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/*
* linux/arch/frv/mm/extable.c
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <asm/uaccess.h>
extern const struct exception_table_entry __attribute__((aligned(8))) __start___ex_table[];
extern const struct exception_table_entry __attribute__((aligned(8))) __stop___ex_table[];
extern const void __memset_end, __memset_user_error_lr, __memset_user_error_handler;
extern const void __memcpy_end, __memcpy_user_error_lr, __memcpy_user_error_handler;
extern spinlock_t modlist_lock;
/*****************************************************************************/
/*
*
*/
static inline unsigned long search_one_table(const struct exception_table_entry *first,
const struct exception_table_entry *last,
unsigned long value)
{
while (first <= last) {
const struct exception_table_entry __attribute__((aligned(8))) *mid;
long diff;
mid = (last - first) / 2 + first;
diff = mid->insn - value;
if (diff == 0)
return mid->fixup;
else if (diff < 0)
first = mid + 1;
else
last = mid - 1;
}
return 0;
} /* end search_one_table() */
/*****************************************************************************/
/*
* see if there's a fixup handler available to deal with a kernel fault
*/
unsigned long search_exception_table(unsigned long pc)
{
unsigned long ret = 0;
/* determine if the fault lay during a memcpy_user or a memset_user */
if (__frame->lr == (unsigned long) &__memset_user_error_lr &&
(unsigned long) &memset <= pc && pc < (unsigned long) &__memset_end
) {
/* the fault occurred in a protected memset
* - we search for the return address (in LR) instead of the program counter
* - it was probably during a clear_user()
*/
return (unsigned long) &__memset_user_error_handler;
}
else if (__frame->lr == (unsigned long) &__memcpy_user_error_lr &&
(unsigned long) &memcpy <= pc && pc < (unsigned long) &__memcpy_end
) {
/* the fault occurred in a protected memset
* - we search for the return address (in LR) instead of the program counter
* - it was probably during a copy_to/from_user()
*/
return (unsigned long) &__memcpy_user_error_handler;
}
#ifndef CONFIG_MODULES
/* there is only the kernel to search. */
ret = search_one_table(__start___ex_table, __stop___ex_table - 1, pc);
return ret;
#else
/* the kernel is the last "module" -- no need to treat it special */
unsigned long flags;
struct module *mp;
spin_lock_irqsave(&modlist_lock, flags);
for (mp = module_list; mp != NULL; mp = mp->next) {
if (mp->ex_table_start == NULL || !(mp->flags & (MOD_RUNNING | MOD_INITIALIZING)))
continue;
ret = search_one_table(mp->ex_table_start, mp->ex_table_end - 1, pc);
if (ret)
break;
}
spin_unlock_irqrestore(&modlist_lock, flags);
return ret;
#endif
} /* end search_exception_table() */
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