[AVR32] Clean up exception handling code
* Use generic BUG() handling
* Remove some useless debug statements
* Use a common function _exception() to send signals or oops when
an exception can't be handled. This makes sure init doesn't
enter an infinite exception loop as well. Borrowed from powerpc.
* Add some basic exception tracing support to the page fault code.
* Rework dump_stack(), show_regs() and friends and move everything
into process.c
* Print information about configuration options and chip type when
oopsing
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
This commit is contained in:
Haavard Skinnemoen
@@ -5,158 +5,25 @@
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#undef DEBUG
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#include <linux/sched.h>
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#include <linux/bug.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/kallsyms.h>
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#include <linux/module.h>
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#include <linux/notifier.h>
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#include <linux/sched.h>
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#include <linux/uaccess.h>
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#include <asm/traps.h>
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#include <asm/sysreg.h>
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#include <asm/addrspace.h>
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#include <asm/ocd.h>
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#include <asm/mmu_context.h>
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#include <asm/uaccess.h>
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static void dump_mem(const char *str, unsigned long bottom, unsigned long top)
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{
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unsigned long p;
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int i;
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printk("%s(0x%08lx to 0x%08lx)\n", str, bottom, top);
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for (p = bottom & ~31; p < top; ) {
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printk("%04lx: ", p & 0xffff);
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for (i = 0; i < 8; i++, p += 4) {
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unsigned int val;
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if (p < bottom || p >= top)
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printk(" ");
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else {
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if (__get_user(val, (unsigned int __user *)p)) {
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printk("\n");
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goto out;
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}
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printk("%08x ", val);
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}
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}
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printk("\n");
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}
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out:
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return;
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}
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static inline int valid_stack_ptr(struct thread_info *tinfo, unsigned long p)
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{
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return (p > (unsigned long)tinfo)
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&& (p < (unsigned long)tinfo + THREAD_SIZE - 3);
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}
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#ifdef CONFIG_FRAME_POINTER
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static inline void __show_trace(struct task_struct *tsk, unsigned long *sp,
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struct pt_regs *regs)
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{
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unsigned long lr, fp;
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struct thread_info *tinfo;
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tinfo = (struct thread_info *)
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((unsigned long)sp & ~(THREAD_SIZE - 1));
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if (regs)
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fp = regs->r7;
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else if (tsk == current)
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asm("mov %0, r7" : "=r"(fp));
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else
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fp = tsk->thread.cpu_context.r7;
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/*
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* Walk the stack as long as the frame pointer (a) is within
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* the kernel stack of the task, and (b) it doesn't move
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* downwards.
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*/
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while (valid_stack_ptr(tinfo, fp)) {
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unsigned long new_fp;
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lr = *(unsigned long *)fp;
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printk(" [<%08lx>] ", lr);
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print_symbol("%s\n", lr);
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new_fp = *(unsigned long *)(fp + 4);
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if (new_fp <= fp)
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break;
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fp = new_fp;
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}
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printk("\n");
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}
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#else
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static inline void __show_trace(struct task_struct *tsk, unsigned long *sp,
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struct pt_regs *regs)
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{
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unsigned long addr;
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while (!kstack_end(sp)) {
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addr = *sp++;
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if (kernel_text_address(addr)) {
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printk(" [<%08lx>] ", addr);
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print_symbol("%s\n", addr);
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}
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}
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}
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#endif
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void show_trace(struct task_struct *tsk, unsigned long *sp,
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struct pt_regs *regs)
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{
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if (regs &&
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(((regs->sr & MODE_MASK) == MODE_EXCEPTION) ||
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((regs->sr & MODE_MASK) == MODE_USER)))
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return;
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printk ("Call trace:");
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#ifdef CONFIG_KALLSYMS
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printk("\n");
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#endif
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__show_trace(tsk, sp, regs);
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printk("\n");
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}
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void show_stack(struct task_struct *tsk, unsigned long *sp)
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{
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unsigned long stack;
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if (!tsk)
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tsk = current;
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if (sp == 0) {
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if (tsk == current) {
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register unsigned long *real_sp __asm__("sp");
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sp = real_sp;
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} else {
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sp = (unsigned long *)tsk->thread.cpu_context.ksp;
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}
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}
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stack = (unsigned long)sp;
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dump_mem("Stack: ", stack,
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THREAD_SIZE + (unsigned long)tsk->thread_info);
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show_trace(tsk, sp, NULL);
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}
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void dump_stack(void)
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{
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show_stack(NULL, NULL);
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}
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EXPORT_SYMBOL(dump_stack);
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#include <asm/ocd.h>
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#include <asm/sysreg.h>
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#include <asm/traps.h>
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ATOMIC_NOTIFIER_HEAD(avr32_die_chain);
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int register_die_notifier(struct notifier_block *nb)
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{
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pr_debug("register_die_notifier: %p\n", nb);
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return atomic_notifier_chain_register(&avr32_die_chain, nb);
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}
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EXPORT_SYMBOL(register_die_notifier);
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@@ -169,93 +36,103 @@ EXPORT_SYMBOL(unregister_die_notifier);
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static DEFINE_SPINLOCK(die_lock);
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void __die(const char *str, struct pt_regs *regs, unsigned long err,
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const char *file, const char *func, unsigned long line)
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void NORET_TYPE die(const char *str, struct pt_regs *regs, long err)
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{
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struct task_struct *tsk = current;
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static int die_counter;
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console_verbose();
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spin_lock_irq(&die_lock);
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bust_spinlocks(1);
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printk(KERN_ALERT "%s", str);
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if (file && func)
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printk(" in %s:%s, line %ld", file, func, line);
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printk("[#%d]:\n", ++die_counter);
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print_modules();
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show_regs(regs);
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printk("Process %s (pid: %d, stack limit = 0x%p)\n",
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tsk->comm, tsk->pid, tsk->thread_info + 1);
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if (!user_mode(regs) || in_interrupt()) {
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dump_mem("Stack: ", regs->sp,
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THREAD_SIZE + (unsigned long)tsk->thread_info);
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printk(KERN_ALERT "Oops: %s, sig: %ld [#%d]\n" KERN_EMERG,
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str, err, ++die_counter);
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#ifdef CONFIG_PREEMPT
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printk("PREEMPT ");
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#endif
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#ifdef CONFIG_FRAME_POINTER
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printk("FRAME_POINTER ");
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#endif
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if (current_cpu_data.features & AVR32_FEATURE_OCD) {
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unsigned long did = __mfdr(DBGREG_DID);
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printk("chip: 0x%03lx:0x%04lx rev %lu\n",
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(did >> 1) & 0x7ff,
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(did >> 12) & 0x7fff,
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(did >> 28) & 0xf);
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} else {
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printk("cpu: arch %u r%u / core %u r%u\n",
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current_cpu_data.arch_type,
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current_cpu_data.arch_revision,
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current_cpu_data.cpu_type,
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current_cpu_data.cpu_revision);
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}
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print_modules();
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show_regs_log_lvl(regs, KERN_EMERG);
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show_stack_log_lvl(current, regs->sp, regs, KERN_EMERG);
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bust_spinlocks(0);
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spin_unlock_irq(&die_lock);
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do_exit(SIGSEGV);
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if (in_interrupt())
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panic("Fatal exception in interrupt");
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if (panic_on_oops)
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panic("Fatal exception");
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do_exit(err);
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}
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void __die_if_kernel(const char *str, struct pt_regs *regs, unsigned long err,
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const char *file, const char *func, unsigned long line)
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void _exception(long signr, struct pt_regs *regs, int code,
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unsigned long addr)
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{
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siginfo_t info;
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if (!user_mode(regs))
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__die(str, regs, err, file, func, line);
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die("Unhandled exception in kernel mode", regs, signr);
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memset(&info, 0, sizeof(info));
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info.si_signo = signr;
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info.si_code = code;
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info.si_addr = (void __user *)addr;
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force_sig_info(signr, &info, current);
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/*
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* Init gets no signals that it doesn't have a handler for.
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* That's all very well, but if it has caused a synchronous
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* exception and we ignore the resulting signal, it will just
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* generate the same exception over and over again and we get
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* nowhere. Better to kill it and let the kernel panic.
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*/
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if (is_init(current)) {
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__sighandler_t handler;
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spin_lock_irq(¤t->sighand->siglock);
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handler = current->sighand->action[signr-1].sa.sa_handler;
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spin_unlock_irq(¤t->sighand->siglock);
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if (handler == SIG_DFL) {
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/* init has generated a synchronous exception
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and it doesn't have a handler for the signal */
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printk(KERN_CRIT "init has generated signal %ld "
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"but has no handler for it\n", signr);
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do_exit(signr);
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}
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}
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}
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asmlinkage void do_nmi(unsigned long ecr, struct pt_regs *regs)
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{
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#ifdef CONFIG_SUBARCH_AVR32B
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/*
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* The exception entry always saves RSR_EX. For NMI, this is
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* wrong; it should be RSR_NMI
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*/
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regs->sr = sysreg_read(RSR_NMI);
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#endif
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printk("NMI taken!!!!\n");
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die("NMI", regs, ecr);
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BUG();
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printk(KERN_ALERT "Got Non-Maskable Interrupt, dumping regs\n");
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show_regs_log_lvl(regs, KERN_ALERT);
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show_stack_log_lvl(current, regs->sp, regs, KERN_ALERT);
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}
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asmlinkage void do_critical_exception(unsigned long ecr, struct pt_regs *regs)
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{
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printk("Unable to handle critical exception %lu at pc = %08lx!\n",
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ecr, regs->pc);
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die("Oops", regs, ecr);
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BUG();
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die("Critical exception", regs, SIGKILL);
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}
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asmlinkage void do_address_exception(unsigned long ecr, struct pt_regs *regs)
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{
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siginfo_t info;
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die_if_kernel("Oops: Address exception in kernel mode", regs, ecr);
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#ifdef DEBUG
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if (ecr == ECR_ADDR_ALIGN_X)
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pr_debug("Instruction Address Exception at pc = %08lx\n",
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regs->pc);
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else if (ecr == ECR_ADDR_ALIGN_R)
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pr_debug("Data Address Exception (Read) at pc = %08lx\n",
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regs->pc);
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else if (ecr == ECR_ADDR_ALIGN_W)
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pr_debug("Data Address Exception (Write) at pc = %08lx\n",
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regs->pc);
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else
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BUG();
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show_regs(regs);
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#endif
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info.si_signo = SIGBUS;
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info.si_errno = 0;
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info.si_code = BUS_ADRALN;
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info.si_addr = (void __user *)regs->pc;
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force_sig_info(SIGBUS, &info, current);
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_exception(SIGBUS, regs, BUS_ADRALN, regs->pc);
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}
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/* This way of handling undefined instructions is stolen from ARM */
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@@ -280,7 +157,8 @@ static int do_cop_absent(u32 insn)
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{
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int cop_nr;
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u32 cpucr;
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if ( (insn & 0xfdf00000) == 0xf1900000 )
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if ((insn & 0xfdf00000) == 0xf1900000)
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/* LDC0 */
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cop_nr = 0;
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else
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@@ -292,136 +170,91 @@ static int do_cop_absent(u32 insn)
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sysreg_write(CPUCR, cpucr);
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cpucr = sysreg_read(CPUCR);
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if ( !(cpucr & (1 << (24 + cop_nr))) ){
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printk("Coprocessor #%i not found!\n", cop_nr);
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return -1;
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}
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if (!(cpucr & (1 << (24 + cop_nr))))
|
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return -ENODEV;
|
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|
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return 0;
|
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}
|
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|
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#ifdef CONFIG_BUG
|
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#ifdef CONFIG_DEBUG_BUGVERBOSE
|
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static inline void do_bug_verbose(struct pt_regs *regs, u32 insn)
|
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int is_valid_bugaddr(unsigned long pc)
|
||||
{
|
||||
char *file;
|
||||
u16 line;
|
||||
char c;
|
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unsigned short opcode;
|
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|
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if (__get_user(line, (u16 __user *)(regs->pc + 2)))
|
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return;
|
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if (__get_user(file, (char * __user *)(regs->pc + 4))
|
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|| (unsigned long)file < PAGE_OFFSET
|
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|| __get_user(c, file))
|
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file = "<bad filename>";
|
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if (pc < PAGE_OFFSET)
|
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return 0;
|
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if (probe_kernel_address((u16 *)pc, opcode))
|
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return 0;
|
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|
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printk(KERN_ALERT "kernel BUG at %s:%d!\n", file, line);
|
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return opcode == AVR32_BUG_OPCODE;
|
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}
|
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#else
|
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static inline void do_bug_verbose(struct pt_regs *regs, u32 insn)
|
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{
|
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|
||||
}
|
||||
#endif
|
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#endif
|
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|
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asmlinkage void do_illegal_opcode(unsigned long ecr, struct pt_regs *regs)
|
||||
{
|
||||
u32 insn;
|
||||
struct undef_hook *hook;
|
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siginfo_t info;
|
||||
void __user *pc;
|
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long code;
|
||||
|
||||
if (!user_mode(regs))
|
||||
goto kernel_trap;
|
||||
if (!user_mode(regs) && (ecr == ECR_ILLEGAL_OPCODE)) {
|
||||
enum bug_trap_type type;
|
||||
|
||||
type = report_bug(regs->pc);
|
||||
switch (type) {
|
||||
case BUG_TRAP_TYPE_NONE:
|
||||
break;
|
||||
case BUG_TRAP_TYPE_WARN:
|
||||
regs->pc += 2;
|
||||
return;
|
||||
case BUG_TRAP_TYPE_BUG:
|
||||
die("Kernel BUG", regs, SIGKILL);
|
||||
}
|
||||
}
|
||||
|
||||
local_irq_enable();
|
||||
|
||||
pc = (void __user *)instruction_pointer(regs);
|
||||
if (__get_user(insn, (u32 __user *)pc))
|
||||
goto invalid_area;
|
||||
if (user_mode(regs)) {
|
||||
pc = (void __user *)instruction_pointer(regs);
|
||||
if (get_user(insn, (u32 __user *)pc))
|
||||
goto invalid_area;
|
||||
|
||||
if (ecr == ECR_COPROC_ABSENT) {
|
||||
if (do_cop_absent(insn) == 0)
|
||||
if (ecr == ECR_COPROC_ABSENT && !do_cop_absent(insn))
|
||||
return;
|
||||
}
|
||||
|
||||
spin_lock_irq(&undef_lock);
|
||||
list_for_each_entry(hook, &undef_hook, node) {
|
||||
if ((insn & hook->insn_mask) == hook->insn_val) {
|
||||
if (hook->fn(regs, insn) == 0) {
|
||||
spin_unlock_irq(&undef_lock);
|
||||
return;
|
||||
spin_lock_irq(&undef_lock);
|
||||
list_for_each_entry(hook, &undef_hook, node) {
|
||||
if ((insn & hook->insn_mask) == hook->insn_val) {
|
||||
if (hook->fn(regs, insn) == 0) {
|
||||
spin_unlock_irq(&undef_lock);
|
||||
return;
|
||||
}
|
||||
}
|
||||
}
|
||||
spin_unlock_irq(&undef_lock);
|
||||
}
|
||||
spin_unlock_irq(&undef_lock);
|
||||
|
||||
invalid_area:
|
||||
|
||||
#ifdef DEBUG
|
||||
printk("Illegal instruction at pc = %08lx\n", regs->pc);
|
||||
if (regs->pc < TASK_SIZE) {
|
||||
unsigned long ptbr, pgd, pte, *p;
|
||||
|
||||
ptbr = sysreg_read(PTBR);
|
||||
p = (unsigned long *)ptbr;
|
||||
pgd = p[regs->pc >> 22];
|
||||
p = (unsigned long *)((pgd & 0x1ffff000) | 0x80000000);
|
||||
pte = p[(regs->pc >> 12) & 0x3ff];
|
||||
printk("page table: 0x%08lx -> 0x%08lx -> 0x%08lx\n", ptbr, pgd, pte);
|
||||
}
|
||||
#endif
|
||||
|
||||
info.si_signo = SIGILL;
|
||||
info.si_errno = 0;
|
||||
info.si_addr = (void __user *)regs->pc;
|
||||
switch (ecr) {
|
||||
case ECR_ILLEGAL_OPCODE:
|
||||
case ECR_UNIMPL_INSTRUCTION:
|
||||
info.si_code = ILL_ILLOPC;
|
||||
break;
|
||||
case ECR_PRIVILEGE_VIOLATION:
|
||||
info.si_code = ILL_PRVOPC;
|
||||
code = ILL_PRVOPC;
|
||||
break;
|
||||
case ECR_COPROC_ABSENT:
|
||||
info.si_code = ILL_COPROC;
|
||||
code = ILL_COPROC;
|
||||
break;
|
||||
default:
|
||||
BUG();
|
||||
code = ILL_ILLOPC;
|
||||
break;
|
||||
}
|
||||
|
||||
force_sig_info(SIGILL, &info, current);
|
||||
_exception(SIGILL, regs, code, regs->pc);
|
||||
return;
|
||||
|
||||
kernel_trap:
|
||||
#ifdef CONFIG_BUG
|
||||
if (__kernel_text_address(instruction_pointer(regs))) {
|
||||
insn = *(u16 *)instruction_pointer(regs);
|
||||
if (insn == AVR32_BUG_OPCODE) {
|
||||
do_bug_verbose(regs, insn);
|
||||
die("Kernel BUG", regs, 0);
|
||||
return;
|
||||
}
|
||||
}
|
||||
#endif
|
||||
|
||||
die("Oops: Illegal instruction in kernel code", regs, ecr);
|
||||
invalid_area:
|
||||
_exception(SIGSEGV, regs, SEGV_MAPERR, regs->pc);
|
||||
}
|
||||
|
||||
asmlinkage void do_fpe(unsigned long ecr, struct pt_regs *regs)
|
||||
{
|
||||
siginfo_t info;
|
||||
|
||||
printk("Floating-point exception at pc = %08lx\n", regs->pc);
|
||||
|
||||
/* We have no FPU... */
|
||||
info.si_signo = SIGILL;
|
||||
info.si_errno = 0;
|
||||
info.si_addr = (void __user *)regs->pc;
|
||||
info.si_code = ILL_COPROC;
|
||||
|
||||
force_sig_info(SIGILL, &info, current);
|
||||
/* We have no FPU yet */
|
||||
_exception(SIGILL, regs, ILL_COPROC, regs->pc);
|
||||
}
|
||||
|
||||
|
||||
|
||||
Reference in New Issue
Block a user