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/*
* linux/arch/alpha/mm/extable.c
*/
#include <linux/config.h>
#include <linux/module.h>
#include <asm/uaccess.h>
extern const struct exception_table_entry __start___ex_table[];
extern const struct exception_table_entry __stop___ex_table[];
static inline unsigned
search_one_table(const struct exception_table_entry *first,
const struct exception_table_entry *last,
signed long value)
{
/* Abort early if the search value is out of range. */
if (value != (signed int)value)
return 0;
while (first <= last) {
const struct exception_table_entry *mid;
long diff;
mid = (last - first) / 2 + first;
diff = mid->insn - value;
if (diff == 0)
return mid->fixup.unit;
else if (diff < 0)
first = mid+1;
else
last = mid-1;
}
return 0;
}
register unsigned long gp __asm__("$29");
static unsigned
search_exception_table_without_gp(unsigned long addr)
{
unsigned ret;
#ifndef CONFIG_MODULES
/* There is only the kernel to search. */
ret = search_one_table(__start___ex_table, __stop___ex_table - 1,
addr - gp);
#else
extern spinlock_t modlist_lock;
unsigned long flags;
/* The kernel is the last "module" -- no need to treat it special. */
struct module *mp;
ret = 0;
spin_lock_irqsave(&modlist_lock, flags);
for (mp = module_list; mp ; mp = mp->next) {
if (!mp->ex_table_start || !(mp->flags&(MOD_RUNNING|MOD_INITIALIZING)))
continue;
ret = search_one_table(mp->ex_table_start,
mp->ex_table_end - 1, addr - mp->gp);
if (ret)
break;
}
spin_unlock_irqrestore(&modlist_lock, flags);
#endif
return ret;
}
unsigned
search_exception_table(unsigned long addr, unsigned long exc_gp)
{
unsigned ret;
#ifndef CONFIG_MODULES
ret = search_one_table(__start___ex_table, __stop___ex_table - 1,
addr - exc_gp);
if (ret) return ret;
#else
extern spinlock_t modlist_lock;
unsigned long flags;
/* The kernel is the last "module" -- no need to treat it special. */
struct module *mp;
ret = 0;
spin_lock_irqsave(&modlist_lock, flags);
for (mp = module_list; mp ; mp = mp->next) {
if (!mp->ex_table_start || !(mp->flags&(MOD_RUNNING|MOD_INITIALIZING)))
continue;
ret = search_one_table(mp->ex_table_start,
mp->ex_table_end - 1, addr - exc_gp);
if (ret)
break;
}
spin_unlock_irqrestore(&modlist_lock, flags);
if (ret) return ret;
#endif
/*
* The search failed with the exception gp. To be safe, try the
* old method before giving up.
*/
ret = search_exception_table_without_gp(addr);
if (ret) {
printk(KERN_ALERT "%s: [%lx] EX_TABLE search fail with"
"exc frame GP, success with raw GP\n",
current->comm, addr);
return ret;
}
return 0;
}
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