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8cd64e00 | 1 | /* Handle TIC6X (DSBT) shared libraries for GDB, the GNU Debugger. |
4a94e368 | 2 | Copyright (C) 2010-2022 Free Software Foundation, Inc. |
8cd64e00 YQ |
3 | |
4 | This file is part of GDB. | |
5 | ||
6 | This program is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 3 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | This program is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ | |
18 | ||
19 | ||
20 | #include "defs.h" | |
8cd64e00 YQ |
21 | #include "inferior.h" |
22 | #include "gdbcore.h" | |
23 | #include "solib.h" | |
24 | #include "solist.h" | |
25 | #include "objfiles.h" | |
26 | #include "symtab.h" | |
27 | #include "language.h" | |
28 | #include "command.h" | |
29 | #include "gdbcmd.h" | |
30 | #include "elf-bfd.h" | |
cbb099e8 | 31 | #include "gdb_bfd.h" |
8cd64e00 YQ |
32 | |
33 | #define GOT_MODULE_OFFSET 4 | |
34 | ||
35 | /* Flag which indicates whether internal debug messages should be printed. */ | |
ccce17b0 | 36 | static unsigned int solib_dsbt_debug = 0; |
8cd64e00 YQ |
37 | |
38 | /* TIC6X pointers are four bytes wide. */ | |
39 | enum { TIC6X_PTR_SIZE = 4 }; | |
40 | ||
41 | /* Representation of loadmap and related structs for the TIC6X DSBT. */ | |
42 | ||
43 | /* External versions; the size and alignment of the fields should be | |
44 | the same as those on the target. When loaded, the placement of | |
45 | the bits in each field will be the same as on the target. */ | |
46 | typedef gdb_byte ext_Elf32_Half[2]; | |
47 | typedef gdb_byte ext_Elf32_Addr[4]; | |
48 | typedef gdb_byte ext_Elf32_Word[4]; | |
49 | ||
50 | struct ext_elf32_dsbt_loadseg | |
51 | { | |
52 | /* Core address to which the segment is mapped. */ | |
53 | ext_Elf32_Addr addr; | |
54 | /* VMA recorded in the program header. */ | |
55 | ext_Elf32_Addr p_vaddr; | |
56 | /* Size of this segment in memory. */ | |
57 | ext_Elf32_Word p_memsz; | |
58 | }; | |
59 | ||
60 | struct ext_elf32_dsbt_loadmap { | |
61 | /* Protocol version number, must be zero. */ | |
62 | ext_Elf32_Word version; | |
63 | /* A pointer to the DSBT table; the DSBT size and the index of this | |
64 | module. */ | |
65 | ext_Elf32_Word dsbt_table_ptr; | |
66 | ext_Elf32_Word dsbt_size; | |
67 | ext_Elf32_Word dsbt_index; | |
68 | /* Number of segments in this map. */ | |
69 | ext_Elf32_Word nsegs; | |
70 | /* The actual memory map. */ | |
71 | struct ext_elf32_dsbt_loadseg segs[1 /* nsegs, actually */]; | |
72 | }; | |
73 | ||
74 | /* Internal versions; the types are GDB types and the data in each | |
75 | of the fields is (or will be) decoded from the external struct | |
76 | for ease of consumption. */ | |
77 | struct int_elf32_dsbt_loadseg | |
78 | { | |
79 | /* Core address to which the segment is mapped. */ | |
80 | CORE_ADDR addr; | |
81 | /* VMA recorded in the program header. */ | |
82 | CORE_ADDR p_vaddr; | |
83 | /* Size of this segment in memory. */ | |
84 | long p_memsz; | |
85 | }; | |
86 | ||
87 | struct int_elf32_dsbt_loadmap | |
88 | { | |
89 | /* Protocol version number, must be zero. */ | |
90 | int version; | |
91 | CORE_ADDR dsbt_table_ptr; | |
92 | /* A pointer to the DSBT table; the DSBT size and the index of this | |
93 | module. */ | |
94 | int dsbt_size, dsbt_index; | |
95 | /* Number of segments in this map. */ | |
96 | int nsegs; | |
97 | /* The actual memory map. */ | |
98 | struct int_elf32_dsbt_loadseg segs[1 /* nsegs, actually */]; | |
99 | }; | |
100 | ||
101 | /* External link_map and elf32_dsbt_loadaddr struct definitions. */ | |
102 | ||
103 | typedef gdb_byte ext_ptr[4]; | |
104 | ||
105 | struct ext_elf32_dsbt_loadaddr | |
106 | { | |
107 | ext_ptr map; /* struct elf32_dsbt_loadmap *map; */ | |
108 | }; | |
109 | ||
110 | struct ext_link_map | |
111 | { | |
112 | struct ext_elf32_dsbt_loadaddr l_addr; | |
113 | ||
114 | /* Absolute file name object was found in. */ | |
115 | ext_ptr l_name; /* char *l_name; */ | |
116 | ||
117 | /* Dynamic section of the shared object. */ | |
118 | ext_ptr l_ld; /* ElfW(Dyn) *l_ld; */ | |
119 | ||
120 | /* Chain of loaded objects. */ | |
121 | ext_ptr l_next, l_prev; /* struct link_map *l_next, *l_prev; */ | |
122 | }; | |
123 | ||
124 | /* Link map info to include in an allocated so_list entry */ | |
125 | ||
d0e449a1 | 126 | struct lm_info_dsbt : public lm_info_base |
8cd64e00 | 127 | { |
b0911207 SM |
128 | ~lm_info_dsbt () |
129 | { | |
130 | xfree (this->map); | |
131 | } | |
132 | ||
8cd64e00 | 133 | /* The loadmap, digested into an easier to use form. */ |
b0911207 | 134 | int_elf32_dsbt_loadmap *map = NULL; |
8cd64e00 YQ |
135 | }; |
136 | ||
137 | /* Per pspace dsbt specific data. */ | |
138 | ||
139 | struct dsbt_info | |
140 | { | |
141 | /* The load map, got value, etc. are not available from the chain | |
142 | of loaded shared objects. ``main_executable_lm_info'' provides | |
143 | a way to get at this information so that it doesn't need to be | |
144 | frequently recomputed. Initialized by dsbt_relocate_main_executable. */ | |
c294730c | 145 | struct lm_info_dsbt *main_executable_lm_info = nullptr; |
8cd64e00 YQ |
146 | |
147 | /* Load maps for the main executable and the interpreter. These are obtained | |
148 | from ptrace. They are the starting point for getting into the program, | |
149 | and are required to find the solib list with the individual load maps for | |
150 | each module. */ | |
c294730c TT |
151 | struct int_elf32_dsbt_loadmap *exec_loadmap = nullptr; |
152 | struct int_elf32_dsbt_loadmap *interp_loadmap = nullptr; | |
8cd64e00 YQ |
153 | |
154 | /* Cached value for lm_base, below. */ | |
c294730c | 155 | CORE_ADDR lm_base_cache = 0; |
8cd64e00 YQ |
156 | |
157 | /* Link map address for main module. */ | |
c294730c | 158 | CORE_ADDR main_lm_addr = 0; |
8cd64e00 | 159 | |
c294730c TT |
160 | CORE_ADDR interp_text_sect_low = 0; |
161 | CORE_ADDR interp_text_sect_high = 0; | |
162 | CORE_ADDR interp_plt_sect_low = 0; | |
163 | CORE_ADDR interp_plt_sect_high = 0; | |
8cd64e00 YQ |
164 | }; |
165 | ||
166 | /* Per-program-space data key. */ | |
c294730c | 167 | static program_space_key<dsbt_info> solib_dsbt_pspace_data; |
8cd64e00 YQ |
168 | |
169 | /* Get the current dsbt data. If none is found yet, add it now. This | |
170 | function always returns a valid object. */ | |
171 | ||
172 | static struct dsbt_info * | |
173 | get_dsbt_info (void) | |
174 | { | |
175 | struct dsbt_info *info; | |
176 | ||
c294730c | 177 | info = solib_dsbt_pspace_data.get (current_program_space); |
8cd64e00 YQ |
178 | if (info != NULL) |
179 | return info; | |
180 | ||
c294730c | 181 | return solib_dsbt_pspace_data.emplace (current_program_space); |
8cd64e00 YQ |
182 | } |
183 | ||
184 | ||
185 | static void | |
186 | dsbt_print_loadmap (struct int_elf32_dsbt_loadmap *map) | |
187 | { | |
188 | int i; | |
189 | ||
190 | if (map == NULL) | |
6cb06a8c | 191 | gdb_printf ("(null)\n"); |
8cd64e00 | 192 | else if (map->version != 0) |
6cb06a8c | 193 | gdb_printf (_("Unsupported map version: %d\n"), map->version); |
8cd64e00 YQ |
194 | else |
195 | { | |
6cb06a8c | 196 | gdb_printf ("version %d\n", map->version); |
8cd64e00 YQ |
197 | |
198 | for (i = 0; i < map->nsegs; i++) | |
6cb06a8c TT |
199 | gdb_printf ("%s:%s -> %s:%s\n", |
200 | print_core_address (target_gdbarch (), | |
201 | map->segs[i].p_vaddr), | |
202 | print_core_address (target_gdbarch (), | |
203 | map->segs[i].p_vaddr | |
204 | + map->segs[i].p_memsz), | |
205 | print_core_address (target_gdbarch (), map->segs[i].addr), | |
206 | print_core_address (target_gdbarch (), map->segs[i].addr | |
207 | + map->segs[i].p_memsz)); | |
8cd64e00 YQ |
208 | } |
209 | } | |
210 | ||
211 | /* Decode int_elf32_dsbt_loadmap from BUF. */ | |
212 | ||
213 | static struct int_elf32_dsbt_loadmap * | |
9018be22 | 214 | decode_loadmap (const gdb_byte *buf) |
8cd64e00 | 215 | { |
f5656ead | 216 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
9018be22 | 217 | const struct ext_elf32_dsbt_loadmap *ext_ldmbuf; |
8cd64e00 YQ |
218 | struct int_elf32_dsbt_loadmap *int_ldmbuf; |
219 | ||
220 | int version, seg, nsegs; | |
22e048c9 | 221 | int int_ldmbuf_size; |
8cd64e00 YQ |
222 | |
223 | ext_ldmbuf = (struct ext_elf32_dsbt_loadmap *) buf; | |
224 | ||
225 | /* Extract the version. */ | |
226 | version = extract_unsigned_integer (ext_ldmbuf->version, | |
227 | sizeof ext_ldmbuf->version, | |
228 | byte_order); | |
229 | if (version != 0) | |
230 | { | |
231 | /* We only handle version 0. */ | |
232 | return NULL; | |
233 | } | |
234 | ||
235 | /* Extract the number of segments. */ | |
236 | nsegs = extract_unsigned_integer (ext_ldmbuf->nsegs, | |
237 | sizeof ext_ldmbuf->nsegs, | |
238 | byte_order); | |
239 | ||
240 | if (nsegs <= 0) | |
241 | return NULL; | |
242 | ||
243 | /* Allocate space into which to put information extract from the | |
244 | external loadsegs. I.e, allocate the internal loadsegs. */ | |
245 | int_ldmbuf_size = (sizeof (struct int_elf32_dsbt_loadmap) | |
246 | + (nsegs - 1) * sizeof (struct int_elf32_dsbt_loadseg)); | |
224c3ddb | 247 | int_ldmbuf = (struct int_elf32_dsbt_loadmap *) xmalloc (int_ldmbuf_size); |
8cd64e00 YQ |
248 | |
249 | /* Place extracted information in internal structs. */ | |
250 | int_ldmbuf->version = version; | |
251 | int_ldmbuf->nsegs = nsegs; | |
252 | for (seg = 0; seg < nsegs; seg++) | |
253 | { | |
254 | int_ldmbuf->segs[seg].addr | |
255 | = extract_unsigned_integer (ext_ldmbuf->segs[seg].addr, | |
256 | sizeof (ext_ldmbuf->segs[seg].addr), | |
257 | byte_order); | |
258 | int_ldmbuf->segs[seg].p_vaddr | |
259 | = extract_unsigned_integer (ext_ldmbuf->segs[seg].p_vaddr, | |
260 | sizeof (ext_ldmbuf->segs[seg].p_vaddr), | |
261 | byte_order); | |
262 | int_ldmbuf->segs[seg].p_memsz | |
263 | = extract_unsigned_integer (ext_ldmbuf->segs[seg].p_memsz, | |
264 | sizeof (ext_ldmbuf->segs[seg].p_memsz), | |
265 | byte_order); | |
266 | } | |
267 | ||
8cd64e00 YQ |
268 | return int_ldmbuf; |
269 | } | |
270 | ||
271 | ||
272 | static struct dsbt_info *get_dsbt_info (void); | |
273 | ||
274 | /* Interrogate the Linux kernel to find out where the program was loaded. | |
275 | There are two load maps; one for the executable and one for the | |
276 | interpreter (only in the case of a dynamically linked executable). */ | |
277 | ||
278 | static void | |
279 | dsbt_get_initial_loadmaps (void) | |
280 | { | |
8cd64e00 | 281 | struct dsbt_info *info = get_dsbt_info (); |
9018be22 | 282 | gdb::optional<gdb::byte_vector> buf |
328d42d8 SM |
283 | = target_read_alloc (current_inferior ()->top_target (), |
284 | TARGET_OBJECT_FDPIC, "exec"); | |
8cd64e00 | 285 | |
9018be22 | 286 | if (!buf || buf->empty ()) |
8cd64e00 YQ |
287 | { |
288 | info->exec_loadmap = NULL; | |
289 | error (_("Error reading DSBT exec loadmap")); | |
290 | } | |
9018be22 | 291 | info->exec_loadmap = decode_loadmap (buf->data ()); |
8cd64e00 YQ |
292 | if (solib_dsbt_debug) |
293 | dsbt_print_loadmap (info->exec_loadmap); | |
294 | ||
328d42d8 SM |
295 | buf = target_read_alloc (current_inferior ()->top_target (), |
296 | TARGET_OBJECT_FDPIC, "exec"); | |
9018be22 | 297 | if (!buf || buf->empty ()) |
8cd64e00 YQ |
298 | { |
299 | info->interp_loadmap = NULL; | |
300 | error (_("Error reading DSBT interp loadmap")); | |
301 | } | |
9018be22 | 302 | info->interp_loadmap = decode_loadmap (buf->data ()); |
8cd64e00 YQ |
303 | if (solib_dsbt_debug) |
304 | dsbt_print_loadmap (info->interp_loadmap); | |
305 | } | |
306 | ||
307 | /* Given address LDMADDR, fetch and decode the loadmap at that address. | |
308 | Return NULL if there is a problem reading the target memory or if | |
309 | there doesn't appear to be a loadmap at the given address. The | |
310 | allocated space (representing the loadmap) returned by this | |
311 | function may be freed via a single call to xfree. */ | |
312 | ||
313 | static struct int_elf32_dsbt_loadmap * | |
314 | fetch_loadmap (CORE_ADDR ldmaddr) | |
315 | { | |
f5656ead | 316 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
8cd64e00 YQ |
317 | struct ext_elf32_dsbt_loadmap ext_ldmbuf_partial; |
318 | struct ext_elf32_dsbt_loadmap *ext_ldmbuf; | |
319 | struct int_elf32_dsbt_loadmap *int_ldmbuf; | |
320 | int ext_ldmbuf_size, int_ldmbuf_size; | |
321 | int version, seg, nsegs; | |
322 | ||
323 | /* Fetch initial portion of the loadmap. */ | |
324 | if (target_read_memory (ldmaddr, (gdb_byte *) &ext_ldmbuf_partial, | |
7ee4732a | 325 | sizeof ext_ldmbuf_partial)) |
8cd64e00 YQ |
326 | { |
327 | /* Problem reading the target's memory. */ | |
328 | return NULL; | |
329 | } | |
330 | ||
331 | /* Extract the version. */ | |
332 | version = extract_unsigned_integer (ext_ldmbuf_partial.version, | |
7ee4732a | 333 | sizeof ext_ldmbuf_partial.version, |
8cd64e00 YQ |
334 | byte_order); |
335 | if (version != 0) | |
336 | { | |
337 | /* We only handle version 0. */ | |
338 | return NULL; | |
339 | } | |
340 | ||
341 | /* Extract the number of segments. */ | |
342 | nsegs = extract_unsigned_integer (ext_ldmbuf_partial.nsegs, | |
343 | sizeof ext_ldmbuf_partial.nsegs, | |
344 | byte_order); | |
345 | ||
346 | if (nsegs <= 0) | |
347 | return NULL; | |
348 | ||
349 | /* Allocate space for the complete (external) loadmap. */ | |
350 | ext_ldmbuf_size = sizeof (struct ext_elf32_dsbt_loadmap) | |
351 | + (nsegs - 1) * sizeof (struct ext_elf32_dsbt_loadseg); | |
224c3ddb | 352 | ext_ldmbuf = (struct ext_elf32_dsbt_loadmap *) xmalloc (ext_ldmbuf_size); |
8cd64e00 YQ |
353 | |
354 | /* Copy over the portion of the loadmap that's already been read. */ | |
355 | memcpy (ext_ldmbuf, &ext_ldmbuf_partial, sizeof ext_ldmbuf_partial); | |
356 | ||
357 | /* Read the rest of the loadmap from the target. */ | |
358 | if (target_read_memory (ldmaddr + sizeof ext_ldmbuf_partial, | |
359 | (gdb_byte *) ext_ldmbuf + sizeof ext_ldmbuf_partial, | |
360 | ext_ldmbuf_size - sizeof ext_ldmbuf_partial)) | |
361 | { | |
362 | /* Couldn't read rest of the loadmap. */ | |
363 | xfree (ext_ldmbuf); | |
364 | return NULL; | |
365 | } | |
366 | ||
367 | /* Allocate space into which to put information extract from the | |
368 | external loadsegs. I.e, allocate the internal loadsegs. */ | |
369 | int_ldmbuf_size = sizeof (struct int_elf32_dsbt_loadmap) | |
370 | + (nsegs - 1) * sizeof (struct int_elf32_dsbt_loadseg); | |
224c3ddb | 371 | int_ldmbuf = (struct int_elf32_dsbt_loadmap *) xmalloc (int_ldmbuf_size); |
8cd64e00 YQ |
372 | |
373 | /* Place extracted information in internal structs. */ | |
374 | int_ldmbuf->version = version; | |
375 | int_ldmbuf->nsegs = nsegs; | |
376 | for (seg = 0; seg < nsegs; seg++) | |
377 | { | |
378 | int_ldmbuf->segs[seg].addr | |
379 | = extract_unsigned_integer (ext_ldmbuf->segs[seg].addr, | |
380 | sizeof (ext_ldmbuf->segs[seg].addr), | |
381 | byte_order); | |
382 | int_ldmbuf->segs[seg].p_vaddr | |
383 | = extract_unsigned_integer (ext_ldmbuf->segs[seg].p_vaddr, | |
384 | sizeof (ext_ldmbuf->segs[seg].p_vaddr), | |
385 | byte_order); | |
386 | int_ldmbuf->segs[seg].p_memsz | |
387 | = extract_unsigned_integer (ext_ldmbuf->segs[seg].p_memsz, | |
388 | sizeof (ext_ldmbuf->segs[seg].p_memsz), | |
389 | byte_order); | |
390 | } | |
391 | ||
392 | xfree (ext_ldmbuf); | |
393 | return int_ldmbuf; | |
394 | } | |
395 | ||
396 | static void dsbt_relocate_main_executable (void); | |
3582629f | 397 | static int enable_break (void); |
8cd64e00 | 398 | |
bf469271 | 399 | /* See solist.h. */ |
8cd64e00 YQ |
400 | |
401 | static int | |
bf469271 | 402 | open_symbol_file_object (int from_tty) |
8cd64e00 YQ |
403 | { |
404 | /* Unimplemented. */ | |
405 | return 0; | |
406 | } | |
407 | ||
408 | /* Given a loadmap and an address, return the displacement needed | |
409 | to relocate the address. */ | |
410 | ||
411 | static CORE_ADDR | |
412 | displacement_from_map (struct int_elf32_dsbt_loadmap *map, | |
7ee4732a | 413 | CORE_ADDR addr) |
8cd64e00 YQ |
414 | { |
415 | int seg; | |
416 | ||
417 | for (seg = 0; seg < map->nsegs; seg++) | |
418 | if (map->segs[seg].p_vaddr <= addr | |
419 | && addr < map->segs[seg].p_vaddr + map->segs[seg].p_memsz) | |
420 | return map->segs[seg].addr - map->segs[seg].p_vaddr; | |
421 | ||
422 | return 0; | |
423 | } | |
424 | ||
425 | /* Return the address from which the link map chain may be found. On | |
426 | DSBT, a pointer to the start of the link map will be located at the | |
427 | word found at base of GOT + GOT_MODULE_OFFSET. | |
428 | ||
429 | The base of GOT may be found in a number of ways. Assuming that the | |
430 | main executable has already been relocated, | |
431 | 1 The easiest way to find this value is to look up the address of | |
432 | _GLOBAL_OFFSET_TABLE_. | |
433 | 2 The other way is to look for tag DT_PLTGOT, which contains the virtual | |
434 | address of Global Offset Table. .*/ | |
435 | ||
436 | static CORE_ADDR | |
437 | lm_base (void) | |
438 | { | |
f5656ead | 439 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
3b7344d5 | 440 | struct bound_minimal_symbol got_sym; |
8cd64e00 YQ |
441 | CORE_ADDR addr; |
442 | gdb_byte buf[TIC6X_PTR_SIZE]; | |
443 | struct dsbt_info *info = get_dsbt_info (); | |
444 | ||
445 | /* One of our assumptions is that the main executable has been relocated. | |
446 | Bail out if this has not happened. (Note that post_create_inferior | |
447 | in infcmd.c will call solib_add prior to solib_create_inferior_hook. | |
448 | If we allow this to happen, lm_base_cache will be initialized with | |
449 | a bogus value. */ | |
450 | if (info->main_executable_lm_info == 0) | |
451 | return 0; | |
452 | ||
453 | /* If we already have a cached value, return it. */ | |
454 | if (info->lm_base_cache) | |
455 | return info->lm_base_cache; | |
456 | ||
457 | got_sym = lookup_minimal_symbol ("_GLOBAL_OFFSET_TABLE_", NULL, | |
a42d7dd8 | 458 | current_program_space->symfile_object_file); |
8cd64e00 | 459 | |
3b7344d5 | 460 | if (got_sym.minsym != 0) |
8cd64e00 | 461 | { |
77e371c0 | 462 | addr = BMSYMBOL_VALUE_ADDRESS (got_sym); |
8cd64e00 | 463 | if (solib_dsbt_debug) |
6cb06a8c TT |
464 | gdb_printf (gdb_stdlog, |
465 | "lm_base: get addr %x by _GLOBAL_OFFSET_TABLE_.\n", | |
466 | (unsigned int) addr); | |
8cd64e00 | 467 | } |
8ddf4645 AM |
468 | else if (gdb_bfd_scan_elf_dyntag (DT_PLTGOT, |
469 | current_program_space->exec_bfd (), | |
470 | &addr, NULL)) | |
8cd64e00 YQ |
471 | { |
472 | struct int_elf32_dsbt_loadmap *ldm; | |
473 | ||
474 | dsbt_get_initial_loadmaps (); | |
475 | ldm = info->exec_loadmap; | |
476 | addr += displacement_from_map (ldm, addr); | |
477 | if (solib_dsbt_debug) | |
6cb06a8c TT |
478 | gdb_printf (gdb_stdlog, |
479 | "lm_base: get addr %x by DT_PLTGOT.\n", | |
480 | (unsigned int) addr); | |
8cd64e00 YQ |
481 | } |
482 | else | |
483 | { | |
484 | if (solib_dsbt_debug) | |
6cb06a8c TT |
485 | gdb_printf (gdb_stdlog, |
486 | "lm_base: _GLOBAL_OFFSET_TABLE_ not found.\n"); | |
8cd64e00 YQ |
487 | return 0; |
488 | } | |
489 | addr += GOT_MODULE_OFFSET; | |
490 | ||
491 | if (solib_dsbt_debug) | |
6cb06a8c TT |
492 | gdb_printf (gdb_stdlog, |
493 | "lm_base: _GLOBAL_OFFSET_TABLE_ + %d = %s\n", | |
494 | GOT_MODULE_OFFSET, hex_string_custom (addr, 8)); | |
8cd64e00 YQ |
495 | |
496 | if (target_read_memory (addr, buf, sizeof buf) != 0) | |
497 | return 0; | |
498 | info->lm_base_cache = extract_unsigned_integer (buf, sizeof buf, byte_order); | |
499 | ||
500 | if (solib_dsbt_debug) | |
6cb06a8c TT |
501 | gdb_printf (gdb_stdlog, |
502 | "lm_base: lm_base_cache = %s\n", | |
503 | hex_string_custom (info->lm_base_cache, 8)); | |
8cd64e00 YQ |
504 | |
505 | return info->lm_base_cache; | |
506 | } | |
507 | ||
508 | ||
509 | /* Build a list of `struct so_list' objects describing the shared | |
510 | objects currently loaded in the inferior. This list does not | |
511 | include an entry for the main executable file. | |
512 | ||
513 | Note that we only gather information directly available from the | |
514 | inferior --- we don't examine any of the shared library files | |
515 | themselves. The declaration of `struct so_list' says which fields | |
516 | we provide values for. */ | |
517 | ||
518 | static struct so_list * | |
519 | dsbt_current_sos (void) | |
520 | { | |
f5656ead | 521 | enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); |
8cd64e00 YQ |
522 | CORE_ADDR lm_addr; |
523 | struct so_list *sos_head = NULL; | |
524 | struct so_list **sos_next_ptr = &sos_head; | |
525 | struct dsbt_info *info = get_dsbt_info (); | |
526 | ||
527 | /* Make sure that the main executable has been relocated. This is | |
528 | required in order to find the address of the global offset table, | |
529 | which in turn is used to find the link map info. (See lm_base | |
530 | for details.) | |
531 | ||
532 | Note that the relocation of the main executable is also performed | |
4d1eb6b4 | 533 | by solib_create_inferior_hook, however, in the case of core |
8cd64e00 | 534 | files, this hook is called too late in order to be of benefit to |
4d1eb6b4 | 535 | solib_add. solib_add eventually calls this function, |
8cd64e00 | 536 | dsbt_current_sos, and also precedes the call to |
4d1eb6b4 | 537 | solib_create_inferior_hook. (See post_create_inferior in |
8cd64e00 YQ |
538 | infcmd.c.) */ |
539 | if (info->main_executable_lm_info == 0 && core_bfd != NULL) | |
540 | dsbt_relocate_main_executable (); | |
541 | ||
542 | /* Locate the address of the first link map struct. */ | |
543 | lm_addr = lm_base (); | |
544 | ||
6471e7d2 | 545 | /* We have at least one link map entry. Fetch the lot of them, |
8cd64e00 YQ |
546 | building the solist chain. */ |
547 | while (lm_addr) | |
548 | { | |
549 | struct ext_link_map lm_buf; | |
550 | ext_Elf32_Word indexword; | |
551 | CORE_ADDR map_addr; | |
552 | int dsbt_index; | |
553 | int ret; | |
554 | ||
555 | if (solib_dsbt_debug) | |
6cb06a8c TT |
556 | gdb_printf (gdb_stdlog, |
557 | "current_sos: reading link_map entry at %s\n", | |
558 | hex_string_custom (lm_addr, 8)); | |
8cd64e00 YQ |
559 | |
560 | ret = target_read_memory (lm_addr, (gdb_byte *) &lm_buf, sizeof (lm_buf)); | |
561 | if (ret) | |
562 | { | |
563 | warning (_("dsbt_current_sos: Unable to read link map entry." | |
564 | " Shared object chain may be incomplete.")); | |
565 | break; | |
566 | } | |
567 | ||
568 | /* Fetch the load map address. */ | |
569 | map_addr = extract_unsigned_integer (lm_buf.l_addr.map, | |
570 | sizeof lm_buf.l_addr.map, | |
571 | byte_order); | |
572 | ||
573 | ret = target_read_memory (map_addr + 12, (gdb_byte *) &indexword, | |
574 | sizeof indexword); | |
575 | if (ret) | |
576 | { | |
577 | warning (_("dsbt_current_sos: Unable to read dsbt index." | |
578 | " Shared object chain may be incomplete.")); | |
579 | break; | |
580 | } | |
581 | dsbt_index = extract_unsigned_integer (indexword, sizeof indexword, | |
582 | byte_order); | |
583 | ||
584 | /* If the DSBT index is zero, then we're looking at the entry | |
585 | for the main executable. By convention, we don't include | |
586 | this in the list of shared objects. */ | |
587 | if (dsbt_index != 0) | |
588 | { | |
8cd64e00 YQ |
589 | struct int_elf32_dsbt_loadmap *loadmap; |
590 | struct so_list *sop; | |
591 | CORE_ADDR addr; | |
592 | ||
593 | loadmap = fetch_loadmap (map_addr); | |
594 | if (loadmap == NULL) | |
595 | { | |
596 | warning (_("dsbt_current_sos: Unable to fetch load map." | |
597 | " Shared object chain may be incomplete.")); | |
598 | break; | |
599 | } | |
600 | ||
8d749320 | 601 | sop = XCNEW (struct so_list); |
b0911207 | 602 | lm_info_dsbt *li = new lm_info_dsbt; |
d0e449a1 SM |
603 | sop->lm_info = li; |
604 | li->map = loadmap; | |
8cd64e00 YQ |
605 | /* Fetch the name. */ |
606 | addr = extract_unsigned_integer (lm_buf.l_name, | |
607 | sizeof (lm_buf.l_name), | |
608 | byte_order); | |
66920317 TT |
609 | gdb::unique_xmalloc_ptr<char> name_buf |
610 | = target_read_string (addr, SO_NAME_MAX_PATH_SIZE - 1); | |
8cd64e00 | 611 | |
66920317 TT |
612 | if (name_buf == nullptr) |
613 | warning (_("Can't read pathname for link map entry.")); | |
8cd64e00 YQ |
614 | else |
615 | { | |
616 | if (solib_dsbt_debug) | |
6cb06a8c TT |
617 | gdb_printf (gdb_stdlog, "current_sos: name = %s\n", |
618 | name_buf.get ()); | |
8cd64e00 | 619 | |
e83e4e24 | 620 | strncpy (sop->so_name, name_buf.get (), SO_NAME_MAX_PATH_SIZE - 1); |
8cd64e00 | 621 | sop->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0'; |
8cd64e00 YQ |
622 | strcpy (sop->so_original_name, sop->so_name); |
623 | } | |
624 | ||
625 | *sos_next_ptr = sop; | |
626 | sos_next_ptr = &sop->next; | |
627 | } | |
628 | else | |
629 | { | |
630 | info->main_lm_addr = lm_addr; | |
631 | } | |
632 | ||
633 | lm_addr = extract_unsigned_integer (lm_buf.l_next, | |
634 | sizeof (lm_buf.l_next), byte_order); | |
635 | } | |
636 | ||
8cd64e00 YQ |
637 | return sos_head; |
638 | } | |
639 | ||
640 | /* Return 1 if PC lies in the dynamic symbol resolution code of the | |
641 | run time loader. */ | |
642 | ||
643 | static int | |
644 | dsbt_in_dynsym_resolve_code (CORE_ADDR pc) | |
645 | { | |
646 | struct dsbt_info *info = get_dsbt_info (); | |
647 | ||
648 | return ((pc >= info->interp_text_sect_low && pc < info->interp_text_sect_high) | |
649 | || (pc >= info->interp_plt_sect_low && pc < info->interp_plt_sect_high) | |
3e5d3a5a | 650 | || in_plt_section (pc)); |
8cd64e00 YQ |
651 | } |
652 | ||
653 | /* Print a warning about being unable to set the dynamic linker | |
654 | breakpoint. */ | |
655 | ||
656 | static void | |
657 | enable_break_failure_warning (void) | |
658 | { | |
659 | warning (_("Unable to find dynamic linker breakpoint function.\n" | |
7ee4732a YQ |
660 | "GDB will be unable to debug shared library initializers\n" |
661 | "and track explicitly loaded dynamic code.")); | |
8cd64e00 YQ |
662 | } |
663 | ||
cb457ae2 YQ |
664 | /* Helper function for gdb_bfd_lookup_symbol. */ |
665 | ||
666 | static int | |
3953f15c | 667 | cmp_name (const asymbol *sym, const void *data) |
cb457ae2 YQ |
668 | { |
669 | return (strcmp (sym->name, (const char *) data) == 0); | |
670 | } | |
671 | ||
8cd64e00 YQ |
672 | /* The dynamic linkers has, as part of its debugger interface, support |
673 | for arranging for the inferior to hit a breakpoint after mapping in | |
674 | the shared libraries. This function enables that breakpoint. | |
675 | ||
3582629f YQ |
676 | On the TIC6X, using the shared library (DSBT), GDB can try to place |
677 | a breakpoint on '_dl_debug_state' to monitor the shared library | |
678 | event. */ | |
8cd64e00 YQ |
679 | |
680 | static int | |
3582629f | 681 | enable_break (void) |
8cd64e00 | 682 | { |
8cd64e00 | 683 | asection *interp_sect; |
3582629f | 684 | struct dsbt_info *info; |
8cd64e00 | 685 | |
7e10abd1 | 686 | if (current_program_space->exec_bfd () == NULL) |
8cd64e00 YQ |
687 | return 0; |
688 | ||
55f6301a | 689 | if (!target_has_execution ()) |
8cd64e00 YQ |
690 | return 0; |
691 | ||
3582629f YQ |
692 | info = get_dsbt_info (); |
693 | ||
8cd64e00 YQ |
694 | info->interp_text_sect_low = 0; |
695 | info->interp_text_sect_high = 0; | |
696 | info->interp_plt_sect_low = 0; | |
697 | info->interp_plt_sect_high = 0; | |
698 | ||
699 | /* Find the .interp section; if not found, warn the user and drop | |
700 | into the old breakpoint at symbol code. */ | |
7e10abd1 TT |
701 | interp_sect = bfd_get_section_by_name (current_program_space->exec_bfd (), |
702 | ".interp"); | |
8cd64e00 YQ |
703 | if (interp_sect) |
704 | { | |
705 | unsigned int interp_sect_size; | |
001f13d8 | 706 | char *buf; |
22e048c9 | 707 | CORE_ADDR addr; |
8cd64e00 | 708 | struct int_elf32_dsbt_loadmap *ldm; |
3582629f | 709 | int ret; |
8cd64e00 YQ |
710 | |
711 | /* Read the contents of the .interp section into a local buffer; | |
7ee4732a | 712 | the contents specify the dynamic linker this program uses. */ |
fd361982 | 713 | interp_sect_size = bfd_section_size (interp_sect); |
224c3ddb | 714 | buf = (char *) alloca (interp_sect_size); |
7e10abd1 TT |
715 | bfd_get_section_contents (current_program_space->exec_bfd (), |
716 | interp_sect, buf, 0, interp_sect_size); | |
8cd64e00 YQ |
717 | |
718 | /* Now we need to figure out where the dynamic linker was | |
7ee4732a YQ |
719 | loaded so that we can load its symbols and place a breakpoint |
720 | in the dynamic linker itself. */ | |
8cd64e00 | 721 | |
192b62ce | 722 | gdb_bfd_ref_ptr tmp_bfd; |
a70b8144 | 723 | try |
7ee4732a YQ |
724 | { |
725 | tmp_bfd = solib_bfd_open (buf); | |
726 | } | |
230d2906 | 727 | catch (const gdb_exception &ex) |
492d29ea PA |
728 | { |
729 | } | |
492d29ea | 730 | |
8cd64e00 YQ |
731 | if (tmp_bfd == NULL) |
732 | { | |
733 | enable_break_failure_warning (); | |
734 | return 0; | |
735 | } | |
736 | ||
737 | dsbt_get_initial_loadmaps (); | |
738 | ldm = info->interp_loadmap; | |
739 | ||
740 | /* Record the relocated start and end address of the dynamic linker | |
7ee4732a | 741 | text and plt section for dsbt_in_dynsym_resolve_code. */ |
192b62ce | 742 | interp_sect = bfd_get_section_by_name (tmp_bfd.get (), ".text"); |
8cd64e00 YQ |
743 | if (interp_sect) |
744 | { | |
fd361982 | 745 | info->interp_text_sect_low = bfd_section_vma (interp_sect); |
8cd64e00 YQ |
746 | info->interp_text_sect_low |
747 | += displacement_from_map (ldm, info->interp_text_sect_low); | |
748 | info->interp_text_sect_high | |
fd361982 | 749 | = info->interp_text_sect_low + bfd_section_size (interp_sect); |
8cd64e00 | 750 | } |
192b62ce | 751 | interp_sect = bfd_get_section_by_name (tmp_bfd.get (), ".plt"); |
8cd64e00 YQ |
752 | if (interp_sect) |
753 | { | |
fd361982 | 754 | info->interp_plt_sect_low = bfd_section_vma (interp_sect); |
8cd64e00 YQ |
755 | info->interp_plt_sect_low |
756 | += displacement_from_map (ldm, info->interp_plt_sect_low); | |
fd361982 AM |
757 | info->interp_plt_sect_high |
758 | = info->interp_plt_sect_low + bfd_section_size (interp_sect); | |
8cd64e00 YQ |
759 | } |
760 | ||
192b62ce TT |
761 | addr = gdb_bfd_lookup_symbol (tmp_bfd.get (), cmp_name, |
762 | "_dl_debug_state"); | |
3582629f | 763 | if (addr != 0) |
8cd64e00 | 764 | { |
3582629f | 765 | if (solib_dsbt_debug) |
6cb06a8c TT |
766 | gdb_printf (gdb_stdlog, |
767 | "enable_break: _dl_debug_state (prior to relocation) = %s\n", | |
768 | hex_string_custom (addr, 8)); | |
3582629f | 769 | addr += displacement_from_map (ldm, addr); |
8cd64e00 | 770 | |
3582629f | 771 | if (solib_dsbt_debug) |
6cb06a8c TT |
772 | gdb_printf (gdb_stdlog, |
773 | "enable_break: _dl_debug_state (after relocation) = %s\n", | |
774 | hex_string_custom (addr, 8)); | |
8cd64e00 | 775 | |
3582629f YQ |
776 | /* Now (finally!) create the solib breakpoint. */ |
777 | create_solib_event_breakpoint (target_gdbarch (), addr); | |
8cd64e00 | 778 | |
3582629f | 779 | ret = 1; |
8cd64e00 | 780 | } |
3582629f | 781 | else |
8cd64e00 YQ |
782 | { |
783 | if (solib_dsbt_debug) | |
6cb06a8c TT |
784 | gdb_printf (gdb_stdlog, |
785 | "enable_break: _dl_debug_state is not found\n"); | |
3582629f | 786 | ret = 0; |
8cd64e00 YQ |
787 | } |
788 | ||
192b62ce | 789 | /* We're done with the loadmap. */ |
8cd64e00 YQ |
790 | xfree (ldm); |
791 | ||
3582629f | 792 | return ret; |
8cd64e00 YQ |
793 | } |
794 | ||
795 | /* Tell the user we couldn't set a dynamic linker breakpoint. */ | |
796 | enable_break_failure_warning (); | |
797 | ||
798 | /* Failure return. */ | |
799 | return 0; | |
800 | } | |
801 | ||
8cd64e00 YQ |
802 | static void |
803 | dsbt_relocate_main_executable (void) | |
804 | { | |
8cd64e00 | 805 | struct int_elf32_dsbt_loadmap *ldm; |
8cd64e00 YQ |
806 | int changed; |
807 | struct obj_section *osect; | |
808 | struct dsbt_info *info = get_dsbt_info (); | |
809 | ||
810 | dsbt_get_initial_loadmaps (); | |
811 | ldm = info->exec_loadmap; | |
812 | ||
b0911207 SM |
813 | delete info->main_executable_lm_info; |
814 | info->main_executable_lm_info = new lm_info_dsbt; | |
8cd64e00 YQ |
815 | info->main_executable_lm_info->map = ldm; |
816 | ||
a42d7dd8 TT |
817 | objfile *objf = current_program_space->symfile_object_file; |
818 | section_offsets new_offsets (objf->section_offsets.size ()); | |
8cd64e00 YQ |
819 | changed = 0; |
820 | ||
a42d7dd8 | 821 | ALL_OBJFILE_OSECTIONS (objf, osect) |
8cd64e00 YQ |
822 | { |
823 | CORE_ADDR orig_addr, addr, offset; | |
824 | int osect_idx; | |
825 | int seg; | |
826 | ||
a42d7dd8 | 827 | osect_idx = osect - objf->sections; |
8cd64e00 YQ |
828 | |
829 | /* Current address of section. */ | |
0c1bcd23 | 830 | addr = osect->addr (); |
8cd64e00 | 831 | /* Offset from where this section started. */ |
a42d7dd8 | 832 | offset = objf->section_offsets[osect_idx]; |
8cd64e00 YQ |
833 | /* Original address prior to any past relocations. */ |
834 | orig_addr = addr - offset; | |
835 | ||
836 | for (seg = 0; seg < ldm->nsegs; seg++) | |
837 | { | |
838 | if (ldm->segs[seg].p_vaddr <= orig_addr | |
839 | && orig_addr < ldm->segs[seg].p_vaddr + ldm->segs[seg].p_memsz) | |
840 | { | |
6a053cb1 | 841 | new_offsets[osect_idx] |
8cd64e00 YQ |
842 | = ldm->segs[seg].addr - ldm->segs[seg].p_vaddr; |
843 | ||
6a053cb1 | 844 | if (new_offsets[osect_idx] != offset) |
8cd64e00 YQ |
845 | changed = 1; |
846 | break; | |
847 | } | |
848 | } | |
849 | } | |
850 | ||
851 | if (changed) | |
a42d7dd8 | 852 | objfile_relocate (objf, new_offsets); |
8cd64e00 | 853 | |
a42d7dd8 TT |
854 | /* Now that OBJF has been relocated, we can compute the GOT value |
855 | and stash it away. */ | |
8cd64e00 YQ |
856 | } |
857 | ||
858 | /* When gdb starts up the inferior, it nurses it along (through the | |
859 | shell) until it is ready to execute it's first instruction. At this | |
4d1eb6b4 | 860 | point, this function gets called via solib_create_inferior_hook. |
8cd64e00 YQ |
861 | |
862 | For the DSBT shared library, the main executable needs to be relocated. | |
4d1eb6b4 | 863 | The shared library breakpoints also need to be enabled. */ |
8cd64e00 YQ |
864 | |
865 | static void | |
866 | dsbt_solib_create_inferior_hook (int from_tty) | |
867 | { | |
868 | /* Relocate main executable. */ | |
869 | dsbt_relocate_main_executable (); | |
870 | ||
871 | /* Enable shared library breakpoints. */ | |
872 | if (!enable_break ()) | |
873 | { | |
874 | warning (_("shared library handler failed to enable breakpoint")); | |
875 | return; | |
876 | } | |
877 | } | |
878 | ||
879 | static void | |
880 | dsbt_clear_solib (void) | |
881 | { | |
882 | struct dsbt_info *info = get_dsbt_info (); | |
883 | ||
884 | info->lm_base_cache = 0; | |
8cd64e00 | 885 | info->main_lm_addr = 0; |
b0911207 SM |
886 | |
887 | delete info->main_executable_lm_info; | |
888 | info->main_executable_lm_info = NULL; | |
8cd64e00 YQ |
889 | } |
890 | ||
891 | static void | |
892 | dsbt_free_so (struct so_list *so) | |
893 | { | |
d0e449a1 SM |
894 | lm_info_dsbt *li = (lm_info_dsbt *) so->lm_info; |
895 | ||
b0911207 | 896 | delete li; |
8cd64e00 YQ |
897 | } |
898 | ||
899 | static void | |
900 | dsbt_relocate_section_addresses (struct so_list *so, | |
7ee4732a | 901 | struct target_section *sec) |
8cd64e00 YQ |
902 | { |
903 | int seg; | |
d0e449a1 SM |
904 | lm_info_dsbt *li = (lm_info_dsbt *) so->lm_info; |
905 | int_elf32_dsbt_loadmap *map = li->map; | |
8cd64e00 YQ |
906 | |
907 | for (seg = 0; seg < map->nsegs; seg++) | |
908 | { | |
909 | if (map->segs[seg].p_vaddr <= sec->addr | |
7ee4732a | 910 | && sec->addr < map->segs[seg].p_vaddr + map->segs[seg].p_memsz) |
8cd64e00 YQ |
911 | { |
912 | CORE_ADDR displ = map->segs[seg].addr - map->segs[seg].p_vaddr; | |
913 | ||
914 | sec->addr += displ; | |
915 | sec->endaddr += displ; | |
916 | break; | |
917 | } | |
918 | } | |
919 | } | |
920 | static void | |
921 | show_dsbt_debug (struct ui_file *file, int from_tty, | |
922 | struct cmd_list_element *c, const char *value) | |
923 | { | |
6cb06a8c | 924 | gdb_printf (file, _("solib-dsbt debugging is %s.\n"), value); |
8cd64e00 YQ |
925 | } |
926 | ||
927 | struct target_so_ops dsbt_so_ops; | |
928 | ||
6c265988 | 929 | void _initialize_dsbt_solib (); |
8cd64e00 | 930 | void |
6c265988 | 931 | _initialize_dsbt_solib () |
8cd64e00 | 932 | { |
8cd64e00 YQ |
933 | dsbt_so_ops.relocate_section_addresses = dsbt_relocate_section_addresses; |
934 | dsbt_so_ops.free_so = dsbt_free_so; | |
935 | dsbt_so_ops.clear_solib = dsbt_clear_solib; | |
936 | dsbt_so_ops.solib_create_inferior_hook = dsbt_solib_create_inferior_hook; | |
8cd64e00 YQ |
937 | dsbt_so_ops.current_sos = dsbt_current_sos; |
938 | dsbt_so_ops.open_symbol_file_object = open_symbol_file_object; | |
939 | dsbt_so_ops.in_dynsym_resolve_code = dsbt_in_dynsym_resolve_code; | |
940 | dsbt_so_ops.bfd_open = solib_bfd_open; | |
941 | ||
942 | /* Debug this file's internals. */ | |
ccce17b0 YQ |
943 | add_setshow_zuinteger_cmd ("solib-dsbt", class_maintenance, |
944 | &solib_dsbt_debug, _("\ | |
8cd64e00 YQ |
945 | Set internal debugging of shared library code for DSBT ELF."), _("\ |
946 | Show internal debugging of shared library code for DSBT ELF."), _("\ | |
947 | When non-zero, DSBT solib specific internal debugging is enabled."), | |
ccce17b0 YQ |
948 | NULL, |
949 | show_dsbt_debug, | |
950 | &setdebuglist, &showdebuglist); | |
8cd64e00 | 951 | } |