1 files changed, 548 insertions, 0 deletions

diff --git a/arch/arm26/kernel/traps.c b/arch/arm26/kernel/traps.c
new file mode 100644
index 000000000000..f64f59022392
--- /dev/null
+++ b/arch/arm26/kernel/traps.c
@@ -0,0 +1,548 @@
+/*
+ *  linux/arch/arm26/kernel/traps.c
+ *
+ *  Copyright (C) 1995-2002 Russell King
+ *  Fragments that appear the same as linux/arch/i386/kernel/traps.c (C) Linus Torvalds
+ *  Copyright (C) 2003 Ian Molton (ARM26)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ *  'traps.c' handles hardware exceptions after we have saved some state in
+ *  'linux/arch/arm26/lib/traps.S'.  Mostly a debugging aid, but will probably
+ *  kill the offending process.
+ */
+
+#include <linux/module.h>
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/spinlock.h>
+#include <linux/personality.h>
+#include <linux/ptrace.h>
+#include <linux/elf.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+
+#include <asm/atomic.h>
+#include <asm/io.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/unistd.h>
+#include <asm/semaphore.h>
+
+#include "ptrace.h"
+
+extern void c_backtrace (unsigned long fp, int pmode);
+extern void show_pte(struct mm_struct *mm, unsigned long addr);
+
+const char *processor_modes[] = { "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" };
+
+static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" "*bad reason*"};
+
+/*
+ * Stack pointers should always be within the kernels view of
+ * physical memory.  If it is not there, then we can't dump
+ * out any information relating to the stack.
+ */
+static int verify_stack(unsigned long sp)
+{
+	if (sp < PAGE_OFFSET || (sp > (unsigned long)high_memory && high_memory != 0))
+		return -EFAULT;
+
+	return 0;
+}
+
+/*
+ * Dump out the contents of some memory nicely...
+ */
+static void dump_mem(const char *str, unsigned long bottom, unsigned long top)
+{
+	unsigned long p = bottom & ~31;
+	mm_segment_t fs;
+	int i;
+
+	/*
+	 * We need to switch to kernel mode so that we can use __get_user
+	 * to safely read from kernel space.  Note that we now dump the
+	 * code first, just in case the backtrace kills us.
+	 */
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+
+	printk("%s", str);
+	printk("(0x%08lx to 0x%08lx)\n", bottom, top);
+
+	for (p = bottom & ~31; p < top;) {
+		printk("%04lx: ", p & 0xffff);
+
+		for (i = 0; i < 8; i++, p += 4) {
+			unsigned int val;
+
+			if (p < bottom || p >= top)
+				printk("         ");
+			else {
+				__get_user(val, (unsigned long *)p);
+				printk("%08x ", val);
+			}
+		}
+		printk ("\n");
+	}
+
+	set_fs(fs);
+}
+
+static void dump_instr(struct pt_regs *regs)
+{
+	unsigned long addr = instruction_pointer(regs);
+	const int width = 8;
+	mm_segment_t fs;
+	int i;
+
+	/*
+	 * We need to switch to kernel mode so that we can use __get_user
+	 * to safely read from kernel space.  Note that we now dump the
+	 * code first, just in case the backtrace kills us.
+	 */
+	fs = get_fs();
+	set_fs(KERNEL_DS);
+
+	printk("Code: ");
+	for (i = -4; i < 1; i++) {
+		unsigned int val, bad;
+
+		bad = __get_user(val, &((u32 *)addr)[i]);
+
+		if (!bad)
+			printk(i == 0 ? "(%0*x) " : "%0*x ", width, val);
+		else {
+			printk("bad PC value.");
+			break;
+		}
+	}
+	printk("\n");
+
+	set_fs(fs);
+}
+
+/*static*/ void __dump_stack(struct task_struct *tsk, unsigned long sp)
+{
+	dump_mem("Stack: ", sp, 8192+(unsigned long)tsk->thread_info);
+}
+
+void dump_stack(void)
+{
+#ifdef CONFIG_DEBUG_ERRORS
+        __backtrace();
+#endif
+}
+
+EXPORT_SYMBOL(dump_stack);
+
+//FIXME - was a static fn
+void dump_backtrace(struct pt_regs *regs, struct task_struct *tsk)
+{
+	unsigned int fp;
+	int ok = 1;
+
+	printk("Backtrace: ");
+	fp = regs->ARM_fp;
+	if (!fp) {
+		printk("no frame pointer");
+		ok = 0;
+	} else if (verify_stack(fp)) {
+		printk("invalid frame pointer 0x%08x", fp);
+		ok = 0;
+	} else if (fp < (unsigned long)(tsk->thread_info + 1))
+		printk("frame pointer underflow");
+	printk("\n");
+
+	if (ok)
+		c_backtrace(fp, processor_mode(regs));
+}
+
+/* FIXME - this is probably wrong.. */
+void show_stack(struct task_struct *task, unsigned long *sp) {
+	dump_mem("Stack: ", (unsigned long)sp, 8192+(unsigned long)task->thread_info);
+}
+
+DEFINE_SPINLOCK(die_lock);
+
+/*
+ * This function is protected against re-entrancy.
+ */
+NORET_TYPE void die(const char *str, struct pt_regs *regs, int err)
+{
+	struct task_struct *tsk = current;
+
+	console_verbose();
+	spin_lock_irq(&die_lock);
+
+	printk("Internal error: %s: %x\n", str, err);
+	printk("CPU: %d\n", smp_processor_id());
+	show_regs(regs);
+	printk("Process %s (pid: %d, stack limit = 0x%p)\n",
+		current->comm, current->pid, tsk->thread_info + 1);
+
+	if (!user_mode(regs) || in_interrupt()) {
+		__dump_stack(tsk, (unsigned long)(regs + 1));
+		dump_backtrace(regs, tsk);
+		dump_instr(regs);
+	}
+while(1);
+	spin_unlock_irq(&die_lock);
+	do_exit(SIGSEGV);
+}
+
+void die_if_kernel(const char *str, struct pt_regs *regs, int err)
+{
+	if (user_mode(regs))
+    		return;
+
+    	die(str, regs, err);
+}
+
+static DECLARE_MUTEX(undef_sem);
+static int (*undef_hook)(struct pt_regs *);
+
+int request_undef_hook(int (*fn)(struct pt_regs *))
+{
+	int ret = -EBUSY;
+
+	down(&undef_sem);
+	if (undef_hook == NULL) {
+		undef_hook = fn;
+		ret = 0;
+	}
+	up(&undef_sem);
+
+	return ret;
+}
+
+int release_undef_hook(int (*fn)(struct pt_regs *))
+{
+	int ret = -EINVAL;
+
+	down(&undef_sem);
+	if (undef_hook == fn) {
+		undef_hook = NULL;
+		ret = 0;
+	}
+	up(&undef_sem);
+
+	return ret;
+}
+
+static int undefined_extension(struct pt_regs *regs, unsigned int op)
+{
+	switch (op) {
+	case 1:	/* 0xde01 / 0x?7f001f0 */
+		ptrace_break(current, regs);
+		return 0;
+	}
+	return 1;
+}
+
+asmlinkage void do_undefinstr(struct pt_regs *regs)
+{
+	siginfo_t info;
+	void *pc;
+
+	regs->ARM_pc -= 4;
+
+	pc = (unsigned long *)instruction_pointer(regs); /* strip PSR */
+
+	if (user_mode(regs)) {
+		u32 instr;
+
+		get_user(instr, (u32 *)pc);
+
+		if ((instr & 0x0fff00ff) == 0x07f000f0 &&
+		    undefined_extension(regs, (instr >> 8) & 255) == 0) {
+			regs->ARM_pc += 4;
+			return;
+		}
+	} else {
+		if (undef_hook && undef_hook(regs) == 0) {
+			regs->ARM_pc += 4;
+			return;
+		}
+	}
+
+#ifdef CONFIG_DEBUG_USER
+	printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",
+		current->comm, current->pid, pc);
+	dump_instr(regs);
+#endif
+
+	current->thread.error_code = 0;
+	current->thread.trap_no = 6;
+
+	info.si_signo = SIGILL;
+	info.si_errno = 0;
+	info.si_code  = ILL_ILLOPC;
+	info.si_addr  = pc;
+
+	force_sig_info(SIGILL, &info, current);
+
+	die_if_kernel("Oops - undefined instruction", regs, 0);
+}
+
+asmlinkage void do_excpt(unsigned long address, struct pt_regs *regs, int mode)
+{
+	siginfo_t info;
+
+#ifdef CONFIG_DEBUG_USER
+	printk(KERN_INFO "%s (%d): address exception: pc=%08lx\n",
+		current->comm, current->pid, instruction_pointer(regs));
+	dump_instr(regs);
+#endif
+
+	current->thread.error_code = 0;
+	current->thread.trap_no = 11;
+
+	info.si_signo = SIGBUS;
+	info.si_errno = 0;
+	info.si_code  = BUS_ADRERR;
+	info.si_addr  = (void *)address;
+
+	force_sig_info(SIGBUS, &info, current);
+
+	die_if_kernel("Oops - address exception", regs, mode);
+}
+
+asmlinkage void do_unexp_fiq (struct pt_regs *regs)
+{
+#ifndef CONFIG_IGNORE_FIQ
+	printk("Hmm.  Unexpected FIQ received, but trying to continue\n");
+	printk("You may have a hardware problem...\n");
+#endif
+}
+
+/*
+ * bad_mode handles the impossible case in the vectors.  If you see one of
+ * these, then it's extremely serious, and could mean you have buggy hardware.
+ * It never returns, and never tries to sync.  We hope that we can at least
+ * dump out some state information...
+ */
+asmlinkage void bad_mode(struct pt_regs *regs, int reason, int proc_mode)
+{
+	unsigned int vectors = vectors_base();
+
+	console_verbose();
+
+	printk(KERN_CRIT "Bad mode in %s handler detected: mode %s\n",
+		handler[reason<5?reason:4], processor_modes[proc_mode]);
+
+	/*
+	 * Dump out the vectors and stub routines.  Maybe a better solution
+	 * would be to dump them out only if we detect that they are corrupted.
+	 */
+	dump_mem(KERN_CRIT "Vectors: ", vectors, vectors + 0x40);
+	dump_mem(KERN_CRIT "Stubs: ", vectors + 0x200, vectors + 0x4b8);
+
+	die("Oops", regs, 0);
+	local_irq_disable();
+	panic("bad mode");
+}
+
+static int bad_syscall(int n, struct pt_regs *regs)
+{
+	struct thread_info *thread = current_thread_info();
+	siginfo_t info;
+
+	if (current->personality != PER_LINUX && thread->exec_domain->handler) {
+		thread->exec_domain->handler(n, regs);
+		return regs->ARM_r0;
+	}
+
+#ifdef CONFIG_DEBUG_USER
+	printk(KERN_ERR "[%d] %s: obsolete system call %08x.\n",
+		current->pid, current->comm, n);
+	dump_instr(regs);
+#endif
+
+	info.si_signo = SIGILL;
+	info.si_errno = 0;
+	info.si_code  = ILL_ILLTRP;
+	info.si_addr  = (void *)instruction_pointer(regs) - 4;
+
+	force_sig_info(SIGILL, &info, current);
+	die_if_kernel("Oops", regs, n);
+	return regs->ARM_r0;
+}
+
+static inline void
+do_cache_op(unsigned long start, unsigned long end, int flags)
+{
+	struct vm_area_struct *vma;
+
+	if (end < start)
+		return;
+
+	vma = find_vma(current->active_mm, start);
+	if (vma && vma->vm_start < end) {
+		if (start < vma->vm_start)
+			start = vma->vm_start;
+		if (end > vma->vm_end)
+			end = vma->vm_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)
+{
+	siginfo_t info;
+
+	if ((no >> 16) != 0x9f)
+		return bad_syscall(no, regs);
+
+	switch (no & 0xffff) {
+	case 0: /* branch through 0 */
+		info.si_signo = SIGSEGV;
+		info.si_errno = 0;
+		info.si_code  = SEGV_MAPERR;
+		info.si_addr  = NULL;
+
+		force_sig_info(SIGSEGV, &info, current);
+
+		die_if_kernel("branch through zero", regs, 0);
+		return 0;
+
+	case NR(breakpoint): /* SWI BREAK_POINT */
+		ptrace_break(current, regs);
+		return regs->ARM_r0;
+
+	case NR(cacheflush):
+		return 0;
+
+	case NR(usr26):
+		break;
+
+	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 <= 0x7ff)
+			return -ENOSYS;
+		break;
+	}
+#ifdef CONFIG_DEBUG_USER
+	/*
+	 * experience shows that these seem to indicate that
+	 * something catastrophic has happened
+	 */
+	printk("[%d] %s: arm syscall %d\n", current->pid, current->comm, no);
+	dump_instr(regs);
+	if (user_mode(regs)) {
+		show_regs(regs);
+		c_backtrace(regs->ARM_fp, processor_mode(regs));
+	}
+#endif
+	info.si_signo = SIGILL;
+	info.si_errno = 0;
+	info.si_code  = ILL_ILLTRP;
+	info.si_addr  = (void *)instruction_pointer(regs) - 4;
+
+	force_sig_info(SIGILL, &info, current);
+	die_if_kernel("Oops", regs, no);
+	return 0;
+}
+
+void __bad_xchg(volatile void *ptr, int size)
+{
+	printk("xchg: bad data size: pc 0x%p, ptr 0x%p, size %d\n",
+		__builtin_return_address(0), ptr, size);
+	BUG();
+}
+
+/*
+ * 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);
+	siginfo_t info;
+
+#ifdef CONFIG_DEBUG_USER
+	printk(KERN_ERR "[%d] %s: bad data abort: code %d instr 0x%08lx\n",
+		current->pid, current->comm, code, instr);
+	dump_instr(regs);
+	show_pte(current->mm, addr);
+#endif
+
+	info.si_signo = SIGILL;
+	info.si_errno = 0;
+	info.si_code  = ILL_ILLOPC;
+	info.si_addr  = (void *)addr;
+
+	force_sig_info(SIGILL, &info, current);
+	die_if_kernel("unknown data abort code", regs, instr);
+}
+
+volatile void __bug(const char *file, int line, void *data)
+{
+	printk(KERN_CRIT"kernel BUG at %s:%d!", file, line);
+	if (data)
+		printk(KERN_CRIT" - extra data = %p", data);
+	printk("\n");
+	*(int *)0 = 0;
+}
+
+void __readwrite_bug(const char *fn)
+{
+	printk("%s called, but not implemented", fn);
+	BUG();
+}
+
+void __pte_error(const char *file, int line, unsigned long val)
+{
+	printk("%s:%d: bad pte %08lx.\n", file, line, val);
+}
+
+void __pmd_error(const char *file, int line, unsigned long val)
+{
+	printk("%s:%d: bad pmd %08lx.\n", file, line, val);
+}
+
+void __pgd_error(const char *file, int line, unsigned long val)
+{
+	printk("%s:%d: bad pgd %08lx.\n", file, line, val);
+}
+
+asmlinkage void __div0(void)
+{
+	printk("Division by zero in kernel.\n");
+	dump_stack();
+}
+
+void abort(void)
+{
+	BUG();
+
+	/* if that doesn't kill us, halt */
+	panic("Oops failed to kill thread");
+}
+
+void __init trap_init(void)
+{
+	extern void __trap_init(unsigned long);
+	unsigned long base = vectors_base();
+
+	__trap_init(base);
+	if (base != 0)
+		printk(KERN_DEBUG "Relocating machine vectors to 0x%08lx\n",
+			base);
+}