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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/arm/kernel/traps.c
downloadlinux-stericsson-2.6.12-rc2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
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!
Diffstat (limited to 'arch/arm/kernel/traps.c')
-rw-r--r--arch/arm/kernel/traps.c590
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);
+}