1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 */
25 /*
26 * Copyright (c) 2013 by Delphix. All rights reserved.
27 * Copyright 2023 Oxide Computer Company
28 */
29
30 #include <stdarg.h>
31 #include <string.h>
32 #include <errno.h>
33 #include "Pcontrol.h"
34
35 /*
36 * This file implements the process services declared in <proc_service.h>.
37 * This enables libproc to be used in conjunction with libc_db and
38 * librtld_db. As most of these facilities are already provided by
39 * (more elegant) interfaces in <libproc.h>, we can just call those.
40 *
41 * NOTE: We explicitly do *not* implement the functions ps_kill() and
42 * ps_lrolltoaddr() in this library. The very existence of these functions
43 * causes libc_db to create an "agent thread" in the target process.
44 * The only way to turn off this behavior is to omit these functions.
45 */
46
47 #pragma weak ps_pdread = ps_pread
48 #pragma weak ps_ptread = ps_pread
49 #pragma weak ps_pdwrite = ps_pwrite
50 #pragma weak ps_ptwrite = ps_pwrite
51
52 ps_err_e
53 ps_pdmodel(struct ps_prochandle *P, int *modelp)
54 {
55 *modelp = P->status.pr_dmodel;
56 return (PS_OK);
57 }
58
59 ps_err_e
60 ps_pread(struct ps_prochandle *P, psaddr_t addr, void *buf, size_t size)
61 {
62 if (P->ops.pop_pread(P, buf, size, addr, P->data) != size)
63 return (PS_BADADDR);
64 return (PS_OK);
65 }
66
67 ps_err_e
68 ps_pwrite(struct ps_prochandle *P, psaddr_t addr, const void *buf, size_t size)
69 {
70 if (P->ops.pop_pwrite(P, buf, size, addr, P->data) != size)
71 return (PS_BADADDR);
72 return (PS_OK);
73 }
74
75 /*
76 * libc_db calls matched pairs of ps_pstop()/ps_pcontinue()
77 * in the belief that the client may have left the process
78 * running while calling in to the libc_db interfaces.
79 *
80 * We interpret the meaning of these functions to be an inquiry
81 * as to whether the process is stopped, not an action to be
82 * performed to make it stopped. For similar reasons, we also
83 * return PS_OK for core files in order to allow libc_db to
84 * operate on these as well.
85 */
86 ps_err_e
87 ps_pstop(struct ps_prochandle *P)
88 {
89 if (P->state != PS_STOP && P->state != PS_DEAD)
90 return (PS_ERR);
91 return (PS_OK);
92 }
93
94 ps_err_e
95 ps_pcontinue(struct ps_prochandle *P)
96 {
97 if (P->state != PS_STOP && P->state != PS_DEAD)
98 return (PS_ERR);
99 return (PS_OK);
100 }
101
102 /*
103 * ps_lstop() and ps_lcontinue() are not called by any code in libc_db
104 * or librtld_db. We make them behave like ps_pstop() and ps_pcontinue().
105 */
106 /* ARGSUSED1 */
107 ps_err_e
108 ps_lstop(struct ps_prochandle *P, lwpid_t lwpid)
109 {
110 if (P->state != PS_STOP && P->state != PS_DEAD)
111 return (PS_ERR);
112 return (PS_OK);
113 }
114
115 /* ARGSUSED1 */
116 ps_err_e
117 ps_lcontinue(struct ps_prochandle *P, lwpid_t lwpid)
118 {
119 if (P->state != PS_STOP && P->state != PS_DEAD)
120 return (PS_ERR);
121 return (PS_OK);
122 }
123
124 ps_err_e
125 ps_lgetregs(struct ps_prochandle *P, lwpid_t lwpid, prgregset_t regs)
126 {
127 if (P->state != PS_STOP && P->state != PS_DEAD)
128 return (PS_ERR);
129
130 if (Plwp_getregs(P, lwpid, regs) == 0)
131 return (PS_OK);
132
133 return (PS_BADLID);
134 }
135
136 ps_err_e
137 ps_lsetregs(struct ps_prochandle *P, lwpid_t lwpid, const prgregset_t regs)
138 {
139 if (P->state != PS_STOP)
140 return (PS_ERR);
141
142 if (Plwp_setregs(P, lwpid, regs) == 0)
143 return (PS_OK);
144
145 return (PS_BADLID);
146 }
147
148 ps_err_e
149 ps_lgetfpregs(struct ps_prochandle *P, lwpid_t lwpid, prfpregset_t *regs)
150 {
151 if (P->state != PS_STOP && P->state != PS_DEAD)
152 return (PS_ERR);
153
154 if (Plwp_getfpregs(P, lwpid, regs) == 0)
155 return (PS_OK);
156
157 return (PS_BADLID);
158 }
159
160 ps_err_e
161 ps_lsetfpregs(struct ps_prochandle *P, lwpid_t lwpid, const prfpregset_t *regs)
162 {
163 if (P->state != PS_STOP)
164 return (PS_ERR);
165
166 if (Plwp_setfpregs(P, lwpid, regs) == 0)
167 return (PS_OK);
168
169 return (PS_BADLID);
170 }
171
172 ps_err_e
173 ps_lgetxregsize(struct ps_prochandle *P, lwpid_t lwpid, int *xrsize)
174 {
175 char fname[PATH_MAX];
176 struct stat statb;
177
178 if (P->state == PS_DEAD) {
179 core_info_t *core = P->data;
180 lwp_info_t *lwp;
181
182 for (lwp = list_head(&core->core_lwp_head); lwp != NULL;
183 lwp = list_next(&core->core_lwp_head, lwp)) {
184 if (lwp->lwp_id == lwpid) {
185 if (lwp->lwp_xregs != NULL &&
186 lwp->lwp_xregsize > 0) {
187 if (lwp->lwp_xregsize >= INT_MAX) {
188 return (PS_ERR);
189 }
190
191 *xrsize = (int)lwp->lwp_xregsize;
192 } else {
193 *xrsize = 0;
194 }
195 return (PS_OK);
196 }
197 }
198
199 return (PS_BADLID);
200 }
201
202 (void) snprintf(fname, sizeof (fname), "%s/%d/lwp/%d/xregs",
203 procfs_path, (int)P->status.pr_pid, (int)lwpid);
204
205 if (stat(fname, &statb) != 0)
206 return (PS_BADLID);
207
208 if (statb.st_size > INT_MAX)
209 return (PS_ERR);
210
211 *xrsize = (int)statb.st_size;
212 return (PS_OK);
213 }
214
215 ps_err_e
216 ps_lgetxregs(struct ps_prochandle *P, lwpid_t lwpid, caddr_t xregs)
217 {
218 size_t xregsize;
219 prxregset_t *prx;
220
221 if (P->state != PS_STOP && P->state != PS_DEAD)
222 return (PS_ERR);
223
224 if (Plwp_getxregs(P, lwpid, &prx, &xregsize) == 0) {
225 (void) memcpy(xregs, prx, xregsize);
226 Plwp_freexregs(P, prx, xregsize);
227 return (PS_OK);
228 }
229
230 if (errno == ENODATA)
231 return (PS_NOXREGS);
232
233 return (PS_BADLID);
234 }
235
236 ps_err_e
237 ps_lsetxregs(struct ps_prochandle *P, lwpid_t lwpid, caddr_t xregs)
238 {
239 size_t xregsize = 0;
240
241 if (P->state != PS_STOP)
242 return (PS_ERR);
243
244 /*
245 * libproc asks the caller for the size of the extended register set.
246 * Unfortunately, right now we aren't given the actual size of this
247 * ourselves and we don't want to break the ABI that folks have used
248 * historically. Therefore, we reach in and ask the structure in a
249 * platform-specific way about what this should be. Sorry, this is a bit
250 * unfortunate. This really shouldn't be a platform-specific #ifdef.
251 */
252 #if defined(__i386) || defined(__amd64)
253 prxregset_hdr_t *hdr = (prxregset_hdr_t *)xregs;
254 xregsize = hdr->pr_size;
255 #endif
256 if (xregsize == 0)
257 return (PS_ERR);
258
259 if (Plwp_setxregs(P, lwpid, (prxregset_t *)xregs, xregsize) == 0)
260 return (PS_OK);
261
262 return (PS_BADLID);
263 }
264
265 #if defined(sparc) || defined(__sparc)
266 ps_err_e
267 ps_lsetxregs(struct ps_prochandle *P, lwpid_t lwpid, caddr_t xregs)
268 {
269 if (P->state != PS_STOP)
270 return (PS_ERR);
271
272 /* LINTED - alignment */
273 if (Plwp_setxregs(P, lwpid, (prxregset_t *)xregs) == 0)
274 return (PS_OK);
275
276 return (PS_BADLID);
277 }
278
279 #endif /* sparc */
280
281 #if defined(__i386) || defined(__amd64)
282
283 ps_err_e
284 ps_lgetLDT(struct ps_prochandle *P, lwpid_t lwpid, struct ssd *ldt)
285 {
286 #if defined(__amd64) && defined(_LP64)
287 if (P->status.pr_dmodel != PR_MODEL_NATIVE) {
288 #endif
289 prgregset_t regs;
290 struct ssd *ldtarray;
291 ps_err_e error;
292 uint_t gs;
293 int nldt;
294 int i;
295
296 if (P->state != PS_STOP && P->state != PS_DEAD)
297 return (PS_ERR);
298
299 /*
300 * We need to get the ldt entry that matches the
301 * value in the lwp's GS register.
302 */
303 if ((error = ps_lgetregs(P, lwpid, regs)) != PS_OK)
304 return (error);
305
306 gs = regs[GS];
307
308 if ((nldt = Pldt(P, NULL, 0)) <= 0 ||
309 (ldtarray = malloc(nldt * sizeof (struct ssd))) == NULL)
310 return (PS_ERR);
311 if ((nldt = Pldt(P, ldtarray, nldt)) <= 0) {
312 free(ldtarray);
313 return (PS_ERR);
314 }
315
316 for (i = 0; i < nldt; i++) {
317 if (gs == ldtarray[i].sel) {
318 *ldt = ldtarray[i];
319 break;
320 }
321 }
322 free(ldtarray);
323
324 if (i < nldt)
325 return (PS_OK);
326 #if defined(__amd64) && defined(_LP64)
327 }
328 #endif
329
330 return (PS_ERR);
331 }
332
333 #endif /* __i386 || __amd64 */
334
335 /*
336 * Libthread_db doesn't use this function currently, but librtld_db uses
337 * it for its debugging output. We turn this on via rd_log if our debugging
338 * switch is on, and then echo the messages sent to ps_plog to stderr.
339 */
340 void
341 ps_plog(const char *fmt, ...)
342 {
343 va_list ap;
344
345 if (_libproc_debug && fmt != NULL && *fmt != '\0') {
346 va_start(ap, fmt);
347 (void) vfprintf(stderr, fmt, ap);
348 va_end(ap);
349 if (fmt[strlen(fmt) - 1] != '\n')
350 (void) fputc('\n', stderr);
351 }
352 }
353
354 /*
355 * Store a pointer to our internal copy of the aux vector at the address
356 * specified by the caller. It should not hold on to this data for too long.
357 */
358 ps_err_e
359 ps_pauxv(struct ps_prochandle *P, const auxv_t **aux)
360 {
361 if (P->auxv == NULL)
362 Preadauxvec(P);
363
364 if (P->auxv == NULL)
365 return (PS_ERR);
366
367 *aux = (const auxv_t *)P->auxv;
368 return (PS_OK);
369 }
370
371 ps_err_e
372 ps_pbrandname(struct ps_prochandle *P, char *buf, size_t len)
373 {
374 return (Pbrandname(P, buf, len) ? PS_OK : PS_ERR);
375 }
376
377 /*
378 * Search for a symbol by name and return the corresponding address.
379 */
380 ps_err_e
381 ps_pglobal_lookup(struct ps_prochandle *P, const char *object_name,
382 const char *sym_name, psaddr_t *sym_addr)
383 {
384 GElf_Sym sym;
385
386 if (Plookup_by_name(P, object_name, sym_name, &sym) == 0) {
387 dprintf("pglobal_lookup <%s> -> %p\n",
388 sym_name, (void *)(uintptr_t)sym.st_value);
389 *sym_addr = (psaddr_t)sym.st_value;
390 return (PS_OK);
391 }
392
393 return (PS_NOSYM);
394 }
395
396 /*
397 * Search for a symbol by name and return the corresponding symbol
398 * information. If we're compiled _LP64, we just call Plookup_by_name
399 * and return because ps_sym_t is defined to be an Elf64_Sym, which
400 * is the same as a GElf_Sym. In the _ILP32 case, we have to convert
401 * Plookup_by_name's result back to a ps_sym_t (which is an Elf32_Sym).
402 */
403 ps_err_e
404 ps_pglobal_sym(struct ps_prochandle *P, const char *object_name,
405 const char *sym_name, ps_sym_t *symp)
406 {
407 #if defined(_ILP32)
408 GElf_Sym sym;
409
410 if (Plookup_by_name(P, object_name, sym_name, &sym) == 0) {
411 symp->st_name = (Elf32_Word)sym.st_name;
412 symp->st_value = (Elf32_Addr)sym.st_value;
413 symp->st_size = (Elf32_Word)sym.st_size;
414 symp->st_info = ELF32_ST_INFO(
415 GELF_ST_BIND(sym.st_info), GELF_ST_TYPE(sym.st_info));
416 symp->st_other = sym.st_other;
417 symp->st_shndx = sym.st_shndx;
418 return (PS_OK);
419 }
420
421 #elif defined(_LP64)
422 if (Plookup_by_name(P, object_name, sym_name, symp) == 0)
423 return (PS_OK);
424 #endif
425 return (PS_NOSYM);
426 }