contrib/gdb-7/gdb/amd64dfly-nat.c

   1 /* Native-dependent code for DragonFly/amd64.
   2
   3    Copyright (C) 2003-2013 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 "regcache.h"
  23 #include "target.h"
  24 #include "gregset.h"
  25
  26 #include "gdb_assert.h"
  27 #include <signal.h>
  28 #include <stddef.h>
  29 #include <sys/types.h>
  30 #include <sys/procfs.h>
  31 #include <sys/ptrace.h>
  32 #include <sys/sysctl.h>
  33 #include <machine/reg.h>
  34
  35 #include "fbsd-nat.h"
  36 #include "amd64-tdep.h"
  37 #include "amd64-nat.h"
  38 #include "amd64bsd-nat.h"
  39 #include "i386-nat.h"
  40 \f
  41
  42 /* Offset in `struct reg' where MEMBER is stored.  */
  43 #define REG_OFFSET(member) offsetof (struct reg, member)
  44
  45 /* At amd64dfly64_r_reg_offset[REGNUM] you'll find the offset in
  46    `struct reg' location where the GDB register REGNUM is stored.
  47    Unsupported registers are marked with `-1'.  */
  48 static int amd64dfly64_r_reg_offset[] =
  49 {
  50   REG_OFFSET (r_rax),
  51   REG_OFFSET (r_rbx),
  52   REG_OFFSET (r_rcx),
  53   REG_OFFSET (r_rdx),
  54   REG_OFFSET (r_rsi),
  55   REG_OFFSET (r_rdi),
  56   REG_OFFSET (r_rbp),
  57   REG_OFFSET (r_rsp),
  58   REG_OFFSET (r_r8),
  59   REG_OFFSET (r_r9),
  60   REG_OFFSET (r_r10),
  61   REG_OFFSET (r_r11),
  62   REG_OFFSET (r_r12),
  63   REG_OFFSET (r_r13),
  64   REG_OFFSET (r_r14),
  65   REG_OFFSET (r_r15),
  66   REG_OFFSET (r_rip),
  67   REG_OFFSET (r_rflags),
  68   REG_OFFSET (r_cs),
  69   REG_OFFSET (r_ss),
  70   -1,
  71   -1,
  72   -1,
  73   -1
  74 };
  75 \f
  76
  77 /* Mapping between the general-purpose registers in DragonFly/amd64
  78    `struct reg' format and GDB's register cache layout for
  79    DragonFly/i386.
  80
  81    Note that most DragonFly/amd64 registers are 64-bit, while the
  82    DragonFly/i386 registers are all 32-bit, but since we're
  83    little-endian we get away with that.  */
  84
  85 /* From <machine/reg.h>.  */
  86 static int amd64dfly32_r_reg_offset[I386_NUM_GREGS] =
  87 {
  88   14 * 8, 13 * 8,               /* %eax, %ecx */
  89   12 * 8, 11 * 8,               /* %edx, %ebx */
  90   20 * 8, 10 * 8,               /* %esp, %ebp */
  91   9 * 8, 8 * 8,                 /* %esi, %edi */
  92   17 * 8, 19 * 8,               /* %eip, %eflags */
  93   18 * 8, 21 * 8,               /* %cs, %ss */
  94   -1, -1, -1, -1                /* %ds, %es, %fs, %gs */
  95 };
  96 \f
  97
  98 #ifdef DFLY_PCB_SUPPLY
  99 /* Transfering the registers between GDB, inferiors and core files.  */
 100
 101 /* Fill GDB's register array with the general-purpose register values
 102    in *GREGSETP.  */
 103
 104 void
 105 supply_gregset (struct regcache *regcache, const gregset_t *gregsetp)
 106 {
 107   amd64_supply_native_gregset (regcache, gregsetp, -1);
 108 }
 109
 110 /* Fill register REGNUM (if it is a general-purpose register) in
 111    *GREGSETPS with the value in GDB's register array.  If REGNUM is -1,
 112    do this for all registers.  */
 113
 114 void
 115 fill_gregset (const struct regcache *regcache, gdb_gregset_t *gregsetp, int regnum)
 116 {
 117   amd64_collect_native_gregset (regcache, gregsetp, regnum);
 118 }
 119
 120 /* Fill GDB's register array with the floating-point register values
 121    in *FPREGSETP.  */
 122
 123 void
 124 supply_fpregset (struct regcache *regcache, const fpregset_t *fpregsetp)
 125 {
 126   amd64_supply_fxsave (regcache, -1, fpregsetp);
 127 }
 128
 129 /* Fill register REGNUM (if it is a floating-point register) in
 130    *FPREGSETP with the value in GDB's register array.  If REGNUM is -1,
 131    do this for all registers.  */
 132
 133 void
 134 fill_fpregset (const struct regcache *regcache, gdb_fpregset_t *fpregsetp, int regnum)
 135 {
 136   amd64_collect_fxsave (regcache, regnum, fpregsetp);
 137 }
 138 \f
 139 /* Support for debugging kernel virtual memory images.  */
 140
 141 #include <sys/types.h>
 142 #include <machine/pcb.h>
 143 #include <osreldate.h>
 144
 145 #include "bsd-kvm.h"
 146
 147 static int
 148 amd64dfly_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 149 {
 150   /* The following is true for FreeBSD 5.2:
 151
 152      The pcb contains %rip, %rbx, %rsp, %rbp, %r12, %r13, %r14, %r15,
 153      %ds, %es, %fs and %gs.  This accounts for all callee-saved
 154      registers specified by the psABI and then some.  Here %esp
 155      contains the stack pointer at the point just after the call to
 156      cpu_switch().  From this information we reconstruct the register
 157      state as it would like when we just returned from cpu_switch().  */
 158
 159   /* The stack pointer shouldn't be zero.  */
 160   if (pcb->pcb_rsp == 0)
 161     return 0;
 162
 163   pcb->pcb_rsp += 8;
 164   regcache_raw_supply (regcache, AMD64_RIP_REGNUM, &pcb->pcb_rip);
 165   regcache_raw_supply (regcache, AMD64_RBX_REGNUM, &pcb->pcb_rbx);
 166   regcache_raw_supply (regcache, AMD64_RSP_REGNUM, &pcb->pcb_rsp);
 167   regcache_raw_supply (regcache, AMD64_RBP_REGNUM, &pcb->pcb_rbp);
 168   regcache_raw_supply (regcache, 12, &pcb->pcb_r12);
 169   regcache_raw_supply (regcache, 13, &pcb->pcb_r13);
 170   regcache_raw_supply (regcache, 14, &pcb->pcb_r14);
 171   regcache_raw_supply (regcache, 15, &pcb->pcb_r15);
 172 #if (__FreeBSD_version < 800075) && (__FreeBSD_kernel_version < 800075)
 173   /* struct pcb provides the pcb_ds/pcb_es/pcb_fs/pcb_gs fields only
 174      up until __FreeBSD_version 800074: The removal of these fields
 175      occurred on 2009-04-01 while the __FreeBSD_version number was
 176      bumped to 800075 on 2009-04-06.  So 800075 is the closest version
 177      number where we should not try to access these fields.  */
 178   regcache_raw_supply (regcache, AMD64_DS_REGNUM, &pcb->pcb_ds);
 179   regcache_raw_supply (regcache, AMD64_ES_REGNUM, &pcb->pcb_es);
 180   regcache_raw_supply (regcache, AMD64_FS_REGNUM, &pcb->pcb_fs);
 181   regcache_raw_supply (regcache, AMD64_GS_REGNUM, &pcb->pcb_gs);
 182 #endif
 183
 184   return 1;
 185 }
 186 #endif /* DFLY_PCB_SUPPLY */
 187 \f
 188
 189 static void (*super_mourn_inferior) (struct target_ops *ops);
 190
 191 /* Work around vkernels not having PT_{GET,SET}DBREGS via ptrace(2) support. */
 192 static int
 193 is_vkernel(void)
 194 {
 195         size_t len;
 196         char buf[64];
 197
 198         len = sizeof(buf);
 199         if (sysctlbyname("kern.vmm_guest", buf, &len, NULL, 0) < 0)
 200                 return 0;
 201         if (strncmp("vkernel", buf, len) == 0)
 202                 return 1;
 203         else
 204                 return 0;
 205 }
 206
 207 static void
 208 amd64dfly_mourn_inferior (struct target_ops *ops)
 209 {
 210 #ifdef HAVE_PT_GETDBREGS
 211   if (!is_vkernel())
 212   i386_cleanup_dregs ();
 213 #endif
 214   super_mourn_inferior (ops);
 215 }
 216
 217 /* Provide a prototype to silence -Wmissing-prototypes.  */
 218 void _initialize_amd64dfly_nat (void);
 219
 220 void
 221 _initialize_amd64dfly_nat (void)
 222 {
 223   struct target_ops *t;
 224   int offset;
 225
 226   amd64_native_gregset32_reg_offset = amd64dfly32_r_reg_offset;
 227   amd64_native_gregset64_reg_offset = amd64dfly64_r_reg_offset;
 228
 229   /* Add some extra features to the common *BSD/i386 target.  */
 230   t = amd64bsd_target ();
 231
 232 #ifdef HAVE_PT_GETDBREGS
 233
 234   if (!is_vkernel()) {
 235   i386_use_watchpoints (t);
 236
 237   i386_dr_low.set_control = amd64bsd_dr_set_control;
 238   i386_dr_low.set_addr = amd64bsd_dr_set_addr;
 239   i386_dr_low.get_addr = amd64bsd_dr_get_addr;
 240   i386_dr_low.get_status = amd64bsd_dr_get_status;
 241   i386_dr_low.get_control = amd64bsd_dr_get_control;
 242   i386_set_debug_register_length (8);
 243   }
 244
 245 #endif /* HAVE_PT_GETDBREGS */
 246
 247   super_mourn_inferior = t->to_mourn_inferior;
 248   t->to_mourn_inferior = amd64dfly_mourn_inferior;
 249
 250   t->to_pid_to_exec_file = fbsd_pid_to_exec_file;
 251   t->to_find_memory_regions = fbsd_find_memory_regions;
 252   t->to_make_corefile_notes = fbsd_make_corefile_notes;
 253   add_target (t);
 254
 255 #ifdef DFLY_PCB_SUPPLY
 256   /* Support debugging kernel virtual memory images.  */
 257   bsd_kvm_add_target (amd64dfly_supply_pcb);
 258 #endif
 259
 260   /* To support the recognition of signal handlers, i386bsd-tdep.c
 261      hardcodes some constants.  Inclusion of this file means that we
 262      are compiling a native debugger, which means that we can use the
 263      system header files and sysctl(3) to get at the relevant
 264      information.  */
 265
 266 #define SC_REG_OFFSET amd64dfly_sc_reg_offset
 267
 268   /* We only check the program counter, stack pointer and frame
 269      pointer since these members of `struct sigcontext' are essential
 270      for providing backtraces.  */
 271
 272 #define SC_RIP_OFFSET SC_REG_OFFSET[AMD64_RIP_REGNUM]
 273 #define SC_RSP_OFFSET SC_REG_OFFSET[AMD64_RSP_REGNUM]
 274 #define SC_RBP_OFFSET SC_REG_OFFSET[AMD64_RBP_REGNUM]
 275
 276   /* Override the default value for the offset of the program counter
 277      in the sigcontext structure.  */
 278   offset = offsetof (struct sigcontext, sc_rip);
 279
 280   if (SC_RIP_OFFSET != offset)
 281     {
 282       warning (_("\
 283 offsetof (struct sigcontext, sc_rip) yields %d instead of %d.\n\
 284 Please report this to <bug-gdb@gnu.org>."),
 285                offset, SC_RIP_OFFSET);
 286     }
 287
 288   SC_RIP_OFFSET = offset;
 289
 290   /* Likewise for the stack pointer.  */
 291   offset = offsetof (struct sigcontext, sc_rsp);
 292
 293   if (SC_RSP_OFFSET != offset)
 294     {
 295       warning (_("\
 296 offsetof (struct sigcontext, sc_rsp) yields %d instead of %d.\n\
 297 Please report this to <bug-gdb@gnu.org>."),
 298                offset, SC_RSP_OFFSET);
 299     }
 300
 301   SC_RSP_OFFSET = offset;
 302
 303   /* And the frame pointer.  */
 304   offset = offsetof (struct sigcontext, sc_rbp);
 305
 306   if (SC_RBP_OFFSET != offset)
 307     {
 308       warning (_("\
 309 offsetof (struct sigcontext, sc_rbp) yields %d instead of %d.\n\
 310 Please report this to <bug-gdb@gnu.org>."),
 311                offset, SC_RBP_OFFSET);
 312     }
 313
 314   SC_RBP_OFFSET = offset;
 315
 316   /* DragonFly provides a kern.ps_strings sysctl that we can use to
 317      locate the sigtramp.  That way we can still recognize a sigtramp
 318      if its location is changed in a new kernel.  Of course this is
 319      still based on the assumption that the sigtramp is placed
 320      directly under the location where the program arguments and
 321      environment can be found.  */
 322   {
 323     int mib[2];
 324     long ps_strings;
 325     size_t len;
 326
 327     mib[0] = CTL_KERN;
 328     mib[1] = KERN_PS_STRINGS;
 329     len = sizeof (ps_strings);
 330     if (sysctl (mib, 2, &ps_strings, &len, NULL, 0) == 0)
 331       {
 332         amd64dfly_sigtramp_start_addr = ps_strings - 32;
 333         amd64dfly_sigtramp_end_addr = ps_strings;
 334       }
 335   }
 336 }