608e261968
The current generic bug implementation has a call to dump_stack() in case a WARN_ON(whatever) gets hit. Since report_bug(), which calls dump_stack(), gets called from an exception handler we can do better: just pass the pt_regs structure to report_bug() and pass it to show_regs() in case of a warning. This will give more debug informations like register contents, etc... In addition this avoids some pointless lines that dump_stack() emits, since it includes a stack backtrace of the exception handler which is of no interest in case of a warning. E.g. on s390 the following lines are currently always present in a stack backtrace if dump_stack() gets called from report_bug(): [<000000000001517a>] show_trace+0x92/0xe8) [<0000000000015270>] show_stack+0xa0/0xd0 [<00000000000152ce>] dump_stack+0x2e/0x3c [<0000000000195450>] report_bug+0x98/0xf8 [<0000000000016cc8>] illegal_op+0x1fc/0x21c [<00000000000227d6>] sysc_return+0x0/0x10 Acked-by: Jeremy Fitzhardinge <jeremy@goop.org> Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com> Cc: Andi Kleen <ak@suse.de> Cc: Kyle McMartin <kyle@parisc-linux.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
250 lines
5.6 KiB
C
250 lines
5.6 KiB
C
/*
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* Copyright (C) 2004-2006 Atmel Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/bug.h>
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#include <linux/init.h>
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#include <linux/kallsyms.h>
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#include <linux/module.h>
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#include <linux/notifier.h>
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#include <linux/sched.h>
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#include <linux/uaccess.h>
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#include <asm/addrspace.h>
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#include <asm/mmu_context.h>
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#include <asm/ocd.h>
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#include <asm/sysreg.h>
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#include <asm/traps.h>
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static DEFINE_SPINLOCK(die_lock);
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void NORET_TYPE die(const char *str, struct pt_regs *regs, long err)
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{
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static int die_counter;
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console_verbose();
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spin_lock_irq(&die_lock);
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bust_spinlocks(1);
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printk(KERN_ALERT "Oops: %s, sig: %ld [#%d]\n" KERN_EMERG,
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str, err, ++die_counter);
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#ifdef CONFIG_PREEMPT
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printk("PREEMPT ");
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#endif
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#ifdef CONFIG_FRAME_POINTER
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printk("FRAME_POINTER ");
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#endif
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if (current_cpu_data.features & AVR32_FEATURE_OCD) {
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unsigned long did = __mfdr(DBGREG_DID);
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printk("chip: 0x%03lx:0x%04lx rev %lu\n",
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(did >> 1) & 0x7ff,
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(did >> 12) & 0x7fff,
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(did >> 28) & 0xf);
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} else {
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printk("cpu: arch %u r%u / core %u r%u\n",
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current_cpu_data.arch_type,
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current_cpu_data.arch_revision,
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current_cpu_data.cpu_type,
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current_cpu_data.cpu_revision);
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}
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print_modules();
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show_regs_log_lvl(regs, KERN_EMERG);
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show_stack_log_lvl(current, regs->sp, regs, KERN_EMERG);
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bust_spinlocks(0);
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spin_unlock_irq(&die_lock);
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if (in_interrupt())
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panic("Fatal exception in interrupt");
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if (panic_on_oops)
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panic("Fatal exception");
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do_exit(err);
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}
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void _exception(long signr, struct pt_regs *regs, int code,
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unsigned long addr)
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{
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siginfo_t info;
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if (!user_mode(regs))
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die("Unhandled exception in kernel mode", regs, signr);
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memset(&info, 0, sizeof(info));
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info.si_signo = signr;
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info.si_code = code;
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info.si_addr = (void __user *)addr;
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force_sig_info(signr, &info, current);
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/*
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* Init gets no signals that it doesn't have a handler for.
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* That's all very well, but if it has caused a synchronous
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* exception and we ignore the resulting signal, it will just
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* generate the same exception over and over again and we get
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* nowhere. Better to kill it and let the kernel panic.
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*/
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if (is_init(current)) {
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__sighandler_t handler;
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spin_lock_irq(¤t->sighand->siglock);
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handler = current->sighand->action[signr-1].sa.sa_handler;
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spin_unlock_irq(¤t->sighand->siglock);
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if (handler == SIG_DFL) {
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/* init has generated a synchronous exception
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and it doesn't have a handler for the signal */
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printk(KERN_CRIT "init has generated signal %ld "
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"but has no handler for it\n", signr);
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do_exit(signr);
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}
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}
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}
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asmlinkage void do_nmi(unsigned long ecr, struct pt_regs *regs)
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{
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printk(KERN_ALERT "Got Non-Maskable Interrupt, dumping regs\n");
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show_regs_log_lvl(regs, KERN_ALERT);
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show_stack_log_lvl(current, regs->sp, regs, KERN_ALERT);
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}
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asmlinkage void do_critical_exception(unsigned long ecr, struct pt_regs *regs)
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{
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die("Critical exception", regs, SIGKILL);
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}
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asmlinkage void do_address_exception(unsigned long ecr, struct pt_regs *regs)
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{
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_exception(SIGBUS, regs, BUS_ADRALN, regs->pc);
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}
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/* This way of handling undefined instructions is stolen from ARM */
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static LIST_HEAD(undef_hook);
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static DEFINE_SPINLOCK(undef_lock);
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void register_undef_hook(struct undef_hook *hook)
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{
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spin_lock_irq(&undef_lock);
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list_add(&hook->node, &undef_hook);
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spin_unlock_irq(&undef_lock);
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}
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void unregister_undef_hook(struct undef_hook *hook)
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{
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spin_lock_irq(&undef_lock);
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list_del(&hook->node);
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spin_unlock_irq(&undef_lock);
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}
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static int do_cop_absent(u32 insn)
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{
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int cop_nr;
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u32 cpucr;
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if ((insn & 0xfdf00000) == 0xf1900000)
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/* LDC0 */
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cop_nr = 0;
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else
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cop_nr = (insn >> 13) & 0x7;
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/* Try enabling the coprocessor */
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cpucr = sysreg_read(CPUCR);
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cpucr |= (1 << (24 + cop_nr));
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sysreg_write(CPUCR, cpucr);
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cpucr = sysreg_read(CPUCR);
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if (!(cpucr & (1 << (24 + cop_nr))))
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return -ENODEV;
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return 0;
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}
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int is_valid_bugaddr(unsigned long pc)
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{
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unsigned short opcode;
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if (pc < PAGE_OFFSET)
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return 0;
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if (probe_kernel_address((u16 *)pc, opcode))
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return 0;
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return opcode == AVR32_BUG_OPCODE;
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}
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asmlinkage void do_illegal_opcode(unsigned long ecr, struct pt_regs *regs)
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{
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u32 insn;
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struct undef_hook *hook;
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void __user *pc;
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long code;
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if (!user_mode(regs) && (ecr == ECR_ILLEGAL_OPCODE)) {
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enum bug_trap_type type;
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type = report_bug(regs->pc, regs);
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switch (type) {
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case BUG_TRAP_TYPE_NONE:
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break;
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case BUG_TRAP_TYPE_WARN:
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regs->pc += 2;
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return;
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case BUG_TRAP_TYPE_BUG:
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die("Kernel BUG", regs, SIGKILL);
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}
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}
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local_irq_enable();
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if (user_mode(regs)) {
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pc = (void __user *)instruction_pointer(regs);
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if (get_user(insn, (u32 __user *)pc))
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goto invalid_area;
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if (ecr == ECR_COPROC_ABSENT && !do_cop_absent(insn))
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return;
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spin_lock_irq(&undef_lock);
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list_for_each_entry(hook, &undef_hook, node) {
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if ((insn & hook->insn_mask) == hook->insn_val) {
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if (hook->fn(regs, insn) == 0) {
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spin_unlock_irq(&undef_lock);
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return;
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}
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}
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}
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spin_unlock_irq(&undef_lock);
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}
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switch (ecr) {
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case ECR_PRIVILEGE_VIOLATION:
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code = ILL_PRVOPC;
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break;
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case ECR_COPROC_ABSENT:
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code = ILL_COPROC;
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break;
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default:
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code = ILL_ILLOPC;
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break;
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}
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_exception(SIGILL, regs, code, regs->pc);
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return;
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invalid_area:
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_exception(SIGSEGV, regs, SEGV_MAPERR, regs->pc);
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}
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asmlinkage void do_fpe(unsigned long ecr, struct pt_regs *regs)
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{
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/* We have no FPU yet */
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_exception(SIGILL, regs, ILL_COPROC, regs->pc);
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}
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void __init trap_init(void)
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{
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}
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