/* * linux/arch/frv/mm/extable.c */ #include <linux/module.h> #include <linux/spinlock.h> #include <asm/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; /*****************************************************************************/ /* * */ 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) { 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() */