94 lines
2.5 KiB
C
94 lines
2.5 KiB
C
/*
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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/config.h>
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#include <asm/uaccess.h>
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#include <asm/module.h>
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static inline int
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compare_entries (struct exception_table_entry *l, struct exception_table_entry *r)
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{
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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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if (lip < rip)
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return -1;
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if (lip == rip)
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return 0;
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else
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return 1;
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}
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static inline void
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swap_entries (struct exception_table_entry *l, struct exception_table_entry *r)
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{
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u64 delta = (u64) r - (u64) l;
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struct exception_table_entry tmp;
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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 may be unordered
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* entries due to multiple text sections (such as the .init text section). Note that the
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* exception-table-entries contain location-relative addresses, which requires a bit of
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* care during sorting to avoid overflows in the offset members (e.g., it would not be
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* safe to make a temporary copy of an exception-table entry on the stack, because the
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* stack may be more than 2GB away from the exception-table).
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*/
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void
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sort_extable (struct exception_table_entry *start, struct exception_table_entry *finish)
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{
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struct exception_table_entry *p, *q;
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/* insertion sort */
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for (p = start + 1; p < finish; ++p)
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/* start .. p-1 is sorted; push p down to it's proper place */
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for (q = p; q > start && compare_entries(&q[0], &q[-1]) < 0; --q)
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swap_entries(&q[0], &q[-1]);
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}
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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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