void math_state_restore(void) kernel_fpu_disable(); __thread_fpu_begin(tsk); if (unlikely(restore_fpu_checking(tsk))) { - drop_init_fpu(tsk); + fpu_reset_state(tsk); force_sig_info(SIGSEGV, SEND_SIG_PRIV, tsk); } else { tsk->thread.fpu_counter++; @@ -925,9 +922,21 @@ dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code) /* Set of traps needed for early debugging. */ void __init early_trap_init(void) { - set_intr_gate_ist(X86_TRAP_DB, &debug, DEBUG_STACK); + /* + * Don't use IST to set DEBUG_STACK as it doesn't work until TSS + * is ready in cpu_init() <-- trap_init(). Before trap_init(), + * CPU runs at ring 0 so it is impossible to hit an invalid + * stack. Using the original stack works well enough at this + * early stage. DEBUG_STACK will be equipped after cpu_init() in + * trap_init(). + * + * We don't need to set trace_idt_table like set_intr_gate(), + * since we don't have trace_debug and it will be reset to + * 'debug' in trap_init() by set_intr_gate_ist(). + */ + set_intr_gate_notrace(X86_TRAP_DB, debug); /* int3 can be called from all */ - set_system_intr_gate_ist(X86_TRAP_BP, &int3, DEBUG_STACK); + set_system_intr_gate(X86_TRAP_BP, &int3); #ifdef CONFIG_X86_32 set_intr_gate(X86_TRAP_PF, page_fault); #endif @@ -1005,6 +1014,15 @@ void __init trap_init(void) */ cpu_init(); + /* + * X86_TRAP_DB and X86_TRAP_BP have been set + * in early_trap_init(). However, ITS works only after + * cpu_init() loads TSS. See comments in early_trap_init(). + */ + set_intr_gate_ist(X86_TRAP_DB, &debug, DEBUG_STACK); + /* int3 can be called from all */ + set_system_intr_gate_ist(X86_TRAP_BP, &int3, DEBUG_STACK); + x86_init.irqs.trap_init(); #ifdef CONFIG_X86_64 |