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  
19  bool help;
20  
21  const char *objname;
22  static struct objtool_file file;
23  
objtool_create_backup(const char * _objname)24  static 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  
objtool_open_read(const char * _objname)82  struct 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  
objtool_pv_add(struct objtool_file * f,int idx,struct symbol * func)115  void 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  
main(int argc,const char ** argv)141  int 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  }
151