diff options
Diffstat (limited to 'arch/x86/kernel/traps.c')
| -rw-r--r-- | arch/x86/kernel/traps.c | 480 |
1 files changed, 281 insertions, 199 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index e6fbb948dac..0d0e922fafc 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -9,6 +9,10 @@ /* * Handle hardware traps and faults. */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/context_tracking.h> #include <linux/interrupt.h> #include <linux/kallsyms.h> #include <linux/spinlock.h> @@ -19,6 +23,7 @@ #include <linux/kernel.h> #include <linux/module.h> #include <linux/ptrace.h> +#include <linux/uprobes.h> #include <linux/string.h> #include <linux/delay.h> #include <linux/errno.h> @@ -37,10 +42,6 @@ #include <linux/eisa.h> #endif -#ifdef CONFIG_MCA -#include <linux/mca.h> -#endif - #if defined(CONFIG_EDAC) #include <linux/edac.h> #endif @@ -50,34 +51,33 @@ #include <asm/processor.h> #include <asm/debugreg.h> #include <linux/atomic.h> -#include <asm/system.h> +#include <asm/ftrace.h> #include <asm/traps.h> #include <asm/desc.h> #include <asm/i387.h> +#include <asm/fpu-internal.h> #include <asm/mce.h> - +#include <asm/fixmap.h> #include <asm/mach_traps.h> +#include <asm/alternative.h> #ifdef CONFIG_X86_64 #include <asm/x86_init.h> #include <asm/pgalloc.h> #include <asm/proto.h> + +/* No need to be aligned, but done to keep all IDTs defined the same way. */ +gate_desc debug_idt_table[NR_VECTORS] __page_aligned_bss; #else #include <asm/processor-flags.h> #include <asm/setup.h> asmlinkage int system_call(void); - -/* Do we ignore FPU interrupts ? */ -char ignore_fpu_irq; - -/* - * The IDT has to be page-aligned to simplify the Pentium - * F0 0F bug workaround. - */ -gate_desc idt_table[NR_VECTORS] __page_aligned_data = { { { { 0, 0 } } }, }; #endif +/* Must be page-aligned because the real IDT is used in a fixmap. */ +gate_desc idt_table[NR_VECTORS] __page_aligned_bss; + DECLARE_BITMAP(used_vectors, NR_VECTORS); EXPORT_SYMBOL_GPL(used_vectors); @@ -89,7 +89,7 @@ static inline void conditional_sti(struct pt_regs *regs) static inline void preempt_conditional_sti(struct pt_regs *regs) { - inc_preempt_count(); + preempt_count_inc(); if (regs->flags & X86_EFLAGS_IF) local_irq_enable(); } @@ -104,35 +104,81 @@ static inline void preempt_conditional_cli(struct pt_regs *regs) { if (regs->flags & X86_EFLAGS_IF) local_irq_disable(); - dec_preempt_count(); + preempt_count_dec(); } -static void __kprobes -do_trap(int trapnr, int signr, char *str, struct pt_regs *regs, - long error_code, siginfo_t *info) +static nokprobe_inline int +do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str, + struct pt_regs *regs, long error_code) { - struct task_struct *tsk = current; - #ifdef CONFIG_X86_32 if (regs->flags & X86_VM_MASK) { /* - * traps 0, 1, 3, 4, and 5 should be forwarded to vm86. + * Traps 0, 1, 3, 4, and 5 should be forwarded to vm86. * On nmi (interrupt 2), do_trap should not be called. */ - if (trapnr < X86_TRAP_UD) - goto vm86_trap; - goto trap_signal; + if (trapnr < X86_TRAP_UD) { + if (!handle_vm86_trap((struct kernel_vm86_regs *) regs, + error_code, trapnr)) + return 0; + } + return -1; } #endif + if (!user_mode(regs)) { + if (!fixup_exception(regs)) { + tsk->thread.error_code = error_code; + tsk->thread.trap_nr = trapnr; + die(str, regs, error_code); + } + return 0; + } - if (!user_mode(regs)) - goto kernel_trap; + return -1; +} -#ifdef CONFIG_X86_32 -trap_signal: -#endif +static siginfo_t *fill_trap_info(struct pt_regs *regs, int signr, int trapnr, + siginfo_t *info) +{ + unsigned long siaddr; + int sicode; + + switch (trapnr) { + default: + return SEND_SIG_PRIV; + + case X86_TRAP_DE: + sicode = FPE_INTDIV; + siaddr = uprobe_get_trap_addr(regs); + break; + case X86_TRAP_UD: + sicode = ILL_ILLOPN; + siaddr = uprobe_get_trap_addr(regs); + break; + case X86_TRAP_AC: + sicode = BUS_ADRALN; + siaddr = 0; + break; + } + + info->si_signo = signr; + info->si_errno = 0; + info->si_code = sicode; + info->si_addr = (void __user *)siaddr; + return info; +} + +static void +do_trap(int trapnr, int signr, char *str, struct pt_regs *regs, + long error_code, siginfo_t *info) +{ + struct task_struct *tsk = current; + + + if (!do_trap_no_signal(tsk, trapnr, str, regs, error_code)) + return; /* - * We want error_code and trap_no set for userspace faults and + * We want error_code and trap_nr set for userspace faults and * kernelspace faults which result in die(), but not * kernelspace faults which are fixed up. die() gives the * process no chance to handle the signal and notice the @@ -141,94 +187,71 @@ trap_signal: * delivered, faults. See also do_general_protection below. */ tsk->thread.error_code = error_code; - tsk->thread.trap_no = trapnr; + tsk->thread.trap_nr = trapnr; #ifdef CONFIG_X86_64 if (show_unhandled_signals && unhandled_signal(tsk, signr) && printk_ratelimit()) { - printk(KERN_INFO - "%s[%d] trap %s ip:%lx sp:%lx error:%lx", - tsk->comm, tsk->pid, str, - regs->ip, regs->sp, error_code); + pr_info("%s[%d] trap %s ip:%lx sp:%lx error:%lx", + tsk->comm, tsk->pid, str, + regs->ip, regs->sp, error_code); print_vma_addr(" in ", regs->ip); - printk("\n"); + pr_cont("\n"); } #endif - if (info) - force_sig_info(signr, info, tsk); - else - force_sig(signr, tsk); - return; + force_sig_info(signr, info ?: SEND_SIG_PRIV, tsk); +} +NOKPROBE_SYMBOL(do_trap); -kernel_trap: - if (!fixup_exception(regs)) { - tsk->thread.error_code = error_code; - tsk->thread.trap_no = trapnr; - die(str, regs, error_code); +static void do_error_trap(struct pt_regs *regs, long error_code, char *str, + unsigned long trapnr, int signr) +{ + enum ctx_state prev_state = exception_enter(); + siginfo_t info; + + if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) != + NOTIFY_STOP) { + conditional_sti(regs); + do_trap(trapnr, signr, str, regs, error_code, + fill_trap_info(regs, signr, trapnr, &info)); } - return; -#ifdef CONFIG_X86_32 -vm86_trap: - if (handle_vm86_trap((struct kernel_vm86_regs *) regs, - error_code, trapnr)) - goto trap_signal; - return; -#endif + exception_exit(prev_state); } #define DO_ERROR(trapnr, signr, str, name) \ dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ { \ - if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ - == NOTIFY_STOP) \ - return; \ - conditional_sti(regs); \ - do_trap(trapnr, signr, str, regs, error_code, NULL); \ -} - -#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \ -dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ -{ \ - siginfo_t info; \ - info.si_signo = signr; \ - info.si_errno = 0; \ - info.si_code = sicode; \ - info.si_addr = (void __user *)siaddr; \ - if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ - == NOTIFY_STOP) \ - return; \ - conditional_sti(regs); \ - do_trap(trapnr, signr, str, regs, error_code, &info); \ + do_error_trap(regs, error_code, str, trapnr, signr); \ } -DO_ERROR_INFO(X86_TRAP_DE, SIGFPE, "divide error", divide_error, FPE_INTDIV, - regs->ip) -DO_ERROR(X86_TRAP_OF, SIGSEGV, "overflow", overflow) -DO_ERROR(X86_TRAP_BR, SIGSEGV, "bounds", bounds) -DO_ERROR_INFO(X86_TRAP_UD, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, - regs->ip) -DO_ERROR(X86_TRAP_OLD_MF, SIGFPE, "coprocessor segment overrun", - coprocessor_segment_overrun) -DO_ERROR(X86_TRAP_TS, SIGSEGV, "invalid TSS", invalid_TSS) -DO_ERROR(X86_TRAP_NP, SIGBUS, "segment not present", segment_not_present) +DO_ERROR(X86_TRAP_DE, SIGFPE, "divide error", divide_error) +DO_ERROR(X86_TRAP_OF, SIGSEGV, "overflow", overflow) +DO_ERROR(X86_TRAP_BR, SIGSEGV, "bounds", bounds) +DO_ERROR(X86_TRAP_UD, SIGILL, "invalid opcode", invalid_op) +DO_ERROR(X86_TRAP_OLD_MF, SIGFPE, "coprocessor segment overrun",coprocessor_segment_overrun) +DO_ERROR(X86_TRAP_TS, SIGSEGV, "invalid TSS", invalid_TSS) +DO_ERROR(X86_TRAP_NP, SIGBUS, "segment not present", segment_not_present) #ifdef CONFIG_X86_32 -DO_ERROR(X86_TRAP_SS, SIGBUS, "stack segment", stack_segment) +DO_ERROR(X86_TRAP_SS, SIGBUS, "stack segment", stack_segment) #endif -DO_ERROR_INFO(X86_TRAP_AC, SIGBUS, "alignment check", alignment_check, - BUS_ADRALN, 0) +DO_ERROR(X86_TRAP_AC, SIGBUS, "alignment check", alignment_check) #ifdef CONFIG_X86_64 /* Runs on IST stack */ dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code) { + enum ctx_state prev_state; + + prev_state = exception_enter(); if (notify_die(DIE_TRAP, "stack segment", regs, error_code, - X86_TRAP_SS, SIGBUS) == NOTIFY_STOP) - return; - preempt_conditional_sti(regs); - do_trap(X86_TRAP_SS, SIGBUS, "stack segment", regs, error_code, NULL); - preempt_conditional_cli(regs); + X86_TRAP_SS, SIGBUS) != NOTIFY_STOP) { + preempt_conditional_sti(regs); + do_trap(X86_TRAP_SS, SIGBUS, "stack segment", regs, error_code, NULL); + preempt_conditional_cli(regs); + } + exception_exit(prev_state); } dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) @@ -236,12 +259,16 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) static const char str[] = "double fault"; struct task_struct *tsk = current; + exception_enter(); /* Return not checked because double check cannot be ignored */ notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV); tsk->thread.error_code = error_code; - tsk->thread.trap_no = X86_TRAP_DF; + tsk->thread.trap_nr = X86_TRAP_DF; +#ifdef CONFIG_DOUBLEFAULT + df_debug(regs, error_code); +#endif /* * This is always a kernel trap and never fixable (and thus must * never return). @@ -251,80 +278,100 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) } #endif -dotraplinkage void __kprobes +dotraplinkage void do_general_protection(struct pt_regs *regs, long error_code) { struct task_struct *tsk; + enum ctx_state prev_state; + prev_state = exception_enter(); conditional_sti(regs); #ifdef CONFIG_X86_32 - if (regs->flags & X86_VM_MASK) - goto gp_in_vm86; + if (regs->flags & X86_VM_MASK) { + local_irq_enable(); + handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code); + goto exit; + } #endif tsk = current; - if (!user_mode(regs)) - goto gp_in_kernel; + if (!user_mode(regs)) { + if (fixup_exception(regs)) + goto exit; + + tsk->thread.error_code = error_code; + tsk->thread.trap_nr = X86_TRAP_GP; + if (notify_die(DIE_GPF, "general protection fault", regs, error_code, + X86_TRAP_GP, SIGSEGV) != NOTIFY_STOP) + die("general protection fault", regs, error_code); + goto exit; + } tsk->thread.error_code = error_code; - tsk->thread.trap_no = X86_TRAP_GP; + tsk->thread.trap_nr = X86_TRAP_GP; if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && printk_ratelimit()) { - printk(KERN_INFO - "%s[%d] general protection ip:%lx sp:%lx error:%lx", + pr_info("%s[%d] general protection ip:%lx sp:%lx error:%lx", tsk->comm, task_pid_nr(tsk), regs->ip, regs->sp, error_code); print_vma_addr(" in ", regs->ip); - printk("\n"); + pr_cont("\n"); } - force_sig(SIGSEGV, tsk); - return; + force_sig_info(SIGSEGV, SEND_SIG_PRIV, tsk); +exit: + exception_exit(prev_state); +} +NOKPROBE_SYMBOL(do_general_protection); -#ifdef CONFIG_X86_32 -gp_in_vm86: - local_irq_enable(); - handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code); - return; -#endif +/* May run on IST stack. */ +dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code) +{ + enum ctx_state prev_state; -gp_in_kernel: - if (fixup_exception(regs)) +#ifdef CONFIG_DYNAMIC_FTRACE + /* + * ftrace must be first, everything else may cause a recursive crash. + * See note by declaration of modifying_ftrace_code in ftrace.c + */ + if (unlikely(atomic_read(&modifying_ftrace_code)) && + ftrace_int3_handler(regs)) return; - - tsk->thread.error_code = error_code; - tsk->thread.trap_no = X86_TRAP_GP; - if (notify_die(DIE_GPF, "general protection fault", regs, error_code, - X86_TRAP_GP, SIGSEGV) == NOTIFY_STOP) +#endif + if (poke_int3_handler(regs)) return; - die("general protection fault", regs, error_code); -} -/* May run on IST stack. */ -dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code) -{ + prev_state = exception_enter(); #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, SIGTRAP) == NOTIFY_STOP) - return; + goto exit; #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */ + #ifdef CONFIG_KPROBES + if (kprobe_int3_handler(regs)) + goto exit; +#endif if (notify_die(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, SIGTRAP) == NOTIFY_STOP) - return; -#else - if (notify_die(DIE_TRAP, "int3", regs, error_code, 3, SIGTRAP) - == NOTIFY_STOP) - return; -#endif + goto exit; + /* + * Let others (NMI) know that the debug stack is in use + * as we may switch to the interrupt stack. + */ + debug_stack_usage_inc(); preempt_conditional_sti(regs); do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL); preempt_conditional_cli(regs); + debug_stack_usage_dec(); +exit: + exception_exit(prev_state); } +NOKPROBE_SYMBOL(do_int3); #ifdef CONFIG_X86_64 /* @@ -332,7 +379,7 @@ dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code) * for scheduling or signal handling. The actual stack switch is done in * entry.S */ -asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs) +asmlinkage __visible struct pt_regs *sync_regs(struct pt_regs *eregs) { struct pt_regs *regs = eregs; /* Did already sync */ @@ -351,6 +398,7 @@ asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs) *regs = *eregs; return regs; } +NOKPROBE_SYMBOL(sync_regs); #endif /* @@ -377,13 +425,16 @@ asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs) * * May run on IST stack. */ -dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) +dotraplinkage void do_debug(struct pt_regs *regs, long error_code) { struct task_struct *tsk = current; + enum ctx_state prev_state; int user_icebp = 0; unsigned long dr6; int si_code; + prev_state = exception_enter(); + get_debugreg(dr6, 6); /* Filter out all the reserved bits which are preset to 1 */ @@ -399,7 +450,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) /* Catch kmemcheck conditions first of all! */ if ((dr6 & DR_STEP) && kmemcheck_trap(regs)) - return; + goto exit; /* DR6 may or may not be cleared by the CPU */ set_debugreg(0, 6); @@ -412,9 +463,20 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) /* Store the virtualized DR6 value */ tsk->thread.debugreg6 = dr6; - if (notify_die(DIE_DEBUG, "debug", regs, PTR_ERR(&dr6), error_code, +#ifdef CONFIG_KPROBES + if (kprobe_debug_handler(regs)) + goto exit; +#endif + + if (notify_die(DIE_DEBUG, "debug", regs, (long)&dr6, error_code, SIGTRAP) == NOTIFY_STOP) - return; + goto exit; + + /* + * Let others (NMI) know that the debug stack is in use + * as we may switch to the interrupt stack. + */ + debug_stack_usage_inc(); /* It's safe to allow irq's after DR6 has been saved */ preempt_conditional_sti(regs); @@ -423,7 +485,8 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, X86_TRAP_DB); preempt_conditional_cli(regs); - return; + debug_stack_usage_dec(); + goto exit; } /* @@ -442,16 +505,19 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp) send_sigtrap(tsk, regs, error_code, si_code); preempt_conditional_cli(regs); + debug_stack_usage_dec(); - return; +exit: + exception_exit(prev_state); } +NOKPROBE_SYMBOL(do_debug); /* * Note that we play around with the 'TS' bit in an attempt to get * the correct behaviour even in the presence of the asynchronous * IRQ13 behaviour */ -void math_error(struct pt_regs *regs, int error_code, int trapnr) +static void math_error(struct pt_regs *regs, int error_code, int trapnr) { struct task_struct *task = current; siginfo_t info; @@ -467,7 +533,7 @@ void math_error(struct pt_regs *regs, int error_code, int trapnr) { if (!fixup_exception(regs)) { task->thread.error_code = error_code; - task->thread.trap_no = trapnr; + task->thread.trap_nr = trapnr; die(str, regs, error_code); } return; @@ -477,11 +543,11 @@ 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); - task->thread.trap_no = trapnr; + task->thread.trap_nr = trapnr; task->thread.error_code = error_code; info.si_signo = SIGFPE; info.si_errno = 0; - info.si_addr = (void __user *)regs->ip; + info.si_addr = (void __user *)uprobe_get_trap_addr(regs); if (trapnr == X86_TRAP_MF) { unsigned short cwd, swd; /* @@ -537,17 +603,21 @@ void math_error(struct pt_regs *regs, int error_code, int trapnr) dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code) { -#ifdef CONFIG_X86_32 - ignore_fpu_irq = 1; -#endif + enum ctx_state prev_state; + prev_state = exception_enter(); math_error(regs, error_code, X86_TRAP_MF); + exception_exit(prev_state); } dotraplinkage void do_simd_coprocessor_error(struct pt_regs *regs, long error_code) { + enum ctx_state prev_state; + + prev_state = exception_enter(); math_error(regs, error_code, X86_TRAP_XF); + exception_exit(prev_state); } dotraplinkage void @@ -556,50 +626,19 @@ do_spurious_interrupt_bug(struct pt_regs *regs, long error_code) conditional_sti(regs); #if 0 /* No need to warn about this any longer. */ - printk(KERN_INFO "Ignoring P6 Local APIC Spurious Interrupt Bug...\n"); + pr_info("Ignoring P6 Local APIC Spurious Interrupt Bug...\n"); #endif } -asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void) +asmlinkage __visible void __attribute__((weak)) smp_thermal_interrupt(void) { } -asmlinkage void __attribute__((weak)) smp_threshold_interrupt(void) +asmlinkage __visible void __attribute__((weak)) smp_threshold_interrupt(void) { } /* - * This gets called with the process already owning the - * FPU state, and with CR0.TS cleared. It just needs to - * restore the FPU register state. - */ -void __math_state_restore(struct task_struct *tsk) -{ - /* We need a safe address that is cheap to find and that is already - in L1. We've just brought in "tsk->thread.has_fpu", so use that */ -#define safe_address (tsk->thread.has_fpu) - - /* AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception - is pending. Clear the x87 state here by setting it to fixed - values. safe_address is a random variable that should be in L1 */ - alternative_input( - ASM_NOP8 ASM_NOP2, - "emms\n\t" /* clear stack tags */ - "fildl %P[addr]", /* set F?P to defined value */ - X86_FEATURE_FXSAVE_LEAK, - [addr] "m" (safe_address)); - - /* - * Paranoid restore. send a SIGSEGV if we fail to restore the state. - */ - if (unlikely(restore_fpu_checking(tsk))) { - __thread_fpu_end(tsk); - force_sig(SIGSEGV, tsk); - return; - } -} - -/* * 'math_state_restore()' saves the current math information in the * old math state array, and gets the new ones from the current task * @@ -629,15 +668,28 @@ void math_state_restore(void) } __thread_fpu_begin(tsk); - __math_state_restore(tsk); - tsk->fpu_counter++; + /* + * Paranoid restore. send a SIGSEGV if we fail to restore the state. + */ + if (unlikely(restore_fpu_checking(tsk))) { + drop_init_fpu(tsk); + force_sig_info(SIGSEGV, SEND_SIG_PRIV, tsk); + return; + } + + tsk->thread.fpu_counter++; } EXPORT_SYMBOL_GPL(math_state_restore); -dotraplinkage void __kprobes +dotraplinkage void do_device_not_available(struct pt_regs *regs, long error_code) { + enum ctx_state prev_state; + + prev_state = exception_enter(); + BUG_ON(use_eager_fpu()); + #ifdef CONFIG_MATH_EMULATION if (read_cr0() & X86_CR0_EM) { struct math_emu_info info = { }; @@ -646,6 +698,7 @@ do_device_not_available(struct pt_regs *regs, long error_code) info.regs = regs; math_emulate(&info); + exception_exit(prev_state); return; } #endif @@ -653,12 +706,17 @@ do_device_not_available(struct pt_regs *regs, long error_code) #ifdef CONFIG_X86_32 conditional_sti(regs); #endif + exception_exit(prev_state); } +NOKPROBE_SYMBOL(do_device_not_available); #ifdef CONFIG_X86_32 dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code) { siginfo_t info; + enum ctx_state prev_state; + + prev_state = exception_enter(); local_irq_enable(); info.si_signo = SIGILL; @@ -666,10 +724,11 @@ dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code) info.si_code = ILL_BADSTK; info.si_addr = NULL; if (notify_die(DIE_TRAP, "iret exception", regs, error_code, - X86_TRAP_IRET, SIGILL) == NOTIFY_STOP) - return; - do_trap(X86_TRAP_IRET, SIGILL, "iret exception", regs, error_code, - &info); + X86_TRAP_IRET, SIGILL) != NOTIFY_STOP) { + do_trap(X86_TRAP_IRET, SIGILL, "iret exception", regs, error_code, + &info); + } + exception_exit(prev_state); } #endif @@ -679,10 +738,19 @@ void __init early_trap_init(void) 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); - set_intr_gate(X86_TRAP_PF, &page_fault); +#ifdef CONFIG_X86_32 + set_intr_gate(X86_TRAP_PF, page_fault); +#endif load_idt(&idt_descr); } +void __init early_trap_pf_init(void) +{ +#ifdef CONFIG_X86_64 + set_intr_gate(X86_TRAP_PF, page_fault); +#endif +} + void __init trap_init(void) { int i; @@ -695,30 +763,30 @@ void __init trap_init(void) early_iounmap(p, 4); #endif - set_intr_gate(X86_TRAP_DE, ÷_error); + set_intr_gate(X86_TRAP_DE, divide_error); set_intr_gate_ist(X86_TRAP_NMI, &nmi, NMI_STACK); /* int4 can be called from all */ set_system_intr_gate(X86_TRAP_OF, &overflow); - set_intr_gate(X86_TRAP_BR, &bounds); - set_intr_gate(X86_TRAP_UD, &invalid_op); - set_intr_gate(X86_TRAP_NM, &device_not_available); + set_intr_gate(X86_TRAP_BR, bounds); + set_intr_gate(X86_TRAP_UD, invalid_op); + set_intr_gate(X86_TRAP_NM, device_not_available); #ifdef CONFIG_X86_32 set_task_gate(X86_TRAP_DF, GDT_ENTRY_DOUBLEFAULT_TSS); #else set_intr_gate_ist(X86_TRAP_DF, &double_fault, DOUBLEFAULT_STACK); #endif - set_intr_gate(X86_TRAP_OLD_MF, &coprocessor_segment_overrun); - set_intr_gate(X86_TRAP_TS, &invalid_TSS); - set_intr_gate(X86_TRAP_NP, &segment_not_present); + set_intr_gate(X86_TRAP_OLD_MF, coprocessor_segment_overrun); + set_intr_gate(X86_TRAP_TS, invalid_TSS); + set_intr_gate(X86_TRAP_NP, segment_not_present); set_intr_gate_ist(X86_TRAP_SS, &stack_segment, STACKFAULT_STACK); - set_intr_gate(X86_TRAP_GP, &general_protection); - set_intr_gate(X86_TRAP_SPURIOUS, &spurious_interrupt_bug); - set_intr_gate(X86_TRAP_MF, &coprocessor_error); - set_intr_gate(X86_TRAP_AC, &alignment_check); + set_intr_gate(X86_TRAP_GP, general_protection); + set_intr_gate(X86_TRAP_SPURIOUS, spurious_interrupt_bug); + set_intr_gate(X86_TRAP_MF, coprocessor_error); + set_intr_gate(X86_TRAP_AC, alignment_check); #ifdef CONFIG_X86_MCE set_intr_gate_ist(X86_TRAP_MC, &machine_check, MCE_STACK); #endif - set_intr_gate(X86_TRAP_XF, &simd_coprocessor_error); + set_intr_gate(X86_TRAP_XF, simd_coprocessor_error); /* Reserve all the builtin and the syscall vector: */ for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++) @@ -735,9 +803,23 @@ void __init trap_init(void) #endif /* + * Set the IDT descriptor to a fixed read-only location, so that the + * "sidt" instruction will not leak the location of the kernel, and + * to defend the IDT against arbitrary memory write vulnerabilities. + * It will be reloaded in cpu_init() */ + __set_fixmap(FIX_RO_IDT, __pa_symbol(idt_table), PAGE_KERNEL_RO); + idt_descr.address = fix_to_virt(FIX_RO_IDT); + + /* * Should be a barrier for any external CPU state: */ cpu_init(); x86_init.irqs.trap_init(); + +#ifdef CONFIG_X86_64 + memcpy(&debug_idt_table, &idt_table, IDT_ENTRIES * 16); + set_nmi_gate(X86_TRAP_DB, &debug); + set_nmi_gate(X86_TRAP_BP, &int3); +#endif } |