* amd64-tdep.c (amd64_sigtramp_frame_sniffer): Rewrite to use new
[deliverable/binutils-gdb.git] / gdb / i386-linux-nat.c
CommitLineData
a4b6fc86
AC
1/* Native-dependent code for GNU/Linux x86.
2
fdfb6fc8 3 Copyright 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
d4f3574e 4
04cd15b6 5 This file is part of GDB.
d4f3574e 6
04cd15b6
MK
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
d4f3574e 11
04cd15b6
MK
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
d4f3574e 16
04cd15b6
MK
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
d4f3574e
SS
21
22#include "defs.h"
23#include "inferior.h"
24#include "gdbcore.h"
4e052eda 25#include "regcache.h"
4de4c07c 26#include "linux-nat.h"
d4f3574e 27
84346e11 28#include "gdb_assert.h"
309367d4 29#include "gdb_string.h"
d4f3574e
SS
30#include <sys/ptrace.h>
31#include <sys/user.h>
32#include <sys/procfs.h>
33
34#ifdef HAVE_SYS_REG_H
35#include <sys/reg.h>
36#endif
37
ce556f85
MK
38#ifndef ORIG_EAX
39#define ORIG_EAX -1
40#endif
41
84346e11
MK
42#ifdef HAVE_SYS_DEBUGREG_H
43#include <sys/debugreg.h>
44#endif
45
46#ifndef DR_FIRSTADDR
47#define DR_FIRSTADDR 0
48#endif
49
50#ifndef DR_LASTADDR
51#define DR_LASTADDR 3
52#endif
53
54#ifndef DR_STATUS
55#define DR_STATUS 6
56#endif
57
58#ifndef DR_CONTROL
59#define DR_CONTROL 7
60#endif
61
6ce2ac0b 62/* Prototypes for supply_gregset etc. */
c60c0f5f
MS
63#include "gregset.h"
64
6ce2ac0b 65/* Prototypes for i387_supply_fsave etc. */
e750d25e 66#include "i387-tdep.h"
6ce2ac0b 67
c3833324
MS
68/* Defines for XMM0_REGNUM etc. */
69#include "i386-tdep.h"
70
5179e78f
AC
71/* Defines I386_LINUX_ORIG_EAX_REGNUM. */
72#include "i386-linux-tdep.h"
73
b757528f
JJ
74/* Defines ps_err_e, struct ps_prochandle. */
75#include "gdb_proc_service.h"
76
756ed206
MK
77/* Prototypes for local functions. */
78static void dummy_sse_values (void);
6ce2ac0b 79\f
d4f3574e 80
a4b6fc86
AC
81/* The register sets used in GNU/Linux ELF core-dumps are identical to
82 the register sets in `struct user' that is used for a.out
83 core-dumps, and is also used by `ptrace'. The corresponding types
84 are `elf_gregset_t' for the general-purpose registers (with
04cd15b6
MK
85 `elf_greg_t' the type of a single GP register) and `elf_fpregset_t'
86 for the floating-point registers.
87
88 Those types used to be available under the names `gregset_t' and
89 `fpregset_t' too, and this file used those names in the past. But
90 those names are now used for the register sets used in the
91 `mcontext_t' type, and have a different size and layout. */
92
93/* Mapping between the general-purpose registers in `struct user'
94 format and GDB's register array layout. */
d4f3574e
SS
95static int regmap[] =
96{
97 EAX, ECX, EDX, EBX,
98 UESP, EBP, ESI, EDI,
99 EIP, EFL, CS, SS,
ce556f85
MK
100 DS, ES, FS, GS,
101 -1, -1, -1, -1, /* st0, st1, st2, st3 */
102 -1, -1, -1, -1, /* st4, st5, st6, st7 */
103 -1, -1, -1, -1, /* fctrl, fstat, ftag, fiseg */
104 -1, -1, -1, -1, /* fioff, foseg, fooff, fop */
105 -1, -1, -1, -1, /* xmm0, xmm1, xmm2, xmm3 */
106 -1, -1, -1, -1, /* xmm4, xmm5, xmm6, xmm6 */
107 -1, /* mxcsr */
108 ORIG_EAX
d4f3574e
SS
109};
110
5c44784c
JM
111/* Which ptrace request retrieves which registers?
112 These apply to the corresponding SET requests as well. */
e64a344c 113
5c44784c 114#define GETREGS_SUPPLIES(regno) \
3fb1c838 115 ((0 <= (regno) && (regno) <= 15) || (regno) == I386_LINUX_ORIG_EAX_REGNUM)
e64a344c 116
5c44784c
JM
117#define GETFPREGS_SUPPLIES(regno) \
118 (FP0_REGNUM <= (regno) && (regno) <= LAST_FPU_CTRL_REGNUM)
e64a344c 119
6ce2ac0b 120#define GETFPXREGS_SUPPLIES(regno) \
5c44784c
JM
121 (FP0_REGNUM <= (regno) && (regno) <= MXCSR_REGNUM)
122
f60300e7
MK
123/* Does the current host support the GETREGS request? */
124int have_ptrace_getregs =
125#ifdef HAVE_PTRACE_GETREGS
126 1
127#else
128 0
129#endif
130;
131
6ce2ac0b 132/* Does the current host support the GETFPXREGS request? The header
5c44784c
JM
133 file may or may not define it, and even if it is defined, the
134 kernel will return EIO if it's running on a pre-SSE processor.
135
136 My instinct is to attach this to some architecture- or
137 target-specific data structure, but really, a particular GDB
138 process can only run on top of one kernel at a time. So it's okay
139 for this to be a simple variable. */
6ce2ac0b
MK
140int have_ptrace_getfpxregs =
141#ifdef HAVE_PTRACE_GETFPXREGS
5c44784c
JM
142 1
143#else
144 0
145#endif
146;
f60300e7 147\f
6ce2ac0b 148
84346e11
MK
149/* Support for the user struct. */
150
151/* Return the address of register REGNUM. BLOCKEND is the value of
152 u.u_ar0, which should point to the registers. */
153
154CORE_ADDR
155register_u_addr (CORE_ADDR blockend, int regnum)
156{
157 return (blockend + 4 * regmap[regnum]);
158}
159
160/* Return the size of the user struct. */
161
162int
163kernel_u_size (void)
164{
165 return (sizeof (struct user));
166}
167\f
168
ce556f85 169/* Accessing registers through the U area, one at a time. */
f60300e7
MK
170
171/* Fetch one register. */
172
173static void
fba45db2 174fetch_register (int regno)
f60300e7 175{
f60300e7 176 int tid;
ce556f85 177 int val;
f60300e7 178
ce556f85
MK
179 gdb_assert (!have_ptrace_getregs);
180 if (cannot_fetch_register (regno))
f60300e7 181 {
ce556f85 182 supply_register (regno, NULL);
f60300e7
MK
183 return;
184 }
185
ce556f85 186 /* GNU/Linux LWP ID's are process ID's. */
e64a344c
MK
187 tid = TIDGET (inferior_ptid);
188 if (tid == 0)
189 tid = PIDGET (inferior_ptid); /* Not a threaded program. */
f60300e7 190
ce556f85
MK
191 errno = 0;
192 val = ptrace (PTRACE_PEEKUSER, tid, register_addr (regno, 0), 0);
193 if (errno != 0)
194 error ("Couldn't read register %s (#%d): %s.", REGISTER_NAME (regno),
195 regno, safe_strerror (errno));
f60300e7 196
ce556f85 197 supply_register (regno, &val);
f60300e7
MK
198}
199
f60300e7
MK
200/* Store one register. */
201
202static void
fba45db2 203store_register (int regno)
f60300e7 204{
f60300e7 205 int tid;
ce556f85 206 int val;
f60300e7 207
ce556f85
MK
208 gdb_assert (!have_ptrace_getregs);
209 if (cannot_store_register (regno))
210 return;
f60300e7 211
ce556f85 212 /* GNU/Linux LWP ID's are process ID's. */
e64a344c
MK
213 tid = TIDGET (inferior_ptid);
214 if (tid == 0)
215 tid = PIDGET (inferior_ptid); /* Not a threaded program. */
f60300e7 216
ce556f85
MK
217 errno = 0;
218 regcache_collect (regno, &val);
219 ptrace (PTRACE_POKEUSER, tid, register_addr (regno, 0), val);
220 if (errno != 0)
e64a344c 221 error ("Couldn't write register %s (#%d): %s.", REGISTER_NAME (regno),
ce556f85 222 regno, safe_strerror (errno));
f60300e7 223}
5c44784c 224\f
6ce2ac0b 225
04cd15b6
MK
226/* Transfering the general-purpose registers between GDB, inferiors
227 and core files. */
228
ad2a4d09 229/* Fill GDB's register array with the general-purpose register values
04cd15b6 230 in *GREGSETP. */
5c44784c 231
d4f3574e 232void
04cd15b6 233supply_gregset (elf_gregset_t *gregsetp)
d4f3574e 234{
04cd15b6 235 elf_greg_t *regp = (elf_greg_t *) gregsetp;
6ce2ac0b 236 int i;
d4f3574e 237
98df6387 238 for (i = 0; i < I386_NUM_GREGS; i++)
14b08c1b 239 supply_register (i, regp + regmap[i]);
3fb1c838 240
82ea117a 241 if (I386_LINUX_ORIG_EAX_REGNUM < NUM_REGS)
14b08c1b 242 supply_register (I386_LINUX_ORIG_EAX_REGNUM, regp + ORIG_EAX);
917317f4
JM
243}
244
04cd15b6
MK
245/* Fill register REGNO (if it is a general-purpose register) in
246 *GREGSETPS with the value in GDB's register array. If REGNO is -1,
247 do this for all registers. */
6ce2ac0b 248
917317f4 249void
04cd15b6 250fill_gregset (elf_gregset_t *gregsetp, int regno)
917317f4 251{
6ce2ac0b
MK
252 elf_greg_t *regp = (elf_greg_t *) gregsetp;
253 int i;
04cd15b6 254
98df6387 255 for (i = 0; i < I386_NUM_GREGS; i++)
099a9414 256 if (regno == -1 || regno == i)
8a406745 257 regcache_collect (i, regp + regmap[i]);
3fb1c838 258
82ea117a
MK
259 if ((regno == -1 || regno == I386_LINUX_ORIG_EAX_REGNUM)
260 && I386_LINUX_ORIG_EAX_REGNUM < NUM_REGS)
76fb44f4 261 regcache_collect (I386_LINUX_ORIG_EAX_REGNUM, regp + ORIG_EAX);
d4f3574e
SS
262}
263
f60300e7
MK
264#ifdef HAVE_PTRACE_GETREGS
265
04cd15b6
MK
266/* Fetch all general-purpose registers from process/thread TID and
267 store their values in GDB's register array. */
d4f3574e 268
5c44784c 269static void
ed9a39eb 270fetch_regs (int tid)
5c44784c 271{
04cd15b6 272 elf_gregset_t regs;
5c44784c 273
6ce2ac0b 274 if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
5c44784c 275 {
f60300e7
MK
276 if (errno == EIO)
277 {
278 /* The kernel we're running on doesn't support the GETREGS
279 request. Reset `have_ptrace_getregs'. */
280 have_ptrace_getregs = 0;
281 return;
282 }
283
6ce2ac0b 284 perror_with_name ("Couldn't get registers");
5c44784c
JM
285 }
286
04cd15b6 287 supply_gregset (&regs);
5c44784c
JM
288}
289
04cd15b6
MK
290/* Store all valid general-purpose registers in GDB's register array
291 into the process/thread specified by TID. */
5c44784c 292
5c44784c 293static void
6ce2ac0b 294store_regs (int tid, int regno)
5c44784c 295{
04cd15b6 296 elf_gregset_t regs;
5c44784c 297
6ce2ac0b
MK
298 if (ptrace (PTRACE_GETREGS, tid, 0, (int) &regs) < 0)
299 perror_with_name ("Couldn't get registers");
5c44784c 300
6ce2ac0b
MK
301 fill_gregset (&regs, regno);
302
303 if (ptrace (PTRACE_SETREGS, tid, 0, (int) &regs) < 0)
304 perror_with_name ("Couldn't write registers");
5c44784c
JM
305}
306
f60300e7
MK
307#else
308
309static void fetch_regs (int tid) {}
6ce2ac0b 310static void store_regs (int tid, int regno) {}
f60300e7
MK
311
312#endif
5c44784c 313\f
5c44784c 314
6ce2ac0b 315/* Transfering floating-point registers between GDB, inferiors and cores. */
d4f3574e 316
04cd15b6 317/* Fill GDB's register array with the floating-point register values in
917317f4 318 *FPREGSETP. */
04cd15b6 319
d4f3574e 320void
04cd15b6 321supply_fpregset (elf_fpregset_t *fpregsetp)
d4f3574e 322{
41d041d6 323 i387_supply_fsave (current_regcache, -1, fpregsetp);
756ed206 324 dummy_sse_values ();
917317f4 325}
d4f3574e 326
04cd15b6
MK
327/* Fill register REGNO (if it is a floating-point register) in
328 *FPREGSETP with the value in GDB's register array. If REGNO is -1,
329 do this for all registers. */
917317f4
JM
330
331void
04cd15b6 332fill_fpregset (elf_fpregset_t *fpregsetp, int regno)
917317f4 333{
6ce2ac0b 334 i387_fill_fsave ((char *) fpregsetp, regno);
d4f3574e
SS
335}
336
f60300e7
MK
337#ifdef HAVE_PTRACE_GETREGS
338
04cd15b6
MK
339/* Fetch all floating-point registers from process/thread TID and store
340 thier values in GDB's register array. */
917317f4 341
d4f3574e 342static void
ed9a39eb 343fetch_fpregs (int tid)
d4f3574e 344{
04cd15b6 345 elf_fpregset_t fpregs;
d4f3574e 346
6ce2ac0b
MK
347 if (ptrace (PTRACE_GETFPREGS, tid, 0, (int) &fpregs) < 0)
348 perror_with_name ("Couldn't get floating point status");
d4f3574e 349
04cd15b6 350 supply_fpregset (&fpregs);
d4f3574e
SS
351}
352
04cd15b6
MK
353/* Store all valid floating-point registers in GDB's register array
354 into the process/thread specified by TID. */
d4f3574e 355
d4f3574e 356static void
6ce2ac0b 357store_fpregs (int tid, int regno)
d4f3574e 358{
04cd15b6 359 elf_fpregset_t fpregs;
d4f3574e 360
6ce2ac0b
MK
361 if (ptrace (PTRACE_GETFPREGS, tid, 0, (int) &fpregs) < 0)
362 perror_with_name ("Couldn't get floating point status");
d4f3574e 363
6ce2ac0b 364 fill_fpregset (&fpregs, regno);
d4f3574e 365
6ce2ac0b
MK
366 if (ptrace (PTRACE_SETFPREGS, tid, 0, (int) &fpregs) < 0)
367 perror_with_name ("Couldn't write floating point status");
d4f3574e
SS
368}
369
f60300e7
MK
370#else
371
372static void fetch_fpregs (int tid) {}
6ce2ac0b 373static void store_fpregs (int tid, int regno) {}
f60300e7
MK
374
375#endif
5c44784c 376\f
d4f3574e 377
6ce2ac0b 378/* Transfering floating-point and SSE registers to and from GDB. */
11cf8741 379
6ce2ac0b 380#ifdef HAVE_PTRACE_GETFPXREGS
04cd15b6
MK
381
382/* Fill GDB's register array with the floating-point and SSE register
6ce2ac0b 383 values in *FPXREGSETP. */
04cd15b6 384
975aec09 385void
6ce2ac0b 386supply_fpxregset (elf_fpxregset_t *fpxregsetp)
d4f3574e 387{
41d041d6 388 i387_supply_fxsave (current_regcache, -1, fpxregsetp);
d4f3574e
SS
389}
390
6ce2ac0b
MK
391/* Fill register REGNO (if it is a floating-point or SSE register) in
392 *FPXREGSETP with the value in GDB's register array. If REGNO is
393 -1, do this for all registers. */
d4f3574e 394
975aec09 395void
6ce2ac0b 396fill_fpxregset (elf_fpxregset_t *fpxregsetp, int regno)
d4f3574e 397{
6ce2ac0b 398 i387_fill_fxsave ((char *) fpxregsetp, regno);
5c44784c
JM
399}
400
6ce2ac0b 401/* Fetch all registers covered by the PTRACE_GETFPXREGS request from
04cd15b6
MK
402 process/thread TID and store their values in GDB's register array.
403 Return non-zero if successful, zero otherwise. */
5c44784c 404
5c44784c 405static int
6ce2ac0b 406fetch_fpxregs (int tid)
5c44784c 407{
6ce2ac0b 408 elf_fpxregset_t fpxregs;
5c44784c 409
6ce2ac0b 410 if (! have_ptrace_getfpxregs)
5c44784c
JM
411 return 0;
412
6ce2ac0b 413 if (ptrace (PTRACE_GETFPXREGS, tid, 0, (int) &fpxregs) < 0)
d4f3574e 414 {
5c44784c
JM
415 if (errno == EIO)
416 {
6ce2ac0b 417 have_ptrace_getfpxregs = 0;
5c44784c
JM
418 return 0;
419 }
420
6ce2ac0b 421 perror_with_name ("Couldn't read floating-point and SSE registers");
d4f3574e
SS
422 }
423
6ce2ac0b 424 supply_fpxregset (&fpxregs);
5c44784c
JM
425 return 1;
426}
d4f3574e 427
04cd15b6 428/* Store all valid registers in GDB's register array covered by the
6ce2ac0b 429 PTRACE_SETFPXREGS request into the process/thread specified by TID.
04cd15b6 430 Return non-zero if successful, zero otherwise. */
5c44784c 431
5c44784c 432static int
6ce2ac0b 433store_fpxregs (int tid, int regno)
5c44784c 434{
6ce2ac0b 435 elf_fpxregset_t fpxregs;
5c44784c 436
6ce2ac0b 437 if (! have_ptrace_getfpxregs)
5c44784c 438 return 0;
6ce2ac0b
MK
439
440 if (ptrace (PTRACE_GETFPXREGS, tid, 0, &fpxregs) == -1)
2866d305
MK
441 {
442 if (errno == EIO)
443 {
444 have_ptrace_getfpxregs = 0;
445 return 0;
446 }
447
448 perror_with_name ("Couldn't read floating-point and SSE registers");
449 }
5c44784c 450
6ce2ac0b 451 fill_fpxregset (&fpxregs, regno);
5c44784c 452
6ce2ac0b
MK
453 if (ptrace (PTRACE_SETFPXREGS, tid, 0, &fpxregs) == -1)
454 perror_with_name ("Couldn't write floating-point and SSE registers");
5c44784c
JM
455
456 return 1;
457}
458
04cd15b6 459/* Fill the XMM registers in the register array with dummy values. For
5c44784c
JM
460 cases where we don't have access to the XMM registers. I think
461 this is cleaner than printing a warning. For a cleaner solution,
462 we should gdbarchify the i386 family. */
04cd15b6 463
5c44784c 464static void
04cd15b6 465dummy_sse_values (void)
5c44784c 466{
7010ca0a 467 struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
5c44784c
JM
468 /* C doesn't have a syntax for NaN's, so write it out as an array of
469 longs. */
470 static long dummy[4] = { 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff };
471 static long mxcsr = 0x1f80;
472 int reg;
473
7010ca0a 474 for (reg = 0; reg < tdep->num_xmm_regs; reg++)
5c44784c 475 supply_register (XMM0_REGNUM + reg, (char *) dummy);
7010ca0a
MK
476 if (tdep->num_xmm_regs > 0)
477 supply_register (MXCSR_REGNUM, (char *) &mxcsr);
d4f3574e
SS
478}
479
5c44784c
JM
480#else
481
f0373401
MK
482static int fetch_fpxregs (int tid) { return 0; }
483static int store_fpxregs (int tid, int regno) { return 0; }
04cd15b6 484static void dummy_sse_values (void) {}
5c44784c 485
6ce2ac0b 486#endif /* HAVE_PTRACE_GETFPXREGS */
5c44784c 487\f
6ce2ac0b 488
5c44784c 489/* Transferring arbitrary registers between GDB and inferior. */
d4f3574e 490
d5d65353
PS
491/* Check if register REGNO in the child process is accessible.
492 If we are accessing registers directly via the U area, only the
493 general-purpose registers are available.
494 All registers should be accessible if we have GETREGS support. */
495
496int
497cannot_fetch_register (int regno)
498{
ce556f85
MK
499 gdb_assert (regno >= 0 && regno < NUM_REGS);
500 return (!have_ptrace_getregs && regmap[regno] == -1);
d5d65353 501}
ce556f85 502
d5d65353
PS
503int
504cannot_store_register (int regno)
505{
ce556f85
MK
506 gdb_assert (regno >= 0 && regno < NUM_REGS);
507 return (!have_ptrace_getregs && regmap[regno] == -1);
d5d65353
PS
508}
509
04cd15b6
MK
510/* Fetch register REGNO from the child process. If REGNO is -1, do
511 this for all registers (including the floating point and SSE
512 registers). */
d4f3574e
SS
513
514void
917317f4 515fetch_inferior_registers (int regno)
d4f3574e 516{
ed9a39eb
JM
517 int tid;
518
f60300e7
MK
519 /* Use the old method of peeking around in `struct user' if the
520 GETREGS request isn't available. */
ce556f85 521 if (!have_ptrace_getregs)
f60300e7 522 {
ce556f85
MK
523 int i;
524
525 for (i = 0; i < NUM_REGS; i++)
526 if (regno == -1 || regno == i)
527 fetch_register (i);
528
f60300e7
MK
529 return;
530 }
531
a4b6fc86 532 /* GNU/Linux LWP ID's are process ID's. */
e64a344c
MK
533 tid = TIDGET (inferior_ptid);
534 if (tid == 0)
535 tid = PIDGET (inferior_ptid); /* Not a threaded program. */
ed9a39eb 536
6ce2ac0b 537 /* Use the PTRACE_GETFPXREGS request whenever possible, since it
04cd15b6 538 transfers more registers in one system call, and we'll cache the
6ce2ac0b 539 results. But remember that fetch_fpxregs can fail, and return
04cd15b6 540 zero. */
5c44784c
JM
541 if (regno == -1)
542 {
ed9a39eb 543 fetch_regs (tid);
f60300e7
MK
544
545 /* The call above might reset `have_ptrace_getregs'. */
ce556f85 546 if (!have_ptrace_getregs)
f60300e7 547 {
ce556f85 548 fetch_inferior_registers (regno);
f60300e7
MK
549 return;
550 }
551
6ce2ac0b 552 if (fetch_fpxregs (tid))
5c44784c 553 return;
ed9a39eb 554 fetch_fpregs (tid);
5c44784c
JM
555 return;
556 }
d4f3574e 557
5c44784c
JM
558 if (GETREGS_SUPPLIES (regno))
559 {
ed9a39eb 560 fetch_regs (tid);
5c44784c
JM
561 return;
562 }
563
6ce2ac0b 564 if (GETFPXREGS_SUPPLIES (regno))
5c44784c 565 {
6ce2ac0b 566 if (fetch_fpxregs (tid))
5c44784c
JM
567 return;
568
569 /* Either our processor or our kernel doesn't support the SSE
570 registers, so read the FP registers in the traditional way,
571 and fill the SSE registers with dummy values. It would be
572 more graceful to handle differences in the register set using
573 gdbarch. Until then, this will at least make things work
574 plausibly. */
ed9a39eb 575 fetch_fpregs (tid);
5c44784c
JM
576 return;
577 }
578
8e65ff28
AC
579 internal_error (__FILE__, __LINE__,
580 "Got request for bad register number %d.", regno);
d4f3574e
SS
581}
582
04cd15b6
MK
583/* Store register REGNO back into the child process. If REGNO is -1,
584 do this for all registers (including the floating point and SSE
585 registers). */
d4f3574e 586void
04cd15b6 587store_inferior_registers (int regno)
d4f3574e 588{
ed9a39eb
JM
589 int tid;
590
f60300e7
MK
591 /* Use the old method of poking around in `struct user' if the
592 SETREGS request isn't available. */
ce556f85 593 if (!have_ptrace_getregs)
f60300e7 594 {
ce556f85
MK
595 int i;
596
597 for (i = 0; i < NUM_REGS; i++)
598 if (regno == -1 || regno == i)
599 store_register (i);
600
f60300e7
MK
601 return;
602 }
603
a4b6fc86 604 /* GNU/Linux LWP ID's are process ID's. */
e64a344c
MK
605 tid = TIDGET (inferior_ptid);
606 if (tid == 0)
607 tid = PIDGET (inferior_ptid); /* Not a threaded program. */
ed9a39eb 608
6ce2ac0b 609 /* Use the PTRACE_SETFPXREGS requests whenever possible, since it
04cd15b6 610 transfers more registers in one system call. But remember that
6ce2ac0b 611 store_fpxregs can fail, and return zero. */
5c44784c
JM
612 if (regno == -1)
613 {
6ce2ac0b
MK
614 store_regs (tid, regno);
615 if (store_fpxregs (tid, regno))
5c44784c 616 return;
6ce2ac0b 617 store_fpregs (tid, regno);
5c44784c
JM
618 return;
619 }
d4f3574e 620
5c44784c
JM
621 if (GETREGS_SUPPLIES (regno))
622 {
6ce2ac0b 623 store_regs (tid, regno);
5c44784c
JM
624 return;
625 }
626
6ce2ac0b 627 if (GETFPXREGS_SUPPLIES (regno))
5c44784c 628 {
6ce2ac0b 629 if (store_fpxregs (tid, regno))
5c44784c
JM
630 return;
631
632 /* Either our processor or our kernel doesn't support the SSE
04cd15b6
MK
633 registers, so just write the FP registers in the traditional
634 way. */
6ce2ac0b 635 store_fpregs (tid, regno);
5c44784c
JM
636 return;
637 }
638
8e65ff28
AC
639 internal_error (__FILE__, __LINE__,
640 "Got request to store bad register number %d.", regno);
d4f3574e 641}
de57eccd 642\f
6ce2ac0b 643
4ffc8466
MK
644/* Support for debug registers. */
645
7bf0983e 646static unsigned long
84346e11
MK
647i386_linux_dr_get (int regnum)
648{
649 int tid;
7bf0983e 650 unsigned long value;
84346e11
MK
651
652 /* FIXME: kettenis/2001-01-29: It's not clear what we should do with
653 multi-threaded processes here. For now, pretend there is just
654 one thread. */
39f77062 655 tid = PIDGET (inferior_ptid);
84346e11 656
b9511b9a
MK
657 /* FIXME: kettenis/2001-03-27: Calling perror_with_name if the
658 ptrace call fails breaks debugging remote targets. The correct
659 way to fix this is to add the hardware breakpoint and watchpoint
660 stuff to the target vectore. For now, just return zero if the
661 ptrace call fails. */
84346e11 662 errno = 0;
ce556f85 663 value = ptrace (PTRACE_PEEKUSER, tid,
84346e11
MK
664 offsetof (struct user, u_debugreg[regnum]), 0);
665 if (errno != 0)
b9511b9a 666#if 0
84346e11 667 perror_with_name ("Couldn't read debug register");
b9511b9a
MK
668#else
669 return 0;
670#endif
84346e11
MK
671
672 return value;
673}
674
675static void
7bf0983e 676i386_linux_dr_set (int regnum, unsigned long value)
84346e11
MK
677{
678 int tid;
679
680 /* FIXME: kettenis/2001-01-29: It's not clear what we should do with
681 multi-threaded processes here. For now, pretend there is just
682 one thread. */
39f77062 683 tid = PIDGET (inferior_ptid);
84346e11
MK
684
685 errno = 0;
ce556f85 686 ptrace (PTRACE_POKEUSER, tid,
84346e11
MK
687 offsetof (struct user, u_debugreg[regnum]), value);
688 if (errno != 0)
689 perror_with_name ("Couldn't write debug register");
690}
691
692void
7bf0983e 693i386_linux_dr_set_control (unsigned long control)
84346e11
MK
694{
695 i386_linux_dr_set (DR_CONTROL, control);
696}
697
698void
699i386_linux_dr_set_addr (int regnum, CORE_ADDR addr)
700{
701 gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR);
702
703 i386_linux_dr_set (DR_FIRSTADDR + regnum, addr);
704}
705
706void
707i386_linux_dr_reset_addr (int regnum)
708{
709 gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR);
710
711 i386_linux_dr_set (DR_FIRSTADDR + regnum, 0L);
712}
713
7bf0983e 714unsigned long
84346e11
MK
715i386_linux_dr_get_status (void)
716{
717 return i386_linux_dr_get (DR_STATUS);
718}
719\f
720
5bca7895
MK
721/* Called by libthread_db. Returns a pointer to the thread local
722 storage (or its descriptor). */
723
724ps_err_e
725ps_get_thread_area (const struct ps_prochandle *ph,
726 lwpid_t lwpid, int idx, void **base)
727{
728 /* NOTE: cagney/2003-08-26: The definition of this buffer is found
729 in the kernel header <asm-i386/ldt.h>. It, after padding, is 4 x
730 4 byte integers in size: `entry_number', `base_addr', `limit',
731 and a bunch of status bits.
732
733 The values returned by this ptrace call should be part of the
734 regcache buffer, and ps_get_thread_area should channel its
735 request through the regcache. That way remote targets could
736 provide the value using the remote protocol and not this direct
737 call.
738
739 Is this function needed? I'm guessing that the `base' is the
740 address of a a descriptor that libthread_db uses to find the
741 thread local address base that GDB needs. Perhaphs that
742 descriptor is defined by the ABI. Anyway, given that
743 libthread_db calls this function without prompting (gdb
744 requesting tls base) I guess it needs info in there anyway. */
745 unsigned int desc[4];
746 gdb_assert (sizeof (int) == 4);
747
748#ifndef PTRACE_GET_THREAD_AREA
749#define PTRACE_GET_THREAD_AREA 25
750#endif
751
752 if (ptrace (PTRACE_GET_THREAD_AREA, lwpid,
753 (void *) idx, (unsigned long) &desc) < 0)
754 return PS_ERR;
755
756 *(int *)base = desc[1];
757 return PS_OK;
758}
759\f
760
a4b6fc86 761/* The instruction for a GNU/Linux system call is:
a6abb2c0
MK
762 int $0x80
763 or 0xcd 0x80. */
764
765static const unsigned char linux_syscall[] = { 0xcd, 0x80 };
766
767#define LINUX_SYSCALL_LEN (sizeof linux_syscall)
768
769/* The system call number is stored in the %eax register. */
770#define LINUX_SYSCALL_REGNUM 0 /* %eax */
771
772/* We are specifically interested in the sigreturn and rt_sigreturn
773 system calls. */
774
775#ifndef SYS_sigreturn
776#define SYS_sigreturn 0x77
777#endif
778#ifndef SYS_rt_sigreturn
779#define SYS_rt_sigreturn 0xad
780#endif
781
782/* Offset to saved processor flags, from <asm/sigcontext.h>. */
783#define LINUX_SIGCONTEXT_EFLAGS_OFFSET (64)
784
785/* Resume execution of the inferior process.
786 If STEP is nonzero, single-step it.
787 If SIGNAL is nonzero, give it that signal. */
788
789void
39f77062 790child_resume (ptid_t ptid, int step, enum target_signal signal)
a6abb2c0 791{
39f77062
KB
792 int pid = PIDGET (ptid);
793
a6abb2c0
MK
794 int request = PTRACE_CONT;
795
796 if (pid == -1)
797 /* Resume all threads. */
798 /* I think this only gets used in the non-threaded case, where "resume
39f77062
KB
799 all threads" and "resume inferior_ptid" are the same. */
800 pid = PIDGET (inferior_ptid);
a6abb2c0
MK
801
802 if (step)
803 {
39f77062 804 CORE_ADDR pc = read_pc_pid (pid_to_ptid (pid));
a6abb2c0
MK
805 unsigned char buf[LINUX_SYSCALL_LEN];
806
807 request = PTRACE_SINGLESTEP;
808
809 /* Returning from a signal trampoline is done by calling a
810 special system call (sigreturn or rt_sigreturn, see
811 i386-linux-tdep.c for more information). This system call
812 restores the registers that were saved when the signal was
813 raised, including %eflags. That means that single-stepping
814 won't work. Instead, we'll have to modify the signal context
815 that's about to be restored, and set the trace flag there. */
816
817 /* First check if PC is at a system call. */
818 if (read_memory_nobpt (pc, (char *) buf, LINUX_SYSCALL_LEN) == 0
819 && memcmp (buf, linux_syscall, LINUX_SYSCALL_LEN) == 0)
820 {
39f77062
KB
821 int syscall = read_register_pid (LINUX_SYSCALL_REGNUM,
822 pid_to_ptid (pid));
a6abb2c0
MK
823
824 /* Then check the system call number. */
825 if (syscall == SYS_sigreturn || syscall == SYS_rt_sigreturn)
826 {
c7f16359 827 CORE_ADDR sp = read_register (I386_ESP_REGNUM);
a6abb2c0
MK
828 CORE_ADDR addr = sp;
829 unsigned long int eflags;
7bf0983e 830
a6abb2c0
MK
831 if (syscall == SYS_rt_sigreturn)
832 addr = read_memory_integer (sp + 8, 4) + 20;
833
834 /* Set the trace flag in the context that's about to be
835 restored. */
836 addr += LINUX_SIGCONTEXT_EFLAGS_OFFSET;
837 read_memory (addr, (char *) &eflags, 4);
838 eflags |= 0x0100;
839 write_memory (addr, (char *) &eflags, 4);
840 }
841 }
842 }
843
844 if (ptrace (request, pid, 0, target_signal_to_host (signal)) == -1)
845 perror_with_name ("ptrace");
846}
4de4c07c
DJ
847
848void
849child_post_startup_inferior (ptid_t ptid)
850{
851 i386_cleanup_dregs ();
852 linux_child_post_startup_inferior (ptid);
853}
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