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);
+}