int 
show_stack()
{
	unsigned long *sp = (unsigned long *)rdusp();
	int i;
	raw_printk("Stack dump [0x%08lx]:\n", (unsigned long)sp);
	for(i = 0; i < 16; i++)
		raw_printk("sp + %d: 0x%08lx\n", i*4, sp[i]);
	return 0;
}
void show_trace(unsigned long * stack)
{
	unsigned long addr, module_start, module_end;
	extern char _stext, _etext;
	int i;

        raw_printk("\nCall Trace: ");

        i = 1;
        module_start = VMALLOC_START;
        module_end = VMALLOC_END;

        while (((long) stack & (THREAD_SIZE-1)) != 0) {
		if (__get_user (addr, stack)) {
			/* This message matches "failing address" marked
			   s390 in ksymoops, so lines containing it will
			   not be filtered out by ksymoops.  */
			raw_printk ("Failing address 0x%lx\n", (unsigned long)stack);
			break;
		}
		stack++;

                /*
                 * If the address is either in the text segment of the
                 * kernel, or in the region which contains vmalloc'ed
                 * memory, it *may* be the address of a calling
                 * routine; if so, print it so that someone tracing
                 * down the cause of the crash will be able to figure
                 * out the call path that was taken.
                 */
                if (((addr >= (unsigned long) &_stext) &&
                     (addr <= (unsigned long) &_etext)) ||
                    ((addr >= module_start) && (addr <= module_end))) {
                        if (i && ((i % 8) == 0))
                                raw_printk("\n       ");
                        raw_printk("[<%08lx>] ", addr);
                        i++;
                }
        }
}
void 
show_stack(struct task_struct *task, unsigned long *sp)
{
        unsigned long *stack, addr;
        int i;

	/*
	 * debugging aid: "show_stack(NULL);" prints a
	 * back trace.
	 */

        if(sp == NULL) {
		if (task)
			sp = (unsigned long*)task->thread.ksp;
		else
			sp = (unsigned long*)rdsp();
	}

        stack = sp;

	raw_printk("\nStack from %08lx:\n       ", (unsigned long)stack);
        for(i = 0; i < kstack_depth_to_print; i++) {
                if (((long) stack & (THREAD_SIZE-1)) == 0)
                        break;
                if (i && ((i % 8) == 0))
                        raw_printk("\n       ");
		if (__get_user (addr, stack)) {
			/* This message matches "failing address" marked
			   s390 in ksymoops, so lines containing it will
			   not be filtered out by ksymoops.  */
			raw_printk ("Failing address 0x%lx\n", (unsigned long)stack);
			break;
		}
		stack++;
		raw_printk("%08lx ", addr);
        }
	show_trace(sp);
}
Exemple #4
0
void
handle_watchdog_bite(struct pt_regs* regs)
{
#if defined(CONFIG_ETRAX_WATCHDOG)
	extern int cause_of_death;

	raw_printk("Watchdog bite\n");

	/* Check if forced restart or unexpected watchdog */
	if (cause_of_death == 0xbedead) {
		while(1);
	}

	/* Unexpected watchdog, stop the watchdog and dump registers*/
	stop_watchdog();
	raw_printk("Oops: bitten by watchdog\n");
        show_registers(regs);
#ifndef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
	reset_watchdog();
#endif
	while(1) /* nothing */;
#endif
}
Exemple #5
0
/* This is normally the 'Oops' routine */
void 
die_if_kernel(const char * str, struct pt_regs * regs, long err)
{
	if(user_mode(regs))
		return;

#ifdef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
	/* This printout might take too long and trigger the 
	 * watchdog normally. If we're in the nice doggy
	 * development mode, stop the watchdog during printout.
	 */
	stop_watchdog();
#endif

	raw_printk("%s: %04lx\n", str, err & 0xffff);

	show_registers(regs);

#ifdef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
	reset_watchdog();
#endif
	do_exit(SIGSEGV);
}
void spinning_cpu(void* addr)
{
  raw_printk("CPU %d spinning on %X\n", smp_processor_id(), addr);
  dump_stack();
}
void oops_nmi_handler(struct pt_regs* regs)
{
  stop_watchdog();
  raw_printk("NMI!\n");
  show_registers(regs);
}
Exemple #8
0
asmlinkage void
do_page_fault(unsigned long address, struct pt_regs *regs,
	      int protection, int writeaccess)
{
	struct task_struct *tsk;
	struct mm_struct *mm;
	struct vm_area_struct * vma;
	siginfo_t info;

        D(printk("Page fault for %lX on %X at %lX, prot %d write %d\n",
                 address, smp_processor_id(), instruction_pointer(regs),
                 protection, writeaccess));

	tsk = current;

	/*
	 * We fault-in kernel-space virtual memory on-demand. The
	 * 'reference' page table is init_mm.pgd.
	 *
	 * NOTE! We MUST NOT take any locks for this case. We may
	 * be in an interrupt or a critical region, and should
	 * only copy the information from the master page table,
	 * nothing more.
	 *
	 * NOTE2: This is done so that, when updating the vmalloc
	 * mappings we don't have to walk all processes pgdirs and
	 * add the high mappings all at once. Instead we do it as they
	 * are used. However vmalloc'ed page entries have the PAGE_GLOBAL
	 * bit set so sometimes the TLB can use a lingering entry.
	 *
	 * This verifies that the fault happens in kernel space
	 * and that the fault was not a protection error (error_code & 1).
	 */

	if (address >= VMALLOC_START &&
	    !protection &&
	    !user_mode(regs))
		goto vmalloc_fault;

	/* When stack execution is not allowed we store the signal
	 * trampolines in the reserved cris_signal_return_page.
	 * Handle this in the exact same way as vmalloc (we know
	 * that the mapping is there and is valid so no need to
	 * call handle_mm_fault).
	 */
	if (cris_signal_return_page &&
	    address == cris_signal_return_page &&
	    !protection && user_mode(regs))
		goto vmalloc_fault;

	/* we can and should enable interrupts at this point */
	local_irq_enable();

	mm = tsk->mm;
	info.si_code = SEGV_MAPERR;

	/*
	 * If we're in an interrupt or have no user
	 * context, we must not take the fault..
	 */

	if (in_atomic() || !mm)
		goto no_context;

	down_read(&mm->mmap_sem);
	vma = find_vma(mm, address);
	if (!vma)
		goto bad_area;
	if (vma->vm_start <= address)
		goto good_area;
	if (!(vma->vm_flags & VM_GROWSDOWN))
		goto bad_area;
	if (user_mode(regs)) {
		/*
		 * accessing the stack below usp is always a bug.
		 * we get page-aligned addresses so we can only check
		 * if we're within a page from usp, but that might be
		 * enough to catch brutal errors at least.
		 */
		if (address + PAGE_SIZE < rdusp())
			goto bad_area;
	}
	if (expand_stack(vma, address))
		goto bad_area;

	/*
	 * Ok, we have a good vm_area for this memory access, so
	 * we can handle it..
	 */

 good_area:
	info.si_code = SEGV_ACCERR;

	/* first do some preliminary protection checks */

	if (writeaccess == 2){
		if (!(vma->vm_flags & VM_EXEC))
			goto bad_area;
	} else if (writeaccess == 1) {
		if (!(vma->vm_flags & VM_WRITE))
			goto bad_area;
	} else {
		if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
			goto bad_area;
	}

	/*
	 * If for any reason at all we couldn't handle the fault,
	 * make sure we exit gracefully rather than endlessly redo
	 * the fault.
	 */

	switch (handle_mm_fault(mm, vma, address, writeaccess & 1)) {
	case VM_FAULT_MINOR:
		tsk->min_flt++;
		break;
	case VM_FAULT_MAJOR:
		tsk->maj_flt++;
		break;
	case VM_FAULT_SIGBUS:
		goto do_sigbus;
	default:
		goto out_of_memory;
	}

	up_read(&mm->mmap_sem);
	return;

	/*
	 * Something tried to access memory that isn't in our memory map..
	 * Fix it, but check if it's kernel or user first..
	 */

 bad_area:
	up_read(&mm->mmap_sem);

 bad_area_nosemaphore:
	DPG(show_registers(regs));

	/* User mode accesses just cause a SIGSEGV */

	if (user_mode(regs)) {
		info.si_signo = SIGSEGV;
		info.si_errno = 0;
		/* info.si_code has been set above */
		info.si_addr = (void *)address;
		force_sig_info(SIGSEGV, &info, tsk);
		return;
	}

 no_context:

	/* Are we prepared to handle this kernel fault?
	 *
	 * (The kernel has valid exception-points in the source 
	 *  when it acesses user-memory. When it fails in one
	 *  of those points, we find it in a table and do a jump
	 *  to some fixup code that loads an appropriate error
	 *  code)
	 */

	if (find_fixup_code(regs))
		return;

	/*
	 * Oops. The kernel tried to access some bad page. We'll have to
	 * terminate things with extreme prejudice.
	 */

	if ((unsigned long) (address) < PAGE_SIZE)
		raw_printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
	else
		raw_printk(KERN_ALERT "Unable to handle kernel access");
	raw_printk(" at virtual address %08lx\n",address);

	die_if_kernel("Oops", regs, (writeaccess << 1) | protection);

	do_exit(SIGKILL);

	/*
	 * We ran out of memory, or some other thing happened to us that made
	 * us unable to handle the page fault gracefully.
	 */

 out_of_memory:
	up_read(&mm->mmap_sem);
	printk("VM: killing process %s\n", tsk->comm);
	if (user_mode(regs))
		do_exit(SIGKILL);
	goto no_context;

 do_sigbus:
	up_read(&mm->mmap_sem);

	/*
	 * Send a sigbus, regardless of whether we were in kernel
	 * or user mode.
	 */
	info.si_signo = SIGBUS;
	info.si_errno = 0;
	info.si_code = BUS_ADRERR;
	info.si_addr = (void *)address;
	force_sig_info(SIGBUS, &info, tsk);

	/* Kernel mode? Handle exceptions or die */
	if (!user_mode(regs))
		goto no_context;
	return;

vmalloc_fault:
	{
		/*
		 * Synchronize this task's top level page-table
		 * with the 'reference' page table.
		 *
		 * Use current_pgd instead of tsk->active_mm->pgd
		 * since the latter might be unavailable if this
		 * code is executed in a misfortunately run irq
		 * (like inside schedule() between switch_mm and
		 *  switch_to...).
		 */

		int offset = pgd_index(address);
		pgd_t *pgd, *pgd_k;
		pud_t *pud, *pud_k;
		pmd_t *pmd, *pmd_k;
		pte_t *pte_k;

		pgd = (pgd_t *)per_cpu(current_pgd, smp_processor_id()) + offset;
		pgd_k = init_mm.pgd + offset;

		/* Since we're two-level, we don't need to do both
		 * set_pgd and set_pmd (they do the same thing). If
		 * we go three-level at some point, do the right thing
		 * with pgd_present and set_pgd here. 
		 * 
		 * Also, since the vmalloc area is global, we don't
		 * need to copy individual PTE's, it is enough to
		 * copy the pgd pointer into the pte page of the
		 * root task. If that is there, we'll find our pte if
		 * it exists.
		 */

		pud = pud_offset(pgd, address);
		pud_k = pud_offset(pgd_k, address);
		if (!pud_present(*pud_k))
			goto no_context;

		pmd = pmd_offset(pud, address);
		pmd_k = pmd_offset(pud_k, address);

		if (!pmd_present(*pmd_k))
			goto bad_area_nosemaphore;

		set_pmd(pmd, *pmd_k);

		/* Make sure the actual PTE exists as well to
		 * catch kernel vmalloc-area accesses to non-mapped
		 * addresses. If we don't do this, this will just
		 * silently loop forever.
		 */

		pte_k = pte_offset_kernel(pmd_k, address);
		if (!pte_present(*pte_k))
			goto no_context;

		return;
	}
}
Exemple #9
0
void 
show_registers(struct pt_regs * regs)
{
	/* We either use rdusp() - the USP register, which might not
	   correspond to the current process for all cases we're called,
	   or we use the current->thread.usp, which is not up to date for
	   the current process.  Experience shows we want the USP
	   register.  */
	unsigned long usp = rdusp();

	raw_printk("IRP: %08lx SRP: %08lx DCCR: %08lx USP: %08lx MOF: %08lx\n",
	       regs->irp, regs->srp, regs->dccr, usp, regs->mof );
	raw_printk(" r0: %08lx  r1: %08lx   r2: %08lx  r3: %08lx\n",
	       regs->r0, regs->r1, regs->r2, regs->r3);
	raw_printk(" r4: %08lx  r5: %08lx   r6: %08lx  r7: %08lx\n",
	       regs->r4, regs->r5, regs->r6, regs->r7);
	raw_printk(" r8: %08lx  r9: %08lx  r10: %08lx r11: %08lx\n",
	       regs->r8, regs->r9, regs->r10, regs->r11);
	raw_printk("r12: %08lx r13: %08lx oR10: %08lx  sp: %08lx\n",
	       regs->r12, regs->r13, regs->orig_r10, regs);
	raw_printk("R_MMU_CAUSE: %08lx\n", (unsigned long)*R_MMU_CAUSE);
	raw_printk("Process %s (pid: %d, stackpage=%08lx)\n",
	       current->comm, current->pid, (unsigned long)current);

	/*
         * When in-kernel, we also print out the stack and code at the
         * time of the fault..
         */
        if (! user_mode(regs)) {
	  	int i;

                show_stack(NULL, (unsigned long*)usp);

		/* Dump kernel stack if the previous dump wasn't one.  */
		if (usp != 0)
			show_stack (NULL, NULL);

                raw_printk("\nCode: ");
                if(regs->irp < PAGE_OFFSET)
                        goto bad;

		/* Often enough the value at regs->irp does not point to
		   the interesting instruction, which is most often the
		   _previous_ instruction.  So we dump at an offset large
		   enough that instruction decoding should be in sync at
		   the interesting point, but small enough to fit on a row
		   (sort of).  We point out the regs->irp location in a
		   ksymoops-friendly way by wrapping the byte for that
		   address in parentheses.  */
                for(i = -12; i < 12; i++)
                {
                        unsigned char c;
                        if(__get_user(c, &((unsigned char*)regs->irp)[i])) {
bad:
                                raw_printk(" Bad IP value.");
                                break;
                        }

			if (i == 0)
			  raw_printk("(%02x) ", c);
			else
			  raw_printk("%02x ", c);
                }
		raw_printk("\n");
        }
}