gdb/arm-linux-nat.c

   1 /* GNU/Linux on ARM native support.
   2    Copyright (C) 1999, 2000, 2001, 2002, 2004, 2005, 2006, 2007
   3    Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   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 3 of the License, or
  10    (at your option) any later version.
  11
  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.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "inferior.h"
  22 #include "gdbcore.h"
  23 #include "gdb_string.h"
  24 #include "regcache.h"
  25 #include "target.h"
  26 #include "linux-nat.h"
  27 #include "target-descriptions.h"
  28
  29 #include "arm-tdep.h"
  30 #include "arm-linux-tdep.h"
  31
  32 #include <sys/user.h>
  33 #include <sys/ptrace.h>
  34 #include <sys/utsname.h>
  35 #include <sys/procfs.h>
  36
  37 /* Prototypes for supply_gregset etc. */
  38 #include "gregset.h"
  39
  40 /* Defines ps_err_e, struct ps_prochandle.  */
  41 #include "gdb_proc_service.h"
  42
  43 #include "features/arm-with-iwmmxt.c"
  44
  45 #ifndef PTRACE_GET_THREAD_AREA
  46 #define PTRACE_GET_THREAD_AREA 22
  47 #endif
  48
  49 #ifndef PTRACE_GETWMMXREGS
  50 #define PTRACE_GETWMMXREGS 18
  51 #define PTRACE_SETWMMXREGS 19
  52 #endif
  53
  54 /* A flag for whether the WMMX registers are available.  */
  55 static int arm_linux_has_wmmx_registers;
  56
  57 extern int arm_apcs_32;
  58
  59 /* The following variables are used to determine the version of the
  60    underlying GNU/Linux operating system.  Examples:
  61
  62    GNU/Linux 2.0.35             GNU/Linux 2.2.12
  63    os_version = 0x00020023      os_version = 0x0002020c
  64    os_major = 2                 os_major = 2
  65    os_minor = 0                 os_minor = 2
  66    os_release = 35              os_release = 12
  67
  68    Note: os_version = (os_major << 16) | (os_minor << 8) | os_release
  69
  70    These are initialized using get_linux_version() from
  71    _initialize_arm_linux_nat().  */
  72
  73 static unsigned int os_version, os_major, os_minor, os_release;
  74
  75 /* On GNU/Linux, threads are implemented as pseudo-processes, in which
  76    case we may be tracing more than one process at a time.  In that
  77    case, inferior_ptid will contain the main process ID and the
  78    individual thread (process) ID.  get_thread_id () is used to get
  79    the thread id if it's available, and the process id otherwise.  */
  80
  81 int
  82 get_thread_id (ptid_t ptid)
  83 {
  84   int tid = TIDGET (ptid);
  85   if (0 == tid)
  86     tid = PIDGET (ptid);
  87   return tid;
  88 }
  89 #define GET_THREAD_ID(PTID)     get_thread_id (PTID)
  90
  91 /* Get the value of a particular register from the floating point
  92    state of the process and store it into regcache.  */
  93
  94 static void
  95 fetch_fpregister (struct regcache *regcache, int regno)
  96 {
  97   int ret, tid;
  98   gdb_byte fp[ARM_LINUX_SIZEOF_NWFPE];
  99
 100   /* Get the thread id for the ptrace call.  */
 101   tid = GET_THREAD_ID (inferior_ptid);
 102
 103   /* Read the floating point state.  */
 104   ret = ptrace (PT_GETFPREGS, tid, 0, fp);
 105   if (ret < 0)
 106     {
 107       warning (_("Unable to fetch floating point register."));
 108       return;
 109     }
 110
 111   /* Fetch fpsr.  */
 112   if (ARM_FPS_REGNUM == regno)
 113     regcache_raw_supply (regcache, ARM_FPS_REGNUM,
 114                          fp + NWFPE_FPSR_OFFSET);
 115
 116   /* Fetch the floating point register.  */
 117   if (regno >= ARM_F0_REGNUM && regno <= ARM_F7_REGNUM)
 118     supply_nwfpe_register (regcache, regno, fp);
 119 }
 120
 121 /* Get the whole floating point state of the process and store it
 122    into regcache.  */
 123
 124 static void
 125 fetch_fpregs (struct regcache *regcache)
 126 {
 127   int ret, regno, tid;
 128   gdb_byte fp[ARM_LINUX_SIZEOF_NWFPE];
 129
 130   /* Get the thread id for the ptrace call.  */
 131   tid = GET_THREAD_ID (inferior_ptid);
 132
 133   /* Read the floating point state.  */
 134   ret = ptrace (PT_GETFPREGS, tid, 0, fp);
 135   if (ret < 0)
 136     {
 137       warning (_("Unable to fetch the floating point registers."));
 138       return;
 139     }
 140
 141   /* Fetch fpsr.  */
 142   regcache_raw_supply (regcache, ARM_FPS_REGNUM,
 143                        fp + NWFPE_FPSR_OFFSET);
 144
 145   /* Fetch the floating point registers.  */
 146   for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
 147     supply_nwfpe_register (regcache, regno, fp);
 148 }
 149
 150 /* Save a particular register into the floating point state of the
 151    process using the contents from regcache.  */
 152
 153 static void
 154 store_fpregister (const struct regcache *regcache, int regno)
 155 {
 156   int ret, tid;
 157   gdb_byte fp[ARM_LINUX_SIZEOF_NWFPE];
 158
 159   /* Get the thread id for the ptrace call.  */
 160   tid = GET_THREAD_ID (inferior_ptid);
 161
 162   /* Read the floating point state.  */
 163   ret = ptrace (PT_GETFPREGS, tid, 0, fp);
 164   if (ret < 0)
 165     {
 166       warning (_("Unable to fetch the floating point registers."));
 167       return;
 168     }
 169
 170   /* Store fpsr.  */
 171   if (ARM_FPS_REGNUM == regno && regcache_valid_p (regcache, ARM_FPS_REGNUM))
 172     regcache_raw_collect (regcache, ARM_FPS_REGNUM, fp + NWFPE_FPSR_OFFSET);
 173
 174   /* Store the floating point register.  */
 175   if (regno >= ARM_F0_REGNUM && regno <= ARM_F7_REGNUM)
 176     collect_nwfpe_register (regcache, regno, fp);
 177
 178   ret = ptrace (PTRACE_SETFPREGS, tid, 0, fp);
 179   if (ret < 0)
 180     {
 181       warning (_("Unable to store floating point register."));
 182       return;
 183     }
 184 }
 185
 186 /* Save the whole floating point state of the process using
 187    the contents from regcache.  */
 188
 189 static void
 190 store_fpregs (const struct regcache *regcache)
 191 {
 192   int ret, regno, tid;
 193   gdb_byte fp[ARM_LINUX_SIZEOF_NWFPE];
 194
 195   /* Get the thread id for the ptrace call.  */
 196   tid = GET_THREAD_ID (inferior_ptid);
 197
 198   /* Read the floating point state.  */
 199   ret = ptrace (PT_GETFPREGS, tid, 0, fp);
 200   if (ret < 0)
 201     {
 202       warning (_("Unable to fetch the floating point registers."));
 203       return;
 204     }
 205
 206   /* Store fpsr.  */
 207   if (regcache_valid_p (regcache, ARM_FPS_REGNUM))
 208     regcache_raw_collect (regcache, ARM_FPS_REGNUM, fp + NWFPE_FPSR_OFFSET);
 209
 210   /* Store the floating point registers.  */
 211   for (regno = ARM_F0_REGNUM; regno <= ARM_F7_REGNUM; regno++)
 212     if (regcache_valid_p (regcache, regno))
 213       collect_nwfpe_register (regcache, regno, fp);
 214
 215   ret = ptrace (PTRACE_SETFPREGS, tid, 0, fp);
 216   if (ret < 0)
 217     {
 218       warning (_("Unable to store floating point registers."));
 219       return;
 220     }
 221 }
 222
 223 /* Fetch a general register of the process and store into
 224    regcache.  */
 225
 226 static void
 227 fetch_register (struct regcache *regcache, int regno)
 228 {
 229   int ret, tid;
 230   elf_gregset_t regs;
 231
 232   /* Get the thread id for the ptrace call.  */
 233   tid = GET_THREAD_ID (inferior_ptid);
 234
 235   ret = ptrace (PTRACE_GETREGS, tid, 0, &regs);
 236   if (ret < 0)
 237     {
 238       warning (_("Unable to fetch general register."));
 239       return;
 240     }
 241
 242   if (regno >= ARM_A1_REGNUM && regno < ARM_PC_REGNUM)
 243     regcache_raw_supply (regcache, regno, (char *) &regs[regno]);
 244
 245   if (ARM_PS_REGNUM == regno)
 246     {
 247       if (arm_apcs_32)
 248         regcache_raw_supply (regcache, ARM_PS_REGNUM,
 249                              (char *) &regs[ARM_CPSR_REGNUM]);
 250       else
 251         regcache_raw_supply (regcache, ARM_PS_REGNUM,
 252                              (char *) &regs[ARM_PC_REGNUM]);
 253     }
 254
 255   if (ARM_PC_REGNUM == regno)
 256     {
 257       regs[ARM_PC_REGNUM] = gdbarch_addr_bits_remove
 258                               (current_gdbarch, regs[ARM_PC_REGNUM]);
 259       regcache_raw_supply (regcache, ARM_PC_REGNUM,
 260                            (char *) &regs[ARM_PC_REGNUM]);
 261     }
 262 }
 263
 264 /* Fetch all general registers of the process and store into
 265    regcache.  */
 266
 267 static void
 268 fetch_regs (struct regcache *regcache)
 269 {
 270   int ret, regno, tid;
 271   elf_gregset_t regs;
 272
 273   /* Get the thread id for the ptrace call.  */
 274   tid = GET_THREAD_ID (inferior_ptid);
 275
 276   ret = ptrace (PTRACE_GETREGS, tid, 0, &regs);
 277   if (ret < 0)
 278     {
 279       warning (_("Unable to fetch general registers."));
 280       return;
 281     }
 282
 283   for (regno = ARM_A1_REGNUM; regno < ARM_PC_REGNUM; regno++)
 284     regcache_raw_supply (regcache, regno, (char *) &regs[regno]);
 285
 286   if (arm_apcs_32)
 287     regcache_raw_supply (regcache, ARM_PS_REGNUM,
 288                          (char *) &regs[ARM_CPSR_REGNUM]);
 289   else
 290     regcache_raw_supply (regcache, ARM_PS_REGNUM,
 291                          (char *) &regs[ARM_PC_REGNUM]);
 292
 293   regs[ARM_PC_REGNUM] = gdbarch_addr_bits_remove
 294                           (current_gdbarch, regs[ARM_PC_REGNUM]);
 295   regcache_raw_supply (regcache, ARM_PC_REGNUM,
 296                        (char *) &regs[ARM_PC_REGNUM]);
 297 }
 298
 299 /* Store all general registers of the process from the values in
 300    regcache.  */
 301
 302 static void
 303 store_register (const struct regcache *regcache, int regno)
 304 {
 305   int ret, tid;
 306   elf_gregset_t regs;
 307
 308   if (!regcache_valid_p (regcache, regno))
 309     return;
 310
 311   /* Get the thread id for the ptrace call.  */
 312   tid = GET_THREAD_ID (inferior_ptid);
 313
 314   /* Get the general registers from the process.  */
 315   ret = ptrace (PTRACE_GETREGS, tid, 0, &regs);
 316   if (ret < 0)
 317     {
 318       warning (_("Unable to fetch general registers."));
 319       return;
 320     }
 321
 322   if (regno >= ARM_A1_REGNUM && regno <= ARM_PC_REGNUM)
 323     regcache_raw_collect (regcache, regno, (char *) &regs[regno]);
 324   else if (arm_apcs_32 && regno == ARM_PS_REGNUM)
 325     regcache_raw_collect (regcache, regno,
 326                          (char *) &regs[ARM_CPSR_REGNUM]);
 327   else if (!arm_apcs_32 && regno == ARM_PS_REGNUM)
 328     regcache_raw_collect (regcache, ARM_PC_REGNUM,
 329                          (char *) &regs[ARM_PC_REGNUM]);
 330
 331   ret = ptrace (PTRACE_SETREGS, tid, 0, &regs);
 332   if (ret < 0)
 333     {
 334       warning (_("Unable to store general register."));
 335       return;
 336     }
 337 }
 338
 339 static void
 340 store_regs (const struct regcache *regcache)
 341 {
 342   int ret, regno, tid;
 343   elf_gregset_t regs;
 344
 345   /* Get the thread id for the ptrace call.  */
 346   tid = GET_THREAD_ID (inferior_ptid);
 347
 348   /* Fetch the general registers.  */
 349   ret = ptrace (PTRACE_GETREGS, tid, 0, &regs);
 350   if (ret < 0)
 351     {
 352       warning (_("Unable to fetch general registers."));
 353       return;
 354     }
 355
 356   for (regno = ARM_A1_REGNUM; regno <= ARM_PC_REGNUM; regno++)
 357     {
 358       if (regcache_valid_p (regcache, regno))
 359         regcache_raw_collect (regcache, regno, (char *) &regs[regno]);
 360     }
 361
 362   if (arm_apcs_32 && regcache_valid_p (regcache, ARM_PS_REGNUM))
 363     regcache_raw_collect (regcache, ARM_PS_REGNUM,
 364                          (char *) &regs[ARM_CPSR_REGNUM]);
 365
 366   ret = ptrace (PTRACE_SETREGS, tid, 0, &regs);
 367
 368   if (ret < 0)
 369     {
 370       warning (_("Unable to store general registers."));
 371       return;
 372     }
 373 }
 374
 375 /* Fetch all WMMX registers of the process and store into
 376    regcache.  */
 377
 378 #define IWMMXT_REGS_SIZE (16 * 8 + 6 * 4)
 379
 380 static void
 381 fetch_wmmx_regs (struct regcache *regcache)
 382 {
 383   char regbuf[IWMMXT_REGS_SIZE];
 384   int ret, regno, tid;
 385
 386   /* Get the thread id for the ptrace call.  */
 387   tid = GET_THREAD_ID (inferior_ptid);
 388
 389   ret = ptrace (PTRACE_GETWMMXREGS, tid, 0, regbuf);
 390   if (ret < 0)
 391     {
 392       warning (_("Unable to fetch WMMX registers."));
 393       return;
 394     }
 395
 396   for (regno = 0; regno < 16; regno++)
 397     regcache_raw_supply (regcache, regno + ARM_WR0_REGNUM,
 398                          &regbuf[regno * 8]);
 399
 400   for (regno = 0; regno < 2; regno++)
 401     regcache_raw_supply (regcache, regno + ARM_WCSSF_REGNUM,
 402                          &regbuf[16 * 8 + regno * 4]);
 403
 404   for (regno = 0; regno < 4; regno++)
 405     regcache_raw_supply (regcache, regno + ARM_WCGR0_REGNUM,
 406                          &regbuf[16 * 8 + 2 * 4 + regno * 4]);
 407 }
 408
 409 static void
 410 store_wmmx_regs (const struct regcache *regcache)
 411 {
 412   char regbuf[IWMMXT_REGS_SIZE];
 413   int ret, regno, tid;
 414
 415   /* Get the thread id for the ptrace call.  */
 416   tid = GET_THREAD_ID (inferior_ptid);
 417
 418   ret = ptrace (PTRACE_GETWMMXREGS, tid, 0, regbuf);
 419   if (ret < 0)
 420     {
 421       warning (_("Unable to fetch WMMX registers."));
 422       return;
 423     }
 424
 425   for (regno = 0; regno < 16; regno++)
 426     if (regcache_valid_p (regcache, regno + ARM_WR0_REGNUM))
 427       regcache_raw_collect (regcache, regno + ARM_WR0_REGNUM,
 428                             &regbuf[regno * 8]);
 429
 430   for (regno = 0; regno < 2; regno++)
 431     if (regcache_valid_p (regcache, regno + ARM_WCSSF_REGNUM))
 432       regcache_raw_collect (regcache, regno + ARM_WCSSF_REGNUM,
 433                             &regbuf[16 * 8 + regno * 4]);
 434
 435   for (regno = 0; regno < 4; regno++)
 436     if (regcache_valid_p (regcache, regno + ARM_WCGR0_REGNUM))
 437       regcache_raw_collect (regcache, regno + ARM_WCGR0_REGNUM,
 438                             &regbuf[16 * 8 + 2 * 4 + regno * 4]);
 439
 440   ret = ptrace (PTRACE_SETWMMXREGS, tid, 0, regbuf);
 441
 442   if (ret < 0)
 443     {
 444       warning (_("Unable to store WMMX registers."));
 445       return;
 446     }
 447 }
 448
 449 /* Fetch registers from the child process.  Fetch all registers if
 450    regno == -1, otherwise fetch all general registers or all floating
 451    point registers depending upon the value of regno.  */
 452
 453 static void
 454 arm_linux_fetch_inferior_registers (struct regcache *regcache, int regno)
 455 {
 456   if (-1 == regno)
 457     {
 458       fetch_regs (regcache);
 459       fetch_fpregs (regcache);
 460       if (arm_linux_has_wmmx_registers)
 461         fetch_wmmx_regs (regcache);
 462     }
 463   else
 464     {
 465       if (regno < ARM_F0_REGNUM || regno == ARM_PS_REGNUM)
 466         fetch_register (regcache, regno);
 467       else if (regno >= ARM_F0_REGNUM && regno <= ARM_FPS_REGNUM)
 468         fetch_fpregister (regcache, regno);
 469       else if (arm_linux_has_wmmx_registers
 470                && regno >= ARM_WR0_REGNUM && regno <= ARM_WCGR7_REGNUM)
 471         fetch_wmmx_regs (regcache);
 472     }
 473 }
 474
 475 /* Store registers back into the inferior.  Store all registers if
 476    regno == -1, otherwise store all general registers or all floating
 477    point registers depending upon the value of regno.  */
 478
 479 static void
 480 arm_linux_store_inferior_registers (struct regcache *regcache, int regno)
 481 {
 482   if (-1 == regno)
 483     {
 484       store_regs (regcache);
 485       store_fpregs (regcache);
 486       if (arm_linux_has_wmmx_registers)
 487         store_wmmx_regs (regcache);
 488     }
 489   else
 490     {
 491       if (regno < ARM_F0_REGNUM || regno == ARM_PS_REGNUM)
 492         store_register (regcache, regno);
 493       else if ((regno >= ARM_F0_REGNUM) && (regno <= ARM_FPS_REGNUM))
 494         store_fpregister (regcache, regno);
 495       else if (arm_linux_has_wmmx_registers
 496                && regno >= ARM_WR0_REGNUM && regno <= ARM_WCGR7_REGNUM)
 497         store_wmmx_regs (regcache);
 498     }
 499 }
 500
 501 /* Wrapper functions for the standard regset handling, used by
 502    thread debugging.  */
 503
 504 void
 505 fill_gregset (const struct regcache *regcache,
 506               gdb_gregset_t *gregsetp, int regno)
 507 {
 508   arm_linux_collect_gregset (NULL, regcache, regno, gregsetp, 0);
 509 }
 510
 511 void
 512 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregsetp)
 513 {
 514   arm_linux_supply_gregset (NULL, regcache, -1, gregsetp, 0);
 515 }
 516
 517 void
 518 fill_fpregset (const struct regcache *regcache,
 519                gdb_fpregset_t *fpregsetp, int regno)
 520 {
 521   arm_linux_collect_nwfpe (NULL, regcache, regno, fpregsetp, 0);
 522 }
 523
 524 /* Fill GDB's register array with the floating-point register values
 525    in *fpregsetp.  */
 526
 527 void
 528 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregsetp)
 529 {
 530   arm_linux_supply_nwfpe (NULL, regcache, -1, fpregsetp, 0);
 531 }
 532
 533 /* Fetch the thread-local storage pointer for libthread_db.  */
 534
 535 ps_err_e
 536 ps_get_thread_area (const struct ps_prochandle *ph,
 537                     lwpid_t lwpid, int idx, void **base)
 538 {
 539   if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
 540     return PS_ERR;
 541
 542   /* IDX is the bias from the thread pointer to the beginning of the
 543      thread descriptor.  It has to be subtracted due to implementation
 544      quirks in libthread_db.  */
 545   *base = (void *) ((char *)*base - idx);
 546
 547   return PS_OK;
 548 }
 549
 550 static unsigned int
 551 get_linux_version (unsigned int *vmajor,
 552                    unsigned int *vminor,
 553                    unsigned int *vrelease)
 554 {
 555   struct utsname info;
 556   char *pmajor, *pminor, *prelease, *tail;
 557
 558   if (-1 == uname (&info))
 559     {
 560       warning (_("Unable to determine GNU/Linux version."));
 561       return -1;
 562     }
 563
 564   pmajor = strtok (info.release, ".");
 565   pminor = strtok (NULL, ".");
 566   prelease = strtok (NULL, ".");
 567
 568   *vmajor = (unsigned int) strtoul (pmajor, &tail, 0);
 569   *vminor = (unsigned int) strtoul (pminor, &tail, 0);
 570   *vrelease = (unsigned int) strtoul (prelease, &tail, 0);
 571
 572   return ((*vmajor << 16) | (*vminor << 8) | *vrelease);
 573 }
 574
 575 static const struct target_desc *
 576 arm_linux_read_description (struct target_ops *ops)
 577 {
 578   int ret;
 579   char regbuf[IWMMXT_REGS_SIZE];
 580
 581   ret = ptrace (PTRACE_GETWMMXREGS, GET_THREAD_ID (inferior_ptid),
 582                 0, regbuf);
 583   if (ret < 0)
 584     arm_linux_has_wmmx_registers = 0;
 585   else
 586     arm_linux_has_wmmx_registers = 1;
 587
 588   if (arm_linux_has_wmmx_registers)
 589     return tdesc_arm_with_iwmmxt;
 590   else
 591     return NULL;
 592 }
 593
 594 void _initialize_arm_linux_nat (void);
 595
 596 void
 597 _initialize_arm_linux_nat (void)
 598 {
 599   struct target_ops *t;
 600
 601   os_version = get_linux_version (&os_major, &os_minor, &os_release);
 602
 603   /* Fill in the generic GNU/Linux methods.  */
 604   t = linux_target ();
 605
 606   /* Add our register access methods.  */
 607   t->to_fetch_registers = arm_linux_fetch_inferior_registers;
 608   t->to_store_registers = arm_linux_store_inferior_registers;
 609
 610   t->to_read_description = arm_linux_read_description;
 611
 612   /* Register the target.  */
 613   linux_nat_add_target (t);
 614
 615   /* Initialize the standard target descriptions.  */
 616   initialize_tdesc_arm_with_iwmmxt ();
 617 }