i386/linux/linux-2.3.21/arch/sparc64/mm/extable.c

   1 /*
   2  * linux/arch/sparc64/mm/extable.c
   3  */
   4
   5 #include <linux/config.h>
   6 #include <linux/module.h>
   7 #include <asm/uaccess.h>
   8
   9 extern const struct exception_table_entry __start___ex_table[];
  10 extern const struct exception_table_entry __stop___ex_table[];
  11
  12 static unsigned long
  13 search_one_table(const struct exception_table_entry *start,
  14                  const struct exception_table_entry *last,
  15                  unsigned long value, unsigned long *g2)
  16 {
  17         const struct exception_table_entry *first = start;
  18         const struct exception_table_entry *mid;
  19         long diff = 0;
  20         while (first <= last) {
  21                 mid = (last - first) / 2 + first;
  22                 diff = mid->insn - value;
  23                 if (diff == 0) {
  24                         if (!mid->fixup) {
  25                                 *g2 = 0;
  26                                 return (mid + 1)->fixup;
  27                         } else
  28                                 return mid->fixup;
  29                 } else if (diff < 0)
  30                         first = mid+1;
  31                 else
  32                         last = mid-1;
  33         }
  34         if (last->insn < value && !last->fixup && last[1].insn > value) {
  35                 *g2 = (value - last->insn)/4;
  36                 return last[1].fixup;
  37         }
  38         if (first > start && first[-1].insn < value
  39             && !first[-1].fixup && first->insn < value) {
  40                 *g2 = (value - first[-1].insn)/4;
  41                 return first->fixup;
  42         }
  43         return 0;
  44 }
  45
  46 unsigned long
  47 search_exception_table(unsigned long addr, unsigned long *g2)
  48 {
  49         unsigned long ret;
  50
  51 #ifndef CONFIG_MODULES
  52         /* There is only the kernel to search.  */
  53         ret = search_one_table(__start___ex_table,
  54                                __stop___ex_table-1, addr, g2);
  55         if (ret) return ret;
  56 #else
  57         /* The kernel is the last "module" -- no need to treat it special.  */
  58         struct module *mp;
  59         for (mp = module_list; mp != NULL; mp = mp->next) {
  60                 if (mp->ex_table_start == NULL)
  61                         continue;
  62                 ret = search_one_table(mp->ex_table_start,
  63                                        mp->ex_table_end-1, addr, g2);
  64                 if (ret) return ret;
  65         }
  66 #endif
  67
  68         return 0;
  69 }