gdb/amd64-fbsd-tdep.c

   1 /* Target-dependent code for FreeBSD/amd64.
   2
   3    Copyright (C) 2003-2022 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 "osabi.h"
  22 #include "regset.h"
  23 #include "target.h"
  24 #include "trad-frame.h"
  25 #include "tramp-frame.h"
  26 #include "i386-fbsd-tdep.h"
  27 #include "gdbsupport/x86-xstate.h"
  28
  29 #include "amd64-tdep.h"
  30 #include "amd64-fbsd-tdep.h"
  31 #include "fbsd-tdep.h"
  32 #include "solib-svr4.h"
  33 #include "inferior.h"
  34
  35 /* The general-purpose regset consists of 22 64-bit slots, most of
  36    which contain individual registers, but a few contain multiple
  37    16-bit segment registers.  */
  38 #define AMD64_FBSD_SIZEOF_GREGSET       (22 * 8)
  39
  40 /* Register maps.  */
  41
  42 static const struct regcache_map_entry amd64_fbsd_gregmap[] =
  43 {
  44   { 1, AMD64_R15_REGNUM, 0 },
  45   { 1, AMD64_R14_REGNUM, 0 },
  46   { 1, AMD64_R13_REGNUM, 0 },
  47   { 1, AMD64_R12_REGNUM, 0 },
  48   { 1, AMD64_R11_REGNUM, 0 },
  49   { 1, AMD64_R10_REGNUM, 0 },
  50   { 1, AMD64_R9_REGNUM, 0 },
  51   { 1, AMD64_R8_REGNUM, 0 },
  52   { 1, AMD64_RDI_REGNUM, 0 },
  53   { 1, AMD64_RSI_REGNUM, 0 },
  54   { 1, AMD64_RBP_REGNUM, 0 },
  55   { 1, AMD64_RBX_REGNUM, 0 },
  56   { 1, AMD64_RDX_REGNUM, 0 },
  57   { 1, AMD64_RCX_REGNUM, 0 },
  58   { 1, AMD64_RAX_REGNUM, 0 },
  59   { 1, REGCACHE_MAP_SKIP, 4 },  /* trapno */
  60   { 1, AMD64_FS_REGNUM, 2 },
  61   { 1, AMD64_GS_REGNUM, 2 },
  62   { 1, REGCACHE_MAP_SKIP, 4 },  /* err */
  63   { 1, AMD64_ES_REGNUM, 2 },
  64   { 1, AMD64_DS_REGNUM, 2 },
  65   { 1, AMD64_RIP_REGNUM, 0 },
  66   { 1, AMD64_CS_REGNUM, 8 },
  67   { 1, AMD64_EFLAGS_REGNUM, 8 },
  68   { 1, AMD64_RSP_REGNUM, 0 },
  69   { 1, AMD64_SS_REGNUM, 8 },
  70   { 0 }
  71 };
  72
  73 /* This layout including fsbase and gsbase was adopted in FreeBSD
  74    8.0.  */
  75
  76 static const struct regcache_map_entry amd64_fbsd_mcregmap[] =
  77 {
  78   { 1, REGCACHE_MAP_SKIP, 8 },  /* mc_onstack */
  79   { 1, AMD64_RDI_REGNUM, 0 },
  80   { 1, AMD64_RSI_REGNUM, 0 },
  81   { 1, AMD64_RDX_REGNUM, 0 },
  82   { 1, AMD64_RCX_REGNUM, 0 },
  83   { 1, AMD64_R8_REGNUM, 0 },
  84   { 1, AMD64_R9_REGNUM, 0 },
  85   { 1, AMD64_RAX_REGNUM, 0 },
  86   { 1, AMD64_RBX_REGNUM, 0 },
  87   { 1, AMD64_RBP_REGNUM, 0 },
  88   { 1, AMD64_R10_REGNUM, 0 },
  89   { 1, AMD64_R11_REGNUM, 0 },
  90   { 1, AMD64_R12_REGNUM, 0 },
  91   { 1, AMD64_R13_REGNUM, 0 },
  92   { 1, AMD64_R14_REGNUM, 0 },
  93   { 1, AMD64_R15_REGNUM, 0 },
  94   { 1, REGCACHE_MAP_SKIP, 4 },  /* mc_trapno */
  95   { 1, AMD64_FS_REGNUM, 2 },
  96   { 1, AMD64_GS_REGNUM, 2 },
  97   { 1, REGCACHE_MAP_SKIP, 8 },  /* mc_addr */
  98   { 1, REGCACHE_MAP_SKIP, 4 },  /* mc_flags */
  99   { 1, AMD64_ES_REGNUM, 2 },
 100   { 1, AMD64_DS_REGNUM, 2 },
 101   { 1, REGCACHE_MAP_SKIP, 8 },  /* mc_err */
 102   { 1, AMD64_RIP_REGNUM, 0 },
 103   { 1, AMD64_CS_REGNUM, 8 },
 104   { 1, AMD64_EFLAGS_REGNUM, 8 },
 105   { 1, AMD64_RSP_REGNUM, 0 },
 106   { 1, AMD64_SS_REGNUM, 8 },
 107   { 1, REGCACHE_MAP_SKIP, 8 },  /* mc_len */
 108   { 1, REGCACHE_MAP_SKIP, 8 },  /* mc_fpformat */
 109   { 1, REGCACHE_MAP_SKIP, 8 },  /* mc_ownedfp */
 110   { 64, REGCACHE_MAP_SKIP, 8 }, /* mc_fpstate */
 111   { 1, AMD64_FSBASE_REGNUM, 0 },
 112   { 1, AMD64_GSBASE_REGNUM, 0 },
 113   { 0 }
 114 };
 115
 116 /* Register set definitions.  */
 117
 118 const struct regset amd64_fbsd_gregset =
 119 {
 120   amd64_fbsd_gregmap, regcache_supply_regset, regcache_collect_regset
 121 };
 122
 123 /* Support for signal handlers.  */
 124
 125 /* In a signal frame, rsp points to a 'struct sigframe' which is
 126    defined as:
 127
 128    struct sigframe {
 129         union {
 130                 __siginfohandler_t      *sf_action;
 131                 __sighandler_t          *sf_handler;
 132         } sf_ahu;
 133         ucontext_t      sf_uc;
 134         ...
 135    }
 136
 137    ucontext_t is defined as:
 138
 139    struct __ucontext {
 140            sigset_t     uc_sigmask;
 141            mcontext_t   uc_mcontext;
 142            ...
 143    };
 144
 145    The mcontext_t contains the general purpose register set as well
 146    as the floating point or XSAVE state.  */
 147
 148 /* NB: There is an 8 byte padding hole between sf_ahu and sf_uc. */
 149 #define AMD64_SIGFRAME_UCONTEXT_OFFSET          16
 150 #define AMD64_UCONTEXT_MCONTEXT_OFFSET          16
 151 #define AMD64_SIZEOF_MCONTEXT_T                 800
 152
 153 /* Implement the "init" method of struct tramp_frame.  */
 154
 155 static void
 156 amd64_fbsd_sigframe_init (const struct tramp_frame *self,
 157                           struct frame_info *this_frame,
 158                           struct trad_frame_cache *this_cache,
 159                           CORE_ADDR func)
 160 {
 161   CORE_ADDR sp = get_frame_register_unsigned (this_frame, AMD64_RSP_REGNUM);
 162   CORE_ADDR mcontext_addr
 163     = (sp
 164        + AMD64_SIGFRAME_UCONTEXT_OFFSET
 165        + AMD64_UCONTEXT_MCONTEXT_OFFSET);
 166
 167   trad_frame_set_reg_regmap (this_cache, amd64_fbsd_mcregmap, mcontext_addr,
 168                              AMD64_SIZEOF_MCONTEXT_T);
 169
 170   /* Don't bother with floating point or XSAVE state for now.  The
 171      current helper routines for parsing FXSAVE and XSAVE state only
 172      work with regcaches.  This could perhaps create a temporary
 173      regcache, collect the register values from mc_fpstate and
 174      mc_xfpustate, and then set register values in the trad_frame.  */
 175
 176   trad_frame_set_id (this_cache, frame_id_build (sp, func));
 177 }
 178
 179 static const struct tramp_frame amd64_fbsd_sigframe =
 180 {
 181   SIGTRAMP_FRAME,
 182   1,
 183   {
 184     {0x48, ULONGEST_MAX},               /* lea     SIGF_UC(%rsp),%rdi */
 185     {0x8d, ULONGEST_MAX},
 186     {0x7c, ULONGEST_MAX},
 187     {0x24, ULONGEST_MAX},
 188     {0x10, ULONGEST_MAX},
 189     {0x6a, ULONGEST_MAX},               /* pushq   $0 */
 190     {0x00, ULONGEST_MAX},
 191     {0x48, ULONGEST_MAX},               /* movq    $SYS_sigreturn,%rax */
 192     {0xc7, ULONGEST_MAX},
 193     {0xc0, ULONGEST_MAX},
 194     {0xa1, ULONGEST_MAX},
 195     {0x01, ULONGEST_MAX},
 196     {0x00, ULONGEST_MAX},
 197     {0x00, ULONGEST_MAX},
 198     {0x0f, ULONGEST_MAX},               /* syscall */
 199     {0x05, ULONGEST_MAX},
 200     {TRAMP_SENTINEL_INSN, ULONGEST_MAX}
 201   },
 202   amd64_fbsd_sigframe_init
 203 };
 204
 205 /* Implement the core_read_description gdbarch method.  */
 206
 207 static const struct target_desc *
 208 amd64fbsd_core_read_description (struct gdbarch *gdbarch,
 209                                  struct target_ops *target,
 210                                  bfd *abfd)
 211 {
 212   return amd64_target_description (i386fbsd_core_read_xcr0 (abfd), true);
 213 }
 214
 215 /* Similar to amd64_supply_fpregset, but use XSAVE extended state.  */
 216
 217 static void
 218 amd64fbsd_supply_xstateregset (const struct regset *regset,
 219                                struct regcache *regcache, int regnum,
 220                                const void *xstateregs, size_t len)
 221 {
 222   amd64_supply_xsave (regcache, regnum, xstateregs);
 223 }
 224
 225 /* Similar to amd64_collect_fpregset, but use XSAVE extended state.  */
 226
 227 static void
 228 amd64fbsd_collect_xstateregset (const struct regset *regset,
 229                                 const struct regcache *regcache,
 230                                 int regnum, void *xstateregs, size_t len)
 231 {
 232   amd64_collect_xsave (regcache, regnum, xstateregs, 1);
 233 }
 234
 235 static const struct regset amd64fbsd_xstateregset =
 236   {
 237     NULL,
 238     amd64fbsd_supply_xstateregset,
 239     amd64fbsd_collect_xstateregset
 240   };
 241
 242 /* Iterate over core file register note sections.  */
 243
 244 static void
 245 amd64fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
 246                                         iterate_over_regset_sections_cb *cb,
 247                                         void *cb_data,
 248                                         const struct regcache *regcache)
 249 {
 250   i386_gdbarch_tdep *tdep = (i386_gdbarch_tdep *) gdbarch_tdep (gdbarch);
 251
 252   cb (".reg", AMD64_FBSD_SIZEOF_GREGSET, AMD64_FBSD_SIZEOF_GREGSET,
 253       &amd64_fbsd_gregset, NULL, cb_data);
 254   cb (".reg2", tdep->sizeof_fpregset, tdep->sizeof_fpregset, &amd64_fpregset,
 255       NULL, cb_data);
 256   cb (".reg-xstate", X86_XSTATE_SIZE (tdep->xcr0), X86_XSTATE_SIZE (tdep->xcr0),
 257       &amd64fbsd_xstateregset, "XSAVE extended state", cb_data);
 258 }
 259
 260 /* Implement the get_thread_local_address gdbarch method.  */
 261
 262 static CORE_ADDR
 263 amd64fbsd_get_thread_local_address (struct gdbarch *gdbarch, ptid_t ptid,
 264                                     CORE_ADDR lm_addr, CORE_ADDR offset)
 265 {
 266   struct regcache *regcache;
 267
 268   regcache = get_thread_arch_regcache (current_inferior ()->process_target (),
 269                                        ptid, gdbarch);
 270
 271   target_fetch_registers (regcache, AMD64_FSBASE_REGNUM);
 272
 273   ULONGEST fsbase;
 274   if (regcache->cooked_read (AMD64_FSBASE_REGNUM, &fsbase) != REG_VALID)
 275     error (_("Unable to fetch %%fsbase"));
 276
 277   CORE_ADDR dtv_addr = fsbase + gdbarch_ptr_bit (gdbarch) / 8;
 278   return fbsd_get_thread_local_address (gdbarch, dtv_addr, lm_addr, offset);
 279 }
 280
 281 static void
 282 amd64fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 283 {
 284   i386_gdbarch_tdep *tdep = (i386_gdbarch_tdep *) gdbarch_tdep (gdbarch);
 285
 286   /* Generic FreeBSD support. */
 287   fbsd_init_abi (info, gdbarch);
 288
 289   /* Obviously FreeBSD is BSD-based.  */
 290   i386bsd_init_abi (info, gdbarch);
 291
 292   amd64_init_abi (info, gdbarch,
 293                   amd64_target_description (X86_XSTATE_SSE_MASK, true));
 294
 295   tramp_frame_prepend_unwinder (gdbarch, &amd64_fbsd_sigframe);
 296
 297   tdep->xsave_xcr0_offset = I386_FBSD_XSAVE_XCR0_OFFSET;
 298
 299   /* Iterate over core file register note sections.  */
 300   set_gdbarch_iterate_over_regset_sections
 301     (gdbarch, amd64fbsd_iterate_over_regset_sections);
 302
 303   set_gdbarch_core_read_description (gdbarch,
 304                                      amd64fbsd_core_read_description);
 305
 306   /* FreeBSD uses SVR4-style shared libraries.  */
 307   set_solib_svr4_fetch_link_map_offsets
 308     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 309
 310   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 311                                              svr4_fetch_objfile_link_map);
 312   set_gdbarch_get_thread_local_address (gdbarch,
 313                                         amd64fbsd_get_thread_local_address);
 314 }
 315
 316 void _initialize_amd64fbsd_tdep ();
 317 void
 318 _initialize_amd64fbsd_tdep ()
 319 {
 320   gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
 321                           GDB_OSABI_FREEBSD, amd64fbsd_init_abi);
 322 }