forked from Minki/linux
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
549 lines
12 KiB
C
549 lines
12 KiB
C
/*
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* linux/arch/arm26/kernel/traps.c
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*
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* Copyright (C) 1995-2002 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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* Copyright (C) 2003 Ian Molton (ARM26)
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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/arm26/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/module.h>
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#include <linux/config.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/signal.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/spinlock.h>
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#include <linux/personality.h>
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#include <linux/ptrace.h>
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#include <linux/elf.h>
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#include <linux/interrupt.h>
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#include <linux/init.h>
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#include <asm/atomic.h>
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#include <asm/io.h>
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#include <asm/pgtable.h>
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#include <asm/system.h>
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#include <asm/uaccess.h>
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#include <asm/unistd.h>
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#include <asm/semaphore.h>
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#include "ptrace.h"
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extern void c_backtrace (unsigned long fp, int pmode);
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extern void show_pte(struct mm_struct *mm, unsigned long addr);
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const char *processor_modes[] = { "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" };
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static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" "*bad reason*"};
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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 || (sp > (unsigned long)high_memory && high_memory != 0))
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return -EFAULT;
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return 0;
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}
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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 *str, unsigned long bottom, unsigned long top)
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{
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unsigned long p = bottom & ~31;
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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", str);
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printk("(0x%08lx to 0x%08lx)\n", bottom, top);
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for (p = bottom & ~31; p < top;) {
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printk("%04lx: ", p & 0xffff);
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for (i = 0; i < 8; i++, p += 4) {
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unsigned int val;
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if (p < bottom || p >= top)
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printk(" ");
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else {
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__get_user(val, (unsigned long *)p);
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printk("%08x ", val);
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}
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}
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printk ("\n");
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}
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set_fs(fs);
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}
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static void dump_instr(struct pt_regs *regs)
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{
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unsigned long addr = instruction_pointer(regs);
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const int width = 8;
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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("Code: ");
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for (i = -4; i < 1; i++) {
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unsigned int val, bad;
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bad = __get_user(val, &((u32 *)addr)[i]);
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if (!bad)
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printk(i == 0 ? "(%0*x) " : "%0*x ", width, val);
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else {
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printk("bad PC value.");
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break;
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}
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}
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printk("\n");
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set_fs(fs);
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}
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/*static*/ void __dump_stack(struct task_struct *tsk, unsigned long sp)
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{
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dump_mem("Stack: ", sp, 8192+(unsigned long)tsk->thread_info);
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}
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void dump_stack(void)
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{
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#ifdef CONFIG_DEBUG_ERRORS
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__backtrace();
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#endif
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}
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EXPORT_SYMBOL(dump_stack);
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//FIXME - was a static fn
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void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
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{
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unsigned int fp;
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int ok = 1;
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printk("Backtrace: ");
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fp = regs->ARM_fp;
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if (!fp) {
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printk("no frame pointer");
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ok = 0;
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} else if (verify_stack(fp)) {
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printk("invalid frame pointer 0x%08x", fp);
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ok = 0;
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} else if (fp < (unsigned long)(tsk->thread_info + 1))
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printk("frame pointer underflow");
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printk("\n");
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if (ok)
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c_backtrace(fp, processor_mode(regs));
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}
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/* FIXME - this is probably wrong.. */
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void show_stack(struct task_struct *task, unsigned long *sp) {
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dump_mem("Stack: ", (unsigned long)sp, 8192+(unsigned long)task->thread_info);
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}
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DEFINE_SPINLOCK(die_lock);
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/*
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* This function is protected against re-entrancy.
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*/
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NORET_TYPE void die(const char *str, struct pt_regs *regs, int err)
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{
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struct task_struct *tsk = current;
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console_verbose();
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spin_lock_irq(&die_lock);
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printk("Internal error: %s: %x\n", str, err);
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printk("CPU: %d\n", smp_processor_id());
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show_regs(regs);
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printk("Process %s (pid: %d, stack limit = 0x%p)\n",
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current->comm, current->pid, tsk->thread_info + 1);
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if (!user_mode(regs) || in_interrupt()) {
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__dump_stack(tsk, (unsigned long)(regs + 1));
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dump_backtrace(regs, tsk);
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dump_instr(regs);
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}
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while(1);
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spin_unlock_irq(&die_lock);
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do_exit(SIGSEGV);
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}
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void die_if_kernel(const char *str, struct pt_regs *regs, int err)
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{
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if (user_mode(regs))
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return;
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die(str, regs, err);
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}
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static DECLARE_MUTEX(undef_sem);
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static int (*undef_hook)(struct pt_regs *);
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int request_undef_hook(int (*fn)(struct pt_regs *))
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{
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int ret = -EBUSY;
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down(&undef_sem);
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if (undef_hook == NULL) {
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undef_hook = fn;
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ret = 0;
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}
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up(&undef_sem);
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return ret;
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}
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int release_undef_hook(int (*fn)(struct pt_regs *))
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{
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int ret = -EINVAL;
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down(&undef_sem);
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if (undef_hook == fn) {
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undef_hook = NULL;
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ret = 0;
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}
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up(&undef_sem);
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return ret;
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}
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static int undefined_extension(struct pt_regs *regs, unsigned int op)
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{
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switch (op) {
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case 1: /* 0xde01 / 0x?7f001f0 */
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ptrace_break(current, regs);
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return 0;
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}
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return 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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siginfo_t info;
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void *pc;
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regs->ARM_pc -= 4;
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pc = (unsigned long *)instruction_pointer(regs); /* strip PSR */
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if (user_mode(regs)) {
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u32 instr;
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get_user(instr, (u32 *)pc);
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if ((instr & 0x0fff00ff) == 0x07f000f0 &&
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undefined_extension(regs, (instr >> 8) & 255) == 0) {
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regs->ARM_pc += 4;
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return;
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}
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} else {
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if (undef_hook && undef_hook(regs) == 0) {
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regs->ARM_pc += 4;
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return;
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}
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}
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#ifdef CONFIG_DEBUG_USER
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printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",
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current->comm, current->pid, pc);
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dump_instr(regs);
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#endif
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current->thread.error_code = 0;
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current->thread.trap_no = 6;
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info.si_signo = SIGILL;
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info.si_errno = 0;
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info.si_code = ILL_ILLOPC;
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info.si_addr = pc;
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force_sig_info(SIGILL, &info, current);
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die_if_kernel("Oops - undefined instruction", regs, 0);
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}
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asmlinkage void do_excpt(unsigned long address, struct pt_regs *regs, int mode)
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{
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siginfo_t info;
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#ifdef CONFIG_DEBUG_USER
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printk(KERN_INFO "%s (%d): address exception: pc=%08lx\n",
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current->comm, current->pid, instruction_pointer(regs));
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dump_instr(regs);
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#endif
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current->thread.error_code = 0;
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current->thread.trap_no = 11;
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info.si_signo = SIGBUS;
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info.si_errno = 0;
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info.si_code = BUS_ADRERR;
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info.si_addr = (void *)address;
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force_sig_info(SIGBUS, &info, current);
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die_if_kernel("Oops - address exception", regs, mode);
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}
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asmlinkage void do_unexp_fiq (struct pt_regs *regs)
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{
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#ifndef CONFIG_IGNORE_FIQ
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printk("Hmm. Unexpected FIQ received, but trying to continue\n");
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printk("You may have a hardware problem...\n");
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#endif
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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, int proc_mode)
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{
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unsigned int vectors = vectors_base();
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console_verbose();
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printk(KERN_CRIT "Bad mode in %s handler detected: mode %s\n",
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handler[reason<5?reason:4], processor_modes[proc_mode]);
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/*
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* Dump out the vectors and stub routines. Maybe a better solution
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* would be to dump them out only if we detect that they are corrupted.
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*/
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dump_mem(KERN_CRIT "Vectors: ", vectors, vectors + 0x40);
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dump_mem(KERN_CRIT "Stubs: ", vectors + 0x200, vectors + 0x4b8);
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die("Oops", 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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struct thread_info *thread = current_thread_info();
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siginfo_t info;
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if (current->personality != PER_LINUX && thread->exec_domain->handler) {
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thread->exec_domain->handler(n, regs);
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return regs->ARM_r0;
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}
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#ifdef CONFIG_DEBUG_USER
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printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n",
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current->pid, current->comm, n);
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dump_instr(regs);
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#endif
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info.si_signo = SIGILL;
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info.si_errno = 0;
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info.si_code = ILL_ILLTRP;
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info.si_addr = (void *)instruction_pointer(regs) - 4;
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force_sig_info(SIGILL, &info, current);
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die_if_kernel("Oops", regs, n);
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return regs->ARM_r0;
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}
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static inline void
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do_cache_op(unsigned long start, unsigned long end, int flags)
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{
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struct vm_area_struct *vma;
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if (end < start)
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return;
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vma = find_vma(current->active_mm, start);
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if (vma && vma->vm_start < end) {
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if (start < vma->vm_start)
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start = vma->vm_start;
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if (end > vma->vm_end)
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end = vma->vm_end;
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}
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}
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/*
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* Handle all unrecognised system calls.
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* 0x9f0000 - 0x9fffff are some more esoteric system calls
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*/
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#define NR(x) ((__ARM_NR_##x) - __ARM_NR_BASE)
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asmlinkage int arm_syscall(int no, struct pt_regs *regs)
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{
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siginfo_t info;
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if ((no >> 16) != 0x9f)
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return bad_syscall(no, regs);
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switch (no & 0xffff) {
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case 0: /* branch through 0 */
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info.si_signo = SIGSEGV;
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info.si_errno = 0;
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info.si_code = SEGV_MAPERR;
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info.si_addr = NULL;
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force_sig_info(SIGSEGV, &info, current);
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die_if_kernel("branch through zero", regs, 0);
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return 0;
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case NR(breakpoint): /* SWI BREAK_POINT */
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ptrace_break(current, regs);
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return regs->ARM_r0;
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case NR(cacheflush):
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return 0;
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case NR(usr26):
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break;
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default:
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/* Calls 9f00xx..9f07ff are defined to return -ENOSYS
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if not implemented, rather than raising SIGILL. This
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way the calling program can gracefully determine whether
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a feature is supported. */
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if (no <= 0x7ff)
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return -ENOSYS;
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break;
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}
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#ifdef CONFIG_DEBUG_USER
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/*
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* experience shows that these seem to indicate that
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* something catastrophic has happened
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*/
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printk("[%d] %s: arm syscall %d\n", current->pid, current->comm, no);
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dump_instr(regs);
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if (user_mode(regs)) {
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show_regs(regs);
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c_backtrace(regs->ARM_fp, processor_mode(regs));
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}
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#endif
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info.si_signo = SIGILL;
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info.si_errno = 0;
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info.si_code = ILL_ILLTRP;
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info.si_addr = (void *)instruction_pointer(regs) - 4;
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force_sig_info(SIGILL, &info, current);
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die_if_kernel("Oops", regs, no);
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return 0;
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}
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void __bad_xchg(volatile void *ptr, int size)
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{
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printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n",
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__builtin_return_address(0), ptr, size);
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BUG();
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}
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/*
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* A data abort trap was taken, but we did not handle the instruction.
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* Try to abort the user program, or panic if it was the kernel.
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*/
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asmlinkage void
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baddataabort(int code, unsigned long instr, struct pt_regs *regs)
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{
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unsigned long addr = instruction_pointer(regs);
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siginfo_t info;
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#ifdef CONFIG_DEBUG_USER
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printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n",
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current->pid, current->comm, code, instr);
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dump_instr(regs);
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show_pte(current->mm, addr);
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#endif
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info.si_signo = SIGILL;
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info.si_errno = 0;
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info.si_code = ILL_ILLOPC;
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info.si_addr = (void *)addr;
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force_sig_info(SIGILL, &info, current);
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die_if_kernel("unknown data abort code", regs, instr);
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}
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volatile void __bug(const char *file, int line, void *data)
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{
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printk(KERN_CRIT"kernel BUG at %s:%d!", file, line);
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if (data)
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printk(KERN_CRIT" - extra data = %p", data);
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printk("\n");
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*(int *)0 = 0;
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}
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void __readwrite_bug(const char *fn)
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{
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printk("%s called, but not implemented", fn);
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BUG();
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}
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void __pte_error(const char *file, int line, unsigned long val)
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{
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printk("%s:%d: bad pte %08lx.\n", file, line, val);
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}
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void __pmd_error(const char *file, int line, unsigned long val)
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{
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printk("%s:%d: bad pmd %08lx.\n", file, line, val);
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}
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void __pgd_error(const char *file, int line, unsigned long val)
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{
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printk("%s:%d: bad pgd %08lx.\n", file, line, val);
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}
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asmlinkage void __div0(void)
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{
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printk("Division by zero in kernel.\n");
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dump_stack();
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}
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void abort(void)
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{
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BUG();
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/* if that doesn't kill us, halt */
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panic("Oops failed to kill thread");
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}
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void __init trap_init(void)
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{
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extern void __trap_init(unsigned long);
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unsigned long base = vectors_base();
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__trap_init(base);
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if (base != 0)
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printk(KERN_DEBUG "Relocating machine vectors to 0x%08lx\n",
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|
base);
|
|
}
|