2019-05-19 13:51:43 +00:00
|
|
|
/* SPDX-License-Identifier: GPL-2.0-or-later */
|
2017-07-24 23:36:57 +00:00
|
|
|
/*
|
|
|
|
|
* Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com>
|
|
|
|
|
*/
|
|
|
|
|
#ifndef _ORC_LOOKUP_H
|
|
|
|
|
#define _ORC_LOOKUP_H
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* This is a lookup table for speeding up access to the .orc_unwind table.
|
|
|
|
|
* Given an input address offset, the corresponding lookup table entry
|
|
|
|
|
* specifies a subset of the .orc_unwind table to search.
|
|
|
|
|
*
|
|
|
|
|
* Each block represents the end of the previous range and the start of the
|
|
|
|
|
* next range. An extra block is added to give the last range an end.
|
|
|
|
|
*
|
|
|
|
|
* The block size should be a power of 2 to avoid a costly 'div' instruction.
|
|
|
|
|
*
|
|
|
|
|
* A block size of 256 was chosen because it roughly doubles unwinder
|
|
|
|
|
* performance while only adding ~5% to the ORC data footprint.
|
|
|
|
|
*/
|
|
|
|
|
#define LOOKUP_BLOCK_ORDER 8
|
|
|
|
|
#define LOOKUP_BLOCK_SIZE (1 << LOOKUP_BLOCK_ORDER)
|
|
|
|
|
|
|
|
|
|
#ifndef LINKER_SCRIPT
|
|
|
|
|
|
|
|
|
|
extern unsigned int orc_lookup[];
|
|
|
|
|
extern unsigned int orc_lookup_end[];
|
|
|
|
|
|
|
|
|
|
#define LOOKUP_START_IP (unsigned long)_stext
|
|
|
|
|
#define LOOKUP_STOP_IP (unsigned long)_etext
|
|
|
|
|
|
|
|
|
|
#endif /* LINKER_SCRIPT */
|
|
|
|
|
|
|
|
|
|
#endif /* _ORC_LOOKUP_H */
|
