fedora core 6 1.2949 + vserver 2.2.0
[linux-2.6.git] / arch / i386 / kernel / traps.c
index f7e1536..cc3bc38 100644 (file)
@@ -11,7 +11,6 @@
  * '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/ptrace.h>
 #include <linux/utsname.h>
 #include <linux/kprobes.h>
+#include <linux/kexec.h>
+#include <linux/unwind.h>
+#include <linux/uaccess.h>
+#include <linux/nmi.h>
+#include <linux/bug.h>
 
 #ifdef CONFIG_EISA
 #include <linux/ioport.h>
 
 #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/unwind.h>
 #include <asm/smp.h>
 #include <asm/arch_hooks.h>
 #include <asm/kdebug.h>
+#include <asm/stacktrace.h>
 
-#include <linux/irq.h>
 #include <linux/module.h>
-#include <linux/vserver/debug.h>
+#include <linux/vs_context.h>
+#include <linux/vserver/history.h>
 
 #include "mach_traps.h"
 
-asmlinkage int system_call(void);
+int panic_on_unrecovered_nmi;
 
-struct desc_struct default_ldt[] = { { 0, 0 }, { 0, 0 }, { 0, 0 },
-               { 0, 0 }, { 0, 0 } };
+asmlinkage int system_call(void);
 
 /* Do we ignore FPU interrupts ? */
 char ignore_fpu_irq = 0;
@@ -92,19 +95,23 @@ asmlinkage void alignment_check(void);
 asmlinkage void spurious_interrupt_bug(void);
 asmlinkage void machine_check(void);
 
-static int kstack_depth_to_print = 24;
-struct notifier_block *i386die_chain;
-static DEFINE_SPINLOCK(die_notifier_lock);
+int kstack_depth_to_print = 24;
+ATOMIC_NOTIFIER_HEAD(i386die_chain);
+
+extern char last_sysfs_file[];
 
 int register_die_notifier(struct notifier_block *nb)
 {
-       int err = 0;
-       unsigned long flags;
-       spin_lock_irqsave(&die_notifier_lock, flags);
-       err = notifier_chain_register(&i386die_chain, nb);
-       spin_unlock_irqrestore(&die_notifier_lock, flags);
-       return err;
+       vmalloc_sync_all();
+       return atomic_notifier_chain_register(&i386die_chain, nb);
 }
+EXPORT_SYMBOL(register_die_notifier); /* used modular by kdb */
+
+int unregister_die_notifier(struct notifier_block *nb)
+{
+       return atomic_notifier_chain_unregister(&i386die_chain, nb);
+}
+EXPORT_SYMBOL(unregister_die_notifier); /* used modular by kdb */
 
 static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
 {
@@ -113,59 +120,135 @@ static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
 }
 
 static inline unsigned long print_context_stack(struct thread_info *tinfo,
-                               unsigned long *stack, unsigned long ebp)
+                               unsigned long *stack, unsigned long ebp,
+                               struct stacktrace_ops *ops, void *data)
 {
        unsigned long addr;
 
 #ifdef CONFIG_FRAME_POINTER
        while (valid_stack_ptr(tinfo, (void *)ebp)) {
+               unsigned long new_ebp;
                addr = *(unsigned long *)(ebp + 4);
-               printk(" [<%08lx>] ", addr);
-               print_symbol("%s", addr);
-               printk("\n");
-               ebp = *(unsigned long *)ebp;
+               ops->address(data, addr);
+               /*
+                * break out of recursive entries (such as
+                * end_of_stack_stop_unwind_function). Also,
+                * we can never allow a frame pointer to
+                * move downwards!
+                */
+               new_ebp = *(unsigned long *)ebp;
+               if (new_ebp <= ebp)
+                       break;
+               ebp = new_ebp;
        }
 #else
        while (valid_stack_ptr(tinfo, stack)) {
                addr = *stack++;
-               if (__kernel_text_address(addr)) {
-                       printk(" [<%08lx>]", addr);
-                       print_symbol(" %s", addr);
-                       printk("\n");
-               }
+               if (__kernel_text_address(addr))
+                       ops->address(data, addr);
        }
 #endif
        return ebp;
 }
 
-void show_trace(struct task_struct *task, unsigned long * stack)
+#define MSG(msg) ops->warning(data, msg)
+
+void dump_trace(struct task_struct *task, struct pt_regs *regs,
+               unsigned long *stack,
+               struct stacktrace_ops *ops, void *data)
 {
-       unsigned long ebp;
+       unsigned long ebp = 0;
 
        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;
+       if (!stack) {
+               unsigned long dummy;
+               stack = &dummy;
+               if (task && task != current)
+                       stack = (unsigned long *)task->thread.esp;
+       }
+
+#ifdef CONFIG_FRAME_POINTER
+       if (!ebp) {
+               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;
+               }
        }
+#endif
 
        while (1) {
                struct thread_info *context;
                context = (struct thread_info *)
                        ((unsigned long)stack & (~(THREAD_SIZE - 1)));
-               ebp = print_context_stack(context, stack, ebp);
+               ebp = print_context_stack(context, stack, ebp, ops, data);
+               /* Should be after the line below, but somewhere
+                  in early boot context comes out corrupted and we
+                  can't reference it -AK */
+               if (ops->stack(data, "IRQ") < 0)
+                       break;
                stack = (unsigned long*)context->previous_esp;
                if (!stack)
                        break;
-               printk(" =======================\n");
+               touch_nmi_watchdog();
        }
 }
+EXPORT_SYMBOL(dump_trace);
 
-void show_stack(struct task_struct *task, unsigned long *esp)
+static void
+print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
+{
+       printk(data);
+       print_symbol(msg, symbol);
+       printk("\n");
+}
+
+static void print_trace_warning(void *data, char *msg)
+{
+       printk("%s%s\n", (char *)data, msg);
+}
+
+static int print_trace_stack(void *data, char *name)
+{
+       return 0;
+}
+
+/*
+ * Print one address/symbol entries per line.
+ */
+static void print_trace_address(void *data, unsigned long addr)
+{
+       printk("%s [<%08lx>] ", (char *)data, addr);
+       print_symbol("%s\n", 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,
+};
+
+static void
+show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
+                  unsigned long * stack, char *log_lvl)
+{
+       dump_trace(task, regs, stack, &print_trace_ops, log_lvl);
+       printk("%s =======================\n", log_lvl);
+}
+
+void show_trace(struct task_struct *task, struct pt_regs *regs,
+               unsigned long * stack)
+{
+       show_trace_log_lvl(task, regs, stack, "");
+}
+
+static void show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
+                              unsigned long *esp, char *log_lvl)
 {
        unsigned long *stack;
        int i;
@@ -182,11 +265,17 @@ void show_stack(struct task_struct *task, unsigned long *esp)
                if (kstack_end(stack))
                        break;
                if (i && ((i % 8) == 0))
-                       printk("\n       ");
+                       printk("\n%s       ", log_lvl);
                printk("%08lx ", *stack++);
        }
-       printk("\nCall Trace:\n");
-       show_trace(task, esp);
+       printk("\n%sCall Trace:\n", log_lvl);
+       show_trace_log_lvl(task, regs, esp, log_lvl);
+}
+
+void show_stack(struct task_struct *task, unsigned long *esp)
+{
+       printk("       ");
+       show_stack_log_lvl(task, NULL, esp, "");
 }
 
 /*
@@ -196,7 +285,7 @@ void dump_stack(void)
 {
        unsigned long stack;
 
-       show_trace(current, &stack);
+       show_trace(current, NULL, &stack);
 }
 
 EXPORT_SYMBOL(dump_stack);
@@ -209,43 +298,54 @@ void show_registers(struct pt_regs *regs)
        unsigned short ss;
 
        esp = (unsigned long) (&regs->esp);
-       ss = __KERNEL_DS;
-       if (regs->xcs & 3) {
+       savesegment(ss, ss);
+       if (user_mode_vm(regs)) {
                in_kernel = 0;
                esp = regs->esp;
                ss = regs->xss & 0xffff;
        }
        print_modules();
-       printk("CPU:    %d\nEIP:    %04x:[<%08lx>]    %s VLI\nEFLAGS: %08lx"
-                       "   (%s) \n",
+       printk(KERN_EMERG "CPU:    %d\n"
+               KERN_EMERG "EIP:    %04x:[<%08lx>]    %s VLI\n"
+               KERN_EMERG "EFLAGS: %08lx   (%s %.*s)\n",
                smp_processor_id(), 0xffff & regs->xcs, regs->eip,
-               print_tainted(), regs->eflags, system_utsname.release);
-       print_symbol("EIP is at %s\n", regs->eip);
-       printk("eax: %08lx   ebx: %08lx   ecx: %08lx   edx: %08lx\n",
+               print_tainted(), regs->eflags, init_utsname()->release,
+               (int)strcspn(init_utsname()->version, " "),
+               init_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("esi: %08lx   edi: %08lx   ebp: %08lx   esp: %08lx\n",
+       printk(KERN_EMERG "esi: %08lx   edi: %08lx   ebp: %08lx   esp: %08lx\n",
                regs->esi, regs->edi, regs->ebp, esp);
-       printk("ds: %04x   es: %04x   ss: %04x\n",
+       printk(KERN_EMERG "ds: %04x   es: %04x   ss: %04x\n",
                regs->xds & 0xffff, regs->xes & 0xffff, ss);
-       printk("Process %s (pid: %d, threadinfo=%p task=%p)",
-               current->comm, current->pid, current_thread_info(), current);
+       printk(KERN_EMERG "Process %.*s (pid: %d[#%u], ti=%p task=%p task.ti=%p)",
+               TASK_COMM_LEN, current->comm, current->pid, current->xid,
+               current_thread_info(), current, current->thread_info);
        /*
         * When in-kernel, we also print out the stack and code at the
         * time of the fault..
         */
        if (in_kernel) {
                u8 *eip;
+               int code_bytes = 64;
+               unsigned char c;
 
-               printk("\nStack: ");
-               show_stack(NULL, (unsigned long*)esp);
+               printk("\n" KERN_EMERG "Stack: ");
+               show_stack_log_lvl(NULL, regs, (unsigned long *)esp, KERN_EMERG);
 
-               printk("Code: ");
+               printk(KERN_EMERG "Code: ");
 
                eip = (u8 *)regs->eip - 43;
-               for (i = 0; i < 64; i++, eip++) {
-                       unsigned char c;
-
-                       if (eip < (u8 *)PAGE_OFFSET || __get_user(c, eip)) {
+               if (eip < (u8 *)PAGE_OFFSET ||
+                       probe_kernel_address(eip, c)) {
+                       /* try starting at EIP */
+                       eip = (u8 *)regs->eip;
+                       code_bytes = 32;
+               }
+               for (i = 0; i < code_bytes; i++, eip++) {
+                       if (eip < (u8 *)PAGE_OFFSET ||
+                               probe_kernel_address(eip, c)) {
                                printk(" Bad EIP value.");
                                break;
                        }
@@ -258,42 +358,22 @@ void show_registers(struct pt_regs *regs)
        printk("\n");
 }      
 
-static void handle_BUG(struct pt_regs *regs)
+int is_valid_bugaddr(unsigned long eip)
 {
        unsigned short ud2;
-       unsigned short line;
-       char *file;
-       char c;
-       unsigned long eip;
-
-       if (regs->xcs & 3)
-               goto no_bug;            /* Not in kernel */
-
-       eip = regs->eip;
 
        if (eip < PAGE_OFFSET)
-               goto no_bug;
-       if (__get_user(ud2, (unsigned short *)eip))
-               goto no_bug;
-       if (ud2 != 0x0b0f)
-               goto no_bug;
-       if (__get_user(line, (unsigned short *)(eip + 2)))
-               goto bug;
-       if (__get_user(file, (char **)(eip + 4)) ||
-               (unsigned long)file < PAGE_OFFSET || __get_user(c, file))
-               file = "<bad filename>";
-
-       printk("------------[ cut here ]------------\n");
-       printk(KERN_ALERT "kernel BUG at %s:%d!\n", file, line);
-
-no_bug:
-       return;
+               return 0;
+       if (probe_kernel_address((unsigned short *)eip, ud2))
+               return 0;
 
-       /* Here we know it was a BUG but file-n-line is unavailable */
-bug:
-       printk("Kernel BUG\n");
+       return ud2 == 0x0b0f;
 }
 
+/*
+ * 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 {
@@ -301,82 +381,120 @@ void die(const char * str, struct pt_regs * regs, long err)
                u32 lock_owner;
                int lock_owner_depth;
        } die = {
-               .lock =                 SPIN_LOCK_UNLOCKED,
+               .lock =                 __SPIN_LOCK_UNLOCKED(die.lock),
                .lock_owner =           -1,
                .lock_owner_depth =     0
        };
        static int die_counter;
+       unsigned long flags;
+
+       oops_enter();
 
        vxh_throw_oops();
-       if (die.lock_owner != _smp_processor_id()) {
+
+       if (die.lock_owner != raw_smp_processor_id()) {
                console_verbose();
-               spin_lock_irq(&die.lock);
+               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;
-               handle_BUG(regs);
-               printk(KERN_ALERT "%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
+               unsigned long esp;
+               unsigned short ss;
+
+               report_bug(regs->eip);
+
+               printk(KERN_EMERG "%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
 #ifdef CONFIG_PREEMPT
-               printk("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");
-       notify_die(DIE_OOPS, (char *)str, regs, err, 255, SIGSEGV);
-               show_registers(regs);
+#ifdef CONFIG_SYSFS
+               printk(KERN_ALERT "last sysfs file: %s\n", last_sysfs_file);
+#endif
+               if (notify_die(DIE_OOPS, str, regs, err,
+                       current->thread.trap_no, SIGSEGV) != NOTIFY_STOP) {
+                       show_registers(regs);
+                       vxh_dump_history();
+                       /* Executive summary in case the oops scrolled away */
+                       esp = (unsigned long) (&regs->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_ERR "Recursive die() failure, output suppressed\n");
+               printk(KERN_EMERG "Recursive die() failure, output suppressed\n");
 
        bust_spinlocks(0);
        die.lock_owner = -1;
-       spin_unlock_irq(&die.lock);
-       vxh_dump_history();
+       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");
-               set_current_state(TASK_UNINTERRUPTIBLE);
-               schedule_timeout(5 * HZ);
+       if (panic_on_oops)
                panic("Fatal exception");
-       }
+
+       oops_exit();
        do_exit(SIGSEGV);
 }
 
 static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
 {
-       if (!(regs->eflags & VM_MASK) && !(3 & regs->xcs))
+       if (!user_mode_vm(regs))
                die(str, regs, err);
 }
 
-static void do_trap(int trapnr, int signr, char *str, int vm86,
-                          struct pt_regs * regs, long error_code, siginfo_t *info)
+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 (!(regs->xcs & 3))
+       if (!user_mode(regs))
                goto kernel_trap;
 
        trap_signal: {
-               struct task_struct *tsk = current;
-               tsk->thread.error_code = error_code;
-               tsk->thread.trap_no = trapnr;
                if (info)
                        force_sig_info(signr, info, tsk);
                else
@@ -449,18 +567,96 @@ 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 operand", invalid_op, ILL_ILLOPN, regs->eip)
+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)
 
-fastcall void do_general_protection(struct pt_regs * regs, long error_code)
+
+/*
+ * 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(&current->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(&current->mm->page_table_lock);
+               if (limit >= TASK_SIZE)
+                       limit = -1UL;
+               current->mm->context.exec_limit = limit;
+       }
+       set_user_cs(&current->mm->context.user_cs, limit);
+
+       desc1 = &current->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();
        struct tss_struct *tss = &per_cpu(init_tss, cpu);
        struct thread_struct *thread = &current->thread;
+       int ok;
 
        /*
         * Perform the lazy TSS's I/O bitmap copy. If the TSS has an
@@ -483,28 +679,45 @@ fastcall void do_general_protection(struct pt_regs * regs, long error_code)
                                tss->io_bitmap_max - thread->io_bitmap_max);
                tss->io_bitmap_max = thread->io_bitmap_max;
                tss->io_bitmap_base = IO_BITMAP_OFFSET;
+               tss->io_bitmap_owner = thread;
                put_cpu();
                return;
        }
-       put_cpu();
+
+       current->thread.error_code = error_code;
+       current->thread.trap_no = 13;
 
        if (regs->eflags & VM_MASK)
                goto gp_in_vm86;
 
-       if (!(regs->xcs & 3))
+       if (!user_mode(regs))
                goto gp_in_kernel;
 
+       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);
+       }
+
        current->thread.error_code = error_code;
        current->thread.trap_no = 13;
        force_sig(SIGSEGV, current);
        return;
 
 gp_in_vm86:
+       put_cpu();
        local_irq_enable();
        handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
        return;
 
 gp_in_kernel:
+       put_cpu();
        if (!fixup_exception(regs)) {
                if (notify_die(DIE_GPF, "general protection fault", regs,
                                error_code, 13, SIGSEGV) == NOTIFY_STOP)
@@ -513,32 +726,33 @@ gp_in_kernel:
        }
 }
 
-static void mem_parity_error(unsigned char reason, struct pt_regs * regs)
+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");
+       printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x on "
+               "CPU %d.\n", reason, smp_processor_id());
+       printk(KERN_EMERG "You have some hardware problem, likely on the PCI bus.\n");
+       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. */
        clear_mem_error(reason);
 }
 
-static void io_check_error(unsigned char reason, struct pt_regs * regs)
+static __kprobes void
+io_check_error(unsigned char reason, struct pt_regs * regs)
 {
-       unsigned long i;
-
-       printk("NMI: IOCK error (debug interrupt?)\n");
+       printk(KERN_EMERG "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);
-       i = 2000;
-       while (--i) udelay(1000);
-       reason &= ~8;
-       outb(reason, 0x61);
+       clear_io_check_error(reason);
 }
 
-static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
+static __kprobes 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
@@ -548,34 +762,49 @@ static void unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
                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");
+       printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x on "
+               "CPU %d.\n", reason, smp_processor_id());
+       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");
 }
 
 static DEFINE_SPINLOCK(nmi_print_lock);
 
-void die_nmi (struct pt_regs *regs, const char *msg)
+void __kprobes 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(msg);
+       printk(KERN_EMERG "%s", msg);
        printk(" on CPU%d, eip %08lx, registers:\n",
                smp_processor_id(), regs->eip);
        show_registers(regs);
-       printk("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)
+static __kprobes void default_do_nmi(struct pt_regs * regs)
 {
        unsigned char reason = 0;
 
@@ -584,7 +813,7 @@ static void default_do_nmi(struct pt_regs * regs)
                reason = get_nmi_reason();
  
        if (!(reason & 0xc0)) {
-               if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 0, SIGINT)
+               if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
                                                        == NOTIFY_STOP)
                        return;
 #ifdef CONFIG_X86_LOCAL_APIC
@@ -592,15 +821,15 @@ static void default_do_nmi(struct pt_regs * regs)
                 * Ok, so this is none of the documented NMI sources,
                 * so it must be the NMI watchdog.
                 */
-               if (nmi_watchdog) {
-                       nmi_watchdog_tick(regs);
+               if (nmi_watchdog_tick(regs, reason))
                        return;
-               }
+               if (!do_nmi_callback(regs, smp_processor_id()))
 #endif
-               unknown_nmi_error(reason, regs);
+                       unknown_nmi_error(reason, regs);
+
                return;
        }
-       if (notify_die(DIE_NMI, "nmi", regs, reason, 0, SIGINT) == NOTIFY_STOP)
+       if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
                return;
        if (reason & 0x80)
                mem_parity_error(reason, regs);
@@ -613,49 +842,31 @@ static void default_do_nmi(struct pt_regs * regs)
        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)
+fastcall __kprobes void do_nmi(struct pt_regs * regs, long error_code)
 {
        int cpu;
 
        nmi_enter();
 
        cpu = smp_processor_id();
+
        ++nmi_count(cpu);
 
-       if (!nmi_callback(regs, cpu))
-               default_do_nmi(regs);
+       default_do_nmi(regs);
 
        nmi_exit();
 }
 
-void set_nmi_callback(nmi_callback_t callback)
-{
-       nmi_callback = callback;
-}
-
-void unset_nmi_callback(void)
-{
-       nmi_callback = dummy_nmi_callback;
-}
-
 #ifdef CONFIG_KPROBES
-fastcall int do_int3(struct pt_regs *regs, long error_code)
+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 1;
+               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);
-       return 0;
 }
 #endif
 
@@ -681,12 +892,12 @@ fastcall int do_int3(struct pt_regs *regs, long error_code)
  * find every occurrence of the TF bit that could be saved away even
  * by user code)
  */
-fastcall void do_debug(struct pt_regs * regs, long error_code)
+fastcall void __kprobes do_debug(struct pt_regs * regs, long error_code)
 {
        unsigned int condition;
        struct task_struct *tsk = current;
 
-       __asm__ __volatile__("movl %%db6,%0" : "=r" (condition));
+       get_debugreg(condition, 6);
 
        if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
                                        SIGTRAP) == NOTIFY_STOP)
@@ -710,8 +921,6 @@ fastcall void do_debug(struct pt_regs * regs, long error_code)
        /*
         * Single-stepping through TF: make sure we ignore any events in
         * kernel space (but re-enable TF when returning to user mode).
-        * And if the event was due to a debugger (PT_DTRACE), clear the
-        * TF flag so that register information is correct.
         */
        if (condition & DR_STEP) {
                /*
@@ -719,13 +928,8 @@ fastcall void do_debug(struct pt_regs * regs, long error_code)
                 * check for kernel mode by just checking the CPL
                 * of CS.
                 */
-               if ((regs->xcs & 3) == 0)
+               if (!user_mode(regs))
                        goto clear_TF_reenable;
-
-               if (likely(tsk->ptrace & PT_DTRACE)) {
-                       tsk->ptrace &= ~PT_DTRACE;
-                       regs->eflags &= ~TF_MASK;
-               }
        }
 
        /* Ok, finally something we can handle */
@@ -735,9 +939,7 @@ fastcall void do_debug(struct pt_regs * regs, long error_code)
         * the signal is delivered.
         */
 clear_dr7:
-       __asm__("movl %0,%%db7"
-               : /* no output */
-               : "r" (0));
+       set_debugreg(0, 7);
        return;
 
 debug_vm86:
@@ -784,15 +986,18 @@ void math_error(void __user *eip)
         */
        cwd = get_fpu_cwd(task);
        swd = get_fpu_swd(task);
-       switch (((~cwd) & swd & 0x3f) | (swd & 0x240)) {
-               case 0x000:
-               default:
+       switch (swd & ~cwd & 0x3f) {
+               case 0x000: /* No unmasked exception */
+                       return;
+               default:    /* Multiple exceptions */
                        break;
                case 0x001: /* Invalid Op */
-               case 0x041: /* Stack Fault */
-               case 0x241: /* Stack Fault | Direction */
+                       /*
+                        * swd & 0x240 == 0x040: Stack Underflow
+                        * swd & 0x240 == 0x240: Stack Overflow
+                        * User must clear the SF bit (0x40) if set
+                        */
                        info.si_code = FPE_FLTINV;
-                       /* Should we clear the SF or let user space do it ???? */
                        break;
                case 0x002: /* Denormalize */
                case 0x010: /* Underflow */
@@ -817,7 +1022,7 @@ fastcall void do_coprocessor_error(struct pt_regs * regs, long error_code)
        math_error((void __user *)regs->eip);
 }
 
-void simd_math_error(void __user *eip)
+static void simd_math_error(void __user *eip)
 {
        struct task_struct * task;
        siginfo_t info;
@@ -882,9 +1087,9 @@ fastcall void do_simd_coprocessor_error(struct pt_regs * regs,
                                          error_code);
                        return;
                }
-               die_if_kernel("cache flush denied", regs, error_code);
                current->thread.trap_no = 19;
                current->thread.error_code = error_code;
+               die_if_kernel("cache flush denied", regs, error_code);
                force_sig(SIGSEGV, current);
        }
 }
@@ -898,6 +1103,26 @@ fastcall void do_spurious_interrupt_bug(struct pt_regs * regs,
 #endif
 }
 
+fastcall unsigned long patch_espfix_desc(unsigned long uesp,
+                                         unsigned long kesp)
+{
+       int cpu = smp_processor_id();
+       struct Xgt_desc_struct *cpu_gdt_descr = &per_cpu(cpu_gdt_descr, cpu);
+       struct desc_struct *gdt = (struct desc_struct *)cpu_gdt_descr->address;
+       unsigned long base = (kesp - uesp) & -THREAD_SIZE;
+       unsigned long new_kesp = kesp - base;
+       unsigned long lim_pages = (new_kesp | (THREAD_SIZE - 1)) >> PAGE_SHIFT;
+       __u64 desc = *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS];
+       /* Set up base for espfix segment */
+       desc &= 0x00f0ff0000000000ULL;
+       desc |= ((((__u64)base) << 16) & 0x000000ffffff0000ULL) |
+               ((((__u64)base) << 32) & 0xff00000000000000ULL) |
+               ((((__u64)lim_pages) << 32) & 0x000f000000000000ULL) |
+               (lim_pages & 0xffff);
+       *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS] = desc;
+       return new_kesp;
+}
+
 /*
  *  'math_state_restore()' saves the current math information in the
  * old math state array, and gets the new ones from the current task
@@ -908,7 +1133,7 @@ fastcall void do_spurious_interrupt_bug(struct pt_regs * regs,
  * 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)
+asmlinkage void math_state_restore(void)
 {
        struct thread_info *thread = current_thread_info();
        struct task_struct *tsk = thread->task;
@@ -918,14 +1143,15 @@ asmlinkage void math_state_restore(struct pt_regs regs)
                init_fpu(tsk);
        restore_fpu(tsk);
        thread->status |= TS_USEDFPU;   /* So we fnsave on switch_to() */
+       tsk->fpu_counter++;
 }
 
 #ifndef CONFIG_MATH_EMULATION
 
 asmlinkage void math_emulate(long arg)
 {
-       printk("math-emulation not enabled and no coprocessor found.\n");
-       printk("killing %s.\n",current->comm);
+       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();
 }
@@ -942,24 +1168,10 @@ void __init trap_init_f00f_bug(void)
         * it uses the read-only mapped virtual address.
         */
        idt_descr.address = fix_to_virt(FIX_F00F_IDT);
-       __asm__ __volatile__("lidt %0" : : "m" (idt_descr));
+       load_idt(&idt_descr);
 }
 #endif
 
-#define _set_gate(gate_addr,type,dpl,addr,seg) \
-do { \
-  int __d0, __d1; \
-  __asm__ __volatile__ ("movw %%dx,%%ax\n\t" \
-       "movw %4,%%dx\n\t" \
-       "movl %%eax,%0\n\t" \
-       "movl %%edx,%1" \
-       :"=m" (*((long *) (gate_addr))), \
-        "=m" (*(1+(long *) (gate_addr))), "=&a" (__d0), "=&d" (__d1) \
-       :"i" ((short) (0x8000+(dpl<<13)+(type<<8))), \
-        "3" ((char *) (addr)),"2" ((seg) << 16)); \
-} while (0)
-
-
 /*
  * This needs to use 'idt_table' rather than 'idt', and
  * thus use the _nonmapped_ version of the IDT, as the
@@ -968,7 +1180,7 @@ do { \
  */
 void set_intr_gate(unsigned int n, void *addr)
 {
-       _set_gate(idt_table+n,14,0,addr,__KERNEL_CS);
+       _set_gate(n, DESCTYPE_INT, addr, __KERNEL_CS);
 }
 
 /*
@@ -976,22 +1188,22 @@ void set_intr_gate(unsigned int n, void *addr)
  */
 static inline void set_system_intr_gate(unsigned int n, void *addr)
 {
-       _set_gate(idt_table+n, 14, 3, addr, __KERNEL_CS);
+       _set_gate(n, DESCTYPE_INT | DESCTYPE_DPL3, addr, __KERNEL_CS);
 }
 
 static void __init set_trap_gate(unsigned int n, void *addr)
 {
-       _set_gate(idt_table+n,15,0,addr,__KERNEL_CS);
+       _set_gate(n, DESCTYPE_TRAP, addr, __KERNEL_CS);
 }
 
 static void __init set_system_gate(unsigned int n, void *addr)
 {
-       _set_gate(idt_table+n,15,3,addr,__KERNEL_CS);
+       _set_gate(n, DESCTYPE_TRAP | DESCTYPE_DPL3, addr, __KERNEL_CS);
 }
 
 static void __init set_task_gate(unsigned int n, unsigned int gdt_entry)
 {
-       _set_gate(idt_table+n,5,0,0,(gdt_entry<<3));
+       _set_gate(n, DESCTYPE_TASK, (void *)0, (gdt_entry<<3));
 }
 
 
@@ -1012,9 +1224,9 @@ void __init trap_init(void)
        set_trap_gate(0,&divide_error);
        set_intr_gate(1,&debug);
        set_intr_gate(2,&nmi);
-       set_system_intr_gate(3, &int3); /* int3-5 can be called from all */
+       set_system_intr_gate(3, &int3); /* int3/4 can be called from all */
        set_system_gate(4,&overflow);
-       set_system_gate(5,&bounds);
+       set_trap_gate(5,&bounds);
        set_trap_gate(6,&invalid_op);
        set_trap_gate(7,&device_not_available);
        set_task_gate(8,GDT_ENTRY_DOUBLEFAULT_TSS);
@@ -1032,6 +1244,28 @@ void __init trap_init(void)
 #endif
        set_trap_gate(19,&simd_coprocessor_error);
 
+       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");
+       }
+
        set_system_gate(SYSCALL_VECTOR,&system_call);
 
        /*
@@ -1041,3 +1275,10 @@ void __init trap_init(void)
 
        trap_init_hook();
 }
+
+static int __init kstack_setup(char *s)
+{
+       kstack_depth_to_print = simple_strtoul(s, NULL, 0);
+       return 1;
+}
+__setup("kstack=", kstack_setup);