xref: /freebsd/lib/librtld_db/rtld_db.c (revision 9a14aa017b21c292740c00ee098195cd46642730)
1 /*
2  * Copyright (c) 2010 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Rui Paulo under sponsorship from the
6  * FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <machine/_inttypes.h>
33 #include <sys/types.h>
34 #include <sys/user.h>
35 
36 #include <err.h>
37 #include <stdio.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include <limits.h>
41 #include <libproc.h>
42 #include <libutil.h>
43 
44 #include "rtld_db.h"
45 
46 static int _librtld_db_debug = 0;
47 #define DPRINTF(...) do {				\
48 	if (_librtld_db_debug) {			\
49 		fprintf(stderr, "librtld_db: DEBUG: ");	\
50 		fprintf(stderr, __VA_ARGS__);		\
51 	}						\
52 } while (0)
53 
54 void
55 rd_delete(rd_agent_t *rdap)
56 {
57 
58 	free(rdap);
59 }
60 
61 const char *
62 rd_errstr(rd_err_e rderr)
63 {
64 
65 	switch (rderr) {
66 	case RD_ERR:
67 		return "generic error";
68 	case RD_OK:
69 		return "no error";
70 	case RD_NOCAPAB:
71 		return "capability not supported";
72 	case RD_DBERR:
73 		return "database error";
74 	case RD_NOBASE:
75 		return "NOBASE";
76 	case RD_NOMAPS:
77 		return "NOMAPS";
78 	default:
79 		return "unknown error";
80 	}
81 }
82 
83 rd_err_e
84 rd_event_addr(rd_agent_t *rdap, rd_event_e event __unused, rd_notify_t *notify)
85 {
86 	DPRINTF("%s rdap %p notify %p\n", __func__, rdap, notify);
87 
88 	notify->type = RD_NOTIFY_BPT;
89 	notify->u.bptaddr = rdap->rda_addr;
90 
91 	return (RD_OK);
92 }
93 
94 rd_err_e
95 rd_event_enable(rd_agent_t *rdap __unused, int onoff)
96 {
97 	DPRINTF("%s onoff %d\n", __func__, onoff);
98 
99 	return (RD_OK);
100 }
101 
102 rd_err_e
103 rd_event_getmsg(rd_agent_t *rdap __unused, rd_event_msg_t *msg)
104 {
105 	DPRINTF("%s\n", __func__);
106 
107 	msg->type = RD_POSTINIT;
108 	msg->u.state = RD_CONSISTENT;
109 
110 	return (RD_OK);
111 }
112 
113 rd_err_e
114 rd_init(int version)
115 {
116 	char *debug = NULL;
117 
118 	if (version == RD_VERSION) {
119 		debug = getenv("LIBRTLD_DB_DEBUG");
120 		_librtld_db_debug = debug ? atoi(debug) : 0;
121 		return (RD_OK);
122 	} else
123 		return (RD_NOCAPAB);
124 }
125 
126 rd_err_e
127 rd_loadobj_iter(rd_agent_t *rdap, rl_iter_f *cb, void *clnt_data)
128 {
129 	int cnt, i, lastvn = 0;
130 	rd_loadobj_t rdl;
131 	struct kinfo_vmentry *kves, *kve;
132 
133 	DPRINTF("%s\n", __func__);
134 
135         if ((kves = kinfo_getvmmap(proc_getpid(rdap->rda_php), &cnt)) == NULL) {
136 		warn("ERROR: kinfo_getvmmap() failed");
137 		return (RD_ERR);
138 	}
139 	for (i = 0; i < cnt; i++) {
140 		kve = kves + i;
141 		if (kve->kve_type == KVME_TYPE_VNODE)
142 			lastvn = i;
143 		memset(&rdl, 0, sizeof(rdl));
144 		/*
145 		 * Map the kinfo_vmentry struct to the rd_loadobj structure.
146 		 */
147 		rdl.rdl_saddr = kve->kve_start;
148 		rdl.rdl_eaddr = kve->kve_end;
149 		rdl.rdl_offset = kve->kve_offset;
150 		if (kve->kve_protection & KVME_PROT_READ)
151 			rdl.rdl_prot |= RD_RDL_R;
152 		if (kve->kve_protection & KVME_PROT_WRITE)
153 			rdl.rdl_prot |= RD_RDL_W;
154 		if (kve->kve_protection & KVME_PROT_EXEC)
155 			rdl.rdl_prot |= RD_RDL_X;
156 		strlcpy(rdl.rdl_path, kves[lastvn].kve_path,
157 			sizeof(rdl.rdl_path));
158 		(*cb)(&rdl, clnt_data);
159 	}
160 	free(kves);
161 
162 	return (RD_OK);
163 }
164 
165 void
166 rd_log(const int onoff)
167 {
168 	DPRINTF("%s\n", __func__);
169 
170 	(void)onoff;
171 }
172 
173 rd_agent_t *
174 rd_new(struct proc_handle *php)
175 {
176 	rd_agent_t *rdap;
177 
178 	rdap = malloc(sizeof(rd_agent_t));
179 	if (rdap) {
180 		memset(rdap, 0, sizeof(rd_agent_t));
181 		rdap->rda_php = php;
182 		rd_reset(rdap);
183 	}
184 
185 	return (rdap);
186 }
187 
188 rd_err_e
189 rd_objpad_enable(rd_agent_t *rdap, size_t padsize)
190 {
191 	DPRINTF("%s\n", __func__);
192 
193 	(void)rdap;
194 	(void)padsize;
195 
196 	return (RD_ERR);
197 }
198 
199 rd_err_e
200 rd_plt_resolution(rd_agent_t *rdap, uintptr_t pc, struct proc *proc,
201     uintptr_t plt_base, rd_plt_info_t *rpi)
202 {
203 	DPRINTF("%s\n", __func__);
204 
205 	(void)rdap;
206 	(void)pc;
207 	(void)proc;
208 	(void)plt_base;
209 	(void)rpi;
210 
211 	return (RD_ERR);
212 }
213 
214 rd_err_e
215 rd_reset(rd_agent_t *rdap)
216 {
217 	GElf_Sym sym;
218 
219 	if (proc_name2sym(rdap->rda_php, "ld-elf.so.1", "r_debug_state",
220 	    &sym) < 0)
221 		return (RD_ERR);
222 	DPRINTF("found r_debug_state at 0x%lx\n", (unsigned long)sym.st_value);
223 	rdap->rda_addr = sym.st_value;
224 
225 	return (RD_OK);
226 }
227