840 строки
20 KiB
C
840 строки
20 KiB
C
/*
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* linux/arch/arm/kernel/traps.c
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*
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* Copyright (C) 1995-2009 Russell King
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* Fragments that appear the same as linux/arch/i386/kernel/traps.c (C) Linus Torvalds
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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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* 'traps.c' handles hardware exceptions after we have saved some state in
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* 'linux/arch/arm/lib/traps.S'. Mostly a debugging aid, but will probably
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* kill the offending process.
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*/
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#include <linux/signal.h>
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#include <linux/personality.h>
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#include <linux/kallsyms.h>
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#include <linux/spinlock.h>
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#include <linux/uaccess.h>
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#include <linux/hardirq.h>
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#include <linux/kdebug.h>
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#include <linux/kprobes.h>
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#include <linux/module.h>
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#include <linux/kexec.h>
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#include <linux/bug.h>
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#include <linux/delay.h>
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#include <linux/init.h>
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#include <linux/sched/signal.h>
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#include <linux/sched/debug.h>
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#include <linux/sched/task_stack.h>
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#include <linux/irq.h>
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#include <linux/atomic.h>
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#include <asm/cacheflush.h>
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#include <asm/exception.h>
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#include <asm/unistd.h>
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#include <asm/traps.h>
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#include <asm/ptrace.h>
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#include <asm/unwind.h>
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#include <asm/tls.h>
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#include <asm/system_misc.h>
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#include <asm/opcodes.h>
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static const char *handler[]= {
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"prefetch abort",
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"data abort",
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"address exception",
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"interrupt",
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"undefined instruction",
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};
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void *vectors_page;
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#ifdef CONFIG_DEBUG_USER
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unsigned int user_debug;
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static int __init user_debug_setup(char *str)
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{
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get_option(&str, &user_debug);
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return 1;
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}
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__setup("user_debug=", user_debug_setup);
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#endif
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static void dump_mem(const char *, const char *, unsigned long, unsigned long);
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void dump_backtrace_entry(unsigned long where, unsigned long from, unsigned long frame)
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{
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#ifdef CONFIG_KALLSYMS
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printk("[<%08lx>] (%ps) from [<%08lx>] (%pS)\n", where, (void *)where, from, (void *)from);
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#else
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printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from);
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#endif
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if (in_entry_text(from))
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dump_mem("", "Exception stack", frame + 4, frame + 4 + sizeof(struct pt_regs));
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}
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void dump_backtrace_stm(u32 *stack, u32 instruction)
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{
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char str[80], *p;
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unsigned int x;
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int reg;
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for (reg = 10, x = 0, p = str; reg >= 0; reg--) {
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if (instruction & BIT(reg)) {
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p += sprintf(p, " r%d:%08x", reg, *stack--);
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if (++x == 6) {
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x = 0;
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p = str;
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printk("%s\n", str);
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}
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}
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}
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if (p != str)
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printk("%s\n", str);
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}
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#ifndef CONFIG_ARM_UNWIND
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/*
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* Stack pointers should always be within the kernels view of
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* physical memory. If it is not there, then we can't dump
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* out any information relating to the stack.
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*/
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static int verify_stack(unsigned long sp)
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{
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if (sp < PAGE_OFFSET ||
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(sp > (unsigned long)high_memory && high_memory != NULL))
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return -EFAULT;
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return 0;
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}
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#endif
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/*
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* Dump out the contents of some memory nicely...
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*/
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static void dump_mem(const char *lvl, const char *str, unsigned long bottom,
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unsigned long top)
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{
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unsigned long first;
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mm_segment_t fs;
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int i;
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/*
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* We need to switch to kernel mode so that we can use __get_user
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* to safely read from kernel space. Note that we now dump the
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* code first, just in case the backtrace kills us.
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*/
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fs = get_fs();
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set_fs(KERNEL_DS);
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printk("%s%s(0x%08lx to 0x%08lx)\n", lvl, str, bottom, top);
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for (first = bottom & ~31; first < top; first += 32) {
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unsigned long p;
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char str[sizeof(" 12345678") * 8 + 1];
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memset(str, ' ', sizeof(str));
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str[sizeof(str) - 1] = '\0';
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for (p = first, i = 0; i < 8 && p < top; i++, p += 4) {
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if (p >= bottom && p < top) {
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unsigned long val;
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if (__get_user(val, (unsigned long *)p) == 0)
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sprintf(str + i * 9, " %08lx", val);
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else
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sprintf(str + i * 9, " ????????");
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}
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}
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printk("%s%04lx:%s\n", lvl, first & 0xffff, str);
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}
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set_fs(fs);
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}
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static void __dump_instr(const char *lvl, struct pt_regs *regs)
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{
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unsigned long addr = instruction_pointer(regs);
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const int thumb = thumb_mode(regs);
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const int width = thumb ? 4 : 8;
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char str[sizeof("00000000 ") * 5 + 2 + 1], *p = str;
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int i;
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/*
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* Note that we now dump the code first, just in case the backtrace
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* kills us.
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*/
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for (i = -4; i < 1 + !!thumb; i++) {
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unsigned int val, bad;
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if (thumb)
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bad = get_user(val, &((u16 *)addr)[i]);
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else
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bad = get_user(val, &((u32 *)addr)[i]);
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if (!bad)
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p += sprintf(p, i == 0 ? "(%0*x) " : "%0*x ",
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width, val);
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else {
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p += sprintf(p, "bad PC value");
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break;
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}
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}
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printk("%sCode: %s\n", lvl, str);
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}
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static void dump_instr(const char *lvl, struct pt_regs *regs)
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{
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mm_segment_t fs;
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if (!user_mode(regs)) {
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fs = get_fs();
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set_fs(KERNEL_DS);
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__dump_instr(lvl, regs);
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set_fs(fs);
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} else {
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__dump_instr(lvl, regs);
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}
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}
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#ifdef CONFIG_ARM_UNWIND
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static inline void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
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{
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unwind_backtrace(regs, tsk);
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}
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#else
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static void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
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{
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unsigned int fp, mode;
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int ok = 1;
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printk("Backtrace: ");
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if (!tsk)
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tsk = current;
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if (regs) {
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fp = frame_pointer(regs);
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mode = processor_mode(regs);
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} else if (tsk != current) {
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fp = thread_saved_fp(tsk);
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mode = 0x10;
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} else {
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asm("mov %0, fp" : "=r" (fp) : : "cc");
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mode = 0x10;
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}
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if (!fp) {
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pr_cont("no frame pointer");
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ok = 0;
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} else if (verify_stack(fp)) {
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pr_cont("invalid frame pointer 0x%08x", fp);
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ok = 0;
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} else if (fp < (unsigned long)end_of_stack(tsk))
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pr_cont("frame pointer underflow");
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pr_cont("\n");
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if (ok)
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c_backtrace(fp, mode);
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}
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#endif
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void show_stack(struct task_struct *tsk, unsigned long *sp)
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{
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dump_backtrace(NULL, tsk);
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barrier();
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}
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#ifdef CONFIG_PREEMPT
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#define S_PREEMPT " PREEMPT"
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#else
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#define S_PREEMPT ""
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#endif
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#ifdef CONFIG_SMP
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#define S_SMP " SMP"
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#else
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#define S_SMP ""
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#endif
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#ifdef CONFIG_THUMB2_KERNEL
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#define S_ISA " THUMB2"
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#else
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#define S_ISA " ARM"
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#endif
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static int __die(const char *str, int err, struct pt_regs *regs)
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{
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struct task_struct *tsk = current;
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static int die_counter;
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int ret;
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pr_emerg("Internal error: %s: %x [#%d]" S_PREEMPT S_SMP S_ISA "\n",
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str, err, ++die_counter);
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/* trap and error numbers are mostly meaningless on ARM */
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ret = notify_die(DIE_OOPS, str, regs, err, tsk->thread.trap_no, SIGSEGV);
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if (ret == NOTIFY_STOP)
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return 1;
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print_modules();
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__show_regs(regs);
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pr_emerg("Process %.*s (pid: %d, stack limit = 0x%p)\n",
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TASK_COMM_LEN, tsk->comm, task_pid_nr(tsk), end_of_stack(tsk));
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if (!user_mode(regs) || in_interrupt()) {
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dump_mem(KERN_EMERG, "Stack: ", regs->ARM_sp,
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THREAD_SIZE + (unsigned long)task_stack_page(tsk));
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dump_backtrace(regs, tsk);
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dump_instr(KERN_EMERG, regs);
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}
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return 0;
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}
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static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
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static int die_owner = -1;
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static unsigned int die_nest_count;
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static unsigned long oops_begin(void)
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{
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int cpu;
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unsigned long flags;
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oops_enter();
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/* racy, but better than risking deadlock. */
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raw_local_irq_save(flags);
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cpu = smp_processor_id();
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if (!arch_spin_trylock(&die_lock)) {
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if (cpu == die_owner)
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/* nested oops. should stop eventually */;
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else
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arch_spin_lock(&die_lock);
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}
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die_nest_count++;
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die_owner = cpu;
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console_verbose();
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bust_spinlocks(1);
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return flags;
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}
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static void oops_end(unsigned long flags, struct pt_regs *regs, int signr)
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{
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if (regs && kexec_should_crash(current))
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crash_kexec(regs);
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bust_spinlocks(0);
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die_owner = -1;
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add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
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die_nest_count--;
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if (!die_nest_count)
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/* Nest count reaches zero, release the lock. */
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arch_spin_unlock(&die_lock);
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raw_local_irq_restore(flags);
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oops_exit();
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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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if (signr)
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do_exit(signr);
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}
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/*
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* This function is protected against re-entrancy.
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*/
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void die(const char *str, struct pt_regs *regs, int err)
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{
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enum bug_trap_type bug_type = BUG_TRAP_TYPE_NONE;
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unsigned long flags = oops_begin();
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int sig = SIGSEGV;
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if (!user_mode(regs))
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bug_type = report_bug(regs->ARM_pc, regs);
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if (bug_type != BUG_TRAP_TYPE_NONE)
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str = "Oops - BUG";
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if (__die(str, err, regs))
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sig = 0;
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oops_end(flags, regs, sig);
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}
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void arm_notify_die(const char *str, struct pt_regs *regs,
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int signo, int si_code, void __user *addr,
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unsigned long err, unsigned long trap)
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{
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if (user_mode(regs)) {
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current->thread.error_code = err;
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current->thread.trap_no = trap;
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force_sig_fault(signo, si_code, addr, current);
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} else {
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die(str, regs, err);
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}
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}
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#ifdef CONFIG_GENERIC_BUG
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int is_valid_bugaddr(unsigned long pc)
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{
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#ifdef CONFIG_THUMB2_KERNEL
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u16 bkpt;
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u16 insn = __opcode_to_mem_thumb16(BUG_INSTR_VALUE);
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#else
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u32 bkpt;
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u32 insn = __opcode_to_mem_arm(BUG_INSTR_VALUE);
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#endif
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if (probe_kernel_address((unsigned *)pc, bkpt))
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return 0;
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return bkpt == insn;
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}
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#endif
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static LIST_HEAD(undef_hook);
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static DEFINE_RAW_SPINLOCK(undef_lock);
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void register_undef_hook(struct undef_hook *hook)
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{
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unsigned long flags;
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raw_spin_lock_irqsave(&undef_lock, flags);
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list_add(&hook->node, &undef_hook);
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raw_spin_unlock_irqrestore(&undef_lock, flags);
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}
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void unregister_undef_hook(struct undef_hook *hook)
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{
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unsigned long flags;
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raw_spin_lock_irqsave(&undef_lock, flags);
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list_del(&hook->node);
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raw_spin_unlock_irqrestore(&undef_lock, flags);
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}
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static nokprobe_inline
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int call_undef_hook(struct pt_regs *regs, unsigned int instr)
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{
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struct undef_hook *hook;
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unsigned long flags;
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int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL;
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raw_spin_lock_irqsave(&undef_lock, flags);
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list_for_each_entry(hook, &undef_hook, node)
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if ((instr & hook->instr_mask) == hook->instr_val &&
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(regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val)
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fn = hook->fn;
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raw_spin_unlock_irqrestore(&undef_lock, flags);
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return fn ? fn(regs, instr) : 1;
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}
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asmlinkage void do_undefinstr(struct pt_regs *regs)
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{
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unsigned int instr;
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void __user *pc;
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pc = (void __user *)instruction_pointer(regs);
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if (processor_mode(regs) == SVC_MODE) {
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#ifdef CONFIG_THUMB2_KERNEL
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if (thumb_mode(regs)) {
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instr = __mem_to_opcode_thumb16(((u16 *)pc)[0]);
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if (is_wide_instruction(instr)) {
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u16 inst2;
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inst2 = __mem_to_opcode_thumb16(((u16 *)pc)[1]);
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instr = __opcode_thumb32_compose(instr, inst2);
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}
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} else
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#endif
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instr = __mem_to_opcode_arm(*(u32 *) pc);
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} else if (thumb_mode(regs)) {
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if (get_user(instr, (u16 __user *)pc))
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goto die_sig;
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instr = __mem_to_opcode_thumb16(instr);
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if (is_wide_instruction(instr)) {
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unsigned int instr2;
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if (get_user(instr2, (u16 __user *)pc+1))
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goto die_sig;
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instr2 = __mem_to_opcode_thumb16(instr2);
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instr = __opcode_thumb32_compose(instr, instr2);
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}
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} else {
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if (get_user(instr, (u32 __user *)pc))
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goto die_sig;
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instr = __mem_to_opcode_arm(instr);
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}
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if (call_undef_hook(regs, instr) == 0)
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return;
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die_sig:
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#ifdef CONFIG_DEBUG_USER
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if (user_debug & UDBG_UNDEFINED) {
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pr_info("%s (%d): undefined instruction: pc=%p\n",
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current->comm, task_pid_nr(current), pc);
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__show_regs(regs);
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dump_instr(KERN_INFO, regs);
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}
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#endif
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arm_notify_die("Oops - undefined instruction", regs,
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SIGILL, ILL_ILLOPC, pc, 0, 6);
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}
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NOKPROBE_SYMBOL(do_undefinstr)
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/*
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* Handle FIQ similarly to NMI on x86 systems.
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*
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* The runtime environment for NMIs is extremely restrictive
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* (NMIs can pre-empt critical sections meaning almost all locking is
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* forbidden) meaning this default FIQ handling must only be used in
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* circumstances where non-maskability improves robustness, such as
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* watchdog or debug logic.
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*
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* This handler is not appropriate for general purpose use in drivers
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* platform code and can be overrideen using set_fiq_handler.
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*/
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asmlinkage void __exception_irq_entry handle_fiq_as_nmi(struct pt_regs *regs)
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{
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struct pt_regs *old_regs = set_irq_regs(regs);
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nmi_enter();
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/* nop. FIQ handlers for special arch/arm features can be added here. */
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nmi_exit();
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set_irq_regs(old_regs);
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}
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/*
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* bad_mode handles the impossible case in the vectors. If you see one of
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* these, then it's extremely serious, and could mean you have buggy hardware.
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* It never returns, and never tries to sync. We hope that we can at least
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* dump out some state information...
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*/
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asmlinkage void bad_mode(struct pt_regs *regs, int reason)
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{
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console_verbose();
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pr_crit("Bad mode in %s handler detected\n", handler[reason]);
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die("Oops - bad mode", regs, 0);
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local_irq_disable();
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panic("bad mode");
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}
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static int bad_syscall(int n, struct pt_regs *regs)
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{
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if ((current->personality & PER_MASK) != PER_LINUX) {
|
|
send_sig(SIGSEGV, current, 1);
|
|
return regs->ARM_r0;
|
|
}
|
|
|
|
#ifdef CONFIG_DEBUG_USER
|
|
if (user_debug & UDBG_SYSCALL) {
|
|
pr_err("[%d] %s: obsolete system call %08x.\n",
|
|
task_pid_nr(current), current->comm, n);
|
|
dump_instr(KERN_ERR, regs);
|
|
}
|
|
#endif
|
|
|
|
arm_notify_die("Oops - bad syscall", regs, SIGILL, ILL_ILLTRP,
|
|
(void __user *)instruction_pointer(regs) -
|
|
(thumb_mode(regs) ? 2 : 4),
|
|
n, 0);
|
|
|
|
return regs->ARM_r0;
|
|
}
|
|
|
|
static inline int
|
|
__do_cache_op(unsigned long start, unsigned long end)
|
|
{
|
|
int ret;
|
|
|
|
do {
|
|
unsigned long chunk = min(PAGE_SIZE, end - start);
|
|
|
|
if (fatal_signal_pending(current))
|
|
return 0;
|
|
|
|
ret = flush_cache_user_range(start, start + chunk);
|
|
if (ret)
|
|
return ret;
|
|
|
|
cond_resched();
|
|
start += chunk;
|
|
} while (start < end);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static inline int
|
|
do_cache_op(unsigned long start, unsigned long end, int flags)
|
|
{
|
|
if (end < start || flags)
|
|
return -EINVAL;
|
|
|
|
if (!access_ok(start, end - start))
|
|
return -EFAULT;
|
|
|
|
return __do_cache_op(start, end);
|
|
}
|
|
|
|
/*
|
|
* Handle all unrecognised system calls.
|
|
* 0x9f0000 - 0x9fffff are some more esoteric system calls
|
|
*/
|
|
#define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE)
|
|
asmlinkage int arm_syscall(int no, struct pt_regs *regs)
|
|
{
|
|
if ((no >> 16) != (__ARM_NR_BASE>> 16))
|
|
return bad_syscall(no, regs);
|
|
|
|
switch (no & 0xffff) {
|
|
case 0: /* branch through 0 */
|
|
arm_notify_die("branch through zero", regs,
|
|
SIGSEGV, SEGV_MAPERR, NULL, 0, 0);
|
|
return 0;
|
|
|
|
case NR(breakpoint): /* SWI BREAK_POINT */
|
|
regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
|
|
ptrace_break(current, regs);
|
|
return regs->ARM_r0;
|
|
|
|
/*
|
|
* Flush a region from virtual address 'r0' to virtual address 'r1'
|
|
* _exclusive_. There is no alignment requirement on either address;
|
|
* user space does not need to know the hardware cache layout.
|
|
*
|
|
* r2 contains flags. It should ALWAYS be passed as ZERO until it
|
|
* is defined to be something else. For now we ignore it, but may
|
|
* the fires of hell burn in your belly if you break this rule. ;)
|
|
*
|
|
* (at a later date, we may want to allow this call to not flush
|
|
* various aspects of the cache. Passing '0' will guarantee that
|
|
* everything necessary gets flushed to maintain consistency in
|
|
* the specified region).
|
|
*/
|
|
case NR(cacheflush):
|
|
return do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2);
|
|
|
|
case NR(usr26):
|
|
if (!(elf_hwcap & HWCAP_26BIT))
|
|
break;
|
|
regs->ARM_cpsr &= ~MODE32_BIT;
|
|
return regs->ARM_r0;
|
|
|
|
case NR(usr32):
|
|
if (!(elf_hwcap & HWCAP_26BIT))
|
|
break;
|
|
regs->ARM_cpsr |= MODE32_BIT;
|
|
return regs->ARM_r0;
|
|
|
|
case NR(set_tls):
|
|
set_tls(regs->ARM_r0);
|
|
return 0;
|
|
|
|
case NR(get_tls):
|
|
return current_thread_info()->tp_value[0];
|
|
|
|
default:
|
|
/* Calls 9f00xx..9f07ff are defined to return -ENOSYS
|
|
if not implemented, rather than raising SIGILL. This
|
|
way the calling program can gracefully determine whether
|
|
a feature is supported. */
|
|
if ((no & 0xffff) <= 0x7ff)
|
|
return -ENOSYS;
|
|
break;
|
|
}
|
|
#ifdef CONFIG_DEBUG_USER
|
|
/*
|
|
* experience shows that these seem to indicate that
|
|
* something catastrophic has happened
|
|
*/
|
|
if (user_debug & UDBG_SYSCALL) {
|
|
pr_err("[%d] %s: arm syscall %d\n",
|
|
task_pid_nr(current), current->comm, no);
|
|
dump_instr("", regs);
|
|
if (user_mode(regs)) {
|
|
__show_regs(regs);
|
|
c_backtrace(frame_pointer(regs), processor_mode(regs));
|
|
}
|
|
}
|
|
#endif
|
|
arm_notify_die("Oops - bad syscall(2)", regs, SIGILL, ILL_ILLTRP,
|
|
(void __user *)instruction_pointer(regs) -
|
|
(thumb_mode(regs) ? 2 : 4),
|
|
no, 0);
|
|
return 0;
|
|
}
|
|
|
|
#ifdef CONFIG_TLS_REG_EMUL
|
|
|
|
/*
|
|
* We might be running on an ARMv6+ processor which should have the TLS
|
|
* register but for some reason we can't use it, or maybe an SMP system
|
|
* using a pre-ARMv6 processor (there are apparently a few prototypes like
|
|
* that in existence) and therefore access to that register must be
|
|
* emulated.
|
|
*/
|
|
|
|
static int get_tp_trap(struct pt_regs *regs, unsigned int instr)
|
|
{
|
|
int reg = (instr >> 12) & 15;
|
|
if (reg == 15)
|
|
return 1;
|
|
regs->uregs[reg] = current_thread_info()->tp_value[0];
|
|
regs->ARM_pc += 4;
|
|
return 0;
|
|
}
|
|
|
|
static struct undef_hook arm_mrc_hook = {
|
|
.instr_mask = 0x0fff0fff,
|
|
.instr_val = 0x0e1d0f70,
|
|
.cpsr_mask = PSR_T_BIT,
|
|
.cpsr_val = 0,
|
|
.fn = get_tp_trap,
|
|
};
|
|
|
|
static int __init arm_mrc_hook_init(void)
|
|
{
|
|
register_undef_hook(&arm_mrc_hook);
|
|
return 0;
|
|
}
|
|
|
|
late_initcall(arm_mrc_hook_init);
|
|
|
|
#endif
|
|
|
|
/*
|
|
* A data abort trap was taken, but we did not handle the instruction.
|
|
* Try to abort the user program, or panic if it was the kernel.
|
|
*/
|
|
asmlinkage void
|
|
baddataabort(int code, unsigned long instr, struct pt_regs *regs)
|
|
{
|
|
unsigned long addr = instruction_pointer(regs);
|
|
|
|
#ifdef CONFIG_DEBUG_USER
|
|
if (user_debug & UDBG_BADABORT) {
|
|
pr_err("[%d] %s: bad data abort: code %d instr 0x%08lx\n",
|
|
task_pid_nr(current), current->comm, code, instr);
|
|
dump_instr(KERN_ERR, regs);
|
|
show_pte(current->mm, addr);
|
|
}
|
|
#endif
|
|
|
|
arm_notify_die("unknown data abort code", regs,
|
|
SIGILL, ILL_ILLOPC, (void __user *)addr, instr, 0);
|
|
}
|
|
|
|
void __readwrite_bug(const char *fn)
|
|
{
|
|
pr_err("%s called, but not implemented\n", fn);
|
|
BUG();
|
|
}
|
|
EXPORT_SYMBOL(__readwrite_bug);
|
|
|
|
void __pte_error(const char *file, int line, pte_t pte)
|
|
{
|
|
pr_err("%s:%d: bad pte %08llx.\n", file, line, (long long)pte_val(pte));
|
|
}
|
|
|
|
void __pmd_error(const char *file, int line, pmd_t pmd)
|
|
{
|
|
pr_err("%s:%d: bad pmd %08llx.\n", file, line, (long long)pmd_val(pmd));
|
|
}
|
|
|
|
void __pgd_error(const char *file, int line, pgd_t pgd)
|
|
{
|
|
pr_err("%s:%d: bad pgd %08llx.\n", file, line, (long long)pgd_val(pgd));
|
|
}
|
|
|
|
asmlinkage void __div0(void)
|
|
{
|
|
pr_err("Division by zero in kernel.\n");
|
|
dump_stack();
|
|
}
|
|
EXPORT_SYMBOL(__div0);
|
|
|
|
void abort(void)
|
|
{
|
|
BUG();
|
|
|
|
/* if that doesn't kill us, halt */
|
|
panic("Oops failed to kill thread");
|
|
}
|
|
|
|
void __init trap_init(void)
|
|
{
|
|
return;
|
|
}
|
|
|
|
#ifdef CONFIG_KUSER_HELPERS
|
|
static void __init kuser_init(void *vectors)
|
|
{
|
|
extern char __kuser_helper_start[], __kuser_helper_end[];
|
|
int kuser_sz = __kuser_helper_end - __kuser_helper_start;
|
|
|
|
memcpy(vectors + 0x1000 - kuser_sz, __kuser_helper_start, kuser_sz);
|
|
|
|
/*
|
|
* vectors + 0xfe0 = __kuser_get_tls
|
|
* vectors + 0xfe8 = hardware TLS instruction at 0xffff0fe8
|
|
*/
|
|
if (tls_emu || has_tls_reg)
|
|
memcpy(vectors + 0xfe0, vectors + 0xfe8, 4);
|
|
}
|
|
#else
|
|
static inline void __init kuser_init(void *vectors)
|
|
{
|
|
}
|
|
#endif
|
|
|
|
void __init early_trap_init(void *vectors_base)
|
|
{
|
|
#ifndef CONFIG_CPU_V7M
|
|
unsigned long vectors = (unsigned long)vectors_base;
|
|
extern char __stubs_start[], __stubs_end[];
|
|
extern char __vectors_start[], __vectors_end[];
|
|
unsigned i;
|
|
|
|
vectors_page = vectors_base;
|
|
|
|
/*
|
|
* Poison the vectors page with an undefined instruction. This
|
|
* instruction is chosen to be undefined for both ARM and Thumb
|
|
* ISAs. The Thumb version is an undefined instruction with a
|
|
* branch back to the undefined instruction.
|
|
*/
|
|
for (i = 0; i < PAGE_SIZE / sizeof(u32); i++)
|
|
((u32 *)vectors_base)[i] = 0xe7fddef1;
|
|
|
|
/*
|
|
* Copy the vectors, stubs and kuser helpers (in entry-armv.S)
|
|
* into the vector page, mapped at 0xffff0000, and ensure these
|
|
* are visible to the instruction stream.
|
|
*/
|
|
memcpy((void *)vectors, __vectors_start, __vectors_end - __vectors_start);
|
|
memcpy((void *)vectors + 0x1000, __stubs_start, __stubs_end - __stubs_start);
|
|
|
|
kuser_init(vectors_base);
|
|
|
|
flush_icache_range(vectors, vectors + PAGE_SIZE * 2);
|
|
#else /* ifndef CONFIG_CPU_V7M */
|
|
/*
|
|
* on V7-M there is no need to copy the vector table to a dedicated
|
|
* memory area. The address is configurable and so a table in the kernel
|
|
* image can be used.
|
|
*/
|
|
#endif
|
|
}
|