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 #ifdef __FBSDID
31 __FBSDID("$FreeBSD: head/lib/librtld_db/rtld_db.c 272488 2014-10-03 23:20:37Z markj $");
32 #else
33 __RCSID("$NetBSD: rtld_db.c,v 1.3 2016/04/26 14:26:49 chs Exp $");
34 #endif
35
36 #include <sys/types.h>
37 #include <sys/sysctl.h>
38
39 #include <inttypes.h>
40 #include <err.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <limits.h>
45 #include <libproc.h>
46 #include <util.h>
47
48 #include "rtld_db.h"
49
50 static int _librtld_db_debug = 0;
51 #define DPRINTF(...) do { \
52 if (_librtld_db_debug) { \
53 fprintf(stderr, "librtld_db: DEBUG: "); \
54 fprintf(stderr, __VA_ARGS__); \
55 } \
56 } while (0)
57
58 void
rd_delete(rd_agent_t * rdap)59 rd_delete(rd_agent_t *rdap)
60 {
61
62 free(rdap);
63 }
64
65 const char *
rd_errstr(rd_err_e rderr)66 rd_errstr(rd_err_e rderr)
67 {
68
69 switch (rderr) {
70 case RD_ERR:
71 return "generic error";
72 case RD_OK:
73 return "no error";
74 case RD_NOCAPAB:
75 return "capability not supported";
76 case RD_DBERR:
77 return "database error";
78 case RD_NOBASE:
79 return "NOBASE";
80 case RD_NOMAPS:
81 return "NOMAPS";
82 default:
83 return "unknown error";
84 }
85 }
86
87 rd_err_e
rd_event_addr(rd_agent_t * rdap,rd_event_e event,rd_notify_t * notify)88 rd_event_addr(rd_agent_t *rdap, rd_event_e event, rd_notify_t *notify)
89 {
90 rd_err_e ret;
91
92 DPRINTF("%s rdap %p event %d notify %p\n", __func__, rdap, event,
93 notify);
94
95 ret = RD_OK;
96 switch (event) {
97 case RD_NONE:
98 break;
99 case RD_PREINIT:
100 notify->type = RD_NOTIFY_BPT;
101 notify->u.bptaddr = rdap->rda_preinit_addr;
102 break;
103 case RD_POSTINIT:
104 notify->type = RD_NOTIFY_BPT;
105 notify->u.bptaddr = rdap->rda_postinit_addr;
106 break;
107 case RD_DLACTIVITY:
108 notify->type = RD_NOTIFY_BPT;
109 notify->u.bptaddr = rdap->rda_dlactivity_addr;
110 break;
111 default:
112 ret = RD_ERR;
113 break;
114 }
115 return (ret);
116 }
117
118 rd_err_e
rd_event_enable(rd_agent_t * rdap __unused,int onoff)119 rd_event_enable(rd_agent_t *rdap __unused, int onoff)
120 {
121 DPRINTF("%s onoff %d\n", __func__, onoff);
122
123 return (RD_OK);
124 }
125
126 rd_err_e
rd_event_getmsg(rd_agent_t * rdap __unused,rd_event_msg_t * msg)127 rd_event_getmsg(rd_agent_t *rdap __unused, rd_event_msg_t *msg)
128 {
129 DPRINTF("%s\n", __func__);
130
131 msg->type = RD_POSTINIT;
132 msg->u.state = RD_CONSISTENT;
133
134 return (RD_OK);
135 }
136
137 rd_err_e
rd_init(int version)138 rd_init(int version)
139 {
140 char *debug = NULL;
141
142 if (version == RD_VERSION) {
143 debug = getenv("LIBRTLD_DB_DEBUG");
144 _librtld_db_debug = debug ? atoi(debug) : 0;
145 return (RD_OK);
146 } else
147 return (RD_NOCAPAB);
148 }
149
150 rd_err_e
rd_loadobj_iter(rd_agent_t * rdap,rl_iter_f * cb,void * clnt_data)151 rd_loadobj_iter(rd_agent_t *rdap, rl_iter_f *cb, void *clnt_data)
152 {
153 size_t cnt, i, lastvn = 0;
154 rd_loadobj_t rdl;
155 struct kinfo_vmentry *kves, *kve;
156
157 DPRINTF("%s\n", __func__);
158
159 if ((kves = kinfo_getvmmap(proc_getpid(rdap->rda_php), &cnt)) == NULL) {
160 warn("ERROR: kinfo_getvmmap() failed");
161 return (RD_ERR);
162 }
163 for (i = 0; i < cnt; i++) {
164 kve = kves + i;
165 if (kve->kve_type == KVME_TYPE_VNODE)
166 lastvn = i;
167 memset(&rdl, 0, sizeof(rdl));
168 /*
169 * Map the kinfo_vmentry struct to the rd_loadobj structure.
170 */
171 rdl.rdl_saddr = kve->kve_start;
172 rdl.rdl_eaddr = kve->kve_end;
173 rdl.rdl_offset = kve->kve_offset;
174 if (kve->kve_protection & KVME_PROT_READ)
175 rdl.rdl_prot |= RD_RDL_R;
176 if (kve->kve_protection & KVME_PROT_WRITE)
177 rdl.rdl_prot |= RD_RDL_W;
178 if (kve->kve_protection & KVME_PROT_EXEC)
179 rdl.rdl_prot |= RD_RDL_X;
180 strlcpy(rdl.rdl_path, kves[lastvn].kve_path,
181 sizeof(rdl.rdl_path));
182 (*cb)(&rdl, clnt_data);
183 }
184 free(kves);
185
186 return (RD_OK);
187 }
188
189 void
rd_log(const int onoff)190 rd_log(const int onoff)
191 {
192 DPRINTF("%s\n", __func__);
193
194 (void)onoff;
195 }
196
197 rd_agent_t *
rd_new(struct proc_handle * php)198 rd_new(struct proc_handle *php)
199 {
200 rd_agent_t *rdap;
201
202 rdap = malloc(sizeof(rd_agent_t));
203 if (rdap) {
204 memset(rdap, 0, sizeof(rd_agent_t));
205 rdap->rda_php = php;
206 rd_reset(rdap);
207 }
208
209 return (rdap);
210 }
211
212 rd_err_e
rd_objpad_enable(rd_agent_t * rdap,size_t padsize)213 rd_objpad_enable(rd_agent_t *rdap, size_t padsize)
214 {
215 DPRINTF("%s\n", __func__);
216
217 (void)rdap;
218 (void)padsize;
219
220 return (RD_ERR);
221 }
222
223 rd_err_e
rd_plt_resolution(rd_agent_t * rdap,uintptr_t pc,struct proc * proc,uintptr_t plt_base,rd_plt_info_t * rpi)224 rd_plt_resolution(rd_agent_t *rdap, uintptr_t pc, struct proc *proc,
225 uintptr_t plt_base, rd_plt_info_t *rpi)
226 {
227 DPRINTF("%s\n", __func__);
228
229 (void)rdap;
230 (void)pc;
231 (void)proc;
232 (void)plt_base;
233 (void)rpi;
234
235 return (RD_ERR);
236 }
237
238 rd_err_e
rd_reset(rd_agent_t * rdap)239 rd_reset(rd_agent_t *rdap)
240 {
241 GElf_Sym sym;
242
243 /*
244 * preinit and dlactivity events are not supported yet.
245 */
246
247 rdap->rda_preinit_addr = (uintptr_t)-1;
248 rdap->rda_dlactivity_addr = (uintptr_t)-1;
249
250 if (proc_name2sym(rdap->rda_php, "ld.elf_so", "_rtld_debug_state",
251 &sym, NULL) < 0)
252 return (RD_ERR);
253 DPRINTF("found _rtld_debug_state at 0x%lx\n",
254 (unsigned long)sym.st_value);
255 rdap->rda_postinit_addr = sym.st_value;
256
257 return (RD_OK);
258 }
259