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* Copyright (c) 2018 Intel Corporation.
* SPDX-License-Identifier: Apache-2.0
* This is used by some architectures to define code ranges which may
* perform operations that could generate a CPU exception that should not
* be fatal. Instead, the exception should return but set the program
* counter to a 'fixup' memory address which will gracefully error out.
* For example, in the case where user mode passes in a C string via
* system call, the length of that string needs to be measured. A specially
* written assembly language version of strlen (arch_user_string_len)
* defines start and end symbols where the memory in the string is examined;
* if this generates a fault, jumping to the fixup symbol within the same
* function will return an error result to the caller.
* To ensure precise control of the state of registers and the stack pointer,
* these functions need to be written in assembly.
* The arch-specific fault handling code will define an array of these
* z_exc_handle structures and return from the exception with the PC updated
* to the fixup address if a match is found.
struct z_exc_handle {
void *start;
void *end;
void *fixup;
#define Z_EXC_HANDLE(name) \
{ name ## _fault_start, name ## _fault_end, name ## _fixup }
#define Z_EXC_DECLARE(name) \
void name ## _fault_start(void); \
void name ## _fault_end(void); \
void name ## _fixup(void)