1 files changed, 590 insertions, 0 deletions

diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
new file mode 100644
index 000000000000..93dc4646cd7f
--- /dev/null
+++ b/arch/arm/kernel/traps.c
@@ -0,0 +1,590 @@
+/*
+ *  linux/arch/arm/kernel/traps.c
+ *
+ *  Copyright (C) 1995-2002 Russell King
+ *  Fragments that appear the same as linux/arch/i386/kernel/traps.c (C) Linus Torvalds
+ *
+ * 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/arm/lib/traps.S'.  Mostly a debugging aid, but will probably
+ *  kill the offending process.
+ */
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/signal.h>
+#include <linux/spinlock.h>
+#include <linux/personality.h>
+#include <linux/ptrace.h>
+#include <linux/kallsyms.h>
+#include <linux/init.h>
+
+#include <asm/atomic.h>
+#include <asm/cacheflush.h>
+#include <asm/io.h>
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/unistd.h>
+#include <asm/traps.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" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
+  "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
+  "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
+  "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
+};
+
+static const char *handler[]= { "prefetch abort", "data abort", "address exception", "interrupt" };
+
+#ifdef CONFIG_DEBUG_USER
+unsigned int user_debug;
+
+static int __init user_debug_setup(char *str)
+{
+        get_option(&str, &user_debug);
+        return 1;
+}
+__setup("user_debug=", user_debug_setup);
+#endif
+
+void dump_backtrace_entry(unsigned long where, unsigned long from)
+{
+#ifdef CONFIG_KALLSYMS
+        printk("[<%08lx>] ", where);
+        print_symbol("(%s) ", where);
+        printk("from [<%08lx>] ", from);
+        print_symbol("(%s)\n", from);
+#else
+        printk("Function entered at [<%08lx>] from [<%08lx>]\n", where, from);
+#endif
+}
+
+/*
+ * 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(0x%08lx to 0x%08lx)\n", str, 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 thumb = thumb_mode(regs);
+        const int width = thumb ? 4 : 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;
+
+                if (thumb)
+                        bad = __get_user(val, &((u16 *)addr)[i]);
+                else
+                        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_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));
+}
+
+void dump_stack(void)
+{
+#ifdef CONFIG_DEBUG_ERRORS
+        __backtrace();
+#endif
+}
+
+EXPORT_SYMBOL(dump_stack);
+
+void show_stack(struct task_struct *tsk, unsigned long *sp)
+{
+        unsigned long fp;
+
+        if (!tsk)
+                tsk = current;
+
+        if (tsk != current)
+                fp = thread_saved_fp(tsk);
+        else
+                asm("mov%? %0, fp" : "=r" (fp));
+
+        c_backtrace(fp, 0x10);
+        barrier();
+}
+
+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;
+        static int die_counter;
+
+        console_verbose();
+        spin_lock_irq(&die_lock);
+        bust_spinlocks(1);
+
+        printk("Internal error: %s: %x [#%d]\n", str, err, ++die_counter);
+        print_modules();
+        printk("CPU: %d\n", smp_processor_id());
+        show_regs(regs);
+        printk("Process %s (pid: %d, stack limit = 0x%p)\n",
+                tsk->comm, tsk->pid, tsk->thread_info + 1);
+
+        if (!user_mode(regs) || in_interrupt()) {
+                dump_mem("Stack: ", regs->ARM_sp, 8192+(unsigned long)tsk->thread_info);
+                dump_backtrace(regs, tsk);
+                dump_instr(regs);
+        }
+
+        bust_spinlocks(0);
+        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 void notify_die(const char *str, struct pt_regs *regs, siginfo_t *info,
+                       unsigned long err, unsigned long trap)
+{
+        if (user_mode(regs)) {
+                current->thread.error_code = err;
+                current->thread.trap_no = trap;
+
+                force_sig_info(info->si_signo, info, current);
+        } else {
+                die(str, regs, err);
+        }
+}
+
+static LIST_HEAD(undef_hook);
+static DEFINE_SPINLOCK(undef_lock);
+
+void register_undef_hook(struct undef_hook *hook)
+{
+        spin_lock_irq(&undef_lock);
+        list_add(&hook->node, &undef_hook);
+        spin_unlock_irq(&undef_lock);
+}
+
+void unregister_undef_hook(struct undef_hook *hook)
+{
+        spin_lock_irq(&undef_lock);
+        list_del(&hook->node);
+        spin_unlock_irq(&undef_lock);
+}
+
+asmlinkage void do_undefinstr(struct pt_regs *regs)
+{
+        unsigned int correction = thumb_mode(regs) ? 2 : 4;
+        unsigned int instr;
+        struct undef_hook *hook;
+        siginfo_t info;
+        void __user *pc;
+
+        /*
+         * According to the ARM ARM, PC is 2 or 4 bytes ahead,
+         * depending whether we're in Thumb mode or not.
+         * Correct this offset.
+         */
+        regs->ARM_pc -= correction;
+
+        pc = (void __user *)instruction_pointer(regs);
+        if (thumb_mode(regs)) {
+                get_user(instr, (u16 __user *)pc);
+        } else {
+                get_user(instr, (u32 __user *)pc);
+        }
+
+        spin_lock_irq(&undef_lock);
+        list_for_each_entry(hook, &undef_hook, node) {
+                if ((instr & hook->instr_mask) == hook->instr_val &&
+                    (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val) {
+                        if (hook->fn(regs, instr) == 0) {
+                                spin_unlock_irq(&undef_lock);
+                                return;
+                        }
+                }
+        }
+        spin_unlock_irq(&undef_lock);
+
+#ifdef CONFIG_DEBUG_USER
+        if (user_debug & UDBG_UNDEFINED) {
+                printk(KERN_INFO "%s (%d): undefined instruction: pc=%p\n",
+                        current->comm, current->pid, pc);
+                dump_instr(regs);
+        }
+#endif
+
+        info.si_signo = SIGILL;
+        info.si_errno = 0;
+        info.si_code  = ILL_ILLOPC;
+        info.si_addr  = pc;
+
+        notify_die("Oops - undefined instruction", regs, &info, 0, 6);
+}
+
+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)
+{
+        console_verbose();
+
+        printk(KERN_CRIT "Bad mode in %s handler detected: mode %s\n",
+                handler[reason], processor_modes[proc_mode]);
+
+        die("Oops - bad mode", 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
+        if (user_debug & UDBG_SYSCALL) {
+                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 __user *)instruction_pointer(regs) -
+                         (thumb_mode(regs) ? 2 : 4);
+
+        notify_die("Oops - bad syscall", regs, &info, n, 0);
+
+        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 || flags)
+                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;
+
+                flush_cache_user_range(vma, 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)
+{
+        struct thread_info *thread = current_thread_info();
+        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;
+
+                notify_die("branch through zero", regs, &info, 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):
+                do_cache_op(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2);
+                return 0;
+
+        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):
+                thread->tp_value = regs->ARM_r0;
+                /*
+                 * Our user accessible TLS ptr is located at 0xffff0ffc.
+                 * On SMP read access to this address must raise a fault
+                 * and be emulated from the data abort handler.
+                 * m
+                 */
+                *((unsigned long *)0xffff0ffc) = thread->tp_value;
+                return 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 <= 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) {
+                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 __user *)instruction_pointer(regs) -
+                         (thumb_mode(regs) ? 2 : 4);
+
+        notify_die("Oops - bad syscall(2)", regs, &info, no, 0);
+        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();
+}
+EXPORT_SYMBOL(__bad_xchg);
+
+/*
+ * 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
+        if (user_debug & UDBG_BADABORT) {
+                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 __user *)addr;
+
+        notify_die("unknown data abort code", regs, &info, instr, 0);
+}
+
+volatile void __bug(const char *file, int line, void *data)
+{
+        printk(KERN_CRIT"kernel BUG at %s:%d!", file, line);
+        if (data)
+                printk(" - extra data = %p", data);
+        printk("\n");
+        *(int *)0 = 0;
+}
+EXPORT_SYMBOL(__bug);
+
+void __readwrite_bug(const char *fn)
+{
+        printk("%s called, but not implemented\n", fn);
+        BUG();
+}
+EXPORT_SYMBOL(__readwrite_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();
+}
+EXPORT_SYMBOL(__div0);
+
+void abort(void)
+{
+        BUG();
+
+        /* if that doesn't kill us, halt */
+        panic("Oops failed to kill thread");
+}
+EXPORT_SYMBOL(abort);
+
+void __init trap_init(void)
+{
+        extern void __trap_init(void);
+
+        __trap_init();
+        flush_icache_range(0xffff0000, 0xffff0000 + PAGE_SIZE);
+        modify_domain(DOMAIN_USER, DOMAIN_CLIENT);
+}