Commit | Line | Data |
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14ed0a8b RM |
1 | /* Auxiliary vector support for GDB, the GNU debugger. |
2 | ||
4c38e0a4 | 3 | Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 |
0fb0cc75 | 4 | Free Software Foundation, Inc. |
14ed0a8b RM |
5 | |
6 | This file is part of GDB. | |
7 | ||
8 | This program is free software; you can redistribute it and/or modify | |
9 | it under the terms of the GNU General Public License as published by | |
a9762ec7 | 10 | the Free Software Foundation; either version 3 of the License, or |
14ed0a8b RM |
11 | (at your option) any later version. |
12 | ||
13 | This program is distributed in the hope that it will be useful, | |
14 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | GNU General Public License for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
a9762ec7 | 19 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
14ed0a8b RM |
20 | |
21 | #include "defs.h" | |
22 | #include "target.h" | |
23 | #include "gdbtypes.h" | |
24 | #include "command.h" | |
25 | #include "inferior.h" | |
26 | #include "valprint.h" | |
27 | #include "gdb_assert.h" | |
9f2982ff | 28 | #include "gdbcore.h" |
14ed0a8b RM |
29 | |
30 | #include "auxv.h" | |
31 | #include "elf/common.h" | |
32 | ||
33 | #include <unistd.h> | |
34 | #include <fcntl.h> | |
35 | ||
36 | ||
9f2982ff JK |
37 | /* This function handles access via /proc/PID/auxv, which is a common method |
38 | for native targets. */ | |
14ed0a8b | 39 | |
9f2982ff JK |
40 | static LONGEST |
41 | procfs_xfer_auxv (gdb_byte *readbuf, | |
36aa5e41 | 42 | const gdb_byte *writebuf, |
14ed0a8b RM |
43 | ULONGEST offset, |
44 | LONGEST len) | |
45 | { | |
46 | char *pathname; | |
47 | int fd; | |
48 | LONGEST n; | |
49 | ||
14ed0a8b RM |
50 | pathname = xstrprintf ("/proc/%d/auxv", PIDGET (inferior_ptid)); |
51 | fd = open (pathname, writebuf != NULL ? O_WRONLY : O_RDONLY); | |
52 | xfree (pathname); | |
53 | if (fd < 0) | |
54 | return -1; | |
55 | ||
56 | if (offset != (ULONGEST) 0 | |
57 | && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset) | |
58 | n = -1; | |
59 | else if (readbuf != NULL) | |
60 | n = read (fd, readbuf, len); | |
61 | else | |
62 | n = write (fd, writebuf, len); | |
63 | ||
64 | (void) close (fd); | |
65 | ||
66 | return n; | |
67 | } | |
68 | ||
9f2982ff JK |
69 | /* This function handles access via ld.so's symbol `_dl_auxv'. */ |
70 | ||
71 | static LONGEST | |
72 | ld_so_xfer_auxv (gdb_byte *readbuf, | |
73 | const gdb_byte *writebuf, | |
74 | ULONGEST offset, | |
75 | LONGEST len) | |
76 | { | |
77 | struct minimal_symbol *msym; | |
78 | CORE_ADDR data_address, pointer_address; | |
79 | struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr; | |
80 | size_t ptr_size = TYPE_LENGTH (ptr_type); | |
81 | size_t auxv_pair_size = 2 * ptr_size; | |
82 | gdb_byte *ptr_buf = alloca (ptr_size); | |
83 | LONGEST retval; | |
84 | size_t block; | |
85 | ||
86 | msym = lookup_minimal_symbol ("_dl_auxv", NULL, NULL); | |
87 | if (msym == NULL) | |
88 | return -1; | |
89 | ||
90 | if (MSYMBOL_SIZE (msym) != ptr_size) | |
91 | return -1; | |
92 | ||
93 | /* POINTER_ADDRESS is a location where the `_dl_auxv' variable resides. | |
94 | DATA_ADDRESS is the inferior value present in `_dl_auxv', therefore the | |
95 | real inferior AUXV address. */ | |
96 | ||
97 | pointer_address = SYMBOL_VALUE_ADDRESS (msym); | |
98 | ||
99 | data_address = read_memory_typed_address (pointer_address, ptr_type); | |
100 | ||
101 | /* Possibly still not initialized such as during an inferior startup. */ | |
102 | if (data_address == 0) | |
103 | return -1; | |
104 | ||
105 | data_address += offset; | |
106 | ||
107 | if (writebuf != NULL) | |
108 | { | |
109 | if (target_write_memory (data_address, writebuf, len) == 0) | |
110 | return len; | |
111 | else | |
112 | return -1; | |
113 | } | |
114 | ||
115 | /* Stop if trying to read past the existing AUXV block. The final AT_NULL | |
116 | was already returned before. */ | |
117 | ||
118 | if (offset >= auxv_pair_size) | |
119 | { | |
120 | if (target_read_memory (data_address - auxv_pair_size, ptr_buf, | |
121 | ptr_size) != 0) | |
122 | return -1; | |
123 | ||
124 | if (extract_typed_address (ptr_buf, ptr_type) == AT_NULL) | |
125 | return 0; | |
126 | } | |
127 | ||
128 | retval = 0; | |
129 | block = 0x400; | |
130 | gdb_assert (block % auxv_pair_size == 0); | |
131 | ||
132 | while (len > 0) | |
133 | { | |
134 | if (block > len) | |
135 | block = len; | |
136 | ||
137 | /* Reading sizes smaller than AUXV_PAIR_SIZE is not supported. Tails | |
138 | unaligned to AUXV_PAIR_SIZE will not be read during a call (they | |
139 | should be completed during next read with new/extended buffer). */ | |
140 | ||
141 | block &= -auxv_pair_size; | |
142 | if (block == 0) | |
143 | return retval; | |
144 | ||
145 | if (target_read_memory (data_address, readbuf, block) != 0) | |
146 | { | |
147 | if (block <= auxv_pair_size) | |
148 | return retval; | |
149 | ||
150 | block = auxv_pair_size; | |
151 | continue; | |
152 | } | |
153 | ||
154 | data_address += block; | |
155 | len -= block; | |
156 | ||
157 | /* Check terminal AT_NULL. This function is being called indefinitely | |
158 | being extended its READBUF until it returns EOF (0). */ | |
159 | ||
160 | while (block >= auxv_pair_size) | |
161 | { | |
162 | retval += auxv_pair_size; | |
163 | ||
164 | if (extract_typed_address (readbuf, ptr_type) == AT_NULL) | |
165 | return retval; | |
166 | ||
167 | readbuf += auxv_pair_size; | |
168 | block -= auxv_pair_size; | |
169 | } | |
170 | } | |
171 | ||
172 | return retval; | |
173 | } | |
174 | ||
175 | /* This function is called like a to_xfer_partial hook, but must be | |
176 | called with TARGET_OBJECT_AUXV. It handles access to AUXV. */ | |
177 | ||
178 | LONGEST | |
179 | memory_xfer_auxv (struct target_ops *ops, | |
180 | enum target_object object, | |
181 | const char *annex, | |
182 | gdb_byte *readbuf, | |
183 | const gdb_byte *writebuf, | |
184 | ULONGEST offset, | |
185 | LONGEST len) | |
186 | { | |
187 | gdb_assert (object == TARGET_OBJECT_AUXV); | |
188 | gdb_assert (readbuf || writebuf); | |
189 | ||
190 | /* ld_so_xfer_auxv is the only function safe for virtual executables being | |
191 | executed by valgrind's memcheck. As using ld_so_xfer_auxv is problematic | |
192 | during inferior startup GDB does call it only for attached processes. */ | |
193 | ||
194 | if (current_inferior ()->attach_flag != 0) | |
195 | { | |
196 | LONGEST retval; | |
197 | ||
198 | retval = ld_so_xfer_auxv (readbuf, writebuf, offset, len); | |
199 | if (retval != -1) | |
200 | return retval; | |
201 | } | |
202 | ||
203 | return procfs_xfer_auxv (readbuf, writebuf, offset, len); | |
204 | } | |
205 | ||
14ed0a8b RM |
206 | /* Read one auxv entry from *READPTR, not reading locations >= ENDPTR. |
207 | Return 0 if *READPTR is already at the end of the buffer. | |
208 | Return -1 if there is insufficient buffer for a whole entry. | |
209 | Return 1 if an entry was read into *TYPEP and *VALP. */ | |
2c0b251b | 210 | static int |
c47ffbe3 | 211 | default_auxv_parse (struct target_ops *ops, gdb_byte **readptr, |
36aa5e41 | 212 | gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp) |
14ed0a8b | 213 | { |
ffe5a37e UW |
214 | const int sizeof_auxv_field = gdbarch_ptr_bit (target_gdbarch) |
215 | / TARGET_CHAR_BIT; | |
e17a4113 | 216 | const enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch); |
36aa5e41 | 217 | gdb_byte *ptr = *readptr; |
14ed0a8b RM |
218 | |
219 | if (endptr == ptr) | |
220 | return 0; | |
221 | ||
222 | if (endptr - ptr < sizeof_auxv_field * 2) | |
223 | return -1; | |
224 | ||
e17a4113 | 225 | *typep = extract_unsigned_integer (ptr, sizeof_auxv_field, byte_order); |
14ed0a8b | 226 | ptr += sizeof_auxv_field; |
e17a4113 | 227 | *valp = extract_unsigned_integer (ptr, sizeof_auxv_field, byte_order); |
14ed0a8b RM |
228 | ptr += sizeof_auxv_field; |
229 | ||
230 | *readptr = ptr; | |
231 | return 1; | |
232 | } | |
233 | ||
c47ffbe3 VP |
234 | /* Read one auxv entry from *READPTR, not reading locations >= ENDPTR. |
235 | Return 0 if *READPTR is already at the end of the buffer. | |
236 | Return -1 if there is insufficient buffer for a whole entry. | |
237 | Return 1 if an entry was read into *TYPEP and *VALP. */ | |
238 | int | |
239 | target_auxv_parse (struct target_ops *ops, gdb_byte **readptr, | |
240 | gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp) | |
241 | { | |
242 | struct target_ops *t; | |
243 | for (t = ops; t != NULL; t = t->beneath) | |
244 | if (t->to_auxv_parse != NULL) | |
245 | return t->to_auxv_parse (t, readptr, endptr, typep, valp); | |
246 | ||
247 | return default_auxv_parse (ops, readptr, endptr, typep, valp); | |
248 | } | |
249 | ||
14ed0a8b RM |
250 | /* Extract the auxiliary vector entry with a_type matching MATCH. |
251 | Return zero if no such entry was found, or -1 if there was | |
252 | an error getting the information. On success, return 1 after | |
253 | storing the entry's value field in *VALP. */ | |
254 | int | |
255 | target_auxv_search (struct target_ops *ops, CORE_ADDR match, CORE_ADDR *valp) | |
256 | { | |
257 | CORE_ADDR type, val; | |
36aa5e41 | 258 | gdb_byte *data; |
13547ab6 | 259 | LONGEST n = target_read_alloc (ops, TARGET_OBJECT_AUXV, NULL, &data); |
36aa5e41 | 260 | gdb_byte *ptr = data; |
14ed0a8b RM |
261 | int ents = 0; |
262 | ||
263 | if (n <= 0) | |
264 | return n; | |
265 | ||
266 | while (1) | |
267 | switch (target_auxv_parse (ops, &ptr, data + n, &type, &val)) | |
268 | { | |
269 | case 1: /* Here's an entry, check it. */ | |
270 | if (type == match) | |
271 | { | |
272 | xfree (data); | |
273 | *valp = val; | |
274 | return 1; | |
275 | } | |
276 | break; | |
277 | case 0: /* End of the vector. */ | |
278 | xfree (data); | |
279 | return 0; | |
280 | default: /* Bogosity. */ | |
281 | xfree (data); | |
282 | return -1; | |
283 | } | |
284 | ||
285 | /*NOTREACHED*/ | |
286 | } | |
287 | ||
288 | ||
289 | /* Print the contents of the target's AUXV on the specified file. */ | |
290 | int | |
291 | fprint_target_auxv (struct ui_file *file, struct target_ops *ops) | |
292 | { | |
293 | CORE_ADDR type, val; | |
36aa5e41 | 294 | gdb_byte *data; |
13547ab6 DJ |
295 | LONGEST len = target_read_alloc (ops, TARGET_OBJECT_AUXV, NULL, |
296 | &data); | |
36aa5e41 | 297 | gdb_byte *ptr = data; |
14ed0a8b RM |
298 | int ents = 0; |
299 | ||
300 | if (len <= 0) | |
301 | return len; | |
302 | ||
303 | while (target_auxv_parse (ops, &ptr, data + len, &type, &val) > 0) | |
304 | { | |
14ed0a8b RM |
305 | const char *name = "???"; |
306 | const char *description = ""; | |
307 | enum { dec, hex, str } flavor = hex; | |
308 | ||
309 | switch (type) | |
310 | { | |
311 | #define TAG(tag, text, kind) \ | |
312 | case tag: name = #tag; description = text; flavor = kind; break | |
edefbb7c AC |
313 | TAG (AT_NULL, _("End of vector"), hex); |
314 | TAG (AT_IGNORE, _("Entry should be ignored"), hex); | |
315 | TAG (AT_EXECFD, _("File descriptor of program"), dec); | |
316 | TAG (AT_PHDR, _("Program headers for program"), hex); | |
317 | TAG (AT_PHENT, _("Size of program header entry"), dec); | |
318 | TAG (AT_PHNUM, _("Number of program headers"), dec); | |
319 | TAG (AT_PAGESZ, _("System page size"), dec); | |
320 | TAG (AT_BASE, _("Base address of interpreter"), hex); | |
321 | TAG (AT_FLAGS, _("Flags"), hex); | |
322 | TAG (AT_ENTRY, _("Entry point of program"), hex); | |
323 | TAG (AT_NOTELF, _("Program is not ELF"), dec); | |
324 | TAG (AT_UID, _("Real user ID"), dec); | |
325 | TAG (AT_EUID, _("Effective user ID"), dec); | |
326 | TAG (AT_GID, _("Real group ID"), dec); | |
327 | TAG (AT_EGID, _("Effective group ID"), dec); | |
328 | TAG (AT_CLKTCK, _("Frequency of times()"), dec); | |
329 | TAG (AT_PLATFORM, _("String identifying platform"), str); | |
330 | TAG (AT_HWCAP, _("Machine-dependent CPU capability hints"), hex); | |
331 | TAG (AT_FPUCW, _("Used FPU control word"), dec); | |
332 | TAG (AT_DCACHEBSIZE, _("Data cache block size"), dec); | |
333 | TAG (AT_ICACHEBSIZE, _("Instruction cache block size"), dec); | |
334 | TAG (AT_UCACHEBSIZE, _("Unified cache block size"), dec); | |
335 | TAG (AT_IGNOREPPC, _("Entry should be ignored"), dec); | |
759cc328 | 336 | TAG (AT_BASE_PLATFORM, _("String identifying base platform"), str); |
ba30a4e9 | 337 | TAG (AT_RANDOM, _("Address of 16 random bytes"), hex); |
759cc328 UW |
338 | TAG (AT_EXECFN, _("File name of executable"), str); |
339 | TAG (AT_SECURE, _("Boolean, was exec setuid-like?"), dec); | |
edefbb7c AC |
340 | TAG (AT_SYSINFO, _("Special system info/entry points"), hex); |
341 | TAG (AT_SYSINFO_EHDR, _("System-supplied DSO's ELF header"), hex); | |
edefbb7c AC |
342 | TAG (AT_SUN_UID, _("Effective user ID"), dec); |
343 | TAG (AT_SUN_RUID, _("Real user ID"), dec); | |
344 | TAG (AT_SUN_GID, _("Effective group ID"), dec); | |
345 | TAG (AT_SUN_RGID, _("Real group ID"), dec); | |
346 | TAG (AT_SUN_LDELF, _("Dynamic linker's ELF header"), hex); | |
347 | TAG (AT_SUN_LDSHDR, _("Dynamic linker's section headers"), hex); | |
348 | TAG (AT_SUN_LDNAME, _("String giving name of dynamic linker"), str); | |
349 | TAG (AT_SUN_LPAGESZ, _("Large pagesize"), dec); | |
350 | TAG (AT_SUN_PLATFORM, _("Platform name string"), str); | |
351 | TAG (AT_SUN_HWCAP, _("Machine-dependent CPU capability hints"), hex); | |
352 | TAG (AT_SUN_IFLUSH, _("Should flush icache?"), dec); | |
353 | TAG (AT_SUN_CPU, _("CPU name string"), str); | |
354 | TAG (AT_SUN_EMUL_ENTRY, _("COFF entry point address"), hex); | |
355 | TAG (AT_SUN_EMUL_EXECFD, _("COFF executable file descriptor"), dec); | |
14ed0a8b | 356 | TAG (AT_SUN_EXECNAME, |
edefbb7c AC |
357 | _("Canonicalized file name given to execve"), str); |
358 | TAG (AT_SUN_MMU, _("String for name of MMU module"), str); | |
359 | TAG (AT_SUN_LDDATA, _("Dynamic linker's data segment address"), hex); | |
77d49ac6 MK |
360 | TAG (AT_SUN_AUXFLAGS, |
361 | _("AF_SUN_ flags passed from the kernel"), hex); | |
14ed0a8b RM |
362 | } |
363 | ||
364 | fprintf_filtered (file, "%-4s %-20s %-30s ", | |
623d3eb1 | 365 | plongest (type), name, description); |
14ed0a8b RM |
366 | switch (flavor) |
367 | { | |
368 | case dec: | |
623d3eb1 | 369 | fprintf_filtered (file, "%s\n", plongest (val)); |
14ed0a8b RM |
370 | break; |
371 | case hex: | |
5af949e3 | 372 | fprintf_filtered (file, "%s\n", paddress (target_gdbarch, val)); |
14ed0a8b RM |
373 | break; |
374 | case str: | |
79a45b7d TT |
375 | { |
376 | struct value_print_options opts; | |
377 | get_user_print_options (&opts); | |
378 | if (opts.addressprint) | |
5af949e3 | 379 | fprintf_filtered (file, "%s", paddress (target_gdbarch, val)); |
6c7a06a3 TT |
380 | val_print_string (builtin_type (target_gdbarch)->builtin_char, |
381 | val, -1, file, &opts); | |
79a45b7d TT |
382 | fprintf_filtered (file, "\n"); |
383 | } | |
14ed0a8b RM |
384 | break; |
385 | } | |
386 | ++ents; | |
7c6467a4 PP |
387 | if (type == AT_NULL) |
388 | break; | |
14ed0a8b RM |
389 | } |
390 | ||
391 | xfree (data); | |
392 | ||
393 | return ents; | |
394 | } | |
395 | ||
396 | static void | |
397 | info_auxv_command (char *cmd, int from_tty) | |
398 | { | |
14ed0a8b | 399 | if (! target_has_stack) |
edefbb7c | 400 | error (_("The program has no auxiliary information now.")); |
14ed0a8b RM |
401 | else |
402 | { | |
403 | int ents = fprint_target_auxv (gdb_stdout, ¤t_target); | |
404 | if (ents < 0) | |
edefbb7c | 405 | error (_("No auxiliary vector found, or failed reading it.")); |
14ed0a8b | 406 | else if (ents == 0) |
edefbb7c | 407 | error (_("Auxiliary vector is empty.")); |
14ed0a8b RM |
408 | } |
409 | } | |
410 | ||
411 | ||
412 | extern initialize_file_ftype _initialize_auxv; /* -Wmissing-prototypes; */ | |
413 | ||
414 | void | |
415 | _initialize_auxv (void) | |
416 | { | |
417 | add_info ("auxv", info_auxv_command, | |
edefbb7c AC |
418 | _("Display the inferior's auxiliary vector.\n\ |
419 | This is information provided by the operating system at program startup.")); | |
14ed0a8b | 420 | } |