diff options
Diffstat (limited to 'arch/ia64/mm/extable.c')
-rw-r--r-- | arch/ia64/mm/extable.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/arch/ia64/mm/extable.c b/arch/ia64/mm/extable.c new file mode 100644 index 000000000..c99a41e29 --- /dev/null +++ b/arch/ia64/mm/extable.c @@ -0,0 +1,115 @@ +/* + * 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 */ +} |