path: root/arch/blackfin/kernel/traps.c

/*
 * File:         arch/blackfin/kernel/traps.c
 * Based on:
 * Author:       Hamish Macdonald
 *
 * Created:
 * Description:  uses S/W interrupt 15 for the system calls
 *
 * Modified:
 *               Copyright 2004-2006 Analog Devices Inc.
 *
 * Bugs:         Enter bugs at http://blackfin.uclinux.org/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see the file COPYING, or write
 * to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include <linux/uaccess.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/fs.h>
#include <asm/traps.h>
#include <asm/cacheflush.h>
#include <asm/blackfin.h>
#include <asm/irq_handler.h>
#include <linux/irq.h>
#include <asm/trace.h>
#include <asm/fixed_code.h>
#include <asm/dma.h>

#ifdef CONFIG_KGDB
# include <linux/debugger.h>
# include <linux/kgdb.h>

# define CHK_DEBUGGER_TRAP() \
	do { \
		CHK_DEBUGGER(trapnr, sig, info.si_code, fp, ); \
	} while (0)
# define CHK_DEBUGGER_TRAP_MAYBE() \
	do { \
		if (kgdb_connected) \
			CHK_DEBUGGER_TRAP(); \
	} while (0)
#else
# define CHK_DEBUGGER_TRAP() do { } while (0)
# define CHK_DEBUGGER_TRAP_MAYBE() do { } while (0)
#endif

/* Initiate the event table handler */
void __init trap_init(void)
{
	CSYNC();
	bfin_write_EVT3(trap);
	CSYNC();
}

void *saved_icplb_fault_addr, *saved_dcplb_fault_addr;

int kstack_depth_to_print = 48;

static void decode_address(char *buf, unsigned long address)
{
	struct vm_list_struct *vml;
	struct task_struct *p;
	struct mm_struct *mm;
	unsigned long flags, offset;
	unsigned char in_atomic = (bfin_read_IPEND() & 0x10) || in_atomic();

#ifdef CONFIG_KALLSYMS
	unsigned long symsize;
	const char *symname;
	char *modname;
	char *delim = ":";
	char namebuf[128];

	/* look up the address and see if we are in kernel space */
	symname = kallsyms_lookup(address, &symsize, &offset, &modname, namebuf);

	if (symname) {
		/* yeah! kernel space! */
		if (!modname)
			modname = delim = "";
		sprintf(buf, "<0x%p> { %s%s%s%s + 0x%lx }",
		              (void *)address, delim, modname, delim, symname,
		              (unsigned long)offset);
		return;

	}
#endif

	/* Problem in fixed code section? */
	if (address >= FIXED_CODE_START && address < FIXED_CODE_END) {
		sprintf(buf, "<0x%p> /* Maybe fixed code section */", (void *)address);
		return;
	}

	/* Problem somewhere before the kernel start address */
	if (address < CONFIG_BOOT_LOAD) {
		sprintf(buf, "<0x%p> /* Maybe null pointer? */", (void *)address);
		return;
	}

	/* looks like we're off in user-land, so let's walk all the
	 * mappings of all our processes and see if we can't be a whee
	 * bit more specific
	 */
	write_lock_irqsave(&tasklist_lock, flags);
	for_each_process(p) {
		mm = (in_atomic ? p->mm : get_task_mm(p));
		if (!mm)
			continue;

		vml = mm->context.vmlist;
		while (vml) {
			struct vm_area_struct *vma = vml->vma;

			if (address >= vma->vm_start && address < vma->vm_end) {
				char _tmpbuf[256];
				char *name = p->comm;
				struct file *file = vma->vm_file;

				if (file)
					name = d_path(&file->f_path, _tmpbuf,
						      sizeof(_tmpbuf));

				/* FLAT does not have its text aligned to the start of
				 * the map while FDPIC ELF does ...
				 */

				/* before we can check flat/fdpic, we need to
				 * make sure current is valid
				 */
				if ((unsigned long)current >= FIXED_CODE_START &&
				    !((unsigned long)current & 0x3)) {
					if (current->mm &&
					    (address > current->mm->start_code) &&
					    (address < current->mm->end_code))
						offset = address - current->mm->start_code;
					else
						offset = (address - vma->vm_start) +
							 (vma->vm_pgoff << PAGE_SHIFT);

					sprintf(buf, "<0x%p> [ %s + 0x%lx ]",
						(void *)address, name, offset);
				} else
					sprintf(buf, "<0x%p> [ %s vma:0x%lx-0x%lx]",
						(void *)address, name,
						vma->vm_start, vma->vm_end);

				if (!in_atomic)
					mmput(mm);

				goto done;
			}

			vml = vml->next;
		}
		if (!in_atomic)
			mmput(mm);
	}

	/* we were unable to find this address anywhere */
	sprintf(buf, "<0x%p> /* unknown address */", (void *)address);

done:
	write_unlock_irqrestore(&tasklist_lock, flags);
}

asmlinkage void double_fault_c(struct pt_regs *fp)
{