Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1#ifndef _ASM_EXTABLE_H
2#define _ASM_EXTABLE_H
3
4/*
5 * About the exception table:
6 *
7 * - insn is a 32-bit pc-relative offset from the faulting insn.
8 * - nextinsn is a 16-bit offset off of the faulting instruction
9 * (not off of the *next* instruction as branches are).
10 * - errreg is the register in which to place -EFAULT.
11 * - valreg is the final target register for the load sequence
12 * and will be zeroed.
13 *
14 * Either errreg or valreg may be $31, in which case nothing happens.
15 *
16 * The exception fixup information "just so happens" to be arranged
17 * as in a MEM format instruction. This lets us emit our three
18 * values like so:
19 *
20 * lda valreg, nextinsn(errreg)
21 *
22 */
23
24struct exception_table_entry
25{
26 signed int insn;
27 union exception_fixup {
28 unsigned unit;
29 struct {
30 signed int nextinsn : 16;
31 unsigned int errreg : 5;
32 unsigned int valreg : 5;
33 } bits;
34 } fixup;
35};
36
37/* Returns the new pc */
38#define fixup_exception(map_reg, _fixup, pc) \
39({ \
40 if ((_fixup)->fixup.bits.valreg != 31) \
41 map_reg((_fixup)->fixup.bits.valreg) = 0; \
42 if ((_fixup)->fixup.bits.errreg != 31) \
43 map_reg((_fixup)->fixup.bits.errreg) = -EFAULT; \
44 (pc) + (_fixup)->fixup.bits.nextinsn; \
45})
46
47#define ARCH_HAS_RELATIVE_EXTABLE
48
49#define swap_ex_entry_fixup(a, b, tmp, delta) \
50 do { \
51 (a)->fixup.unit = (b)->fixup.unit; \
52 (b)->fixup.unit = (tmp).fixup.unit; \
53 } while (0)
54
55#endif