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

   1/*
   2 * linux/arch/frv/mm/extable.c
   3 */
   4
   5#include <linux/module.h>
   6#include <linux/spinlock.h>
   7#include <asm/uaccess.h>
   8
   9extern const void __memset_end, __memset_user_error_lr, __memset_user_error_handler;
  10extern const void __memcpy_end, __memcpy_user_error_lr, __memcpy_user_error_handler;
  11extern spinlock_t modlist_lock;
  12
  13
  14/*****************************************************************************/
  15/*
  16 * see if there's a fixup handler available to deal with a kernel fault
  17 */
  18unsigned long search_exception_table(unsigned long pc)
  19{
  20        const struct exception_table_entry *extab;
  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        }
  32
  33        if (__frame->lr == (unsigned long) &__memcpy_user_error_lr &&
  34            (unsigned long) &memcpy <= pc && pc < (unsigned long) &__memcpy_end
  35            ) {
  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
  43        extab = search_exception_tables(pc);
  44        if (extab)
  45                return extab->fixup;
  46
  47        return 0;
  48
  49} /* end search_exception_table() */
  50