1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright (C) 2015 Josh Poimboeuf <jpoimboe@redhat.com>
  4 */
  5
  6#include <stdio.h>
  7#include <stdbool.h>
  8#include <string.h>
  9#include <stdlib.h>
 10#include <unistd.h>
 11#include <subcmd/exec-cmd.h>
 12#include <subcmd/pager.h>
 13#include <linux/kernel.h>
 14
 15#include <objtool/builtin.h>
 16#include <objtool/objtool.h>
 17#include <objtool/warn.h>
 18
 19bool help;
 20
 21const char *objname;
 22static struct objtool_file file;
 23
 24static bool objtool_create_backup(const char *_objname)
 25{
 26	int len = strlen(_objname);
 27	char *buf, *base, *name = malloc(len+6);
 28	int s, d, l, t;
 29
 30	if (!name) {
 31		perror("failed backup name malloc");
 32		return false;
 33	}
 34
 35	strcpy(name, _objname);
 36	strcpy(name + len, ".orig");
 37
 38	d = open(name, O_CREAT|O_WRONLY|O_TRUNC, 0644);
 39	if (d < 0) {
 40		perror("failed to create backup file");
 41		return false;
 42	}
 43
 44	s = open(_objname, O_RDONLY);
 45	if (s < 0) {
 46		perror("failed to open orig file");
 47		return false;
 48	}
 49
 50	buf = malloc(4096);
 51	if (!buf) {
 52		perror("failed backup data malloc");
 53		return false;
 54	}
 55
 56	while ((l = read(s, buf, 4096)) > 0) {
 57		base = buf;
 58		do {
 59			t = write(d, base, l);
 60			if (t < 0) {
 61				perror("failed backup write");
 62				return false;
 63			}
 64			base += t;
 65			l -= t;
 66		} while (l);
 67	}
 68
 69	if (l < 0) {
 70		perror("failed backup read");
 71		return false;
 72	}
 73
 74	free(name);
 75	free(buf);
 76	close(d);
 77	close(s);
 78
 79	return true;
 80}
 81
 82struct objtool_file *objtool_open_read(const char *_objname)
 83{
 84	if (objname) {
 85		if (strcmp(objname, _objname)) {
 86			WARN("won't handle more than one file at a time");
 87			return NULL;
 88		}
 89		return &file;
 90	}
 91	objname = _objname;
 92
 93	file.elf = elf_open_read(objname, O_RDWR);
 94	if (!file.elf)
 95		return NULL;
 96
 97	if (opts.backup && !objtool_create_backup(objname)) {
 98		WARN("can't create backup file");
 99		return NULL;
100	}
101
102	hash_init(file.insn_hash);
103	INIT_LIST_HEAD(&file.retpoline_call_list);
104	INIT_LIST_HEAD(&file.return_thunk_list);
105	INIT_LIST_HEAD(&file.static_call_list);
106	INIT_LIST_HEAD(&file.mcount_loc_list);
107	INIT_LIST_HEAD(&file.endbr_list);
108	INIT_LIST_HEAD(&file.call_list);
109	file.ignore_unreachables = opts.no_unreachable;
110	file.hints = false;
111
112	return &file;
113}
114
115void objtool_pv_add(struct objtool_file *f, int idx, struct symbol *func)
116{
117	if (!opts.noinstr)
118		return;
119
120	if (!f->pv_ops) {
121		WARN("paravirt confusion");
122		return;
123	}
124
125	/*
126	 * These functions will be patched into native code,
127	 * see paravirt_patch().
128	 */
129	if (!strcmp(func->name, "_paravirt_nop") ||
130	    !strcmp(func->name, "_paravirt_ident_64"))
131		return;
132
133	/* already added this function */
134	if (!list_empty(&func->pv_target))
135		return;
136
137	list_add(&func->pv_target, &f->pv_ops[idx].targets);
138	f->pv_ops[idx].clean = false;
139}
140
141int main(int argc, const char **argv)
142{
143	static const char *UNUSED = "OBJTOOL_NOT_IMPLEMENTED";
144
145	/* libsubcmd init */
146	exec_cmd_init("objtool", UNUSED, UNUSED, UNUSED);
147	pager_init(UNUSED);
148
149	return objtool_run(argc, argv);
150}