gdb/amd64-linux-nat.c

   1 /* Native-dependent code for GNU/Linux x86-64.
   2
   3    Copyright 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
   4    Contributed by Jiri Smid, SuSE Labs.
   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
  10    the Free Software Foundation; either version 2 of the License, or
  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
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 59 Temple Place - Suite 330,
  21    Boston, MA 02111-1307, USA.  */
  22
  23 #include "defs.h"
  24 #include "inferior.h"
  25 #include "gdbcore.h"
  26 #include "regcache.h"
  27 #include "linux-nat.h"
  28
  29 #include "gdb_assert.h"
  30 #include "gdb_string.h"
  31 #include <sys/ptrace.h>
  32 #include <sys/debugreg.h>
  33 #include <sys/syscall.h>
  34 #include <sys/procfs.h>
  35 #include <asm/prctl.h>
  36 /* FIXME ezannoni-2003-07-09: we need <sys/reg.h> to be included after
  37    <asm/ptrace.h> because the latter redefines FS and GS for no apparent
  38    reason, and those definitions don't match the ones that libpthread_db
  39    uses, which come from <sys/reg.h>.  */
  40 /* ezannoni-2003-07-09: I think this is fixed. The extraneous defs have
  41    been removed from ptrace.h in the kernel.  However, better safe than
  42    sorry.  */
  43 #include <asm/ptrace.h>
  44 #include <sys/reg.h>
  45 #include "gdb_proc_service.h"
  46
  47 /* Prototypes for supply_gregset etc.  */
  48 #include "gregset.h"
  49
  50 #include "amd64-tdep.h"
  51 #include "i386-linux-tdep.h"
  52 #include "amd64-nat.h"
  53
  54 /* Mapping between the general-purpose registers in GNU/Linux x86-64
  55    `struct user' format and GDB's register cache layout.  */
  56
  57 static int amd64_linux_gregset64_reg_offset[] =
  58 {
  59   RAX * 8, RBX * 8,             /* %rax, %rbx */
  60   RCX * 8, RDX * 8,             /* %rcx, %rdx */
  61   RSI * 8, RDI * 8,             /* %rsi, %rdi */
  62   RBP * 8, RSP * 8,             /* %rbp, %rsp */
  63   R8 * 8, R9 * 8,               /* %r8 ... */
  64   R10 * 8, R11 * 8,
  65   R12 * 8, R13 * 8,
  66   R14 * 8, R15 * 8,             /* ... %r15 */
  67   RIP * 8, EFLAGS * 8,          /* %rip, %eflags */
  68   CS * 8, SS * 8,               /* %cs, %ss */
  69   DS * 8, ES * 8,               /* %ds, %es */
  70   FS * 8, GS * 8                /* %fs, %gs */
  71 };
  72 \f
  73
  74 /* Mapping between the general-purpose registers in GNU/Linux x86-64
  75    `struct user' format and GDB's register cache layout for GNU/Linux
  76    i386.
  77
  78    Note that most GNU/Linux x86-64 registers are 64-bit, while the
  79    GNU/Linux i386 registers are all 32-bit, but since we're
  80    little-endian we get away with that.  */
  81
  82 /* From <sys/reg.h> on GNU/Linux i386.  */
  83 static int amd64_linux_gregset32_reg_offset[] =
  84 {
  85   RAX * 8, RCX * 8,             /* %eax, %ecx */
  86   RDX * 8, RBX * 8,             /* %edx, %ebx */
  87   RSP * 8, RBP * 8,             /* %esp, %ebp */
  88   RSI * 8, RDI * 8,             /* %esi, %edi */
  89   RIP * 8, EFLAGS * 8,          /* %eip, %eflags */
  90   CS * 8, SS * 8,               /* %cs, %ss */
  91   DS * 8, ES * 8,               /* %ds, %es */
  92   FS * 8, GS * 8,               /* %fs, %gs */
  93   -1, -1, -1, -1, -1, -1, -1, -1,
  94   -1, -1, -1, -1, -1, -1, -1, -1,
  95   -1, -1, -1, -1, -1, -1, -1, -1, -1,
  96   ORIG_RAX * 8                  /* "orig_eax" */
  97 };
  98 \f
  99
 100 /* Transfering the general-purpose registers between GDB, inferiors
 101    and core files.  */
 102
 103 /* Fill GDB's register cache with the general-purpose register values
 104    in *GREGSETP.  */
 105
 106 void
 107 supply_gregset (elf_gregset_t *gregsetp)
 108 {
 109   amd64_supply_native_gregset (current_regcache, gregsetp, -1);
 110 }
 111
 112 /* Fill register REGNUM (if it is a general-purpose register) in
 113    *GREGSETP with the value in GDB's register cache.  If REGNUM is -1,
 114    do this for all registers.  */
 115
 116 void
 117 fill_gregset (elf_gregset_t *gregsetp, int regnum)
 118 {
 119   amd64_collect_native_gregset (current_regcache, gregsetp, regnum);
 120 }
 121
 122 /* Transfering floating-point registers between GDB, inferiors and cores.  */
 123
 124 /* Fill GDB's register cache with the floating-point and SSE register
 125    values in *FPREGSETP.  */
 126
 127 void
 128 supply_fpregset (elf_fpregset_t *fpregsetp)
 129 {
 130   amd64_supply_fxsave (current_regcache, -1, fpregsetp);
 131 }
 132
 133 /* Fill register REGNUM (if it is a floating-point or SSE register) in
 134    *FPREGSETP with the value in GDB's register cache.  If REGNUM is
 135    -1, do this for all registers.  */
 136
 137 void
 138 fill_fpregset (elf_fpregset_t *fpregsetp, int regnum)
 139 {
 140   amd64_collect_fxsave (current_regcache, regnum, fpregsetp);
 141 }
 142 \f
 143
 144 /* Transferring arbitrary registers between GDB and inferior.  */
 145
 146 /* Fetch register REGNUM from the child process.  If REGNUM is -1, do
 147    this for all registers (including the floating point and SSE
 148    registers).  */
 149
 150 void
 151 fetch_inferior_registers (int regnum)
 152 {
 153   int tid;
 154
 155   /* GNU/Linux LWP ID's are process ID's.  */
 156   tid = TIDGET (inferior_ptid);
 157   if (tid == 0)
 158     tid = PIDGET (inferior_ptid); /* Not a threaded program.  */
 159
 160   if (regnum == -1 || amd64_native_gregset_supplies_p (regnum))
 161     {
 162       elf_gregset_t regs;
 163
 164       if (ptrace (PTRACE_GETREGS, tid, 0, (long) &regs) < 0)
 165         perror_with_name ("Couldn't get registers");
 166
 167       amd64_supply_native_gregset (current_regcache, &regs, -1);
 168       if (regnum != -1)
 169         return;
 170     }
 171
 172   if (regnum == -1 || !amd64_native_gregset_supplies_p (regnum))
 173     {
 174       elf_fpregset_t fpregs;
 175
 176       if (ptrace (PTRACE_GETFPREGS, tid, 0, (long) &fpregs) < 0)
 177         perror_with_name ("Couldn't get floating point status");
 178
 179       amd64_supply_fxsave (current_regcache, -1, &fpregs);
 180     }
 181 }
 182
 183 /* Store register REGNUM back into the child process.  If REGNUM is
 184    -1, do this for all registers (including the floating-point and SSE
 185    registers).  */
 186
 187 void
 188 store_inferior_registers (int regnum)
 189 {
 190   int tid;
 191
 192   /* GNU/Linux LWP ID's are process ID's.  */
 193   tid = TIDGET (inferior_ptid);
 194   if (tid == 0)
 195     tid = PIDGET (inferior_ptid); /* Not a threaded program.  */
 196
 197   if (regnum == -1 || amd64_native_gregset_supplies_p (regnum))
 198     {
 199       elf_gregset_t regs;
 200
 201       if (ptrace (PTRACE_GETREGS, tid, 0, (long) &regs) < 0)
 202         perror_with_name ("Couldn't get registers");
 203
 204       amd64_collect_native_gregset (current_regcache, &regs, regnum);
 205
 206       if (ptrace (PTRACE_SETREGS, tid, 0, (long) &regs) < 0)
 207         perror_with_name ("Couldn't write registers");
 208
 209       if (regnum != -1)
 210         return;
 211     }
 212
 213   if (regnum == -1 || !amd64_native_gregset_supplies_p (regnum))
 214     {
 215       elf_fpregset_t fpregs;
 216
 217       if (ptrace (PTRACE_GETFPREGS, tid, 0, (long) &fpregs) < 0)
 218         perror_with_name ("Couldn't get floating point status");
 219
 220       amd64_collect_fxsave (current_regcache, regnum, &fpregs);
 221
 222       if (ptrace (PTRACE_SETFPREGS, tid, 0, (long) &fpregs) < 0)
 223         perror_with_name ("Couldn't write floating point status");
 224
 225       return;
 226     }
 227 }
 228 \f
 229
 230 static unsigned long
 231 amd64_linux_dr_get (int regnum)
 232 {
 233   int tid;
 234   unsigned long value;
 235
 236   /* FIXME: kettenis/2001-01-29: It's not clear what we should do with
 237      multi-threaded processes here.  For now, pretend there is just
 238      one thread.  */
 239   tid = PIDGET (inferior_ptid);
 240
 241   /* FIXME: kettenis/2001-03-27: Calling perror_with_name if the
 242      ptrace call fails breaks debugging remote targets.  The correct
 243      way to fix this is to add the hardware breakpoint and watchpoint
 244      stuff to the target vectore.  For now, just return zero if the
 245      ptrace call fails.  */
 246   errno = 0;
 247   value = ptrace (PT_READ_U, tid,
 248                   offsetof (struct user, u_debugreg[regnum]), 0);
 249   if (errno != 0)
 250 #if 0
 251     perror_with_name ("Couldn't read debug register");
 252 #else
 253     return 0;
 254 #endif
 255
 256   return value;
 257 }
 258
 259 static void
 260 amd64_linux_dr_set (int regnum, unsigned long value)
 261 {
 262   int tid;
 263
 264   /* FIXME: kettenis/2001-01-29: It's not clear what we should do with
 265      multi-threaded processes here.  For now, pretend there is just
 266      one thread.  */
 267   tid = PIDGET (inferior_ptid);
 268
 269   errno = 0;
 270   ptrace (PT_WRITE_U, tid, offsetof (struct user, u_debugreg[regnum]), value);
 271   if (errno != 0)
 272     perror_with_name ("Couldn't write debug register");
 273 }
 274
 275 void
 276 amd64_linux_dr_set_control (unsigned long control)
 277 {
 278   amd64_linux_dr_set (DR_CONTROL, control);
 279 }
 280
 281 void
 282 amd64_linux_dr_set_addr (int regnum, CORE_ADDR addr)
 283 {
 284   gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR);
 285
 286   amd64_linux_dr_set (DR_FIRSTADDR + regnum, addr);
 287 }
 288
 289 void
 290 amd64_linux_dr_reset_addr (int regnum)
 291 {
 292   gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR);
 293
 294   amd64_linux_dr_set (DR_FIRSTADDR + regnum, 0L);
 295 }
 296
 297 unsigned long
 298 amd64_linux_dr_get_status (void)
 299 {
 300   return amd64_linux_dr_get (DR_STATUS);
 301 }
 302 \f
 303
 304 /* This function is called by libthread_db as part of its handling of
 305    a request for a thread's local storage address.  */
 306
 307 ps_err_e
 308 ps_get_thread_area (const struct ps_prochandle *ph,
 309                     lwpid_t lwpid, int idx, void **base)
 310 {
 311   if (gdbarch_ptr_bit (current_gdbarch) == 32)
 312     {
 313       /* The full structure is found in <asm-i386/ldt.h>.  The second
 314          integer is the LDT's base_address and that is used to locate
 315          the thread's local storage.  See i386-linux-nat.c more
 316          info.  */
 317       unsigned int desc[4];
 318
 319       /* This code assumes that "int" is 32 bits and that
 320          GET_THREAD_AREA returns no more than 4 int values.  */
 321       gdb_assert (sizeof (int) == 4);
 322 #ifndef PTRACE_GET_THREAD_AREA
 323 #define PTRACE_GET_THREAD_AREA 25
 324 #endif
 325       if  (ptrace (PTRACE_GET_THREAD_AREA,
 326                    lwpid, (void *) (long) idx, (unsigned long) &desc) < 0)
 327         return PS_ERR;
 328
 329       /* Extend the value to 64 bits.  Here it's assumed that a "long"
 330          and a "void *" are the same.  */
 331       (*base) = (void *) (long) desc[1];
 332       return PS_OK;
 333     }
 334   else
 335     {
 336       /* This definition comes from prctl.h, but some kernels may not
 337          have it.  */
 338 #ifndef PTRACE_ARCH_PRCTL
 339 #define PTRACE_ARCH_PRCTL      30
 340 #endif
 341       /* FIXME: ezannoni-2003-07-09 see comment above about include
 342          file order.  We could be getting bogus values for these two.  */
 343       gdb_assert (FS < ELF_NGREG);
 344       gdb_assert (GS < ELF_NGREG);
 345       switch (idx)
 346         {
 347         case FS:
 348           if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_FS) == 0)
 349             return PS_OK;
 350           break;
 351         case GS:
 352           if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_GS) == 0)
 353             return PS_OK;
 354           break;
 355         default:                   /* Should not happen.  */
 356           return PS_BADADDR;
 357         }
 358     }
 359   return PS_ERR;               /* ptrace failed.  */
 360 }
 361 \f
 362
 363 void
 364 child_post_startup_inferior (ptid_t ptid)
 365 {
 366   i386_cleanup_dregs ();
 367   linux_child_post_startup_inferior (ptid);
 368 }
 369 \f
 370
 371 /* Provide a prototype to silence -Wmissing-prototypes.  */
 372 void _initialize_amd64_linux_nat (void);
 373
 374 void
 375 _initialize_amd64_linux_nat (void)
 376 {
 377   amd64_native_gregset32_reg_offset = amd64_linux_gregset32_reg_offset;
 378   amd64_native_gregset32_num_regs = I386_LINUX_NUM_REGS;
 379   amd64_native_gregset64_reg_offset = amd64_linux_gregset64_reg_offset;
 380
 381   gdb_assert (ARRAY_SIZE (amd64_linux_gregset32_reg_offset)
 382               == amd64_native_gregset32_num_regs);
 383   gdb_assert (ARRAY_SIZE (amd64_linux_gregset64_reg_offset)
 384               == amd64_native_gregset64_num_regs);
 385 }