gdb/aarch64-fbsd-tdep.c

   1 /* Target-dependent code for FreeBSD/aarch64.
   2
   3    Copyright (C) 2017-2023 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
  22 #include "gdbarch.h"
  23 #include "fbsd-tdep.h"
  24 #include "aarch64-tdep.h"
  25 #include "aarch64-fbsd-tdep.h"
  26 #include "inferior.h"
  27 #include "osabi.h"
  28 #include "solib-svr4.h"
  29 #include "target.h"
  30 #include "tramp-frame.h"
  31 #include "trad-frame.h"
  32
  33 /* Register maps.  */
  34
  35 static const struct regcache_map_entry aarch64_fbsd_gregmap[] =
  36   {
  37     { 30, AARCH64_X0_REGNUM, 8 }, /* x0 ... x29 */
  38     { 1, AARCH64_LR_REGNUM, 8 },
  39     { 1, AARCH64_SP_REGNUM, 8 },
  40     { 1, AARCH64_PC_REGNUM, 8 },
  41     { 1, AARCH64_CPSR_REGNUM, 4 },
  42     { 0 }
  43   };
  44
  45 static const struct regcache_map_entry aarch64_fbsd_fpregmap[] =
  46   {
  47     { 32, AARCH64_V0_REGNUM, 16 }, /* v0 ... v31 */
  48     { 1, AARCH64_FPSR_REGNUM, 4 },
  49     { 1, AARCH64_FPCR_REGNUM, 4 },
  50     { 0 }
  51   };
  52
  53 /* Register numbers are relative to tdep->tls_regnum_base.  */
  54
  55 static const struct regcache_map_entry aarch64_fbsd_tls_regmap[] =
  56   {
  57     { 1, 0, 8 },        /* tpidr */
  58     { 0 }
  59   };
  60
  61 /* In a signal frame, sp points to a 'struct sigframe' which is
  62    defined as:
  63
  64    struct sigframe {
  65            siginfo_t    sf_si;
  66            ucontext_t   sf_uc;
  67    };
  68
  69    ucontext_t is defined as:
  70
  71    struct __ucontext {
  72            sigset_t     uc_sigmask;
  73            mcontext_t   uc_mcontext;
  74            ...
  75    };
  76
  77    The mcontext_t contains the general purpose register set followed
  78    by the floating point register set.  The floating point register
  79    set is only valid if the _MC_FP_VALID flag is set in mc_flags.  */
  80
  81 #define AARCH64_SIGFRAME_UCONTEXT_OFFSET        80
  82 #define AARCH64_UCONTEXT_MCONTEXT_OFFSET        16
  83 #define AARCH64_MCONTEXT_FPREGS_OFFSET          272
  84 #define AARCH64_MCONTEXT_FLAGS_OFFSET           800
  85 #define AARCH64_MCONTEXT_FLAG_FP_VALID          0x1
  86
  87 /* Implement the "init" method of struct tramp_frame.  */
  88
  89 static void
  90 aarch64_fbsd_sigframe_init (const struct tramp_frame *self,
  91                              frame_info_ptr this_frame,
  92                              struct trad_frame_cache *this_cache,
  93                              CORE_ADDR func)
  94 {
  95   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  96   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  97   CORE_ADDR sp = get_frame_register_unsigned (this_frame, AARCH64_SP_REGNUM);
  98   CORE_ADDR mcontext_addr
  99     = (sp
 100        + AARCH64_SIGFRAME_UCONTEXT_OFFSET
 101        + AARCH64_UCONTEXT_MCONTEXT_OFFSET);
 102   gdb_byte buf[4];
 103
 104   trad_frame_set_reg_regmap (this_cache, aarch64_fbsd_gregmap, mcontext_addr,
 105                              regcache_map_entry_size (aarch64_fbsd_gregmap));
 106
 107   if (target_read_memory (mcontext_addr + AARCH64_MCONTEXT_FLAGS_OFFSET, buf,
 108                           4) == 0
 109       && (extract_unsigned_integer (buf, 4, byte_order)
 110           & AARCH64_MCONTEXT_FLAG_FP_VALID))
 111     trad_frame_set_reg_regmap (this_cache, aarch64_fbsd_fpregmap,
 112                                mcontext_addr + AARCH64_MCONTEXT_FPREGS_OFFSET,
 113                                regcache_map_entry_size (aarch64_fbsd_fpregmap));
 114
 115   trad_frame_set_id (this_cache, frame_id_build (sp, func));
 116 }
 117
 118 static const struct tramp_frame aarch64_fbsd_sigframe =
 119 {
 120   SIGTRAMP_FRAME,
 121   4,
 122   {
 123     {0x910003e0, ULONGEST_MAX},         /* mov  x0, sp  */
 124     {0x91014000, ULONGEST_MAX},         /* add  x0, x0, #SF_UC  */
 125     {0xd2803428, ULONGEST_MAX},         /* mov  x8, #SYS_sigreturn  */
 126     {0xd4000001, ULONGEST_MAX},         /* svc  0x0  */
 127     {TRAMP_SENTINEL_INSN, ULONGEST_MAX}
 128   },
 129   aarch64_fbsd_sigframe_init
 130 };
 131
 132 /* Register set definitions.  */
 133
 134 const struct regset aarch64_fbsd_gregset =
 135   {
 136     aarch64_fbsd_gregmap,
 137     regcache_supply_regset, regcache_collect_regset
 138   };
 139
 140 const struct regset aarch64_fbsd_fpregset =
 141   {
 142     aarch64_fbsd_fpregmap,
 143     regcache_supply_regset, regcache_collect_regset
 144   };
 145
 146 static void
 147 aarch64_fbsd_supply_tls_regset (const struct regset *regset,
 148                                 struct regcache *regcache,
 149                                 int regnum, const void *buf, size_t size)
 150 {
 151   struct gdbarch *gdbarch = regcache->arch ();
 152   aarch64_gdbarch_tdep *tdep = gdbarch_tdep<aarch64_gdbarch_tdep> (gdbarch);
 153
 154   regcache->supply_regset (regset, tdep->tls_regnum_base, regnum, buf, size);
 155 }
 156
 157 static void
 158 aarch64_fbsd_collect_tls_regset (const struct regset *regset,
 159                                  const struct regcache *regcache,
 160                                  int regnum, void *buf, size_t size)
 161 {
 162   struct gdbarch *gdbarch = regcache->arch ();
 163   aarch64_gdbarch_tdep *tdep = gdbarch_tdep<aarch64_gdbarch_tdep> (gdbarch);
 164
 165   regcache->collect_regset (regset, tdep->tls_regnum_base, regnum, buf, size);
 166 }
 167
 168 const struct regset aarch64_fbsd_tls_regset =
 169   {
 170     aarch64_fbsd_tls_regmap,
 171     aarch64_fbsd_supply_tls_regset, aarch64_fbsd_collect_tls_regset
 172   };
 173
 174 /* Implement the "iterate_over_regset_sections" gdbarch method.  */
 175
 176 static void
 177 aarch64_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
 178                                            iterate_over_regset_sections_cb *cb,
 179                                            void *cb_data,
 180                                            const struct regcache *regcache)
 181 {
 182   aarch64_gdbarch_tdep *tdep = gdbarch_tdep<aarch64_gdbarch_tdep> (gdbarch);
 183
 184   cb (".reg", AARCH64_FBSD_SIZEOF_GREGSET, AARCH64_FBSD_SIZEOF_GREGSET,
 185       &aarch64_fbsd_gregset, NULL, cb_data);
 186   cb (".reg2", AARCH64_FBSD_SIZEOF_FPREGSET, AARCH64_FBSD_SIZEOF_FPREGSET,
 187       &aarch64_fbsd_fpregset, NULL, cb_data);
 188
 189   if (tdep->has_tls ())
 190     cb (".reg-aarch-tls", AARCH64_FBSD_SIZEOF_TLSREGSET,
 191         AARCH64_FBSD_SIZEOF_TLSREGSET, &aarch64_fbsd_tls_regset,
 192         "TLS register", cb_data);
 193 }
 194
 195 /* Implement the "core_read_description" gdbarch method.  */
 196
 197 static const struct target_desc *
 198 aarch64_fbsd_core_read_description (struct gdbarch *gdbarch,
 199                                     struct target_ops *target, bfd *abfd)
 200 {
 201   asection *tls = bfd_get_section_by_name (abfd, ".reg-aarch-tls");
 202
 203   aarch64_features features;
 204   features.tls = tls != nullptr? 1 : 0;
 205
 206   return aarch64_read_description (features);
 207 }
 208
 209 /* Implement the get_thread_local_address gdbarch method.  */
 210
 211 static CORE_ADDR
 212 aarch64_fbsd_get_thread_local_address (struct gdbarch *gdbarch, ptid_t ptid,
 213                                        CORE_ADDR lm_addr, CORE_ADDR offset)
 214 {
 215   aarch64_gdbarch_tdep *tdep = gdbarch_tdep<aarch64_gdbarch_tdep> (gdbarch);
 216   struct regcache *regcache;
 217
 218   regcache = get_thread_arch_regcache (current_inferior ()->process_target (),
 219                                        ptid, gdbarch);
 220
 221   target_fetch_registers (regcache, tdep->tls_regnum_base);
 222
 223   ULONGEST tpidr;
 224   if (regcache->cooked_read (tdep->tls_regnum_base, &tpidr) != REG_VALID)
 225     error (_("Unable to fetch %%tpidr"));
 226
 227   /* %tpidr points to the TCB whose first member is the dtv
 228       pointer.  */
 229   CORE_ADDR dtv_addr = tpidr;
 230   return fbsd_get_thread_local_address (gdbarch, dtv_addr, lm_addr, offset);
 231 }
 232
 233 /* Implement the 'init_osabi' method of struct gdb_osabi_handler.  */
 234
 235 static void
 236 aarch64_fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 237 {
 238   aarch64_gdbarch_tdep *tdep = gdbarch_tdep<aarch64_gdbarch_tdep> (gdbarch);
 239
 240   /* Generic FreeBSD support.  */
 241   fbsd_init_abi (info, gdbarch);
 242
 243   set_solib_svr4_fetch_link_map_offsets (gdbarch,
 244                                          svr4_lp64_fetch_link_map_offsets);
 245
 246   tramp_frame_prepend_unwinder (gdbarch, &aarch64_fbsd_sigframe);
 247
 248   /* Enable longjmp.  */
 249   tdep->jb_pc = 13;
 250
 251   set_gdbarch_iterate_over_regset_sections
 252     (gdbarch, aarch64_fbsd_iterate_over_regset_sections);
 253   set_gdbarch_core_read_description (gdbarch,
 254                                      aarch64_fbsd_core_read_description);
 255
 256   if (tdep->has_tls ())
 257     {
 258       set_gdbarch_fetch_tls_load_module_address (gdbarch,
 259                                                  svr4_fetch_objfile_link_map);
 260       set_gdbarch_get_thread_local_address
 261         (gdbarch, aarch64_fbsd_get_thread_local_address);
 262     }
 263 }
 264
 265 void _initialize_aarch64_fbsd_tdep ();
 266 void
 267 _initialize_aarch64_fbsd_tdep ()
 268 {
 269   gdbarch_register_osabi (bfd_arch_aarch64, 0, GDB_OSABI_FREEBSD,
 270                           aarch64_fbsd_init_abi);
 271 }