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#include <xen/config.h>
#include <xen/init.h>
#include <xen/perfc.h>
#include <xen/sort.h>
#include <xen/spinlock.h>
#include <asm/uaccess.h>
#define EX_FIELD(ptr, field) ((unsigned long)&(ptr)->field + (ptr)->field)
static inline unsigned long ex_addr(const struct exception_table_entry *x)
{
return EX_FIELD(x, addr);
}
static inline unsigned long ex_cont(const struct exception_table_entry *x)
{
return EX_FIELD(x, cont);
}
static int __init cmp_ex(const void *a, const void *b)
{
const struct exception_table_entry *l = a, *r = b;
unsigned long lip = ex_addr(l);
unsigned long rip = ex_addr(r);
/* avoid overflow */
if (lip > rip)
return 1;
if (lip < rip)
return -1;
return 0;
}
#ifndef swap_ex
static void __init swap_ex(void *a, void *b, int size)
{
struct exception_table_entry *l = a, *r = b, tmp;
long delta = b - a;
tmp = *l;
l->addr = r->addr + delta;
l->cont = r->cont + delta;
r->addr = tmp.addr - delta;
r->cont = tmp.cont - delta;
}
#endif
void __init sort_exception_tables(void)
{
sort(__start___ex_table, __stop___ex_table - __start___ex_table,
sizeof(struct exception_table_entry), cmp_ex, swap_ex);
sort(__start___pre_ex_table,
__stop___pre_ex_table - __start___pre_ex_table,
sizeof(struct exception_table_entry), cmp_ex, swap_ex);
}
static inline unsigned long
search_one_table(const struct exception_table_entry *first,
const struct exception_table_entry *last,
unsigned long value)
{
const struct exception_table_entry *mid;
long diff;
while ( first <= last )
{
mid = (last - first) / 2 + first;
diff = ex_addr(mid) - value;
if (diff == 0)
return ex_cont(mid);
else if (diff < 0)
first = mid+1;
else
last = mid-1;
}
return 0;
}
unsigned long
search_exception_table(unsigned long addr)
{
return search_one_table(
__start___ex_table, __stop___ex_table-1, addr);
}
unsigned long
search_pre_exception_table(struct cpu_user_regs *regs)
{
unsigned long addr = (unsigned long)regs->eip;
unsigned long fixup = search_one_table(
__start___pre_ex_table, __stop___pre_ex_table-1, addr);
if ( fixup )
{
dprintk(XENLOG_INFO, "Pre-exception: %p -> %p\n", _p(addr), _p(fixup));
perfc_incr(exception_fixed);
}
return fixup;
}
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