gdb/aarch64-fbsd-tdep.c

   1 /* Target-dependent code for FreeBSD/aarch64.
   2
   3    Copyright (C) 2017-2024 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
  21 #include "gdbarch.h"
  22 #include "fbsd-tdep.h"
  23 #include "aarch64-tdep.h"
  24 #include "aarch64-fbsd-tdep.h"
  25 #include "inferior.h"
  26 #include "osabi.h"
  27 #include "solib-svr4.h"
  28 #include "target.h"
  29 #include "tramp-frame.h"
  30 #include "trad-frame.h"
  31
  32 /* Register maps.  */
  33
  34 static const struct regcache_map_entry aarch64_fbsd_gregmap[] =
  35   {
  36     { 30, AARCH64_X0_REGNUM, 8 }, /* x0 ... x29 */
  37     { 1, AARCH64_LR_REGNUM, 8 },
  38     { 1, AARCH64_SP_REGNUM, 8 },
  39     { 1, AARCH64_PC_REGNUM, 8 },
  40     { 1, AARCH64_CPSR_REGNUM, 4 },
  41     { 0 }
  42   };
  43
  44 static const struct regcache_map_entry aarch64_fbsd_fpregmap[] =
  45   {
  46     { 32, AARCH64_V0_REGNUM, 16 }, /* v0 ... v31 */
  47     { 1, AARCH64_FPSR_REGNUM, 4 },
  48     { 1, AARCH64_FPCR_REGNUM, 4 },
  49     { 0 }
  50   };
  51
  52 /* Register numbers are relative to tdep->tls_regnum_base.  */
  53
  54 static const struct regcache_map_entry aarch64_fbsd_tls_regmap[] =
  55   {
  56     { 1, 0, 8 },        /* tpidr */
  57     { 0 }
  58   };
  59
  60 /* In a signal frame, sp points to a 'struct sigframe' which is
  61    defined as:
  62
  63    struct sigframe {
  64            siginfo_t    sf_si;
  65            ucontext_t   sf_uc;
  66    };
  67
  68    ucontext_t is defined as:
  69
  70    struct __ucontext {
  71            sigset_t     uc_sigmask;
  72            mcontext_t   uc_mcontext;
  73            ...
  74    };
  75
  76    The mcontext_t contains the general purpose register set followed
  77    by the floating point register set.  The floating point register
  78    set is only valid if the _MC_FP_VALID flag is set in mc_flags.  */
  79
  80 #define AARCH64_SIGFRAME_UCONTEXT_OFFSET        80
  81 #define AARCH64_UCONTEXT_MCONTEXT_OFFSET        16
  82 #define AARCH64_MCONTEXT_FPREGS_OFFSET          272
  83 #define AARCH64_MCONTEXT_FLAGS_OFFSET           800
  84 #define AARCH64_MCONTEXT_FLAG_FP_VALID          0x1
  85
  86 /* Implement the "init" method of struct tramp_frame.  */
  87
  88 static void
  89 aarch64_fbsd_sigframe_init (const struct tramp_frame *self,
  90                             const frame_info_ptr &this_frame,
  91                             struct trad_frame_cache *this_cache,
  92                             CORE_ADDR func)
  93 {
  94   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  95   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  96   CORE_ADDR sp = get_frame_register_unsigned (this_frame, AARCH64_SP_REGNUM);
  97   CORE_ADDR mcontext_addr
  98     = (sp
  99        + AARCH64_SIGFRAME_UCONTEXT_OFFSET
 100        + AARCH64_UCONTEXT_MCONTEXT_OFFSET);
 101   gdb_byte buf[4];
 102
 103   trad_frame_set_reg_regmap (this_cache, aarch64_fbsd_gregmap, mcontext_addr,
 104                              regcache_map_entry_size (aarch64_fbsd_gregmap));
 105
 106   if (target_read_memory (mcontext_addr + AARCH64_MCONTEXT_FLAGS_OFFSET, buf,
 107                           4) == 0
 108       && (extract_unsigned_integer (buf, 4, byte_order)
 109           & AARCH64_MCONTEXT_FLAG_FP_VALID))
 110     trad_frame_set_reg_regmap (this_cache, aarch64_fbsd_fpregmap,
 111                                mcontext_addr + AARCH64_MCONTEXT_FPREGS_OFFSET,
 112                                regcache_map_entry_size (aarch64_fbsd_fpregmap));
 113
 114   trad_frame_set_id (this_cache, frame_id_build (sp, func));
 115 }
 116
 117 static const struct tramp_frame aarch64_fbsd_sigframe =
 118 {
 119   SIGTRAMP_FRAME,
 120   4,
 121   {
 122     {0x910003e0, ULONGEST_MAX},         /* mov  x0, sp  */
 123     {0x91014000, ULONGEST_MAX},         /* add  x0, x0, #SF_UC  */
 124     {0xd2803428, ULONGEST_MAX},         /* mov  x8, #SYS_sigreturn  */
 125     {0xd4000001, ULONGEST_MAX},         /* svc  0x0  */
 126     {TRAMP_SENTINEL_INSN, ULONGEST_MAX}
 127   },
 128   aarch64_fbsd_sigframe_init
 129 };
 130
 131 /* Register set definitions.  */
 132
 133 const struct regset aarch64_fbsd_gregset =
 134   {
 135     aarch64_fbsd_gregmap,
 136     regcache_supply_regset, regcache_collect_regset
 137   };
 138
 139 const struct regset aarch64_fbsd_fpregset =
 140   {
 141     aarch64_fbsd_fpregmap,
 142     regcache_supply_regset, regcache_collect_regset
 143   };
 144
 145 static void
 146 aarch64_fbsd_supply_tls_regset (const struct regset *regset,
 147                                 struct regcache *regcache,
 148                                 int regnum, const void *buf, size_t size)
 149 {
 150   struct gdbarch *gdbarch = regcache->arch ();
 151   aarch64_gdbarch_tdep *tdep = gdbarch_tdep<aarch64_gdbarch_tdep> (gdbarch);
 152
 153   regcache->supply_regset (regset, tdep->tls_regnum_base, regnum, buf, size);
 154 }
 155
 156 static void
 157 aarch64_fbsd_collect_tls_regset (const struct regset *regset,
 158                                  const struct regcache *regcache,
 159                                  int regnum, void *buf, size_t size)
 160 {
 161   struct gdbarch *gdbarch = regcache->arch ();
 162   aarch64_gdbarch_tdep *tdep = gdbarch_tdep<aarch64_gdbarch_tdep> (gdbarch);
 163
 164   regcache->collect_regset (regset, tdep->tls_regnum_base, regnum, buf, size);
 165 }
 166
 167 const struct regset aarch64_fbsd_tls_regset =
 168   {
 169     aarch64_fbsd_tls_regmap,
 170     aarch64_fbsd_supply_tls_regset, aarch64_fbsd_collect_tls_regset
 171   };
 172
 173 /* Implement the "iterate_over_regset_sections" gdbarch method.  */
 174
 175 static void
 176 aarch64_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
 177                                            iterate_over_regset_sections_cb *cb,
 178                                            void *cb_data,
 179                                            const struct regcache *regcache)
 180 {
 181   aarch64_gdbarch_tdep *tdep = gdbarch_tdep<aarch64_gdbarch_tdep> (gdbarch);
 182
 183   cb (".reg", AARCH64_FBSD_SIZEOF_GREGSET, AARCH64_FBSD_SIZEOF_GREGSET,
 184       &aarch64_fbsd_gregset, NULL, cb_data);
 185   cb (".reg2", AARCH64_FBSD_SIZEOF_FPREGSET, AARCH64_FBSD_SIZEOF_FPREGSET,
 186       &aarch64_fbsd_fpregset, NULL, cb_data);
 187
 188   if (tdep->has_tls ())
 189     cb (".reg-aarch-tls", AARCH64_FBSD_SIZEOF_TLSREGSET,
 190         AARCH64_FBSD_SIZEOF_TLSREGSET, &aarch64_fbsd_tls_regset,
 191         "TLS register", cb_data);
 192 }
 193
 194 /* Implement the "core_read_description" gdbarch method.  */
 195
 196 static const struct target_desc *
 197 aarch64_fbsd_core_read_description (struct gdbarch *gdbarch,
 198                                     struct target_ops *target, bfd *abfd)
 199 {
 200   asection *tls = bfd_get_section_by_name (abfd, ".reg-aarch-tls");
 201
 202   aarch64_features features;
 203   features.tls = tls != nullptr? 1 : 0;
 204
 205   return aarch64_read_description (features);
 206 }
 207
 208 /* Implement the get_thread_local_address gdbarch method.  */
 209
 210 static CORE_ADDR
 211 aarch64_fbsd_get_thread_local_address (struct gdbarch *gdbarch, ptid_t ptid,
 212                                        CORE_ADDR lm_addr, CORE_ADDR offset)
 213 {
 214   aarch64_gdbarch_tdep *tdep = gdbarch_tdep<aarch64_gdbarch_tdep> (gdbarch);
 215   struct regcache *regcache;
 216
 217   regcache = get_thread_arch_regcache (current_inferior (), ptid, gdbarch);
 218
 219   target_fetch_registers (regcache, tdep->tls_regnum_base);
 220
 221   ULONGEST tpidr;
 222   if (regcache->cooked_read (tdep->tls_regnum_base, &tpidr) != REG_VALID)
 223     error (_("Unable to fetch %%tpidr"));
 224
 225   /* %tpidr points to the TCB whose first member is the dtv
 226       pointer.  */
 227   CORE_ADDR dtv_addr = tpidr;
 228   return fbsd_get_thread_local_address (gdbarch, dtv_addr, lm_addr, offset);
 229 }
 230
 231 /* Implement the 'init_osabi' method of struct gdb_osabi_handler.  */
 232
 233 static void
 234 aarch64_fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 235 {
 236   aarch64_gdbarch_tdep *tdep = gdbarch_tdep<aarch64_gdbarch_tdep> (gdbarch);
 237
 238   /* Generic FreeBSD support.  */
 239   fbsd_init_abi (info, gdbarch);
 240
 241   set_solib_svr4_fetch_link_map_offsets (gdbarch,
 242                                          svr4_lp64_fetch_link_map_offsets);
 243
 244   tramp_frame_prepend_unwinder (gdbarch, &aarch64_fbsd_sigframe);
 245
 246   /* Enable longjmp.  */
 247   tdep->jb_pc = 13;
 248
 249   set_gdbarch_iterate_over_regset_sections
 250     (gdbarch, aarch64_fbsd_iterate_over_regset_sections);
 251   set_gdbarch_core_read_description (gdbarch,
 252                                      aarch64_fbsd_core_read_description);
 253
 254   if (tdep->has_tls ())
 255     {
 256       set_gdbarch_fetch_tls_load_module_address (gdbarch,
 257                                                  svr4_fetch_objfile_link_map);
 258       set_gdbarch_get_thread_local_address
 259         (gdbarch, aarch64_fbsd_get_thread_local_address);
 260     }
 261 }
 262
 263 void _initialize_aarch64_fbsd_tdep ();
 264 void
 265 _initialize_aarch64_fbsd_tdep ()
 266 {
 267   gdbarch_register_osabi (bfd_arch_aarch64, 0, GDB_OSABI_FREEBSD,
 268                           aarch64_fbsd_init_abi);
 269 }