// SPDX-License-Identifier: GPL-2.0-or-later/* * Copyright (C) 2017 Josh Poimboeuf <jpoimboe@redhat.com> */ #include <stdlib.h>#include <string.h> #include "check.h"#include "warn.h" int create_orc(struct objtool_file *file){	struct instruction *insn; 	for_each_insn(file, insn) {		struct orc_entry *orc = &insn->orc;		struct cfi_reg *cfa = &insn->cfi.cfa;		struct cfi_reg *bp = &insn->cfi.regs[CFI_BP]; 		orc->end = insn->cfi.end; 		if (cfa->base == CFI_UNDEFINED) {			orc->sp_reg = ORC_REG_UNDEFINED;			continue;		} 		switch (cfa->base) {		case CFI_SP:			orc->sp_reg = ORC_REG_SP;			break;		case CFI_SP_INDIRECT:			orc->sp_reg = ORC_REG_SP_INDIRECT;			break;		case CFI_BP:			orc->sp_reg = ORC_REG_BP;			break;		case CFI_BP_INDIRECT:			orc->sp_reg = ORC_REG_BP_INDIRECT;			break;		case CFI_R10:			orc->sp_reg = ORC_REG_R10;			break;		case CFI_R13:			orc->sp_reg = ORC_REG_R13;			break;		case CFI_DI:			orc->sp_reg = ORC_REG_DI;			break;		case CFI_DX:			orc->sp_reg = ORC_REG_DX;			break;		default:			WARN_FUNC("unknown CFA base reg %d",				  insn->sec, insn->offset, cfa->base);			return -1;		} 		switch(bp->base) {		case CFI_UNDEFINED:			orc->bp_reg = ORC_REG_UNDEFINED;			break;		case CFI_CFA:			orc->bp_reg = ORC_REG_PREV_SP;			break;		case CFI_BP:			orc->bp_reg = ORC_REG_BP;			break;		default:			WARN_FUNC("unknown BP base reg %d",				  insn->sec, insn->offset, bp->base);			return -1;		} 		orc->sp_offset = cfa->offset;		orc->bp_offset = bp->offset;		orc->type = insn->cfi.type;	} 	return 0;} static int create_orc_entry(struct elf *elf, struct section *u_sec, struct section *ip_relocsec,				unsigned int idx, struct section *insn_sec,				unsigned long insn_off, struct orc_entry *o){	struct orc_entry *orc;	struct reloc *reloc; 	/* populate ORC data */	orc = (struct orc_entry *)u_sec->data->d_buf + idx;	memcpy(orc, o, sizeof(*orc)); 	/* populate reloc for ip */	reloc = malloc(sizeof(*reloc));	if (!reloc) {		perror("malloc");		return -1;	}	memset(reloc, 0, sizeof(*reloc)); 	if (insn_sec->sym) {		reloc->sym = insn_sec->sym;		reloc->addend = insn_off;	} else {		/*		 * The Clang assembler doesn't produce section symbols, so we		 * have to reference the function symbol instead:		 */		reloc->sym = find_symbol_containing(insn_sec, insn_off);		if (!reloc->sym) {			/*			 * Hack alert.  This happens when we need to reference			 * the NOP pad insn immediately after the function.			 */			reloc->sym = find_symbol_containing(insn_sec,							   insn_off - 1);		}		if (!reloc->sym) {			WARN("missing symbol for insn at offset 0x%lx\n",			     insn_off);			return -1;		} 		reloc->addend = insn_off - reloc->sym->offset;	} 	reloc->type = R_X86_64_PC32;	reloc->offset = idx * sizeof(int);	reloc->sec = ip_relocsec; 	elf_add_reloc(elf, reloc); 	return 0;} int create_orc_sections(struct objtool_file *file){	struct instruction *insn, *prev_insn;	struct section *sec, *u_sec, *ip_relocsec;	unsigned int idx; 	struct orc_entry empty = {		.sp_reg = ORC_REG_UNDEFINED,		.bp_reg  = ORC_REG_UNDEFINED,		.type    = ORC_TYPE_CALL,	}; 	sec = find_section_by_name(file->elf, ".orc_unwind");	if (sec) {		WARN("file already has .orc_unwind section, skipping");		return -1;	} 	/* count the number of needed orcs */	idx = 0;	for_each_sec(file, sec) {		if (!sec->text)			continue; 		prev_insn = NULL;		sec_for_each_insn(file, sec, insn) {			if (!prev_insn ||			    memcmp(&insn->orc, &prev_insn->orc,				   sizeof(struct orc_entry))) {				idx++;			}			prev_insn = insn;		} 		/* section terminator */		if (prev_insn)			idx++;	}	if (!idx)		return -1;  	/* create .orc_unwind_ip and .rela.orc_unwind_ip sections */	sec = elf_create_section(file->elf, ".orc_unwind_ip", sizeof(int), idx);	if (!sec)		return -1; 	ip_relocsec = elf_create_reloc_section(file->elf, sec, SHT_RELA);	if (!ip_relocsec)		return -1; 	/* create .orc_unwind section */	u_sec = elf_create_section(file->elf, ".orc_unwind",				   sizeof(struct orc_entry), idx); 	/* populate sections */	idx = 0;	for_each_sec(file, sec) {		if (!sec->text)			continue; 		prev_insn = NULL;		sec_for_each_insn(file, sec, insn) {			if (!prev_insn || memcmp(&insn->orc, &prev_insn->orc,						 sizeof(struct orc_entry))) { 				if (create_orc_entry(file->elf, u_sec, ip_relocsec, idx,						     insn->sec, insn->offset,						     &insn->orc))					return -1; 				idx++;			}			prev_insn = insn;		} 		/* section terminator */		if (prev_insn) {			if (create_orc_entry(file->elf, u_sec, ip_relocsec, idx,					     prev_insn->sec,					     prev_insn->offset + prev_insn->len,					     &empty))				return -1; 			idx++;		}	} 	if (elf_rebuild_reloc_section(file->elf, ip_relocsec))		return -1; 	return 0;}