// SPDX-License-Identifier: GPL-2.0-or-later/* * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com> */ #include <stdlib.h>#include <string.h> #include <linux/objtool_types.h>#include <asm/orc_types.h> #include <objtool/check.h>#include <objtool/orc.h>#include <objtool/warn.h> struct orc_list_entry {	struct list_head list;	struct orc_entry orc;	struct section *insn_sec;	unsigned long insn_off;}; static int orc_list_add(struct list_head *orc_list, struct orc_entry *orc,			struct section *sec, unsigned long offset){	struct orc_list_entry *entry = malloc(sizeof(*entry)); 	if (!entry) {		WARN("malloc failed");		return -1;	} 	entry->orc	= *orc;	entry->insn_sec = sec;	entry->insn_off = offset; 	list_add_tail(&entry->list, orc_list);	return 0;} static unsigned long alt_group_len(struct alt_group *alt_group){	return alt_group->last_insn->offset +	       alt_group->last_insn->len -	       alt_group->first_insn->offset;} int orc_create(struct objtool_file *file){	struct section *sec, *orc_sec;	unsigned int nr = 0, idx = 0;	struct orc_list_entry *entry;	struct list_head orc_list; 	struct orc_entry null = { .type = ORC_TYPE_UNDEFINED }; 	/* Build a deduplicated list of ORC entries: */	INIT_LIST_HEAD(&orc_list);	for_each_sec(file->elf, sec) {		struct orc_entry orc, prev_orc = {0};		struct instruction *insn;		bool empty = true; 		if (!sec->text)			continue; 		sec_for_each_insn(file, sec, insn) {			struct alt_group *alt_group = insn->alt_group;			int i; 			if (!alt_group) {				if (init_orc_entry(&orc, insn->cfi, insn))					return -1;				if (!memcmp(&prev_orc, &orc, sizeof(orc)))					continue;				if (orc_list_add(&orc_list, &orc, sec,						 insn->offset))					return -1;				nr++;				prev_orc = orc;				empty = false;				continue;			} 			/*			 * Alternatives can have different stack layout			 * possibilities (but they shouldn't conflict).			 * Instead of traversing the instructions, use the			 * alt_group's flattened byte-offset-addressed CFI			 * array.			 */			for (i = 0; i < alt_group_len(alt_group); i++) {				struct cfi_state *cfi = alt_group->cfi[i];				if (!cfi)					continue;				/* errors are reported on the original insn */				if (init_orc_entry(&orc, cfi, insn))					return -1;				if (!memcmp(&prev_orc, &orc, sizeof(orc)))					continue;				if (orc_list_add(&orc_list, &orc, insn->sec,						 insn->offset + i))					return -1;				nr++;				prev_orc = orc;				empty = false;			} 			/* Skip to the end of the alt_group */			insn = alt_group->last_insn;		} 		/* Add a section terminator */		if (!empty) {			orc_list_add(&orc_list, &null, sec, sec->sh.sh_size);			nr++;		}	}	if (!nr)		return 0; 	/* Create .orc_unwind, .orc_unwind_ip and .rela.orc_unwind_ip sections: */	sec = find_section_by_name(file->elf, ".orc_unwind");	if (sec) {		WARN("file already has .orc_unwind section, skipping");		return -1;	}	orc_sec = elf_create_section(file->elf, ".orc_unwind",				     nr * sizeof(struct orc_entry),				     sizeof(struct orc_entry),				     SHT_PROGBITS,				     1,				     SHF_ALLOC);	if (!orc_sec)		return -1; 	sec = elf_create_section_pair(file->elf, ".orc_unwind_ip", sizeof(int), nr, nr);	if (!sec)		return -1; 	/* Write ORC entries to sections: */	list_for_each_entry(entry, &orc_list, list) {		if (write_orc_entry(file->elf, orc_sec, sec, idx++,				    entry->insn_sec, entry->insn_off,				    &entry->orc))			return -1;	} 	return 0;}