/*
* 'traps.c' handles hardware traps and faults after we have saved some
* state in 'entry.S'.
*
* SuperH version: Copyright (C) 1999 Niibe Yutaka
* Copyright (C) 2000 Philipp Rumpf
* Copyright (C) 2000 David Howells
* Copyright (C) 2002 - 2007 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/kernel.h>
#include <linux/ptrace.h>
#include <linux/hardirq.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/io.h>
#include <linux/bug.h>
#include <linux/debug_locks.h>
#include <linux/kdebug.h>
#include <linux/kexec.h>
#include <linux/limits.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/fpu.h>
#include <asm/kprobes.h>
#ifdef CONFIG_CPU_SH2
# define TRAP_RESERVED_INST 4
# define TRAP_ILLEGAL_SLOT_INST 6
# define TRAP_ADDRESS_ERROR 9
# ifdef CONFIG_CPU_SH2A
# define TRAP_FPU_ERROR 13
# define TRAP_DIVZERO_ERROR 17
# define TRAP_DIVOVF_ERROR 18
# endif
#else
#define TRAP_RESERVED_INST 12
#define TRAP_ILLEGAL_SLOT_INST 13
#endif
static void dump_mem(const char *str, unsigned long bottom, unsigned long top)
{
unsigned long p;
int i;
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 {
if (__get_user(val, (unsigned int __user *)p)) {
printk("\n");
return;
}
printk("%08x ", val);
}
}
printk("\n");
}
}
static DEFINE_SPINLOCK(die_lock);
void die(const char * str, struct pt_regs * regs, long err)
{
static int die_counter;
oops_enter();
console_verbose();
spin_lock_irq(&die_lock);
bust_spinlocks(1);
printk("%s: %04lx [#%d]\n", str, err & 0xffff, ++die_counter);
print_modules();
show_regs(regs);
printk("Process: %s (pid: %d, stack limit = %p)\n", current->comm,
task_pid_nr(current), task_stack_page(current) + 1);
if (!user_mode(regs) || in_interrupt())
dump_mem("Stack: ", regs->regs[15], THREAD_SIZE +
(unsigned long)task_stack_page(current));
notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV);
bust_spinlocks(0);
add_taint(TAINT_DIE);
spin_unlock_irq(&die_lock);
if (kexec_should_crash(current))
crash_kexec(regs);
if (in_interrupt())
panic("Fatal exception in interrupt");
if (panic_on_oops)
panic("Fatal exception");
oops_exit();
do_exit(SIGSEGV);
}
static inline void die_if_kernel(const char *str, struct pt_regs *regs,
long err)
{
if (!user_mode(regs))
die(str, regs, err);
}
/*
* try and fix up kernelspace address errors
* - userspace errors just cause EFAULT to be returned, resulting in SEGV
* - kernel/userspace interfaces cause a jump to an appropriate handler
* - other kernel errors are bad
*/
static void die_if_no_fixup(const char * str, struct pt_regs * regs, long err)
{
if (!user_mode(regs)) {
const struct exception_table_entry *fixup;
fixup = search_exception_tables(regs->pc);
if (fixup) {
regs->pc = fixup->fixup;
return;
}
die(str, regs, err);
}
}
static inline void sign_extend(unsigned int count, unsigned char *dst)
{
#ifdef __LITTLE_ENDIAN__
if ((count == 1) && dst[0] & 0x80) {
dst[1] = 0xff;
dst[2] = 0xff;
dst[3] = 0xff;
}
if ((count == 2) && dst[1] & 0x80) {
dst[2] = 0xff;
dst[3] = 0xff;
}
#else
if ((count == 1) && dst[3] & 0x80) {
dst[2] = 0xff;
dst[1] = 0xff;
dst[0] = 0xff;
}
if ((count == 2) && dst[2] & 0x80) {
dst[1] = 0xff;
dst[0] = 0xff;
}
#endif
}
static struct mem_access user_mem_access = {
copy_from_user,
copy_to_user,
};
/*
* handle an instruction that does an unaligned memory access by emulating the
* desired behaviour
* - note that PC _may not_ point to the faulting instruction
* (if that instruction is in a branch delay slot)
* - return 0 if emulation okay, -EFAULT on existential error
*/
static int handle_unaligned_ins(opcode_t instruction