linux/arch/frv/mm/extable.c
Al Viro 9a7513cfa2 frv: switch to use of fixup_exception()
Massage frv search_exception_table() to
	a) taking pt_regs pointer as explicit argument
	b) updating ->pc on success
Simplifies callers a bit and allows to convert to generic extable.h,
while we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-28 18:23:32 -04:00

49 lines
1.4 KiB
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;
int fixup_exception(struct pt_regs *regs)
{
const struct exception_table_entry *extab;
unsigned long pc = regs->pc;
/* determine if the fault lay during a memcpy_user or a memset_user */
if (regs->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()
*/
regs->pc = (unsigned long) &__memset_user_error_handler;
return 1;
}
if (regs->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()
*/
regs->pc = (unsigned long) &__memcpy_user_error_handler;
return 1;
}
extab = search_exception_tables(pc);
if (extab) {
regs->pc = extab->fixup;
return 1;
}
return 0;
}