Release 4.14 arch/alpha/include/asm/extable.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_EXTABLE_H

#define _ASM_EXTABLE_H

/*
 * About the exception table:
 *
 * - insn is a 32-bit pc-relative offset from the faulting insn.
 * - nextinsn is a 16-bit offset off of the faulting instruction
 *   (not off of the *next* instruction as branches are).
 * - errreg is the register in which to place -EFAULT.
 * - valreg is the final target register for the load sequence
 *   and will be zeroed.
 *
 * Either errreg or valreg may be $31, in which case nothing happens.
 *
 * The exception fixup information "just so happens" to be arranged
 * as in a MEM format instruction.  This lets us emit our three
 * values like so:
 *
 *      lda valreg, nextinsn(errreg)
 *
 */


struct exception_table_entry
{
	
signed int insn;
	
union exception_fixup {
		
unsigned unit;
		struct {
			
signed int nextinsn : 16;
			
unsigned int errreg : 5;
			
unsigned int valreg : 5;
		
} bits;
	
} fixup;
};

/* Returns the new pc */

#define fixup_exception(map_reg, _fixup, pc)			\
({                                                              \
        if ((_fixup)->fixup.bits.valreg != 31)                  \
                map_reg((_fixup)->fixup.bits.valreg) = 0;       \
        if ((_fixup)->fixup.bits.errreg != 31)                  \
                map_reg((_fixup)->fixup.bits.errreg) = -EFAULT; \
        (pc) + (_fixup)->fixup.bits.nextinsn;                   \
})


#define ARCH_HAS_RELATIVE_EXTABLE


#define swap_ex_entry_fixup(a, b, tmp, delta)			\
	do {                                                    \
                (a)->fixup.unit = (b)->fixup.unit;              \
                (b)->fixup.unit = (tmp).fixup.unit;             \
        } while (0)

#endif
Overall Contributors
Person
Tokens
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Al Viro
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1
50.00%
Greg Kroah-Hartman
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1
50.00%
Total
81
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2
100.00%
Directory: arch/alpha/include/asm

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