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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __PARISC_EXTABLE_H
#define __PARISC_EXTABLE_H
#include <asm/ptrace.h>
#include <linux/compiler.h>
/*
* The exception table consists of three addresses:
*
* - A relative address to the instruction that is allowed to fault.
* - A relative address at which the program should continue (fixup routine)
* - An asm statement which specifies which CPU register will
* receive -EFAULT when an exception happens if the lowest bit in
* the fixup address is set.
*
* Note: The register specified in the err_opcode instruction will be
* modified at runtime if a fault happens. Register %r0 will be ignored.
*
* Since relative addresses are used, 32bit values are sufficient even on
* 64bit kernel.
*/
struct pt_regs;
int fixup_exception(struct pt_regs *regs);
#define ARCH_HAS_RELATIVE_EXTABLE
struct exception_table_entry {
int insn; /* relative address of insn that is allowed to fault. */
int fixup; /* relative address of fixup routine */
int err_opcode; /* sample opcode with register which holds error code */
};
#define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr, opcode )\
".section __ex_table,\"aw\"\n" \
".align 4\n" \
".word (" #fault_addr " - .), (" #except_addr " - .)\n" \
opcode "\n" \
".previous\n"
/*
* ASM_EXCEPTIONTABLE_ENTRY_EFAULT() creates a special exception table entry
* (with lowest bit set) for which the fault handler in fixup_exception() will
* load -EFAULT on fault into the register specified by the err_opcode instruction,
* and zeroes the target register in case of a read fault in get_user().
*/
#define ASM_EXCEPTIONTABLE_VAR(__err_var) \
int __err_var = 0
#define ASM_EXCEPTIONTABLE_ENTRY_EFAULT( fault_addr, except_addr, register )\
ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr + 1, "or %%r0,%%r0," register)
static inline void swap_ex_entry_fixup(struct exception_table_entry *a,
struct exception_table_entry *b,
struct exception_table_entry tmp,
int delta)
{
a->fixup = b->fixup + delta;
b->fixup = tmp.fixup - delta;
a->err_opcode = b->err_opcode;
b->err_opcode = tmp.err_opcode;
}
#define swap_ex_entry_fixup swap_ex_entry_fixup
#endif
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