gdb/amd64-fbsd-nat.c

   1 /* Native-dependent code for FreeBSD/amd64.
   2
   3    Copyright (C) 2003-2024 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 "inferior.h"
  21 #include "regcache.h"
  22 #include "target.h"
  23
  24 #include <signal.h>
  25 #include <sys/types.h>
  26 #include <sys/ptrace.h>
  27 #include <sys/sysctl.h>
  28 #include <sys/user.h>
  29 #include <machine/reg.h>
  30
  31 #include "amd64-tdep.h"
  32 #include "amd64-fbsd-tdep.h"
  33 #include "i387-tdep.h"
  34 #include "amd64-nat.h"
  35 #include "x86-nat.h"
  36 #include "x86-fbsd-nat.h"
  37
  38 class amd64_fbsd_nat_target final : public x86_fbsd_nat_target
  39 {
  40 public:
  41   void fetch_registers (struct regcache *, int) override;
  42   void store_registers (struct regcache *, int) override;
  43
  44   const struct target_desc *read_description () override;
  45 };
  46
  47 static amd64_fbsd_nat_target the_amd64_fbsd_nat_target;
  48
  49 /* This is a layout of the amd64 'struct reg' but with i386
  50    registers.  */
  51
  52 static const struct regcache_map_entry amd64_fbsd32_gregmap[] =
  53 {
  54   { 8, REGCACHE_MAP_SKIP, 8 },
  55   { 1, I386_EDI_REGNUM, 8 },
  56   { 1, I386_ESI_REGNUM, 8 },
  57   { 1, I386_EBP_REGNUM, 8 },
  58   { 1, I386_EBX_REGNUM, 8 },
  59   { 1, I386_EDX_REGNUM, 8 },
  60   { 1, I386_ECX_REGNUM, 8 },
  61   { 1, I386_EAX_REGNUM, 8 },
  62   { 1, REGCACHE_MAP_SKIP, 4 },  /* trapno */
  63   { 1, I386_FS_REGNUM, 2 },
  64   { 1, I386_GS_REGNUM, 2 },
  65   { 1, REGCACHE_MAP_SKIP, 4 },  /* err */
  66   { 1, I386_ES_REGNUM, 2 },
  67   { 1, I386_DS_REGNUM, 2 },
  68   { 1, I386_EIP_REGNUM, 8 },
  69   { 1, I386_CS_REGNUM, 8 },
  70   { 1, I386_EFLAGS_REGNUM, 8 },
  71   { 1, I386_ESP_REGNUM, 0 },
  72   { 1, I386_SS_REGNUM, 8 },
  73   { 0 }
  74 };
  75
  76 static const struct regset amd64_fbsd32_gregset =
  77 {
  78   amd64_fbsd32_gregmap, regcache_supply_regset, regcache_collect_regset
  79 };
  80
  81 /* Return the regset to use for 'struct reg' for the GDBARCH.  */
  82
  83 static const struct regset *
  84 find_gregset (struct gdbarch *gdbarch)
  85 {
  86   if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
  87     return &amd64_fbsd32_gregset;
  88   else
  89     return &amd64_fbsd_gregset;
  90 }
  91
  92 /* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
  93    for all registers.  */
  94
  95 void
  96 amd64_fbsd_nat_target::fetch_registers (struct regcache *regcache, int regnum)
  97 {
  98   struct gdbarch *gdbarch = regcache->arch ();
  99 #if defined(PT_GETFSBASE) || defined(PT_GETGSBASE)
 100   const i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);
 101 #endif
 102   pid_t pid = get_ptrace_pid (regcache->ptid ());
 103   const struct regset *gregset = find_gregset (gdbarch);
 104
 105   if (fetch_register_set<struct reg> (regcache, regnum, PT_GETREGS, gregset))
 106     {
 107       if (regnum != -1)
 108         return;
 109     }
 110
 111 #ifdef PT_GETFSBASE
 112   if (regnum == -1 || regnum == tdep->fsbase_regnum)
 113     {
 114       register_t base;
 115
 116       if (ptrace (PT_GETFSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1)
 117         perror_with_name (_("Couldn't get segment register fs_base"));
 118
 119       regcache->raw_supply (tdep->fsbase_regnum, &base);
 120       if (regnum != -1)
 121         return;
 122     }
 123 #endif
 124 #ifdef PT_GETGSBASE
 125   if (regnum == -1 || regnum == tdep->fsbase_regnum + 1)
 126     {
 127       register_t base;
 128
 129       if (ptrace (PT_GETGSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1)
 130         perror_with_name (_("Couldn't get segment register gs_base"));
 131
 132       regcache->raw_supply (tdep->fsbase_regnum + 1, &base);
 133       if (regnum != -1)
 134         return;
 135     }
 136 #endif
 137
 138   /* There is no amd64_fxsave_supplies or amd64_xsave_supplies.
 139      Instead, the earlier register sets return early if the request
 140      was for a specific register that was already satisified to avoid
 141      fetching the FPU/XSAVE state unnecessarily.  */
 142
 143 #ifdef PT_GETXSTATE_INFO
 144   if (m_xsave_info.xsave_len != 0)
 145     {
 146       void *xstateregs = alloca (m_xsave_info.xsave_len);
 147
 148       if (ptrace (PT_GETXSTATE, pid, (PTRACE_TYPE_ARG3) xstateregs, 0) == -1)
 149         perror_with_name (_("Couldn't get extended state status"));
 150
 151       amd64_supply_xsave (regcache, regnum, xstateregs);
 152       return;
 153     }
 154 #endif
 155
 156   struct fpreg fpregs;
 157
 158   if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 159     perror_with_name (_("Couldn't get floating point status"));
 160
 161   amd64_supply_fxsave (regcache, regnum, &fpregs);
 162 }
 163
 164 /* Store register REGNUM back into the inferior.  If REGNUM is -1, do
 165    this for all registers.  */
 166
 167 void
 168 amd64_fbsd_nat_target::store_registers (struct regcache *regcache, int regnum)
 169 {
 170   struct gdbarch *gdbarch = regcache->arch ();
 171 #if defined(PT_GETFSBASE) || defined(PT_GETGSBASE)
 172   const i386_gdbarch_tdep *tdep = gdbarch_tdep<i386_gdbarch_tdep> (gdbarch);
 173 #endif
 174   pid_t pid = get_ptrace_pid (regcache->ptid ());
 175   const struct regset *gregset = find_gregset (gdbarch);
 176
 177   if (store_register_set<struct reg> (regcache, regnum, PT_GETREGS, PT_SETREGS,
 178                                       gregset))
 179     {
 180       if (regnum != -1)
 181         return;
 182     }
 183
 184 #ifdef PT_SETFSBASE
 185   if (regnum == -1 || regnum == tdep->fsbase_regnum)
 186     {
 187       register_t base;
 188
 189       /* Clear the full base value to support 32-bit targets.  */
 190       base = 0;
 191       regcache->raw_collect (tdep->fsbase_regnum, &base);
 192
 193       if (ptrace (PT_SETFSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1)
 194         perror_with_name (_("Couldn't write segment register fs_base"));
 195       if (regnum != -1)
 196         return;
 197     }
 198 #endif
 199 #ifdef PT_SETGSBASE
 200   if (regnum == -1 || regnum == tdep->fsbase_regnum + 1)
 201     {
 202       register_t base;
 203
 204       /* Clear the full base value to support 32-bit targets.  */
 205       base = 0;
 206       regcache->raw_collect (tdep->fsbase_regnum + 1, &base);
 207
 208       if (ptrace (PT_SETGSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1)
 209         perror_with_name (_("Couldn't write segment register gs_base"));
 210       if (regnum != -1)
 211         return;
 212     }
 213 #endif
 214
 215   /* There is no amd64_fxsave_supplies or amd64_xsave_supplies.
 216      Instead, the earlier register sets return early if the request
 217      was for a specific register that was already satisified to avoid
 218      fetching the FPU/XSAVE state unnecessarily.  */
 219
 220 #ifdef PT_GETXSTATE_INFO
 221   if (m_xsave_info.xsave_len != 0)
 222     {
 223       void *xstateregs = alloca (m_xsave_info.xsave_len);
 224
 225       if (ptrace (PT_GETXSTATE, pid, (PTRACE_TYPE_ARG3) xstateregs, 0) == -1)
 226         perror_with_name (_("Couldn't get extended state status"));
 227
 228       amd64_collect_xsave (regcache, regnum, xstateregs, 0);
 229
 230       if (ptrace (PT_SETXSTATE, pid, (PTRACE_TYPE_ARG3) xstateregs,
 231                   m_xsave_info.xsave_len) == -1)
 232         perror_with_name (_("Couldn't write extended state status"));
 233       return;
 234     }
 235 #endif
 236
 237   struct fpreg fpregs;
 238
 239   if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 240     perror_with_name (_("Couldn't get floating point status"));
 241
 242   amd64_collect_fxsave (regcache, regnum, &fpregs);
 243
 244   if (ptrace (PT_SETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 245     perror_with_name (_("Couldn't write floating point status"));
 246 }
 247
 248 /* Support for debugging kernel virtual memory images.  */
 249
 250 #include <machine/pcb.h>
 251 #include <osreldate.h>
 252
 253 #include "bsd-kvm.h"
 254
 255 static int
 256 amd64fbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 257 {
 258   /* The following is true for FreeBSD 5.2:
 259
 260      The pcb contains %rip, %rbx, %rsp, %rbp, %r12, %r13, %r14, %r15,
 261      %ds, %es, %fs and %gs.  This accounts for all callee-saved
 262      registers specified by the psABI and then some.  Here %esp
 263      contains the stack pointer at the point just after the call to
 264      cpu_switch().  From this information we reconstruct the register
 265      state as it would like when we just returned from cpu_switch().  */
 266
 267   /* The stack pointer shouldn't be zero.  */
 268   if (pcb->pcb_rsp == 0)
 269     return 0;
 270
 271   pcb->pcb_rsp += 8;
 272   regcache->raw_supply (AMD64_RIP_REGNUM, &pcb->pcb_rip);
 273   regcache->raw_supply (AMD64_RBX_REGNUM, &pcb->pcb_rbx);
 274   regcache->raw_supply (AMD64_RSP_REGNUM, &pcb->pcb_rsp);
 275   regcache->raw_supply (AMD64_RBP_REGNUM, &pcb->pcb_rbp);
 276   regcache->raw_supply (12, &pcb->pcb_r12);
 277   regcache->raw_supply (13, &pcb->pcb_r13);
 278   regcache->raw_supply (14, &pcb->pcb_r14);
 279   regcache->raw_supply (15, &pcb->pcb_r15);
 280 #if (__FreeBSD_version < 800075) && (__FreeBSD_kernel_version < 800075)
 281   /* struct pcb provides the pcb_ds/pcb_es/pcb_fs/pcb_gs fields only
 282      up until __FreeBSD_version 800074: The removal of these fields
 283      occurred on 2009-04-01 while the __FreeBSD_version number was
 284      bumped to 800075 on 2009-04-06.  So 800075 is the closest version
 285      number where we should not try to access these fields.  */
 286   regcache->raw_supply (AMD64_DS_REGNUM, &pcb->pcb_ds);
 287   regcache->raw_supply (AMD64_ES_REGNUM, &pcb->pcb_es);
 288   regcache->raw_supply (AMD64_FS_REGNUM, &pcb->pcb_fs);
 289   regcache->raw_supply (AMD64_GS_REGNUM, &pcb->pcb_gs);
 290 #endif
 291
 292   return 1;
 293 }
 294 \f
 295
 296 /* Implement the read_description method.  */
 297
 298 const struct target_desc *
 299 amd64_fbsd_nat_target::read_description ()
 300 {
 301   struct reg regs;
 302   int is64;
 303
 304   if (inferior_ptid == null_ptid)
 305     return this->beneath ()->read_description ();
 306
 307   if (ptrace (PT_GETREGS, inferior_ptid.pid (),
 308               (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 309     perror_with_name (_("Couldn't get registers"));
 310   is64 = (regs.r_cs == GSEL (GUCODE_SEL, SEL_UPL));
 311 #ifdef PT_GETXSTATE_INFO
 312   probe_xsave_layout (inferior_ptid.pid ());
 313   if (m_xsave_info.xsave_len != 0)
 314     {
 315       if (is64)
 316         return amd64_target_description (m_xsave_info.xsave_mask, true);
 317       else
 318         return i386_target_description (m_xsave_info.xsave_mask, true);
 319     }
 320 #endif
 321   if (is64)
 322     return amd64_target_description (X86_XSTATE_SSE_MASK, true);
 323   else
 324     return i386_target_description (X86_XSTATE_SSE_MASK, true);
 325 }
 326
 327 void _initialize_amd64fbsd_nat ();
 328 void
 329 _initialize_amd64fbsd_nat ()
 330 {
 331   add_inf_child_target (&the_amd64_fbsd_nat_target);
 332
 333   /* Support debugging kernel virtual memory images.  */
 334   bsd_kvm_add_target (amd64fbsd_supply_pcb);
 335 }