gdb/amd64-fbsd-tdep.c

   1 /* Target-dependent code for FreeBSD/amd64.
   2
   3    Copyright (C) 2003-2020 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 "gdbsupport/x86-xstate.h"
  29
  30 #include "amd64-tdep.h"
  31 #include "fbsd-tdep.h"
  32 #include "solib-svr4.h"
  33 #include "inferior.h"
  34
  35 /* Support for signal handlers.  */
  36
  37 /* Return whether THIS_FRAME corresponds to a FreeBSD sigtramp
  38    routine.  */
  39
  40 static const gdb_byte amd64fbsd_sigtramp_code[] =
  41 {
  42   0x48, 0x8d, 0x7c, 0x24, 0x10, /* lea     SIGF_UC(%rsp),%rdi */
  43   0x6a, 0x00,                   /* pushq   $0 */
  44   0x48, 0xc7, 0xc0, 0xa1, 0x01, 0x00, 0x00,
  45                                 /* movq    $SYS_sigreturn,%rax */
  46   0x0f, 0x05                    /* syscall */
  47 };
  48
  49 static int
  50 amd64fbsd_sigtramp_p (struct frame_info *this_frame)
  51 {
  52   CORE_ADDR pc = get_frame_pc (this_frame);
  53   gdb_byte buf[sizeof amd64fbsd_sigtramp_code];
  54
  55   if (!safe_frame_unwind_memory (this_frame, pc, buf, sizeof buf))
  56     return 0;
  57   if (memcmp (buf, amd64fbsd_sigtramp_code, sizeof amd64fbsd_sigtramp_code)
  58       != 0)
  59     return 0;
  60
  61   return 1;
  62 }
  63
  64 /* Assuming THIS_FRAME is for a BSD sigtramp routine, return the
  65    address of the associated sigcontext structure.  */
  66
  67 static CORE_ADDR
  68 amd64fbsd_sigcontext_addr (struct frame_info *this_frame)
  69 {
  70   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  71   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  72   CORE_ADDR sp;
  73   gdb_byte buf[8];
  74
  75   /* The `struct sigcontext' (which really is an `ucontext_t' on
  76      FreeBSD/amd64) lives at a fixed offset in the signal frame.  See
  77      <machine/sigframe.h>.  */
  78   get_frame_register (this_frame, AMD64_RSP_REGNUM, buf);
  79   sp = extract_unsigned_integer (buf, 8, byte_order);
  80   return sp + 16;
  81 }
  82 \f
  83 /* FreeBSD 5.1-RELEASE or later.  */
  84
  85 /* Mapping between the general-purpose registers in `struct reg'
  86    format and GDB's register cache layout.
  87
  88    Note that some registers are 32-bit, but since we're little-endian
  89    we get away with that.  */
  90
  91 /* From <machine/reg.h>.  */
  92 static int amd64fbsd_r_reg_offset[] =
  93 {
  94   14 * 8,                       /* %rax */
  95   11 * 8,                       /* %rbx */
  96   13 * 8,                       /* %rcx */
  97   12 * 8,                       /* %rdx */
  98   9 * 8,                        /* %rsi */
  99   8 * 8,                        /* %rdi */
 100   10 * 8,                       /* %rbp */
 101   20 * 8,                       /* %rsp */
 102   7 * 8,                        /* %r8 ...  */
 103   6 * 8,
 104   5 * 8,
 105   4 * 8,
 106   3 * 8,
 107   2 * 8,
 108   1 * 8,
 109   0 * 8,                        /* ... %r15 */
 110   17 * 8,                       /* %rip */
 111   19 * 8,                       /* %eflags */
 112   18 * 8,                       /* %cs */
 113   21 * 8,                       /* %ss */
 114   -1,                           /* %ds */
 115   -1,                           /* %es */
 116   -1,                           /* %fs */
 117   -1                            /* %gs */
 118 };
 119
 120 /* Location of the signal trampoline.  */
 121 CORE_ADDR amd64fbsd_sigtramp_start_addr;
 122 CORE_ADDR amd64fbsd_sigtramp_end_addr;
 123
 124 /* From <machine/signal.h>.  */
 125 int amd64fbsd_sc_reg_offset[] =
 126 {
 127   24 + 6 * 8,                   /* %rax */
 128   24 + 7 * 8,                   /* %rbx */
 129   24 + 3 * 8,                   /* %rcx */
 130   24 + 2 * 8,                   /* %rdx */
 131   24 + 1 * 8,                   /* %rsi */
 132   24 + 0 * 8,                   /* %rdi */
 133   24 + 8 * 8,                   /* %rbp */
 134   24 + 22 * 8,                  /* %rsp */
 135   24 + 4 * 8,                   /* %r8 ...  */
 136   24 + 5 * 8,
 137   24 + 9 * 8,
 138   24 + 10 * 8,
 139   24 + 11 * 8,
 140   24 + 12 * 8,
 141   24 + 13 * 8,
 142   24 + 14 * 8,                  /* ... %r15 */
 143   24 + 19 * 8,                  /* %rip */
 144   24 + 21 * 8,                  /* %eflags */
 145   24 + 20 * 8,                  /* %cs */
 146   24 + 23 * 8,                  /* %ss */
 147   -1,                           /* %ds */
 148   -1,                           /* %es */
 149   -1,                           /* %fs */
 150   -1                            /* %gs */
 151 };
 152
 153 /* Implement the core_read_description gdbarch method.  */
 154
 155 static const struct target_desc *
 156 amd64fbsd_core_read_description (struct gdbarch *gdbarch,
 157                                  struct target_ops *target,
 158                                  bfd *abfd)
 159 {
 160   return amd64_target_description (i386fbsd_core_read_xcr0 (abfd), true);
 161 }
 162
 163 /* Similar to amd64_supply_fpregset, but use XSAVE extended state.  */
 164
 165 static void
 166 amd64fbsd_supply_xstateregset (const struct regset *regset,
 167                                struct regcache *regcache, int regnum,
 168                                const void *xstateregs, size_t len)
 169 {
 170   amd64_supply_xsave (regcache, regnum, xstateregs);
 171 }
 172
 173 /* Similar to amd64_collect_fpregset, but use XSAVE extended state.  */
 174
 175 static void
 176 amd64fbsd_collect_xstateregset (const struct regset *regset,
 177                                 const struct regcache *regcache,
 178                                 int regnum, void *xstateregs, size_t len)
 179 {
 180   amd64_collect_xsave (regcache, regnum, xstateregs, 1);
 181 }
 182
 183 static const struct regset amd64fbsd_xstateregset =
 184   {
 185     NULL,
 186     amd64fbsd_supply_xstateregset,
 187     amd64fbsd_collect_xstateregset
 188   };
 189
 190 /* Iterate over core file register note sections.  */
 191
 192 static void
 193 amd64fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
 194                                         iterate_over_regset_sections_cb *cb,
 195                                         void *cb_data,
 196                                         const struct regcache *regcache)
 197 {
 198   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 199
 200   cb (".reg", tdep->sizeof_gregset, tdep->sizeof_gregset, &i386_gregset, NULL,
 201       cb_data);
 202   cb (".reg2", tdep->sizeof_fpregset, tdep->sizeof_fpregset, &amd64_fpregset,
 203       NULL, cb_data);
 204   cb (".reg-xstate", X86_XSTATE_SIZE (tdep->xcr0), X86_XSTATE_SIZE (tdep->xcr0),
 205       &amd64fbsd_xstateregset, "XSAVE extended state", cb_data);
 206 }
 207
 208 /* Implement the get_thread_local_address gdbarch method.  */
 209
 210 static CORE_ADDR
 211 amd64fbsd_get_thread_local_address (struct gdbarch *gdbarch, ptid_t ptid,
 212                                     CORE_ADDR lm_addr, CORE_ADDR offset)
 213 {
 214   struct regcache *regcache;
 215
 216   regcache = get_thread_arch_regcache (current_inferior ()->process_target (),
 217                                        ptid, gdbarch);
 218
 219   target_fetch_registers (regcache, AMD64_FSBASE_REGNUM);
 220
 221   ULONGEST fsbase;
 222   if (regcache->cooked_read (AMD64_FSBASE_REGNUM, &fsbase) != REG_VALID)
 223     error (_("Unable to fetch %%fsbase"));
 224
 225   CORE_ADDR dtv_addr = fsbase + gdbarch_ptr_bit (gdbarch) / 8;
 226   return fbsd_get_thread_local_address (gdbarch, dtv_addr, lm_addr, offset);
 227 }
 228
 229 static void
 230 amd64fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 231 {
 232   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 233
 234   /* Generic FreeBSD support. */
 235   fbsd_init_abi (info, gdbarch);
 236
 237   /* Obviously FreeBSD is BSD-based.  */
 238   i386bsd_init_abi (info, gdbarch);
 239
 240   tdep->gregset_reg_offset = amd64fbsd_r_reg_offset;
 241   tdep->gregset_num_regs = ARRAY_SIZE (amd64fbsd_r_reg_offset);
 242   tdep->sizeof_gregset = 22 * 8;
 243
 244   amd64_init_abi (info, gdbarch,
 245                   amd64_target_description (X86_XSTATE_SSE_MASK, true));
 246
 247   tdep->sigtramp_p = amd64fbsd_sigtramp_p;
 248   tdep->sigtramp_start = amd64fbsd_sigtramp_start_addr;
 249   tdep->sigtramp_end = amd64fbsd_sigtramp_end_addr;
 250   tdep->sigcontext_addr = amd64fbsd_sigcontext_addr;
 251   tdep->sc_reg_offset = amd64fbsd_sc_reg_offset;
 252   tdep->sc_num_regs = ARRAY_SIZE (amd64fbsd_sc_reg_offset);
 253
 254   tdep->xsave_xcr0_offset = I386_FBSD_XSAVE_XCR0_OFFSET;
 255
 256   /* Iterate over core file register note sections.  */
 257   set_gdbarch_iterate_over_regset_sections
 258     (gdbarch, amd64fbsd_iterate_over_regset_sections);
 259
 260   set_gdbarch_core_read_description (gdbarch,
 261                                      amd64fbsd_core_read_description);
 262
 263   /* FreeBSD uses SVR4-style shared libraries.  */
 264   set_solib_svr4_fetch_link_map_offsets
 265     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 266
 267   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 268                                              svr4_fetch_objfile_link_map);
 269   set_gdbarch_get_thread_local_address (gdbarch,
 270                                         amd64fbsd_get_thread_local_address);
 271 }
 272
 273 void
 274 _initialize_amd64fbsd_tdep (void)
 275 {
 276   gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
 277                           GDB_OSABI_FREEBSD, amd64fbsd_init_abi);
 278 }