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- /*
- * Kernel exception handling table support. Derived from arch/alpha/mm/extable.c.
- *
- * Copyright (C) 1998, 1999, 2001-2002, 2004 Hewlett-Packard Co
- * David Mosberger-Tang <davidm@hpl.hp.com>
- */
- #include <linux/sort.h>
- #include <asm/uaccess.h>
- #include <linux/module.h>
- static int cmp_ex(const void *a, const void *b)
- {
- const struct exception_table_entry *l = a, *r = b;
- u64 lip = (u64) &l->addr + l->addr;
- u64 rip = (u64) &r->addr + r->addr;
- /* avoid overflow */
- if (lip > rip)
- return 1;
- if (lip < rip)
- return -1;
- return 0;
- }
- static void swap_ex(void *a, void *b, int size)
- {
- struct exception_table_entry *l = a, *r = b, tmp;
- u64 delta = (u64) r - (u64) l;
- tmp = *l;
- l->addr = r->addr + delta;
- l->cont = r->cont + delta;
- r->addr = tmp.addr - delta;
- r->cont = tmp.cont - delta;
- }
- /*
- * Sort the exception table. It's usually already sorted, but there
- * may be unordered entries due to multiple text sections (such as the
- * .init text section). Note that the exception-table-entries contain
- * location-relative addresses, which requires a bit of care during
- * sorting to avoid overflows in the offset members (e.g., it would
- * not be safe to make a temporary copy of an exception-table entry on
- * the stack, because the stack may be more than 2GB away from the
- * exception-table).
- */
- void sort_extable (struct exception_table_entry *start,
- struct exception_table_entry *finish)
- {
- sort(start, finish - start, sizeof(struct exception_table_entry),
- cmp_ex, swap_ex);
- }
- static inline unsigned long ex_to_addr(const struct exception_table_entry *x)
- {
- return (unsigned long)&x->addr + x->addr;
- }
- #ifdef CONFIG_MODULES
- /*
- * Any entry referring to the module init will be at the beginning or
- * the end.
- */
- void trim_init_extable(struct module *m)
- {
- /*trim the beginning*/
- while (m->num_exentries &&
- within_module_init(ex_to_addr(&m->extable[0]), m)) {
- m->extable++;
- m->num_exentries--;
- }
- /*trim the end*/
- while (m->num_exentries &&
- within_module_init(ex_to_addr(&m->extable[m->num_exentries-1]),
- m))
- m->num_exentries--;
- }
- #endif /* CONFIG_MODULES */
- const struct exception_table_entry *
- search_extable (const struct exception_table_entry *first,
- const struct exception_table_entry *last,
- unsigned long ip)
- {
- const struct exception_table_entry *mid;
- unsigned long mid_ip;
- long diff;
- while (first <= last) {
- mid = &first[(last - first)/2];
- mid_ip = (u64) &mid->addr + mid->addr;
- diff = mid_ip - ip;
- if (diff == 0)
- return mid;
- else if (diff < 0)
- first = mid + 1;
- else
- last = mid - 1;
- }
- return NULL;
- }
- void
- ia64_handle_exception (struct pt_regs *regs, const struct exception_table_entry *e)
- {
- long fix = (u64) &e->cont + e->cont;
- regs->r8 = -EFAULT;
- if (fix & 4)
- regs->r9 = 0;
- regs->cr_iip = fix & ~0xf;
- ia64_psr(regs)->ri = fix & 0x3; /* set continuation slot number */
- }
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