--- /dev/null
+/*
+ * 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
+ *
+ * $Id: traps.c,v 1.36 2002/03/24 11:09:10 ak Exp $
+ */
+
+/*
+ * 'Traps.c' handles hardware traps and faults after we have saved some
+ * state in 'entry.S'.
+ */
+#include <linux/config.h>
+#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/module.h>
+#include <linux/moduleparam.h>
+#include <linux/nmi.h>
+#include <linux/kprobes.h>
+#include <linux/kexec.h>
+
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm/atomic.h>
+#include <asm/debugreg.h>
+#include <asm/desc.h>
+#include <asm/i387.h>
+#include <asm/kdebug.h>
+#include <asm/processor.h>
+
+#include <asm/smp.h>
+#include <asm/pgalloc.h>
+#include <asm/pda.h>
+#include <asm/proto.h>
+#include <asm/nmi.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);
+
+ATOMIC_NOTIFIER_HEAD(die_chain);
+
+int register_die_notifier(struct notifier_block *nb)
+{
+ vmalloc_sync_all();
+ return atomic_notifier_chain_register(&die_chain, nb);
+}
+EXPORT_SYMBOL(register_die_notifier);
+
+int unregister_die_notifier(struct notifier_block *nb)
+{
+ return atomic_notifier_chain_unregister(&die_chain, nb);
+}
+EXPORT_SYMBOL(unregister_die_notifier);
+
+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();
+ preempt_enable_no_resched();
+}
+
+static int kstack_depth_to_print = 10;
+
+#ifdef CONFIG_KALLSYMS
+#include <linux/kallsyms.h>
+int 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)
+ return printk("[<%016lx>]", address);
+ if (!modname)
+ modname = delim = "";
+ return printk("<%016lx>{%s%s%s%s%+ld}",
+ address, delim, modname, delim, symname, offset);
+}
+#else
+int printk_address(unsigned long address)
+{
+ return printk("[<%016lx>]", address);
+}
+#endif
+
+static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
+ unsigned *usedp, const char **idp)
+{
+#ifndef CONFIG_X86_NO_TSS
+ 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;
+
+ for (k = 0; k < N_EXCEPTION_STACKS; k++) {
+ unsigned long end;
+
+ switch (k + 1) {
+#if DEBUG_STKSZ > EXCEPTION_STKSZ
+ case DEBUG_STACK:
+ end = cpu_pda(cpu)->debugstack + DEBUG_STKSZ;
+ break;
+#endif
+ default:
+ end = per_cpu(init_tss, cpu).ist[k];
+ break;
+ }
+ if (stack >= end)
+ continue;
+ if (stack >= end - EXCEPTION_STKSZ) {
+ if (*usedp & (1U << k))
+ break;
+ *usedp |= 1U << k;
+ *idp = ids[k];
+ return (unsigned long *)end;
+ }
+#if DEBUG_STKSZ > EXCEPTION_STKSZ
+ if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
+ unsigned j = N_EXCEPTION_STACKS - 1;
+
+ 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
+ }
+#endif
+ return NULL;
+}
+
+/*
+ * x86-64 can have upto three kernel stacks:
+ * process stack
+ * interrupt stack
+ * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
+ */
+
+void show_trace(unsigned long *stack)
+{
+ const unsigned cpu = safe_smp_processor_id();
+ unsigned long *irqstack_end = (unsigned long *)cpu_pda(cpu)->irqstackptr;
+ int i;
+ unsigned used = 0;
+
+ printk("\nCall Trace:");
+
+#define HANDLE_STACK(cond) \
+ do while (cond) { \
+ unsigned long addr = *stack++; \
+ if (kernel_text_address(addr)) { \
+ if (i > 50) { \
+ printk("\n "); \
+ i = 0; \
+ } \
+ else \
+ i += printk(" "); \
+ /* \
+ * 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. \
+ */ \
+ i += printk_address(addr); \
+ } \
+ } while (0)
+
+ for(i = 11; ; ) {
+ const char *id;
+ unsigned long *estack_end;
+ estack_end = in_exception_stack(cpu, (unsigned long)stack,
+ &used, &id);
+
+ if (estack_end) {
+ i += printk(" <%s>", id);
+ HANDLE_STACK (stack < estack_end);
+ i += printk(" <EOE>");
+ 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) {
+ i += printk(" <IRQ>");
+ HANDLE_STACK (stack < irqstack_end);
+ stack = (unsigned long *) (irqstack_end[-1]);
+ irqstack_end = NULL;
+ i += printk(" <EOI>");
+ continue;
+ }
+ }
+ break;
+ }
+
+ HANDLE_STACK (((long) stack & (THREAD_SIZE-1)) != 0);
+#undef HANDLE_STACK
+ printk("\n");
+}
+
+void show_stack(struct task_struct *tsk, unsigned long * rsp)
+{
+ unsigned long *stack;
+ int i;
+ const int cpu = safe_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((unsigned long *)rsp);
+}
+
+/*
+ * The architecture-independent dump_stack generator
+ */
+void dump_stack(void)
+{
+ unsigned long dummy;
+ show_trace(&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 = safe_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, (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");
+}
+
+void handle_BUG(struct pt_regs *regs)
+{
+ struct bug_frame f;
+ long len;
+ const char *prefix = "";
+
+ if (user_mode(regs))
+ return;
+ if (__copy_from_user(&f, (const void __user *) regs->rip,
+ sizeof(struct bug_frame)))
+ return;
+ if (f.filename >= 0 ||
+ f.ud2[0] != 0x0f || f.ud2[1] != 0x0b)
+ return;
+ len = __strnlen_user((char *)(long)f.filename, PATH_MAX) - 1;
+ if (len < 0 || len >= PATH_MAX)
+ f.filename = (int)(long)"unmapped filename";
+ else if (len > 50) {
+ f.filename += len - 50;
+ prefix = "...";
+ }
+ printk("----------- [cut here ] --------- [please bite here ] ---------\n");
+ printk(KERN_ALERT "Kernel BUG at %s%.50s:%d\n", prefix, (char *)(long)f.filename, f.line);
+}
+
+#ifdef CONFIG_BUG
+void out_of_line_bug(void)
+{
+ 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 = safe_smp_processor_id();
+ unsigned long flags;
+
+ /* racy, but better than risking deadlock. */
+ local_irq_save(flags);
+ 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("Oops");
+}
+
+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);
+ /* 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();
+
+ handle_BUG(regs);
+ __die(str, regs, err);
+ oops_end(flags);
+ do_exit(SIGSEGV);
+}
+
+#ifdef CONFIG_X86_LOCAL_APIC
+void __kprobes die_nmi(char *str, struct pt_regs *regs)
+{
+ unsigned long flags = oops_begin();
+
+ /*
+ * We are in trouble anyway, lets at least try
+ * to get a message out.
+ */
+ printk(str, safe_smp_processor_id());
+ show_registers(regs);
+ if (kexec_should_crash(current))
+ crash_kexec(regs);
+ if (panic_on_timeout || panic_on_oops)
+ panic("nmi watchdog");
+ printk("console shuts up ...\n");
+ oops_end(flags);
+ nmi_exit();
+ local_irq_enable();
+ do_exit(SIGSEGV);
+}
+#endif
+
+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;
+
+ conditional_sti(regs);
+
+ tsk->thread.error_code = error_code;
+ tsk->thread.trap_no = trapnr;
+
+ if (user_mode(regs)) {
+ if (exception_trace && unhandled_signal(tsk, signr))
+ 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
+ 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; \
+ 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; \
+ 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)
+DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
+
+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);
+
+ tsk->thread.error_code = error_code;
+ tsk->thread.trap_no = 13;
+
+ if (user_mode(regs)) {
+ if (exception_trace && unhandled_signal(tsk, SIGSEGV))
+ 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;
+ }
+ 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("Uhhuh. NMI received. Dazed and confused, but trying to continue\n");
+ printk("You probably have a hardware problem with your RAM chips\n");
+
+#if 0 /* XEN */
+ /* Clear and disable the memory parity error line. */
+ reason = (reason & 0xf) | 4;
+ outb(reason, 0x61);
+#endif /* XEN */
+}
+
+static __kprobes void
+io_check_error(unsigned char reason, struct pt_regs * regs)
+{
+ printk("NMI: IOCK error (debug interrupt?)\n");
+ show_registers(regs);
+
+#if 0 /* XEN */
+ /* Re-enable the IOCK line, wait for a few seconds */
+ reason = (reason & 0xf) | 8;
+ outb(reason, 0x61);
+ mdelay(2000);
+ reason &= ~8;
+ outb(reason, 0x61);
+#endif /* XEN */
+}
+
+static __kprobes void
+unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
+{ printk("Uhhuh. NMI received for unknown reason %02x.\n", reason);
+ printk("Dazed and confused, but trying to continue\n");
+ printk("Do you have a strange power saving mode enabled?\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;
+#ifdef CONFIG_X86_LOCAL_APIC
+ /*
+ * Ok, so this is none of the documented NMI sources,
+ * so it must be the NMI watchdog.
+ */
+ if (nmi_watchdog > 0) {
+ nmi_watchdog_tick(regs,reason);
+ return;
+ }
+#endif
+ 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;
+ }
+ do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
+ return;
+}
+
+/* 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)
+{
+}
+
+#if 0
+asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
+{
+}
+#endif
+
+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(); */ /* 'clts' is done for us by Xen during virtual trap. */
+
+ if (!used_math())
+ init_fpu(me);
+ restore_fpu_checking(&me->thread.i387.fxsave);
+ task_thread_info(me)->status |= TS_USEDFPU;
+}
+
+
+/*
+ * NB. All these are "interrupt gates" (i.e. events_mask is set) because we
+ * specify <dpl>|4 in the second field.
+ */
+static trap_info_t trap_table[] = {
+ { 0, 0|4, __KERNEL_CS, (unsigned long)divide_error },
+ { 1, 0|4, __KERNEL_CS, (unsigned long)debug },
+ { 3, 3|4, __KERNEL_CS, (unsigned long)int3 },
+ { 4, 3|4, __KERNEL_CS, (unsigned long)overflow },
+ { 5, 0|4, __KERNEL_CS, (unsigned long)bounds },
+ { 6, 0|4, __KERNEL_CS, (unsigned long)invalid_op },
+ { 7, 0|4, __KERNEL_CS, (unsigned long)device_not_available },
+ { 9, 0|4, __KERNEL_CS, (unsigned long)coprocessor_segment_overrun},
+ { 10, 0|4, __KERNEL_CS, (unsigned long)invalid_TSS },
+ { 11, 0|4, __KERNEL_CS, (unsigned long)segment_not_present },
+ { 12, 0|4, __KERNEL_CS, (unsigned long)stack_segment },
+ { 13, 0|4, __KERNEL_CS, (unsigned long)general_protection },
+ { 14, 0|4, __KERNEL_CS, (unsigned long)page_fault },
+ { 15, 0|4, __KERNEL_CS, (unsigned long)spurious_interrupt_bug },
+ { 16, 0|4, __KERNEL_CS, (unsigned long)coprocessor_error },
+ { 17, 0|4, __KERNEL_CS, (unsigned long)alignment_check },
+#ifdef CONFIG_X86_MCE
+ { 18, 0|4, __KERNEL_CS, (unsigned long)machine_check },
+#endif
+ { 19, 0|4, __KERNEL_CS, (unsigned long)simd_coprocessor_error },
+#ifdef CONFIG_IA32_EMULATION
+ { IA32_SYSCALL_VECTOR, 3|4, __KERNEL_CS, (unsigned long)ia32_syscall},
+#endif
+ { 0, 0, 0, 0 }
+};
+
+void __init trap_init(void)
+{
+ int ret;
+
+ ret = HYPERVISOR_set_trap_table(trap_table);
+
+ if (ret)
+ printk("HYPERVISOR_set_trap_table faild: error %d\n",
+ ret);
+
+ /*
+ * Should be a barrier for any external CPU state.
+ */
+ cpu_init();
+}
+
+void smp_trap_init(trap_info_t *trap_ctxt)
+{
+ trap_info_t *t = trap_table;
+
+ for (t = trap_table; t->address; t++) {
+ trap_ctxt[t->vector].flags = t->flags;
+ trap_ctxt[t->vector].cs = t->cs;
+ trap_ctxt[t->vector].address = t->address;
+ }
+}
+
+
+/* Actual parsing is done early in setup.c. */
+static int __init oops_dummy(char *s)
+{
+ panic_on_oops = 1;
+ return 1;
+}
+__setup("oops=", oops_dummy);
+
+static int __init kstack_setup(char *s)
+{
+ kstack_depth_to_print = simple_strtoul(s,NULL,0);
+ return 1;
+}
+__setup("kstack=", kstack_setup);
+
git://git.onelab.eu / linux-2.6.git / blobdiff