--- /dev/null
+/*
+ * linux/arch/i386/traps.c
+ *
+ * Copyright (C) 1991, 1992 Linus Torvalds
+ *
+ * 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 'asm.s'.
+ */
+#include <linux/config.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.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/highmem.h>
+#include <linux/kallsyms.h>
+#include <linux/ptrace.h>
+#include <linux/utsname.h>
+#include <linux/kprobes.h>
+#include <linux/kexec.h>
+
+#ifdef CONFIG_EISA
+#include <linux/ioport.h>
+#include <linux/eisa.h>
+#endif
+
+#ifdef CONFIG_MCA
+#include <linux/mca.h>
+#endif
+
+#include <asm/processor.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/nmi.h>
+
+#include <asm/smp.h>
+#include <asm/arch_hooks.h>
+#include <asm/kdebug.h>
+
+#include <linux/module.h>
+
+#include "mach_traps.h"
+
+asmlinkage int system_call(void);
+
+struct desc_struct default_ldt[] = { { 0, 0 }, { 0, 0 }, { 0, 0 },
+ { 0, 0 }, { 0, 0 } };
+
+/* Do we ignore FPU interrupts ? */
+char ignore_fpu_irq = 0;
+
+#ifndef CONFIG_X86_NO_IDT
+/*
+ * The IDT has to be page-aligned to simplify the Pentium
+ * F0 0F bug workaround.. We have a special link segment
+ * for this.
+ */
+struct desc_struct idt_table[256] __attribute__((__section__(".data.idt"))) = { {0, 0}, };
+#endif
+
+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 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 alignment_check(void);
+#ifndef CONFIG_XEN
+asmlinkage void spurious_interrupt_bug(void);
+#else
+asmlinkage void fixup_4gb_segment(void);
+#endif
+asmlinkage void machine_check(void);
+
+static int kstack_depth_to_print = 24;
+ATOMIC_NOTIFIER_HEAD(i386die_chain);
+
+int register_die_notifier(struct notifier_block *nb)
+{
+ vmalloc_sync_all();
+ return atomic_notifier_chain_register(&i386die_chain, nb);
+}
+EXPORT_SYMBOL(register_die_notifier);
+
+int unregister_die_notifier(struct notifier_block *nb)
+{
+ return atomic_notifier_chain_unregister(&i386die_chain, nb);
+}
+EXPORT_SYMBOL(unregister_die_notifier);
+
+static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
+{
+ return p > (void *)tinfo &&
+ p < (void *)tinfo + THREAD_SIZE - 3;
+}
+
+/*
+ * Print CONFIG_STACK_BACKTRACE_COLS address/symbol entries per line.
+ */
+static inline int print_addr_and_symbol(unsigned long addr, char *log_lvl,
+ int printed)
+{
+ if (!printed)
+ printk(log_lvl);
+
+#if CONFIG_STACK_BACKTRACE_COLS == 1
+ printk(" [<%08lx>] ", addr);
+#else
+ printk(" <%08lx> ", addr);
+#endif
+ print_symbol("%s", addr);
+
+ printed = (printed + 1) % CONFIG_STACK_BACKTRACE_COLS;
+ if (printed)
+ printk(" ");
+ else
+ printk("\n");
+
+ return printed;
+}
+
+static inline unsigned long print_context_stack(struct thread_info *tinfo,
+ unsigned long *stack, unsigned long ebp,
+ char *log_lvl)
+{
+ unsigned long addr;
+ int printed = 0; /* nr of entries already printed on current line */
+
+#ifdef CONFIG_FRAME_POINTER
+ while (valid_stack_ptr(tinfo, (void *)ebp)) {
+ addr = *(unsigned long *)(ebp + 4);
+ printed = print_addr_and_symbol(addr, log_lvl, printed);
+ ebp = *(unsigned long *)ebp;
+ }
+#else
+ while (valid_stack_ptr(tinfo, stack)) {
+ addr = *stack++;
+ if (__kernel_text_address(addr))
+ printed = print_addr_and_symbol(addr, log_lvl, printed);
+ }
+#endif
+ if (printed)
+ printk("\n");
+
+ return ebp;
+}
+
+static void show_trace_log_lvl(struct task_struct *task,
+ unsigned long *stack, char *log_lvl)
+{
+ unsigned long ebp;
+
+ if (!task)
+ task = current;
+
+ if (task == current) {
+ /* Grab ebp right from our regs */
+ asm ("movl %%ebp, %0" : "=r" (ebp) : );
+ } else {
+ /* ebp is the last reg pushed by switch_to */
+ ebp = *(unsigned long *) task->thread.esp;
+ }
+
+ while (1) {
+ struct thread_info *context;
+ context = (struct thread_info *)
+ ((unsigned long)stack & (~(THREAD_SIZE - 1)));
+ ebp = print_context_stack(context, stack, ebp, log_lvl);
+ stack = (unsigned long*)context->previous_esp;
+ if (!stack)
+ break;
+ printk("%s =======================\n", log_lvl);
+ }
+}
+
+void show_trace(struct task_struct *task, unsigned long * stack)
+{
+ show_trace_log_lvl(task, stack, "");
+}
+
+static void show_stack_log_lvl(struct task_struct *task, unsigned long *esp,
+ char *log_lvl)
+{
+ unsigned long *stack;
+ int i;
+
+ if (esp == NULL) {
+ if (task)
+ esp = (unsigned long*)task->thread.esp;
+ else
+ esp = (unsigned long *)&esp;
+ }
+
+ stack = esp;
+ printk(log_lvl);
+ for(i = 0; i < kstack_depth_to_print; i++) {
+ if (kstack_end(stack))
+ break;
+ if (i && ((i % 8) == 0))
+ printk("\n%s ", log_lvl);
+ printk("%08lx ", *stack++);
+ }
+ printk("\n%sCall Trace:\n", log_lvl);
+ show_trace_log_lvl(task, esp, log_lvl);
+}
+
+void show_stack(struct task_struct *task, unsigned long *esp)
+{
+ printk(" ");
+ show_stack_log_lvl(task, esp, "");
+}
+
+/*
+ * The architecture-independent dump_stack generator
+ */
+void dump_stack(void)
+{
+ unsigned long stack;
+
+ show_trace(current, &stack);
+}
+
+EXPORT_SYMBOL(dump_stack);
+
+void show_registers(struct pt_regs *regs)
+{
+ int i;
+ int in_kernel = 1;
+ unsigned long esp;
+ unsigned short ss;
+
+ esp = (unsigned long) (®s->esp);
+ savesegment(ss, ss);
+ if (user_mode_vm(regs)) {
+ in_kernel = 0;
+ esp = regs->esp;
+ ss = regs->xss & 0xffff;
+ }
+ print_modules();
+ printk(KERN_EMERG "CPU: %d\nEIP: %04x:[<%08lx>] %s VLI\n"
+ "EFLAGS: %08lx (%s %.*s) \n",
+ smp_processor_id(), 0xffff & regs->xcs, regs->eip,
+ print_tainted(), regs->eflags, system_utsname.release,
+ (int)strcspn(system_utsname.version, " "),
+ system_utsname.version);
+ print_symbol(KERN_EMERG "EIP is at %s\n", regs->eip);
+ printk(KERN_EMERG "eax: %08lx ebx: %08lx ecx: %08lx edx: %08lx\n",
+ regs->eax, regs->ebx, regs->ecx, regs->edx);
+ printk(KERN_EMERG "esi: %08lx edi: %08lx ebp: %08lx esp: %08lx\n",
+ regs->esi, regs->edi, regs->ebp, esp);
+ printk(KERN_EMERG "ds: %04x es: %04x ss: %04x\n",
+ regs->xds & 0xffff, regs->xes & 0xffff, ss);
+ printk(KERN_EMERG "Process %s (pid: %d, threadinfo=%p task=%p)",
+ current->comm, current->pid, current_thread_info(), current);
+ /*
+ * When in-kernel, we also print out the stack and code at the
+ * time of the fault..
+ */
+ if (in_kernel) {
+ u8 __user *eip;
+
+ printk("\n" KERN_EMERG "Stack: ");
+ show_stack_log_lvl(NULL, (unsigned long *)esp, KERN_EMERG);
+
+ printk(KERN_EMERG "Code: ");
+
+ eip = (u8 __user *)regs->eip - 43;
+ for (i = 0; i < 64; i++, eip++) {
+ unsigned char c;
+
+ if (eip < (u8 __user *)PAGE_OFFSET || __get_user(c, eip)) {
+ printk(" Bad EIP value.");
+ break;
+ }
+ if (eip == (u8 __user *)regs->eip)
+ printk("<%02x> ", c);
+ else
+ printk("%02x ", c);
+ }
+ }
+ printk("\n");
+}
+
+static void handle_BUG(struct pt_regs *regs)
+{
+ unsigned short ud2;
+ unsigned short line;
+ char *file;
+ char c;
+ unsigned long eip;
+
+ eip = regs->eip;
+
+ if (eip < PAGE_OFFSET)
+ goto no_bug;
+ if (__get_user(ud2, (unsigned short __user *)eip))
+ goto no_bug;
+ if (ud2 != 0x0b0f)
+ goto no_bug;
+ if (__get_user(line, (unsigned short __user *)(eip + 2)))
+ goto bug;
+ if (__get_user(file, (char * __user *)(eip + 4)) ||
+ (unsigned long)file < PAGE_OFFSET || __get_user(c, file))
+ file = "<bad filename>";
+
+ printk(KERN_EMERG "------------[ cut here ]------------\n");
+ printk(KERN_EMERG "kernel BUG at %s:%d!\n", file, line);
+
+no_bug:
+ return;
+
+ /* Here we know it was a BUG but file-n-line is unavailable */
+bug:
+ printk(KERN_EMERG "Kernel BUG\n");
+}
+
+/* This is gone through when something in the kernel
+ * has done something bad and is about to be terminated.
+*/
+void die(const char * str, struct pt_regs * regs, long err)
+{
+ static struct {
+ spinlock_t lock;
+ u32 lock_owner;
+ int lock_owner_depth;
+ } die = {
+ .lock = SPIN_LOCK_UNLOCKED,
+ .lock_owner = -1,
+ .lock_owner_depth = 0
+ };
+ static int die_counter;
+ unsigned long flags;
+
+ oops_enter();
+
+ if (die.lock_owner != raw_smp_processor_id()) {
+ console_verbose();
+ spin_lock_irqsave(&die.lock, flags);
+ die.lock_owner = smp_processor_id();
+ die.lock_owner_depth = 0;
+ bust_spinlocks(1);
+ }
+ else
+ local_save_flags(flags);
+
+ if (++die.lock_owner_depth < 3) {
+ int nl = 0;
+ unsigned long esp;
+ unsigned short ss;
+
+ handle_BUG(regs);
+ printk(KERN_EMERG "%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
+#ifdef CONFIG_PREEMPT
+ printk(KERN_EMERG "PREEMPT ");
+ nl = 1;
+#endif
+#ifdef CONFIG_SMP
+ if (!nl)
+ printk(KERN_EMERG);
+ printk("SMP ");
+ nl = 1;
+#endif
+#ifdef CONFIG_DEBUG_PAGEALLOC
+ if (!nl)
+ printk(KERN_EMERG);
+ printk("DEBUG_PAGEALLOC");
+ nl = 1;
+#endif
+ if (nl)
+ printk("\n");
+ if (notify_die(DIE_OOPS, str, regs, err,
+ current->thread.trap_no, SIGSEGV) !=
+ NOTIFY_STOP) {
+ show_registers(regs);
+ /* Executive summary in case the oops scrolled away */
+ esp = (unsigned long) (®s->esp);
+ savesegment(ss, ss);
+ if (user_mode(regs)) {
+ esp = regs->esp;
+ ss = regs->xss & 0xffff;
+ }
+ printk(KERN_EMERG "EIP: [<%08lx>] ", regs->eip);
+ print_symbol("%s", regs->eip);
+ printk(" SS:ESP %04x:%08lx\n", ss, esp);
+ }
+ else
+ regs = NULL;
+ } else
+ printk(KERN_EMERG "Recursive die() failure, output suppressed\n");
+
+ bust_spinlocks(0);
+ die.lock_owner = -1;
+ spin_unlock_irqrestore(&die.lock, flags);
+
+ if (!regs)
+ return;
+
+ if (kexec_should_crash(current))
+ crash_kexec(regs);
+
+ if (in_interrupt())
+ panic("Fatal exception in interrupt");
+
+ if (panic_on_oops) {
+ printk(KERN_EMERG "Fatal exception: panic in 5 seconds\n");
+ ssleep(5);
+ panic("Fatal exception");
+ }
+ oops_exit();
+ do_exit(SIGSEGV);
+}
+
+static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
+{
+ if (!user_mode_vm(regs))
+ die(str, regs, err);
+}
+
+static void __kprobes do_trap(int trapnr, int signr, char *str, int vm86,
+ struct pt_regs * regs, long error_code,
+ siginfo_t *info)
+{
+ struct task_struct *tsk = current;
+ tsk->thread.error_code = error_code;
+ tsk->thread.trap_no = trapnr;
+
+ if (regs->eflags & VM_MASK) {
+ if (vm86)
+ goto vm86_trap;
+ goto trap_signal;
+ }
+
+ if (!user_mode(regs))
+ goto kernel_trap;
+
+ trap_signal: {
+ if (info)
+ force_sig_info(signr, info, tsk);
+ else
+ force_sig(signr, tsk);
+ return;
+ }
+
+ kernel_trap: {
+ if (!fixup_exception(regs))
+ die(str, regs, error_code);
+ return;
+ }
+
+ vm86_trap: {
+ int ret = handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, trapnr);
+ if (ret) goto trap_signal;
+ return;
+ }
+}
+
+#define DO_ERROR(trapnr, signr, str, name) \
+fastcall 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, 0, regs, error_code, NULL); \
+}
+
+#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
+fastcall 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, 0, regs, error_code, &info); \
+}
+
+#define DO_VM86_ERROR(trapnr, signr, str, name) \
+fastcall 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, 1, regs, error_code, NULL); \
+}
+
+#define DO_VM86_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
+fastcall 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, 1, regs, error_code, &info); \
+}
+
+DO_VM86_ERROR_INFO( 0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->eip)
+#ifndef CONFIG_KPROBES
+DO_VM86_ERROR( 3, SIGTRAP, "int3", int3)
+#endif
+DO_VM86_ERROR( 4, SIGSEGV, "overflow", overflow)
+DO_VM86_ERROR( 5, SIGSEGV, "bounds", bounds)
+DO_ERROR_INFO( 6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->eip)
+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(12, SIGBUS, "stack segment", stack_segment)
+DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
+
+
+/*
+ * lazy-check for CS validity on exec-shield binaries:
+ *
+ * the original non-exec stack patch was written by
+ * Solar Designer <solar at openwall.com>. Thanks!
+ */
+static int
+check_lazy_exec_limit(int cpu, struct pt_regs *regs, long error_code)
+{
+ struct desc_struct *desc1, *desc2;
+ struct vm_area_struct *vma;
+ unsigned long limit;
+
+ if (current->mm == NULL)
+ return 0;
+
+ limit = -1UL;
+ if (current->mm->context.exec_limit != -1UL) {
+ limit = PAGE_SIZE;
+ spin_lock(¤t->mm->page_table_lock);
+ for (vma = current->mm->mmap; vma; vma = vma->vm_next)
+ if ((vma->vm_flags & VM_EXEC) && (vma->vm_end > limit))
+ limit = vma->vm_end;
+ spin_unlock(¤t->mm->page_table_lock);
+ if (limit >= TASK_SIZE)
+ limit = -1UL;
+ current->mm->context.exec_limit = limit;
+ }
+ set_user_cs(¤t->mm->context.user_cs, limit);
+
+ desc1 = ¤t->mm->context.user_cs;
+ desc2 = &get_cpu_gdt_table(cpu)[GDT_ENTRY_DEFAULT_USER_CS];
+
+ if (desc1->a != desc2->a || desc1->b != desc2->b) {
+ /*
+ * The CS was not in sync - reload it and retry the
+ * instruction. If the instruction still faults then
+ * we won't hit this branch next time around.
+ */
+ if (print_fatal_signals >= 2) {
+ printk("#GPF fixup (%ld[seg:%lx]) at %08lx, CPU#%d.\n", error_code, error_code/8, regs->eip, smp_processor_id());
+ printk(" exec_limit: %08lx, user_cs: %08lx/%08lx, CPU_cs: %08lx/%08lx.\n", current->mm->context.exec_limit, desc1->a, desc1->b, desc2->a, desc2->b);
+ }
+ load_user_cs_desc(cpu, current->mm);
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
+ * The fixup code for errors in iret jumps to here (iret_exc). It loses
+ * the original trap number and error code. The bogus trap 32 and error
+ * code 0 are what the vanilla kernel delivers via:
+ * DO_ERROR_INFO(32, SIGSEGV, "iret exception", iret_error, ILL_BADSTK, 0)
+ *
+ * In case of a general protection fault in the iret instruction, we
+ * need to check for a lazy CS update for exec-shield.
+ */
+fastcall void do_iret_error(struct pt_regs *regs, long error_code)
+{
+ int ok = check_lazy_exec_limit(get_cpu(), regs, error_code);
+ put_cpu();
+ if (!ok && notify_die(DIE_TRAP, "iret exception", regs,
+ error_code, 32, SIGSEGV) != NOTIFY_STOP) {
+ siginfo_t info;
+ info.si_signo = SIGSEGV;
+ info.si_errno = 0;
+ info.si_code = ILL_BADSTK;
+ info.si_addr = 0;
+ do_trap(32, SIGSEGV, "iret exception", 0, regs, error_code,
+ &info);
+ }
+}
+
+fastcall void __kprobes do_general_protection(struct pt_regs * regs,
+ long error_code)
+{
+ int cpu = get_cpu();
+ int ok;
+
+ ok = check_lazy_exec_limit(cpu, regs, error_code);
+ put_cpu();
+
+ if (ok)
+ return;
+
+ if (print_fatal_signals) {
+ printk("#GPF(%ld[seg:%lx]) at %08lx, CPU#%d.\n", error_code, error_code/8, regs->eip, smp_processor_id());
+ printk(" exec_limit: %08lx, user_cs: %08lx/%08lx.\n", current->mm->context.exec_limit, current->mm->context.user_cs.a, current->mm->context.user_cs.b);
+ }
+
+ if (regs->eflags & VM_MASK)
+ goto gp_in_vm86;
+
+ if (!user_mode(regs))
+ goto gp_in_kernel;
+
+ current->thread.error_code = error_code;
+ current->thread.trap_no = 13;
+ force_sig(SIGSEGV, current);
+ return;
+
+gp_in_vm86:
+ local_irq_enable();
+ handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
+ return;
+
+gp_in_kernel:
+ if (!fixup_exception(regs)) {
+ if (notify_die(DIE_GPF, "general protection fault", regs,
+ error_code, 13, SIGSEGV) == NOTIFY_STOP)
+ return;
+ die("general protection fault", regs, error_code);
+ }
+}
+
+static void mem_parity_error(unsigned char reason, struct pt_regs * regs)
+{
+ printk(KERN_EMERG "Uhhuh. NMI received. Dazed and confused, but trying "
+ "to continue\n");
+ printk(KERN_EMERG "You probably have a hardware problem with your RAM "
+ "chips\n");
+
+ /* Clear and disable the memory parity error line. */
+ clear_mem_error(reason);
+}
+
+static void io_check_error(unsigned char reason, struct pt_regs * regs)
+{
+ printk(KERN_EMERG "NMI: IOCK error (debug interrupt?)\n");
+ show_registers(regs);
+
+ /* Re-enable the IOCK line, wait for a few seconds */
+ clear_io_check_error(reason);
+}
+
+static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
+{
+#ifdef CONFIG_MCA
+ /* Might actually be able to figure out what the guilty party
+ * is. */
+ if( MCA_bus ) {
+ mca_handle_nmi();
+ return;
+ }
+#endif
+ printk("Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
+ reason, smp_processor_id());
+ printk("Dazed and confused, but trying to continue\n");
+ printk("Do you have a strange power saving mode enabled?\n");
+}
+
+static DEFINE_SPINLOCK(nmi_print_lock);
+
+void die_nmi (struct pt_regs *regs, const char *msg)
+{
+ if (notify_die(DIE_NMIWATCHDOG, msg, regs, 0, 2, SIGINT) ==
+ NOTIFY_STOP)
+ return;
+
+ spin_lock(&nmi_print_lock);
+ /*
+ * We are in trouble anyway, lets at least try
+ * to get a message out.
+ */
+ bust_spinlocks(1);
+ printk(KERN_EMERG "%s", msg);
+ printk(" on CPU%d, eip %08lx, registers:\n",
+ smp_processor_id(), regs->eip);
+ show_registers(regs);
+ printk(KERN_EMERG "console shuts up ...\n");
+ console_silent();
+ spin_unlock(&nmi_print_lock);
+ bust_spinlocks(0);
+
+ /* If we are in kernel we are probably nested up pretty bad
+ * and might aswell get out now while we still can.
+ */
+ if (!user_mode_vm(regs)) {
+ current->thread.trap_no = 2;
+ crash_kexec(regs);
+ }
+
+ do_exit(SIGSEGV);
+}
+
+static void default_do_nmi(struct pt_regs * regs)
+{
+ unsigned char reason = 0;
+
+ /* Only the BSP gets external NMIs from the system. */
+ if (!smp_processor_id())
+ 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) {
+ nmi_watchdog_tick(regs);
+ return;
+ }
+#endif
+ unknown_nmi_error(reason, regs);
+ return;
+ }
+ if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
+ return;
+ if (reason & 0x80)
+ mem_parity_error(reason, regs);
+ if (reason & 0x40)
+ io_check_error(reason, regs);
+ /*
+ * Reassert NMI in case it became active meanwhile
+ * as it's edge-triggered.
+ */
+ reassert_nmi();
+}
+
+static int dummy_nmi_callback(struct pt_regs * regs, int cpu)
+{
+ return 0;
+}
+
+static nmi_callback_t nmi_callback = dummy_nmi_callback;
+
+fastcall void do_nmi(struct pt_regs * regs, long error_code)
+{
+ int cpu;
+
+ nmi_enter();
+
+ cpu = smp_processor_id();
+
+ ++nmi_count(cpu);
+
+ if (!rcu_dereference(nmi_callback)(regs, cpu))
+ default_do_nmi(regs);
+
+ nmi_exit();
+}
+
+void set_nmi_callback(nmi_callback_t callback)
+{
+ vmalloc_sync_all();
+ rcu_assign_pointer(nmi_callback, callback);
+}
+EXPORT_SYMBOL_GPL(set_nmi_callback);
+
+void unset_nmi_callback(void)
+{
+ nmi_callback = dummy_nmi_callback;
+}
+EXPORT_SYMBOL_GPL(unset_nmi_callback);
+
+#ifdef CONFIG_KPROBES
+fastcall 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;
+ /* This is an interrupt gate, because kprobes wants interrupts
+ disabled. Normal trap handlers don't. */
+ restore_interrupts(regs);
+ do_trap(3, SIGTRAP, "int3", 1, regs, error_code, NULL);
+}
+#endif
+
+/*
+ * Our handling of the processor debug registers is non-trivial.
+ * We do not clear them on entry and exit from the kernel. Therefore
+ * it is possible to get a watchpoint trap here from inside the kernel.
+ * However, the code in ./ptrace.c has ensured that the user can
+ * only set watchpoints on userspace addresses. Therefore the in-kernel
+ * watchpoint trap can only occur in code which is reading/writing
+ * from user space. Such code must not hold kernel locks (since it
+ * can equally take a page fault), therefore it is safe to call
+ * force_sig_info even though that claims and releases locks.
+ *
+ * Code in ./signal.c ensures that the debug control register
+ * is restored before we deliver any signal, and therefore that
+ * user code runs with the correct debug control register even though
+ * we clear it here.
+ *
+ * Being careful here means that we don't have to be as careful in a
+ * lot of more complicated places (task switching can be a bit lazy
+ * about restoring all the debug state, and ptrace doesn't have to
+ * find every occurrence of the TF bit that could be saved away even
+ * by user code)
+ */
+fastcall void __kprobes do_debug(struct pt_regs * regs, long error_code)
+{
+ unsigned int condition;
+ struct task_struct *tsk = current;
+
+ get_debugreg(condition, 6);
+
+ if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
+ SIGTRAP) == NOTIFY_STOP)
+ return;
+ /* It's safe to allow irq's after DR6 has been saved */
+ if (regs->eflags & X86_EFLAGS_IF)
+ local_irq_enable();
+
+ /* Mask out spurious debug traps due to lazy DR7 setting */
+ if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
+ if (!tsk->thread.debugreg[7])
+ goto clear_dr7;
+ }
+
+ if (regs->eflags & VM_MASK)
+ goto debug_vm86;
+
+ /* Save debug status register where ptrace can see it */
+ tsk->thread.debugreg[6] = condition;
+
+ /*
+ * Single-stepping through TF: make sure we ignore any events in
+ * kernel space (but re-enable TF when returning to user mode).
+ */
+ if (condition & DR_STEP) {
+ /*
+ * We already checked v86 mode above, so we can
+ * check for kernel mode by just checking the CPL
+ * of CS.
+ */
+ if (!user_mode(regs))
+ goto clear_TF_reenable;
+ }
+
+ /* Ok, finally something we can handle */
+ send_sigtrap(tsk, regs, error_code);
+
+ /* Disable additional traps. They'll be re-enabled when
+ * the signal is delivered.
+ */
+clear_dr7:
+ set_debugreg(0, 7);
+ return;
+
+debug_vm86:
+ handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 1);
+ return;
+
+clear_TF_reenable:
+ set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
+ regs->eflags &= ~TF_MASK;
+ return;
+}
+
+/*
+ * 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(void __user *eip)
+{
+ struct task_struct * task;
+ siginfo_t info;
+ unsigned short cwd, swd;
+
+ /*
+ * 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 = eip;
+ /*
+ * (~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 syncronizing 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: /* No unmasked exception */
+ return;
+ default: /* Multiple exceptions */
+ 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);
+}
+
+fastcall void do_coprocessor_error(struct pt_regs * regs, long error_code)
+{
+ ignore_fpu_irq = 1;
+ math_error((void __user *)regs->eip);
+}
+
+static void simd_math_error(void __user *eip)
+{
+ struct task_struct * task;
+ siginfo_t info;
+ unsigned short mxcsr;
+
+ /*
+ * 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 = eip;
+ /*
+ * 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);
+}
+
+fastcall void do_simd_coprocessor_error(struct pt_regs * regs,
+ long error_code)
+{
+ if (cpu_has_xmm) {
+ /* Handle SIMD FPU exceptions on PIII+ processors. */
+ ignore_fpu_irq = 1;
+ simd_math_error((void __user *)regs->eip);
+ } else {
+ /*
+ * Handle strange cache flush from user space exception
+ * in all other cases. This is undocumented behaviour.
+ */
+ if (regs->eflags & VM_MASK) {
+ handle_vm86_fault((struct kernel_vm86_regs *)regs,
+ error_code);
+ return;
+ }
+ current->thread.trap_no = 19;
+ current->thread.error_code = error_code;
+ die_if_kernel("cache flush denied", regs, error_code);
+ force_sig(SIGSEGV, current);
+ }
+}
+
+#ifndef CONFIG_XEN
+fastcall void do_spurious_interrupt_bug(struct pt_regs * regs,
+ long error_code)
+{
+#if 0
+ /* No need to warn about this any longer. */
+ printk("Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
+#endif
+}
+
+fastcall void setup_x86_bogus_stack(unsigned char * stk)
+{
+ unsigned long *switch16_ptr, *switch32_ptr;
+ struct pt_regs *regs;
+ unsigned long stack_top, stack_bot;
+ unsigned short iret_frame16_off;
+ int cpu = smp_processor_id();
+ /* reserve the space on 32bit stack for the magic switch16 pointer */
+ memmove(stk, stk + 8, sizeof(struct pt_regs));
+ switch16_ptr = (unsigned long *)(stk + sizeof(struct pt_regs));
+ regs = (struct pt_regs *)stk;
+ /* now the switch32 on 16bit stack */
+ stack_bot = (unsigned long)&per_cpu(cpu_16bit_stack, cpu);
+ stack_top = stack_bot + CPU_16BIT_STACK_SIZE;
+ switch32_ptr = (unsigned long *)(stack_top - 8);
+ iret_frame16_off = CPU_16BIT_STACK_SIZE - 8 - 20;
+ /* copy iret frame on 16bit stack */
+ memcpy((void *)(stack_bot + iret_frame16_off), ®s->eip, 20);
+ /* fill in the switch pointers */
+ switch16_ptr[0] = (regs->esp & 0xffff0000) | iret_frame16_off;
+ switch16_ptr[1] = __ESPFIX_SS;
+ switch32_ptr[0] = (unsigned long)stk + sizeof(struct pt_regs) +
+ 8 - CPU_16BIT_STACK_SIZE;
+ switch32_ptr[1] = __KERNEL_DS;
+}
+
+fastcall unsigned char * fixup_x86_bogus_stack(unsigned short sp)
+{
+ unsigned long *switch32_ptr;
+ unsigned char *stack16, *stack32;
+ unsigned long stack_top, stack_bot;
+ int len;
+ int cpu = smp_processor_id();
+ stack_bot = (unsigned long)&per_cpu(cpu_16bit_stack, cpu);
+ stack_top = stack_bot + CPU_16BIT_STACK_SIZE;
+ switch32_ptr = (unsigned long *)(stack_top - 8);
+ /* copy the data from 16bit stack to 32bit stack */
+ len = CPU_16BIT_STACK_SIZE - 8 - sp;
+ stack16 = (unsigned char *)(stack_bot + sp);
+ stack32 = (unsigned char *)
+ (switch32_ptr[0] + CPU_16BIT_STACK_SIZE - 8 - len);
+ memcpy(stack32, stack16, len);
+ return stack32;
+}
+#endif
+
+/*
+ * '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.
+ *
+ * Must be called with kernel preemption disabled (in this case,
+ * local interrupts are disabled at the call-site in entry.S).
+ */
+asmlinkage void math_state_restore(struct pt_regs regs)
+{
+ struct thread_info *thread = current_thread_info();
+ struct task_struct *tsk = thread->task;
+
+ /* NB. 'clts' is done for us by Xen during virtual trap. */
+ if (!tsk_used_math(tsk))
+ init_fpu(tsk);
+ restore_fpu(tsk);
+ thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */
+}
+
+#ifndef CONFIG_MATH_EMULATION
+
+asmlinkage void math_emulate(long arg)
+{
+ printk(KERN_EMERG "math-emulation not enabled and no coprocessor found.\n");
+ printk(KERN_EMERG "killing %s.\n",current->comm);
+ force_sig(SIGFPE,current);
+ schedule();
+}
+
+#endif /* CONFIG_MATH_EMULATION */
+
+#ifdef CONFIG_X86_F00F_BUG
+void __init trap_init_f00f_bug(void)
+{
+ __set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
+
+ /*
+ * Update the IDT descriptor and reload the IDT so that
+ * it uses the read-only mapped virtual address.
+ */
+ idt_descr.address = fix_to_virt(FIX_F00F_IDT);
+ load_idt(&idt_descr);
+}
+#endif
+
+
+/*
+ * NB. All these are "trap gates" (i.e. events_mask isn't set) except
+ * for those that specify <dpl>|4 in the second field.
+ */
+static trap_info_t trap_table[] = {
+ { 0, 0, __KERNEL_CS, (unsigned long)divide_error },
+ { 1, 0|4, __KERNEL_CS, (unsigned long)debug },
+ { 3, 3|4, __KERNEL_CS, (unsigned long)int3 },
+ { 4, 3, __KERNEL_CS, (unsigned long)overflow },
+ { 5, 0, __KERNEL_CS, (unsigned long)bounds },
+ { 6, 0, __KERNEL_CS, (unsigned long)invalid_op },
+ { 7, 0|4, __KERNEL_CS, (unsigned long)device_not_available },
+ { 9, 0, __KERNEL_CS, (unsigned long)coprocessor_segment_overrun },
+ { 10, 0, __KERNEL_CS, (unsigned long)invalid_TSS },
+ { 11, 0, __KERNEL_CS, (unsigned long)segment_not_present },
+ { 12, 0, __KERNEL_CS, (unsigned long)stack_segment },
+ { 13, 0, __KERNEL_CS, (unsigned long)general_protection },
+ { 14, 0|4, __KERNEL_CS, (unsigned long)page_fault },
+ { 15, 0, __KERNEL_CS, (unsigned long)fixup_4gb_segment },
+ { 16, 0, __KERNEL_CS, (unsigned long)coprocessor_error },
+ { 17, 0, __KERNEL_CS, (unsigned long)alignment_check },
+#ifdef CONFIG_X86_MCE
+ { 18, 0, __KERNEL_CS, (unsigned long)machine_check },
+#endif
+ { 19, 0, __KERNEL_CS, (unsigned long)simd_coprocessor_error },
+ { SYSCALL_VECTOR, 3, __KERNEL_CS, (unsigned long)system_call },
+ { 0, 0, 0, 0 }
+};
+
+void __init trap_init(void)
+{
+ HYPERVISOR_set_trap_table(trap_table);
+
+ if (cpu_has_fxsr) {
+ /*
+ * Verify that the FXSAVE/FXRSTOR data will be 16-byte aligned.
+ * Generates a compile-time "error: zero width for bit-field" if
+ * the alignment is wrong.
+ */
+ struct fxsrAlignAssert {
+ int _:!(offsetof(struct task_struct,
+ thread.i387.fxsave) & 15);
+ };
+
+ printk(KERN_INFO "Enabling fast FPU save and restore... ");
+ set_in_cr4(X86_CR4_OSFXSR);
+ printk("done.\n");
+ }
+ if (cpu_has_xmm) {
+ printk(KERN_INFO "Enabling unmasked SIMD FPU exception "
+ "support... ");
+ set_in_cr4(X86_CR4_OSXMMEXCPT);
+ printk("done.\n");
+ }
+
+ /*
+ * 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;
+ }
+}
+
+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