[mirror_ubuntu-artful-kernel.git] / arch / frv / mm / extable.c

/*
 * linux/arch/frv/mm/extable.c
 */

#include <linux/extable.h>
#include <linux/spinlock.h>
#include <linux/uaccess.h>

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;


/*****************************************************************************/
/*
 * see if there's a fixup handler available to deal with a kernel fault
 */
unsigned long search_exception_table(unsigned long pc)
{
	const struct exception_table_entry *extab;

	/* 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;
	}

	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;
	}

	extab = search_exception_tables(pc);
	if (extab)
		return extab->fixup;

	return 0;

} /* end search_exception_table() */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/frv/mm/extable.c
	3	*/
	4
ece74f63	5	#include <linux/extable.h>
1da177e4	6	#include <linux/spinlock.h>
7c0f6ba6	7	#include <linux/uaccess.h>
1da177e4	8
1da177e4 LT	9	extern const void __memset_end, __memset_user_error_lr, __memset_user_error_handler;
	10	extern const void __memcpy_end, __memcpy_user_error_lr, __memcpy_user_error_handler;
	11	extern spinlock_t modlist_lock;
	12
1da177e4 LT	13
	14	/*****************************************************************************/
	15	/*
	16	* see if there's a fixup handler available to deal with a kernel fault
	17	*/
	18	unsigned long search_exception_table(unsigned long pc)
	19	{
018b8d12	20	const struct exception_table_entry *extab;
1da177e4 LT	21
	22	/* determine if the fault lay during a memcpy_user or a memset_user */
	23	if (__frame->lr == (unsigned long) &__memset_user_error_lr &&
	24	(unsigned long) &memset <= pc && pc < (unsigned long) &__memset_end
	25	) {
	26	/* the fault occurred in a protected memset
	27	* - we search for the return address (in LR) instead of the program counter
	28	* - it was probably during a clear_user()
	29	*/
	30	return (unsigned long) &__memset_user_error_handler;
	31	}
018b8d12 DH	32
	33	if (__frame->lr == (unsigned long) &__memcpy_user_error_lr &&
	34	(unsigned long) &memcpy <= pc && pc < (unsigned long) &__memcpy_end
	35	) {
1da177e4 LT	36	/* the fault occurred in a protected memset
	37	* - we search for the return address (in LR) instead of the program counter
	38	* - it was probably during a copy_to/from_user()
	39	*/
	40	return (unsigned long) &__memcpy_user_error_handler;
	41	}
	42
018b8d12 DH	43	extab = search_exception_tables(pc);
	44	if (extab)
	45	return extab->fixup;
1da177e4	46
018b8d12	47	return 0;
1da177e4	48
1da177e4	49	} /* end search_exception_table() */