gdb/arm-linux-nat.c

   1 /* GNU/Linux on ARM native support.
   2    Copyright (C) 1999, 2000, 2001, 2002, 2004, 2005, 2006, 2007, 2008, 2009
   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                               (get_regcache_arch (regcache),
 259                                regs[ARM_PC_REGNUM]);
 260       regcache_raw_supply (regcache, ARM_PC_REGNUM,
 261                            (char *) &regs[ARM_PC_REGNUM]);
 262     }
 263 }
 264
 265 /* Fetch all general registers of the process and store into
 266    regcache.  */
 267
 268 static void
 269 fetch_regs (struct regcache *regcache)
 270 {
 271   int ret, regno, tid;
 272   elf_gregset_t regs;
 273
 274   /* Get the thread id for the ptrace call.  */
 275   tid = GET_THREAD_ID (inferior_ptid);
 276
 277   ret = ptrace (PTRACE_GETREGS, tid, 0, &regs);
 278   if (ret < 0)
 279     {
 280       warning (_("Unable to fetch general registers."));
 281       return;
 282     }
 283
 284   for (regno = ARM_A1_REGNUM; regno < ARM_PC_REGNUM; regno++)
 285     regcache_raw_supply (regcache, regno, (char *) &regs[regno]);
 286
 287   if (arm_apcs_32)
 288     regcache_raw_supply (regcache, ARM_PS_REGNUM,
 289                          (char *) &regs[ARM_CPSR_REGNUM]);
 290   else
 291     regcache_raw_supply (regcache, ARM_PS_REGNUM,
 292                          (char *) &regs[ARM_PC_REGNUM]);
 293
 294   regs[ARM_PC_REGNUM] = gdbarch_addr_bits_remove
 295                           (get_regcache_arch (regcache), regs[ARM_PC_REGNUM]);
 296   regcache_raw_supply (regcache, ARM_PC_REGNUM,
 297                        (char *) &regs[ARM_PC_REGNUM]);
 298 }
 299
 300 /* Store all general registers of the process from the values in
 301    regcache.  */
 302
 303 static void
 304 store_register (const struct regcache *regcache, int regno)
 305 {
 306   int ret, tid;
 307   elf_gregset_t regs;
 308
 309   if (!regcache_valid_p (regcache, regno))
 310     return;
 311
 312   /* Get the thread id for the ptrace call.  */
 313   tid = GET_THREAD_ID (inferior_ptid);
 314
 315   /* Get the general registers from the process.  */
 316   ret = ptrace (PTRACE_GETREGS, tid, 0, &regs);
 317   if (ret < 0)
 318     {
 319       warning (_("Unable to fetch general registers."));
 320       return;
 321     }
 322
 323   if (regno >= ARM_A1_REGNUM && regno <= ARM_PC_REGNUM)
 324     regcache_raw_collect (regcache, regno, (char *) &regs[regno]);
 325   else if (arm_apcs_32 && regno == ARM_PS_REGNUM)
 326     regcache_raw_collect (regcache, regno,
 327                          (char *) &regs[ARM_CPSR_REGNUM]);
 328   else if (!arm_apcs_32 && regno == ARM_PS_REGNUM)
 329     regcache_raw_collect (regcache, ARM_PC_REGNUM,
 330                          (char *) &regs[ARM_PC_REGNUM]);
 331
 332   ret = ptrace (PTRACE_SETREGS, tid, 0, &regs);
 333   if (ret < 0)
 334     {
 335       warning (_("Unable to store general register."));
 336       return;
 337     }
 338 }
 339
 340 static void
 341 store_regs (const struct regcache *regcache)
 342 {
 343   int ret, regno, tid;
 344   elf_gregset_t regs;
 345
 346   /* Get the thread id for the ptrace call.  */
 347   tid = GET_THREAD_ID (inferior_ptid);
 348
 349   /* Fetch the general registers.  */
 350   ret = ptrace (PTRACE_GETREGS, tid, 0, &regs);
 351   if (ret < 0)
 352     {
 353       warning (_("Unable to fetch general registers."));
 354       return;
 355     }
 356
 357   for (regno = ARM_A1_REGNUM; regno <= ARM_PC_REGNUM; regno++)
 358     {
 359       if (regcache_valid_p (regcache, regno))
 360         regcache_raw_collect (regcache, regno, (char *) &regs[regno]);
 361     }
 362
 363   if (arm_apcs_32 && regcache_valid_p (regcache, ARM_PS_REGNUM))
 364     regcache_raw_collect (regcache, ARM_PS_REGNUM,
 365                          (char *) &regs[ARM_CPSR_REGNUM]);
 366
 367   ret = ptrace (PTRACE_SETREGS, tid, 0, &regs);
 368
 369   if (ret < 0)
 370     {
 371       warning (_("Unable to store general registers."));
 372       return;
 373     }
 374 }
 375
 376 /* Fetch all WMMX registers of the process and store into
 377    regcache.  */
 378
 379 #define IWMMXT_REGS_SIZE (16 * 8 + 6 * 4)
 380
 381 static void
 382 fetch_wmmx_regs (struct regcache *regcache)
 383 {
 384   char regbuf[IWMMXT_REGS_SIZE];
 385   int ret, regno, tid;
 386
 387   /* Get the thread id for the ptrace call.  */
 388   tid = GET_THREAD_ID (inferior_ptid);
 389
 390   ret = ptrace (PTRACE_GETWMMXREGS, tid, 0, regbuf);
 391   if (ret < 0)
 392     {
 393       warning (_("Unable to fetch WMMX registers."));
 394       return;
 395     }
 396
 397   for (regno = 0; regno < 16; regno++)
 398     regcache_raw_supply (regcache, regno + ARM_WR0_REGNUM,
 399                          &regbuf[regno * 8]);
 400
 401   for (regno = 0; regno < 2; regno++)
 402     regcache_raw_supply (regcache, regno + ARM_WCSSF_REGNUM,
 403                          &regbuf[16 * 8 + regno * 4]);
 404
 405   for (regno = 0; regno < 4; regno++)
 406     regcache_raw_supply (regcache, regno + ARM_WCGR0_REGNUM,
 407                          &regbuf[16 * 8 + 2 * 4 + regno * 4]);
 408 }
 409
 410 static void
 411 store_wmmx_regs (const struct regcache *regcache)
 412 {
 413   char regbuf[IWMMXT_REGS_SIZE];
 414   int ret, regno, tid;
 415
 416   /* Get the thread id for the ptrace call.  */
 417   tid = GET_THREAD_ID (inferior_ptid);
 418
 419   ret = ptrace (PTRACE_GETWMMXREGS, tid, 0, regbuf);
 420   if (ret < 0)
 421     {
 422       warning (_("Unable to fetch WMMX registers."));
 423       return;
 424     }
 425
 426   for (regno = 0; regno < 16; regno++)
 427     if (regcache_valid_p (regcache, regno + ARM_WR0_REGNUM))
 428       regcache_raw_collect (regcache, regno + ARM_WR0_REGNUM,
 429                             &regbuf[regno * 8]);
 430
 431   for (regno = 0; regno < 2; regno++)
 432     if (regcache_valid_p (regcache, regno + ARM_WCSSF_REGNUM))
 433       regcache_raw_collect (regcache, regno + ARM_WCSSF_REGNUM,
 434                             &regbuf[16 * 8 + regno * 4]);
 435
 436   for (regno = 0; regno < 4; regno++)
 437     if (regcache_valid_p (regcache, regno + ARM_WCGR0_REGNUM))
 438       regcache_raw_collect (regcache, regno + ARM_WCGR0_REGNUM,
 439                             &regbuf[16 * 8 + 2 * 4 + regno * 4]);
 440
 441   ret = ptrace (PTRACE_SETWMMXREGS, tid, 0, regbuf);
 442
 443   if (ret < 0)
 444     {
 445       warning (_("Unable to store WMMX registers."));
 446       return;
 447     }
 448 }
 449
 450 /* Fetch registers from the child process.  Fetch all registers if
 451    regno == -1, otherwise fetch all general registers or all floating
 452    point registers depending upon the value of regno.  */
 453
 454 static void
 455 arm_linux_fetch_inferior_registers (struct target_ops *ops,
 456                                     struct regcache *regcache, int regno)
 457 {
 458   if (-1 == regno)
 459     {
 460       fetch_regs (regcache);
 461       fetch_fpregs (regcache);
 462       if (arm_linux_has_wmmx_registers)
 463         fetch_wmmx_regs (regcache);
 464     }
 465   else
 466     {
 467       if (regno < ARM_F0_REGNUM || regno == ARM_PS_REGNUM)
 468         fetch_register (regcache, regno);
 469       else if (regno >= ARM_F0_REGNUM && regno <= ARM_FPS_REGNUM)
 470         fetch_fpregister (regcache, regno);
 471       else if (arm_linux_has_wmmx_registers
 472                && regno >= ARM_WR0_REGNUM && regno <= ARM_WCGR7_REGNUM)
 473         fetch_wmmx_regs (regcache);
 474     }
 475 }
 476
 477 /* Store registers back into the inferior.  Store all registers if
 478    regno == -1, otherwise store all general registers or all floating
 479    point registers depending upon the value of regno.  */
 480
 481 static void
 482 arm_linux_store_inferior_registers (struct target_ops *ops,
 483                                     struct regcache *regcache, int regno)
 484 {
 485   if (-1 == regno)
 486     {
 487       store_regs (regcache);
 488       store_fpregs (regcache);
 489       if (arm_linux_has_wmmx_registers)
 490         store_wmmx_regs (regcache);
 491     }
 492   else
 493     {
 494       if (regno < ARM_F0_REGNUM || regno == ARM_PS_REGNUM)
 495         store_register (regcache, regno);
 496       else if ((regno >= ARM_F0_REGNUM) && (regno <= ARM_FPS_REGNUM))
 497         store_fpregister (regcache, regno);
 498       else if (arm_linux_has_wmmx_registers
 499                && regno >= ARM_WR0_REGNUM && regno <= ARM_WCGR7_REGNUM)
 500         store_wmmx_regs (regcache);
 501     }
 502 }
 503
 504 /* Wrapper functions for the standard regset handling, used by
 505    thread debugging.  */
 506
 507 void
 508 fill_gregset (const struct regcache *regcache,
 509               gdb_gregset_t *gregsetp, int regno)
 510 {
 511   arm_linux_collect_gregset (NULL, regcache, regno, gregsetp, 0);
 512 }
 513
 514 void
 515 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregsetp)
 516 {
 517   arm_linux_supply_gregset (NULL, regcache, -1, gregsetp, 0);
 518 }
 519
 520 void
 521 fill_fpregset (const struct regcache *regcache,
 522                gdb_fpregset_t *fpregsetp, int regno)
 523 {
 524   arm_linux_collect_nwfpe (NULL, regcache, regno, fpregsetp, 0);
 525 }
 526
 527 /* Fill GDB's register array with the floating-point register values
 528    in *fpregsetp.  */
 529
 530 void
 531 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t *fpregsetp)
 532 {
 533   arm_linux_supply_nwfpe (NULL, regcache, -1, fpregsetp, 0);
 534 }
 535
 536 /* Fetch the thread-local storage pointer for libthread_db.  */
 537
 538 ps_err_e
 539 ps_get_thread_area (const struct ps_prochandle *ph,
 540                     lwpid_t lwpid, int idx, void **base)
 541 {
 542   if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, NULL, base) != 0)
 543     return PS_ERR;
 544
 545   /* IDX is the bias from the thread pointer to the beginning of the
 546      thread descriptor.  It has to be subtracted due to implementation
 547      quirks in libthread_db.  */
 548   *base = (void *) ((char *)*base - idx);
 549
 550   return PS_OK;
 551 }
 552
 553 static unsigned int
 554 get_linux_version (unsigned int *vmajor,
 555                    unsigned int *vminor,
 556                    unsigned int *vrelease)
 557 {
 558   struct utsname info;
 559   char *pmajor, *pminor, *prelease, *tail;
 560
 561   if (-1 == uname (&info))
 562     {
 563       warning (_("Unable to determine GNU/Linux version."));
 564       return -1;
 565     }
 566
 567   pmajor = strtok (info.release, ".");
 568   pminor = strtok (NULL, ".");
 569   prelease = strtok (NULL, ".");
 570
 571   *vmajor = (unsigned int) strtoul (pmajor, &tail, 0);
 572   *vminor = (unsigned int) strtoul (pminor, &tail, 0);
 573   *vrelease = (unsigned int) strtoul (prelease, &tail, 0);
 574
 575   return ((*vmajor << 16) | (*vminor << 8) | *vrelease);
 576 }
 577
 578 static const struct target_desc *
 579 arm_linux_read_description (struct target_ops *ops)
 580 {
 581   int ret;
 582   char regbuf[IWMMXT_REGS_SIZE];
 583
 584   ret = ptrace (PTRACE_GETWMMXREGS, GET_THREAD_ID (inferior_ptid),
 585                 0, regbuf);
 586   if (ret < 0)
 587     arm_linux_has_wmmx_registers = 0;
 588   else
 589     arm_linux_has_wmmx_registers = 1;
 590
 591   if (arm_linux_has_wmmx_registers)
 592     return tdesc_arm_with_iwmmxt;
 593   else
 594     return NULL;
 595 }
 596
 597 void _initialize_arm_linux_nat (void);
 598
 599 void
 600 _initialize_arm_linux_nat (void)
 601 {
 602   struct target_ops *t;
 603
 604   os_version = get_linux_version (&os_major, &os_minor, &os_release);
 605
 606   /* Fill in the generic GNU/Linux methods.  */
 607   t = linux_target ();
 608
 609   /* Add our register access methods.  */
 610   t->to_fetch_registers = arm_linux_fetch_inferior_registers;
 611   t->to_store_registers = arm_linux_store_inferior_registers;
 612
 613   t->to_read_description = arm_linux_read_description;
 614
 615   /* Register the target.  */
 616   linux_nat_add_target (t);
 617
 618   /* Initialize the standard target descriptions.  */
 619   initialize_tdesc_arm_with_iwmmxt ();
 620 }