gdb/amd64-fbsd-tdep.c

   1 /* Target-dependent code for FreeBSD/amd64.
   2
   3    Copyright (C) 2003-2019 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 "arch-utils.h"
  22 #include "frame.h"
  23 #include "gdbcore.h"
  24 #include "regcache.h"
  25 #include "osabi.h"
  26 #include "regset.h"
  27 #include "i386-fbsd-tdep.h"
  28 #include "common/x86-xstate.h"
  29
  30 #include "amd64-tdep.h"
  31 #include "fbsd-tdep.h"
  32 #include "solib-svr4.h"
  33
  34 /* Support for signal handlers.  */
  35
  36 /* Return whether THIS_FRAME corresponds to a FreeBSD sigtramp
  37    routine.  */
  38
  39 static const gdb_byte amd64fbsd_sigtramp_code[] =
  40 {
  41   0x48, 0x8d, 0x7c, 0x24, 0x10, /* lea     SIGF_UC(%rsp),%rdi */
  42   0x6a, 0x00,                   /* pushq   $0 */
  43   0x48, 0xc7, 0xc0, 0xa1, 0x01, 0x00, 0x00,
  44                                 /* movq    $SYS_sigreturn,%rax */
  45   0x0f, 0x05                    /* syscall */
  46 };
  47
  48 static int
  49 amd64fbsd_sigtramp_p (struct frame_info *this_frame)
  50 {
  51   CORE_ADDR pc = get_frame_pc (this_frame);
  52   gdb_byte buf[sizeof amd64fbsd_sigtramp_code];
  53
  54   if (!safe_frame_unwind_memory (this_frame, pc, buf, sizeof buf))
  55     return 0;
  56   if (memcmp (buf, amd64fbsd_sigtramp_code, sizeof amd64fbsd_sigtramp_code)
  57       != 0)
  58     return 0;
  59
  60   return 1;
  61 }
  62
  63 /* Assuming THIS_FRAME is for a BSD sigtramp routine, return the
  64    address of the associated sigcontext structure.  */
  65
  66 static CORE_ADDR
  67 amd64fbsd_sigcontext_addr (struct frame_info *this_frame)
  68 {
  69   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  70   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  71   CORE_ADDR sp;
  72   gdb_byte buf[8];
  73
  74   /* The `struct sigcontext' (which really is an `ucontext_t' on
  75      FreeBSD/amd64) lives at a fixed offset in the signal frame.  See
  76      <machine/sigframe.h>.  */
  77   get_frame_register (this_frame, AMD64_RSP_REGNUM, buf);
  78   sp = extract_unsigned_integer (buf, 8, byte_order);
  79   return sp + 16;
  80 }
  81 \f
  82 /* FreeBSD 5.1-RELEASE or later.  */
  83
  84 /* Mapping between the general-purpose registers in `struct reg'
  85    format and GDB's register cache layout.
  86
  87    Note that some registers are 32-bit, but since we're little-endian
  88    we get away with that.  */
  89
  90 /* From <machine/reg.h>.  */
  91 static int amd64fbsd_r_reg_offset[] =
  92 {
  93   14 * 8,                       /* %rax */
  94   11 * 8,                       /* %rbx */
  95   13 * 8,                       /* %rcx */
  96   12 * 8,                       /* %rdx */
  97   9 * 8,                        /* %rsi */
  98   8 * 8,                        /* %rdi */
  99   10 * 8,                       /* %rbp */
 100   20 * 8,                       /* %rsp */
 101   7 * 8,                        /* %r8 ...  */
 102   6 * 8,
 103   5 * 8,
 104   4 * 8,
 105   3 * 8,
 106   2 * 8,
 107   1 * 8,
 108   0 * 8,                        /* ... %r15 */
 109   17 * 8,                       /* %rip */
 110   19 * 8,                       /* %eflags */
 111   18 * 8,                       /* %cs */
 112   21 * 8,                       /* %ss */
 113   -1,                           /* %ds */
 114   -1,                           /* %es */
 115   -1,                           /* %fs */
 116   -1                            /* %gs */
 117 };
 118
 119 /* Location of the signal trampoline.  */
 120 CORE_ADDR amd64fbsd_sigtramp_start_addr;
 121 CORE_ADDR amd64fbsd_sigtramp_end_addr;
 122
 123 /* From <machine/signal.h>.  */
 124 int amd64fbsd_sc_reg_offset[] =
 125 {
 126   24 + 6 * 8,                   /* %rax */
 127   24 + 7 * 8,                   /* %rbx */
 128   24 + 3 * 8,                   /* %rcx */
 129   24 + 2 * 8,                   /* %rdx */
 130   24 + 1 * 8,                   /* %rsi */
 131   24 + 0 * 8,                   /* %rdi */
 132   24 + 8 * 8,                   /* %rbp */
 133   24 + 22 * 8,                  /* %rsp */
 134   24 + 4 * 8,                   /* %r8 ...  */
 135   24 + 5 * 8,
 136   24 + 9 * 8,
 137   24 + 10 * 8,
 138   24 + 11 * 8,
 139   24 + 12 * 8,
 140   24 + 13 * 8,
 141   24 + 14 * 8,                  /* ... %r15 */
 142   24 + 19 * 8,                  /* %rip */
 143   24 + 21 * 8,                  /* %eflags */
 144   24 + 20 * 8,                  /* %cs */
 145   24 + 23 * 8,                  /* %ss */
 146   -1,                           /* %ds */
 147   -1,                           /* %es */
 148   -1,                           /* %fs */
 149   -1                            /* %gs */
 150 };
 151
 152 /* Implement the core_read_description gdbarch method.  */
 153
 154 static const struct target_desc *
 155 amd64fbsd_core_read_description (struct gdbarch *gdbarch,
 156                                  struct target_ops *target,
 157                                  bfd *abfd)
 158 {
 159   return amd64_target_description (i386fbsd_core_read_xcr0 (abfd), true);
 160 }
 161
 162 /* Similar to amd64_supply_fpregset, but use XSAVE extended state.  */
 163
 164 static void
 165 amd64fbsd_supply_xstateregset (const struct regset *regset,
 166                                struct regcache *regcache, int regnum,
 167                                const void *xstateregs, size_t len)
 168 {
 169   amd64_supply_xsave (regcache, regnum, xstateregs);
 170 }
 171
 172 /* Similar to amd64_collect_fpregset, but use XSAVE extended state.  */
 173
 174 static void
 175 amd64fbsd_collect_xstateregset (const struct regset *regset,
 176                                 const struct regcache *regcache,
 177                                 int regnum, void *xstateregs, size_t len)
 178 {
 179   amd64_collect_xsave (regcache, regnum, xstateregs, 1);
 180 }
 181
 182 static const struct regset amd64fbsd_xstateregset =
 183   {
 184     NULL,
 185     amd64fbsd_supply_xstateregset,
 186     amd64fbsd_collect_xstateregset
 187   };
 188
 189 /* Iterate over core file register note sections.  */
 190
 191 static void
 192 amd64fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
 193                                         iterate_over_regset_sections_cb *cb,
 194                                         void *cb_data,
 195                                         const struct regcache *regcache)
 196 {
 197   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 198
 199   cb (".reg", tdep->sizeof_gregset, tdep->sizeof_gregset, &i386_gregset, NULL,
 200       cb_data);
 201   cb (".reg2", tdep->sizeof_fpregset, tdep->sizeof_fpregset, &amd64_fpregset,
 202       NULL, cb_data);
 203   cb (".reg-xstate", X86_XSTATE_SIZE (tdep->xcr0), X86_XSTATE_SIZE (tdep->xcr0),
 204       &amd64fbsd_xstateregset, "XSAVE extended state", cb_data);
 205 }
 206
 207 /* Implement the get_thread_local_address gdbarch method.  */
 208
 209 static CORE_ADDR
 210 amd64fbsd_get_thread_local_address (struct gdbarch *gdbarch, ptid_t ptid,
 211                                     CORE_ADDR lm_addr, CORE_ADDR offset)
 212 {
 213   struct regcache *regcache;
 214
 215   regcache = get_thread_arch_regcache (ptid, gdbarch);
 216
 217   target_fetch_registers (regcache, AMD64_FSBASE_REGNUM);
 218
 219   ULONGEST fsbase;
 220   if (regcache->cooked_read (AMD64_FSBASE_REGNUM, &fsbase) != REG_VALID)
 221     error (_("Unable to fetch %%fsbase"));
 222
 223   CORE_ADDR dtv_addr = fsbase + gdbarch_ptr_bit (gdbarch) / 8;
 224   return fbsd_get_thread_local_address (gdbarch, dtv_addr, lm_addr, offset);
 225 }
 226
 227 static void
 228 amd64fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 229 {
 230   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 231
 232   /* Generic FreeBSD support. */
 233   fbsd_init_abi (info, gdbarch);
 234
 235   /* Obviously FreeBSD is BSD-based.  */
 236   i386bsd_init_abi (info, gdbarch);
 237
 238   tdep->gregset_reg_offset = amd64fbsd_r_reg_offset;
 239   tdep->gregset_num_regs = ARRAY_SIZE (amd64fbsd_r_reg_offset);
 240   tdep->sizeof_gregset = 22 * 8;
 241
 242   amd64_init_abi (info, gdbarch,
 243                   amd64_target_description (X86_XSTATE_SSE_MASK, true));
 244
 245   tdep->sigtramp_p = amd64fbsd_sigtramp_p;
 246   tdep->sigtramp_start = amd64fbsd_sigtramp_start_addr;
 247   tdep->sigtramp_end = amd64fbsd_sigtramp_end_addr;
 248   tdep->sigcontext_addr = amd64fbsd_sigcontext_addr;
 249   tdep->sc_reg_offset = amd64fbsd_sc_reg_offset;
 250   tdep->sc_num_regs = ARRAY_SIZE (amd64fbsd_sc_reg_offset);
 251
 252   tdep->xsave_xcr0_offset = I386_FBSD_XSAVE_XCR0_OFFSET;
 253
 254   /* Iterate over core file register note sections.  */
 255   set_gdbarch_iterate_over_regset_sections
 256     (gdbarch, amd64fbsd_iterate_over_regset_sections);
 257
 258   set_gdbarch_core_read_description (gdbarch,
 259                                      amd64fbsd_core_read_description);
 260
 261   /* FreeBSD uses SVR4-style shared libraries.  */
 262   set_solib_svr4_fetch_link_map_offsets
 263     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 264
 265   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 266                                              svr4_fetch_objfile_link_map);
 267   set_gdbarch_get_thread_local_address (gdbarch,
 268                                         amd64fbsd_get_thread_local_address);
 269 }
 270
 271 void
 272 _initialize_amd64fbsd_tdep (void)
 273 {
 274   gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
 275                           GDB_OSABI_FREEBSD, amd64fbsd_init_abi);
 276 }