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