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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/arm26/kernel/traps.c
downloadconfigs-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.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/arm26/kernel/traps.c')
-rw-r--r--arch/arm26/kernel/traps.c548
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 00000000000..f64f5902239
--- /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);
+}