diff options
Diffstat (limited to 'arch/x86/kernel/traps_64.c')
| -rw-r--r-- | arch/x86/kernel/traps_64.c | 1138 |
1 files changed, 1138 insertions, 0 deletions
diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c new file mode 100644 index 000000000000..03888420775d --- /dev/null +++ b/arch/x86/kernel/traps_64.c @@ -0,0 +1,1138 @@ +/* + * linux/arch/x86-64/traps.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs + * + * Pentium III FXSR, SSE support + * Gareth Hughes <gareth@valinux.com>, May 2000 + */ + +/* + * 'Traps.c' handles hardware traps and faults after we have saved some + * state in 'entry.S'. + */ +#include <linux/sched.h> +#include <linux/kernel.h> +#include <linux/string.h> +#include <linux/errno.h> +#include <linux/ptrace.h> +#include <linux/timer.h> +#include <linux/mm.h> +#include <linux/init.h> +#include <linux/delay.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <linux/kallsyms.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/nmi.h> +#include <linux/kprobes.h> +#include <linux/kexec.h> +#include <linux/unwind.h> +#include <linux/uaccess.h> +#include <linux/bug.h> +#include <linux/kdebug.h> + +#if defined(CONFIG_EDAC) +#include <linux/edac.h> +#endif + +#include <asm/system.h> +#include <asm/io.h> +#include <asm/atomic.h> +#include <asm/debugreg.h> +#include <asm/desc.h> +#include <asm/i387.h> +#include <asm/processor.h> +#include <asm/unwind.h> +#include <asm/smp.h> +#include <asm/pgalloc.h> +#include <asm/pda.h> +#include <asm/proto.h> +#include <asm/nmi.h> +#include <asm/stacktrace.h> + +asmlinkage void divide_error(void); +asmlinkage void debug(void); +asmlinkage void nmi(void); +asmlinkage void int3(void); +asmlinkage void overflow(void); +asmlinkage void bounds(void); +asmlinkage void invalid_op(void); +asmlinkage void device_not_available(void); +asmlinkage void double_fault(void); +asmlinkage void coprocessor_segment_overrun(void); +asmlinkage void invalid_TSS(void); +asmlinkage void segment_not_present(void); +asmlinkage void stack_segment(void); +asmlinkage void general_protection(void); +asmlinkage void page_fault(void); +asmlinkage void coprocessor_error(void); +asmlinkage void simd_coprocessor_error(void); +asmlinkage void reserved(void); +asmlinkage void alignment_check(void); +asmlinkage void machine_check(void); +asmlinkage void spurious_interrupt_bug(void); + +static inline void conditional_sti(struct pt_regs *regs) +{ + if (regs->eflags & X86_EFLAGS_IF) + local_irq_enable(); +} + +static inline void preempt_conditional_sti(struct pt_regs *regs) +{ + preempt_disable(); + if (regs->eflags & X86_EFLAGS_IF) + local_irq_enable(); +} + +static inline void preempt_conditional_cli(struct pt_regs *regs) +{ + if (regs->eflags & X86_EFLAGS_IF) + local_irq_disable(); + /* Make sure to not schedule here because we could be running + on an exception stack. */ + preempt_enable_no_resched(); +} + +int kstack_depth_to_print = 12; + +#ifdef CONFIG_KALLSYMS +void printk_address(unsigned long address) +{ + unsigned long offset = 0, symsize; + const char *symname; + char *modname; + char *delim = ":"; + char namebuf[128]; + + symname = kallsyms_lookup(address, &symsize, &offset, + &modname, namebuf); + if (!symname) { + printk(" [<%016lx>]\n", address); + return; + } + if (!modname) + modname = delim = ""; + printk(" [<%016lx>] %s%s%s%s+0x%lx/0x%lx\n", + address, delim, modname, delim, symname, offset, symsize); +} +#else +void printk_address(unsigned long address) +{ + printk(" [<%016lx>]\n", address); +} +#endif + +static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack, + unsigned *usedp, char **idp) +{ + static char ids[][8] = { + [DEBUG_STACK - 1] = "#DB", + [NMI_STACK - 1] = "NMI", + [DOUBLEFAULT_STACK - 1] = "#DF", + [STACKFAULT_STACK - 1] = "#SS", + [MCE_STACK - 1] = "#MC", +#if DEBUG_STKSZ > EXCEPTION_STKSZ + [N_EXCEPTION_STACKS ... N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]" +#endif + }; + unsigned k; + + /* + * Iterate over all exception stacks, and figure out whether + * 'stack' is in one of them: + */ + for (k = 0; k < N_EXCEPTION_STACKS; k++) { + unsigned long end = per_cpu(orig_ist, cpu).ist[k]; + /* + * Is 'stack' above this exception frame's end? + * If yes then skip to the next frame. + */ + if (stack >= end) + continue; + /* + * Is 'stack' above this exception frame's start address? + * If yes then we found the right frame. + */ + if (stack >= end - EXCEPTION_STKSZ) { + /* + * Make sure we only iterate through an exception + * stack once. If it comes up for the second time + * then there's something wrong going on - just + * break out and return NULL: + */ + if (*usedp & (1U << k)) + break; + *usedp |= 1U << k; + *idp = ids[k]; + return (unsigned long *)end; + } + /* + * If this is a debug stack, and if it has a larger size than + * the usual exception stacks, then 'stack' might still + * be within the lower portion of the debug stack: + */ +#if DEBUG_STKSZ > EXCEPTION_STKSZ + if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) { + unsigned j = N_EXCEPTION_STACKS - 1; + + /* + * Black magic. A large debug stack is composed of + * multiple exception stack entries, which we + * iterate through now. Dont look: + */ + do { + ++j; + end -= EXCEPTION_STKSZ; + ids[j][4] = '1' + (j - N_EXCEPTION_STACKS); + } while (stack < end - EXCEPTION_STKSZ); + if (*usedp & (1U << j)) + break; + *usedp |= 1U << j; + *idp = ids[j]; + return (unsigned long *)end; + } +#endif + } + return NULL; +} + +#define MSG(txt) ops->warning(data, txt) + +/* + * x86-64 can have upto three kernel stacks: + * process stack + * interrupt stack + * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack + */ + +static inline int valid_stack_ptr(struct thread_info *tinfo, void *p) +{ + void *t = (void *)tinfo; + return p > t && p < t + THREAD_SIZE - 3; +} + +void dump_trace(struct task_struct *tsk, struct pt_regs *regs, + unsigned long *stack, + struct stacktrace_ops *ops, void *data) +{ + const unsigned cpu = get_cpu(); + unsigned long *irqstack_end = (unsigned long*)cpu_pda(cpu)->irqstackptr; + unsigned used = 0; + struct thread_info *tinfo; + + if (!tsk) + tsk = current; + + if (!stack) { + unsigned long dummy; + stack = &dummy; + if (tsk && tsk != current) + stack = (unsigned long *)tsk->thread.rsp; + } + + /* + * Print function call entries within a stack. 'cond' is the + * "end of stackframe" condition, that the 'stack++' + * iteration will eventually trigger. + */ +#define HANDLE_STACK(cond) \ + do while (cond) { \ + unsigned long addr = *stack++; \ + /* Use unlocked access here because except for NMIs \ + we should be already protected against module unloads */ \ + if (__kernel_text_address(addr)) { \ + /* \ + * If the address is either in the text segment of the \ + * kernel, or in the region which contains vmalloc'ed \ + * memory, it *may* be the address of a calling \ + * routine; if so, print it so that someone tracing \ + * down the cause of the crash will be able to figure \ + * out the call path that was taken. \ + */ \ + ops->address(data, addr); \ + } \ + } while (0) + + /* + * Print function call entries in all stacks, starting at the + * current stack address. If the stacks consist of nested + * exceptions + */ + for (;;) { + char *id; + unsigned long *estack_end; + estack_end = in_exception_stack(cpu, (unsigned long)stack, + &used, &id); + + if (estack_end) { + if (ops->stack(data, id) < 0) + break; + HANDLE_STACK (stack < estack_end); + ops->stack(data, "<EOE>"); + /* + * We link to the next stack via the + * second-to-last pointer (index -2 to end) in the + * exception stack: + */ + stack = (unsigned long *) estack_end[-2]; + continue; + } + if (irqstack_end) { + unsigned long *irqstack; + irqstack = irqstack_end - + (IRQSTACKSIZE - 64) / sizeof(*irqstack); + + if (stack >= irqstack && stack < irqstack_end) { + if (ops->stack(data, "IRQ") < 0) + break; + HANDLE_STACK (stack < irqstack_end); + /* + * We link to the next stack (which would be + * the process stack normally) the last + * pointer (index -1 to end) in the IRQ stack: + */ + stack = (unsigned long *) (irqstack_end[-1]); + irqstack_end = NULL; + ops->stack(data, "EOI"); + continue; + } + } + break; + } + + /* + * This handles the process stack: + */ + tinfo = task_thread_info(tsk); + HANDLE_STACK (valid_stack_ptr(tinfo, stack)); +#undef HANDLE_STACK + put_cpu(); +} +EXPORT_SYMBOL(dump_trace); + +static void +print_trace_warning_symbol(void *data, char *msg, unsigned long symbol) +{ + print_symbol(msg, symbol); + printk("\n"); +} + +static void print_trace_warning(void *data, char *msg) +{ + printk("%s\n", msg); +} + +static int print_trace_stack(void *data, char *name) +{ + printk(" <%s> ", name); + return 0; +} + +static void print_trace_address(void *data, unsigned long addr) +{ + touch_nmi_watchdog(); + printk_address(addr); +} + +static struct stacktrace_ops print_trace_ops = { + .warning = print_trace_warning, + .warning_symbol = print_trace_warning_symbol, + .stack = print_trace_stack, + .address = print_trace_address, +}; + +void +show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack) +{ + printk("\nCall Trace:\n"); + dump_trace(tsk, regs, stack, &print_trace_ops, NULL); + printk("\n"); +} + +static void +_show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *rsp) +{ + unsigned long *stack; + int i; + const int cpu = smp_processor_id(); + unsigned long *irqstack_end = (unsigned long *) (cpu_pda(cpu)->irqstackptr); + unsigned long *irqstack = (unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE); + + // debugging aid: "show_stack(NULL, NULL);" prints the + // back trace for this cpu. + + if (rsp == NULL) { + if (tsk) + rsp = (unsigned long *)tsk->thread.rsp; + else + rsp = (unsigned long *)&rsp; + } + + stack = rsp; + for(i=0; i < kstack_depth_to_print; i++) { + if (stack >= irqstack && stack <= irqstack_end) { + if (stack == irqstack_end) { + stack = (unsigned long *) (irqstack_end[-1]); + printk(" <EOI> "); + } + } else { + if (((long) stack & (THREAD_SIZE-1)) == 0) + break; + } + if (i && ((i % 4) == 0)) + printk("\n"); + printk(" %016lx", *stack++); + touch_nmi_watchdog(); + } + show_trace(tsk, regs, rsp); +} + +void show_stack(struct task_struct *tsk, unsigned long * rsp) +{ + _show_stack(tsk, NULL, rsp); +} + +/* + * The architecture-independent dump_stack generator + */ +void dump_stack(void) +{ + unsigned long dummy; + show_trace(NULL, NULL, &dummy); +} + +EXPORT_SYMBOL(dump_stack); + +void show_registers(struct pt_regs *regs) +{ + int i; + int in_kernel = !user_mode(regs); + unsigned long rsp; + const int cpu = smp_processor_id(); + struct task_struct *cur = cpu_pda(cpu)->pcurrent; + + rsp = regs->rsp; + printk("CPU %d ", cpu); + __show_regs(regs); + printk("Process %s (pid: %d, threadinfo %p, task %p)\n", + cur->comm, cur->pid, task_thread_info(cur), cur); + + /* + * When in-kernel, we also print out the stack and code at the + * time of the fault.. + */ + if (in_kernel) { + printk("Stack: "); + _show_stack(NULL, regs, (unsigned long*)rsp); + + printk("\nCode: "); + if (regs->rip < PAGE_OFFSET) + goto bad; + + for (i=0; i<20; i++) { + unsigned char c; + if (__get_user(c, &((unsigned char*)regs->rip)[i])) { +bad: + printk(" Bad RIP value."); + break; + } + printk("%02x ", c); + } + } + printk("\n"); +} + +int is_valid_bugaddr(unsigned long rip) +{ + unsigned short ud2; + + if (__copy_from_user(&ud2, (const void __user *) rip, sizeof(ud2))) + return 0; + + return ud2 == 0x0b0f; +} + +#ifdef CONFIG_BUG +void out_of_line_bug(void) +{ + BUG(); +} +EXPORT_SYMBOL(out_of_line_bug); +#endif + +static DEFINE_SPINLOCK(die_lock); +static int die_owner = -1; +static unsigned int die_nest_count; + +unsigned __kprobes long oops_begin(void) +{ + int cpu; + unsigned long flags; + + oops_enter(); + + /* racy, but better than risking deadlock. */ + local_irq_save(flags); + cpu = smp_processor_id(); + if (!spin_trylock(&die_lock)) { + if (cpu == die_owner) + /* nested oops. should stop eventually */; + else + spin_lock(&die_lock); + } + die_nest_count++; + die_owner = cpu; + console_verbose(); + bust_spinlocks(1); + return flags; +} + +void __kprobes oops_end(unsigned long flags) +{ + die_owner = -1; + bust_spinlocks(0); + die_nest_count--; + if (die_nest_count) + /* We still own the lock */ + local_irq_restore(flags); + else + /* Nest count reaches zero, release the lock. */ + spin_unlock_irqrestore(&die_lock, flags); + if (panic_on_oops) + panic("Fatal exception"); + oops_exit(); +} + +void __kprobes __die(const char * str, struct pt_regs * regs, long err) +{ + static int die_counter; + printk(KERN_EMERG "%s: %04lx [%u] ", str, err & 0xffff,++die_counter); +#ifdef CONFIG_PREEMPT + printk("PREEMPT "); +#endif +#ifdef CONFIG_SMP + printk("SMP "); +#endif +#ifdef CONFIG_DEBUG_PAGEALLOC + printk("DEBUG_PAGEALLOC"); +#endif + printk("\n"); + notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV); + show_registers(regs); + add_taint(TAINT_DIE); + /* Executive summary in case the oops scrolled away */ + printk(KERN_ALERT "RIP "); + printk_address(regs->rip); + printk(" RSP <%016lx>\n", regs->rsp); + if (kexec_should_crash(current)) + crash_kexec(regs); +} + +void die(const char * str, struct pt_regs * regs, long err) +{ + unsigned long flags = oops_begin(); + + if (!user_mode(regs)) + report_bug(regs->rip, regs); + + __die(str, regs, err); + oops_end(flags); + do_exit(SIGSEGV); +} + +void __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic) +{ + unsigned long flags = oops_begin(); + + /* + * We are in trouble anyway, lets at least try + * to get a message out. + */ + printk(str, smp_processor_id()); + show_registers(regs); + if (kexec_should_crash(current)) + crash_kexec(regs); + if (do_panic || panic_on_oops) + panic("Non maskable interrupt"); + oops_end(flags); + nmi_exit(); + local_irq_enable(); + do_exit(SIGSEGV); +} + +static void __kprobes do_trap(int trapnr, int signr, char *str, + struct pt_regs * regs, long error_code, + siginfo_t *info) +{ + struct task_struct *tsk = current; + + if (user_mode(regs)) { + /* + * We want error_code and trap_no 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 kernel fault information, + * so that won't result in polluting the information + * about previously queued, but not yet delivered, + * faults. See also do_general_protection below. + */ + tsk->thread.error_code = error_code; + tsk->thread.trap_no = trapnr; + + if (show_unhandled_signals && unhandled_signal(tsk, signr) && + printk_ratelimit()) + printk(KERN_INFO + "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n", + tsk->comm, tsk->pid, str, + regs->rip, regs->rsp, error_code); + + if (info) + force_sig_info(signr, info, tsk); + else + force_sig(signr, tsk); + return; + } + + + /* kernel trap */ + { + const struct exception_table_entry *fixup; + fixup = search_exception_tables(regs->rip); + if (fixup) + regs->rip = fixup->fixup; + else { + tsk->thread.error_code = error_code; + tsk->thread.trap_no = trapnr; + die(str, regs, error_code); + } + return; + } +} + +#define DO_ERROR(trapnr, signr, str, name) \ +asmlinkage 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) \ +asmlinkage 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_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->rip) +DO_ERROR( 4, SIGSEGV, "overflow", overflow) +DO_ERROR( 5, SIGSEGV, "bounds", bounds) +DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->rip) +DO_ERROR( 7, SIGSEGV, "device not available", device_not_available) +DO_ERROR( 9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun) +DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS) +DO_ERROR(11, SIGBUS, "segment not present", segment_not_present) +DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0) +DO_ERROR(18, SIGSEGV, "reserved", reserved) + +/* Runs on IST stack */ +asmlinkage void do_stack_segment(struct pt_regs *regs, long error_code) +{ + if (notify_die(DIE_TRAP, "stack segment", regs, error_code, + 12, SIGBUS) == NOTIFY_STOP) + return; + preempt_conditional_sti(regs); + do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL); + preempt_conditional_cli(regs); +} + +asmlinkage void do_double_fault(struct pt_regs * regs, long error_code) +{ + static const char str[] = "double fault"; + struct task_struct *tsk = current; + + /* Return not checked because double check cannot be ignored */ + notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV); + + tsk->thread.error_code = error_code; + tsk->thread.trap_no = 8; + + /* This is always a kernel trap and never fixable (and thus must + never return). */ + for (;;) + die(str, regs, error_code); +} + +asmlinkage void __kprobes do_general_protection(struct pt_regs * regs, + long error_code) +{ + struct task_struct *tsk = current; + + conditional_sti(regs); + + if (user_mode(regs)) { + tsk->thread.error_code = error_code; + tsk->thread.trap_no = 13; + + if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && + printk_ratelimit()) + printk(KERN_INFO + "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n", + tsk->comm, tsk->pid, + regs->rip, regs->rsp, error_code); + + force_sig(SIGSEGV, tsk); + return; + } + + /* kernel gp */ + { + const struct exception_table_entry *fixup; + fixup = search_exception_tables(regs->rip); + if (fixup) { + regs->rip = fixup->fixup; + return; + } + + tsk->thread.error_code = error_code; + tsk->thread.trap_no = 13; + if (notify_die(DIE_GPF, "general protection fault", regs, + error_code, 13, SIGSEGV) == NOTIFY_STOP) + return; + die("general protection fault", regs, error_code); + } +} + +static __kprobes void +mem_parity_error(unsigned char reason, struct pt_regs * regs) +{ + printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n", + reason); + printk(KERN_EMERG "You have some hardware problem, likely on the PCI bus.\n"); + +#if defined(CONFIG_EDAC) + if(edac_handler_set()) { + edac_atomic_assert_error(); + return; + } +#endif + + if (panic_on_unrecovered_nmi) + panic("NMI: Not continuing"); + + printk(KERN_EMERG "Dazed and confused, but trying to continue\n"); + + /* Clear and disable the memory parity error line. */ + reason = (reason & 0xf) | 4; + outb(reason, 0x61); +} + +static __kprobes void +io_check_error(unsigned char reason, struct pt_regs * regs) +{ + printk("NMI: IOCK error (debug interrupt?)\n"); + show_registers(regs); + + /* Re-enable the IOCK line, wait for a few seconds */ + reason = (reason & 0xf) | 8; + outb(reason, 0x61); + mdelay(2000); + reason &= ~8; + outb(reason, 0x61); +} + +static __kprobes void +unknown_nmi_error(unsigned char reason, struct pt_regs * regs) +{ + printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n", + reason); + printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n"); + + if (panic_on_unrecovered_nmi) + panic("NMI: Not continuing"); + + printk(KERN_EMERG "Dazed and confused, but trying to continue\n"); +} + +/* Runs on IST stack. This code must keep interrupts off all the time. + Nested NMIs are prevented by the CPU. */ +asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs) +{ + unsigned char reason = 0; + int cpu; + + cpu = smp_processor_id(); + + /* Only the BSP gets external NMIs from the system. */ + if (!cpu) + reason = get_nmi_reason(); + + if (!(reason & 0xc0)) { + if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT) + == NOTIFY_STOP) + return; + /* + * Ok, so this is none of the documented NMI sources, + * so it must be the NMI watchdog. + */ + if (nmi_watchdog_tick(regs,reason)) + return; + if (!do_nmi_callback(regs,cpu)) + unknown_nmi_error(reason, regs); + + return; + } + if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP) + return; + + /* AK: following checks seem to be broken on modern chipsets. FIXME */ + + if (reason & 0x80) + mem_parity_error(reason, regs); + if (reason & 0x40) + io_check_error(reason, regs); +} + +/* runs on IST stack. */ +asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code) +{ + if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) { + return; + } + preempt_conditional_sti(regs); + do_trap(3, SIGTRAP, "int3", regs, error_code, NULL); + preempt_conditional_cli(regs); +} + +/* Help handler running on IST stack to switch back to user stack + 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) +{ + struct pt_regs *regs = eregs; + /* Did already sync */ + if (eregs == (struct pt_regs *)eregs->rsp) + ; + /* Exception from user space */ + else if (user_mode(eregs)) + regs = task_pt_regs(current); + /* Exception from kernel and interrupts are enabled. Move to + kernel process stack. */ + else if (eregs->eflags & X86_EFLAGS_IF) + regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs)); + if (eregs != regs) + *regs = *eregs; + return regs; +} + +/* runs on IST stack. */ +asmlinkage void __kprobes do_debug(struct pt_regs * regs, + unsigned long error_code) +{ + unsigned long condition; + struct task_struct *tsk = current; + siginfo_t info; + + get_debugreg(condition, 6); + + if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code, + SIGTRAP) == NOTIFY_STOP) + return; + + preempt_conditional_sti(regs); + + /* Mask out spurious debug traps due to lazy DR7 setting */ + if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) { + if (!tsk->thread.debugreg7) { + goto clear_dr7; + } + } + + tsk->thread.debugreg6 = condition; + + /* Mask out spurious TF errors due to lazy TF clearing */ + if (condition & DR_STEP) { + /* + * The TF error should be masked out only if the current + * process is not traced and if the TRAP flag has been set + * previously by a tracing process (condition detected by + * the PT_DTRACE flag); remember that the i386 TRAP flag + * can be modified by the process itself in user mode, + * allowing programs to debug themselves without the ptrace() + * interface. + */ + if (!user_mode(regs)) + goto clear_TF_reenable; + /* + * Was the TF flag set by a debugger? If so, clear it now, + * so that register information is correct. + */ + if (tsk->ptrace & PT_DTRACE) { + regs->eflags &= ~TF_MASK; + tsk->ptrace &= ~PT_DTRACE; + } + } + + /* Ok, finally something we can handle */ + tsk->thread.trap_no = 1; + tsk->thread.error_code = error_code; + info.si_signo = SIGTRAP; + info.si_errno = 0; + info.si_code = TRAP_BRKPT; + info.si_addr = user_mode(regs) ? (void __user *)regs->rip : NULL; + force_sig_info(SIGTRAP, &info, tsk); + +clear_dr7: + set_debugreg(0UL, 7); + preempt_conditional_cli(regs); + return; + +clear_TF_reenable: + set_tsk_thread_flag(tsk, TIF_SINGLESTEP); + regs->eflags &= ~TF_MASK; + preempt_conditional_cli(regs); +} + +static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr) +{ + const struct exception_table_entry *fixup; + fixup = search_exception_tables(regs->rip); + if (fixup) { + regs->rip = fixup->fixup; + return 1; + } + notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE); + /* Illegal floating point operation in the kernel */ + current->thread.trap_no = trapnr; + die(str, regs, 0); + return 0; +} + +/* + * 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 + */ +asmlinkage void do_coprocessor_error(struct pt_regs *regs) +{ + void __user *rip = (void __user *)(regs->rip); + struct task_struct * task; + siginfo_t info; + unsigned short cwd, swd; + + conditional_sti(regs); + if (!user_mode(regs) && + kernel_math_error(regs, "kernel x87 math error", 16)) + return; + + /* + * Save the info for the exception handler and clear the error. + */ + task = current; + save_init_fpu(task); + task->thread.trap_no = 16; + task->thread.error_code = 0; + info.si_signo = SIGFPE; + info.si_errno = 0; + info.si_code = __SI_FAULT; + info.si_addr = rip; + /* + * (~cwd & swd) will mask out exceptions that are not set to unmasked + * status. 0x3f is the exception bits in these regs, 0x200 is the + * C1 reg you need in case of a stack fault, 0x040 is the stack + * fault bit. We should only be taking one exception at a time, + * so if this combination doesn't produce any single exception, + * then we have a bad program that isn't synchronizing its FPU usage + * and it will suffer the consequences since we won't be able to + * fully reproduce the context of the exception + */ + cwd = get_fpu_cwd(task); + swd = get_fpu_swd(task); + switch (swd & ~cwd & 0x3f) { + case 0x000: + default: + break; + case 0x001: /* Invalid Op */ + /* + * swd & 0x240 == 0x040: Stack Underflow + * swd & 0x240 == 0x240: Stack Overflow + * User must clear the SF bit (0x40) if set + */ + info.si_code = FPE_FLTINV; + break; + case 0x002: /* Denormalize */ + case 0x010: /* Underflow */ + info.si_code = FPE_FLTUND; + break; + case 0x004: /* Zero Divide */ + info.si_code = FPE_FLTDIV; + break; + case 0x008: /* Overflow */ + info.si_code = FPE_FLTOVF; + break; + case 0x020: /* Precision */ + info.si_code = FPE_FLTRES; + break; + } + force_sig_info(SIGFPE, &info, task); +} + +asmlinkage void bad_intr(void) +{ + printk("bad interrupt"); +} + +asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs) +{ + void __user *rip = (void __user *)(regs->rip); + struct task_struct * task; + siginfo_t info; + unsigned short mxcsr; + + conditional_sti(regs); + if (!user_mode(regs) && + kernel_math_error(regs, "kernel simd math error", 19)) + return; + + /* + * Save the info for the exception handler and clear the error. + */ + task = current; + save_init_fpu(task); + task->thread.trap_no = 19; + task->thread.error_code = 0; + info.si_signo = SIGFPE; + info.si_errno = 0; + info.si_code = __SI_FAULT; + info.si_addr = rip; + /* + * The SIMD FPU exceptions are handled a little differently, as there + * is only a single status/control register. Thus, to determine which + * unmasked exception was caught we must mask the exception mask bits + * at 0x1f80, and then use these to mask the exception bits at 0x3f. + */ + mxcsr = get_fpu_mxcsr(task); + switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) { + case 0x000: + default: + break; + case 0x001: /* Invalid Op */ + info.si_code = FPE_FLTINV; + break; + case 0x002: /* Denormalize */ + case 0x010: /* Underflow */ + info.si_code = FPE_FLTUND; + break; + case 0x004: /* Zero Divide */ + info.si_code = FPE_FLTDIV; + break; + case 0x008: /* Overflow */ + info.si_code = FPE_FLTOVF; + break; + case 0x020: /* Precision */ + info.si_code = FPE_FLTRES; + break; + } + force_sig_info(SIGFPE, &info, task); +} + +asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs) +{ +} + +asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void) +{ +} + +asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void) +{ +} + +/* + * 'math_state_restore()' saves the current math information in the + * old math state array, and gets the new ones from the current task + * + * Careful.. There are problems with IBM-designed IRQ13 behaviour. + * Don't touch unless you *really* know how it works. + */ +asmlinkage void math_state_restore(void) +{ + struct task_struct *me = current; + clts(); /* Allow maths ops (or we recurse) */ + + if (!used_math()) + init_fpu(me); + restore_fpu_checking(&me->thread.i387.fxsave); + task_thread_info(me)->status |= TS_USEDFPU; + me->fpu_counter++; +} + +void __init trap_init(void) +{ + set_intr_gate(0,÷_error); + set_intr_gate_ist(1,&debug,DEBUG_STACK); + set_intr_gate_ist(2,&nmi,NMI_STACK); + set_system_gate_ist(3,&int3,DEBUG_STACK); /* int3 can be called from all */ + set_system_gate(4,&overflow); /* int4 can be called from all */ + set_intr_gate(5,&bounds); + set_intr_gate(6,&invalid_op); + set_intr_gate(7,&device_not_available); + set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK); + set_intr_gate(9,&coprocessor_segment_overrun); + set_intr_gate(10,&invalid_TSS); + set_intr_gate(11,&segment_not_present); + set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK); + set_intr_gate(13,&general_protection); + set_intr_gate(14,&page_fault); + set_intr_gate(15,&spurious_interrupt_bug); + set_intr_gate(16,&coprocessor_error); + set_intr_gate(17,&alignment_check); +#ifdef CONFIG_X86_MCE + set_intr_gate_ist(18,&machine_check, MCE_STACK); +#endif + set_intr_gate(19,&simd_coprocessor_error); + +#ifdef CONFIG_IA32_EMULATION + set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall); +#endif + + /* + * Should be a barrier for any external CPU state. + */ + cpu_init(); +} + + +static int __init oops_setup(char *s) +{ + if (!s) + return -EINVAL; + if (!strcmp(s, "panic")) + panic_on_oops = 1; + return 0; +} +early_param("oops", oops_setup); + +static int __init kstack_setup(char *s) +{ + if (!s) + return -EINVAL; + kstack_depth_to_print = simple_strtoul(s,NULL,0); + return 0; +} +early_param("kstack", kstack_setup); |