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