gdb/ppc-fbsd-tdep.c

   1 /* Target-dependent code for PowerPC systems running FreeBSD.
   2
   3    Copyright (C) 2013-2020 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 "frame-unwind.h"
  25 #include "gdbtypes.h"
  26 #include "osabi.h"
  27 #include "regcache.h"
  28 #include "regset.h"
  29 #include "symtab.h"
  30 #include "target.h"
  31 #include "trad-frame.h"
  32
  33 #include "ppc-tdep.h"
  34 #include "ppc64-tdep.h"
  35 #include "ppc-fbsd-tdep.h"
  36 #include "fbsd-tdep.h"
  37 #include "solib-svr4.h"
  38
  39
  40 /* 32-bit regset descriptions.  */
  41
  42 static const struct ppc_reg_offsets ppc32_fbsd_reg_offsets =
  43   {
  44         /* General-purpose registers.  */
  45         /* .r0_offset = */     0,
  46         /* .gpr_size = */      4,
  47         /* .xr_size = */       4,
  48         /* .pc_offset = */     144,
  49         /* .ps_offset = */     -1,
  50         /* .cr_offset = */     132,
  51         /* .lr_offset = */     128,
  52         /* .ctr_offset = */    140,
  53         /* .xer_offset = */    136,
  54         /* .mq_offset = */     -1,
  55
  56         /* Floating-point registers.  */
  57         /* .f0_offset = */     0,
  58         /* .fpscr_offset = */  256,
  59         /* .fpscr_size = */    8
  60   };
  61
  62 /* 64-bit regset descriptions.  */
  63
  64 static const struct ppc_reg_offsets ppc64_fbsd_reg_offsets =
  65   {
  66         /* General-purpose registers.  */
  67         /* .r0_offset = */     0,
  68         /* .gpr_size = */      8,
  69         /* .xr_size = */       8,
  70         /* .pc_offset = */     288,
  71         /* .ps_offset = */     -1,
  72         /* .cr_offset = */     264,
  73         /* .lr_offset = */     256,
  74         /* .ctr_offset = */    280,
  75         /* .xer_offset = */    272,
  76         /* .mq_offset = */     -1,
  77
  78         /* Floating-point registers.  */
  79         /* .f0_offset = */     0,
  80         /* .fpscr_offset = */  256,
  81         /* .fpscr_size = */    8
  82   };
  83
  84 /* 32-bit general-purpose register set.  */
  85
  86 static const struct regset ppc32_fbsd_gregset = {
  87   &ppc32_fbsd_reg_offsets,
  88   ppc_supply_gregset,
  89   ppc_collect_gregset
  90 };
  91
  92 /* 64-bit general-purpose register set.  */
  93
  94 static const struct regset ppc64_fbsd_gregset = {
  95   &ppc64_fbsd_reg_offsets,
  96   ppc_supply_gregset,
  97   ppc_collect_gregset
  98 };
  99
 100 /* 32-/64-bit floating-point register set.  */
 101
 102 static const struct regset ppc32_fbsd_fpregset = {
 103   &ppc32_fbsd_reg_offsets,
 104   ppc_supply_fpregset,
 105   ppc_collect_fpregset
 106 };
 107
 108 const struct regset *
 109 ppc_fbsd_gregset (int wordsize)
 110 {
 111   return wordsize == 8 ? &ppc64_fbsd_gregset : &ppc32_fbsd_gregset;
 112 }
 113
 114 const struct regset *
 115 ppc_fbsd_fpregset (void)
 116 {
 117   return &ppc32_fbsd_fpregset;
 118 }
 119
 120 /* Iterate over core file register note sections.  */
 121
 122 static void
 123 ppcfbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
 124                                       iterate_over_regset_sections_cb *cb,
 125                                       void *cb_data,
 126                                       const struct regcache *regcache)
 127 {
 128   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 129
 130   if (tdep->wordsize == 4)
 131     cb (".reg", 148, 148, &ppc32_fbsd_gregset, NULL, cb_data);
 132   else
 133     cb (".reg", 296, 296, &ppc64_fbsd_gregset, NULL, cb_data);
 134   cb (".reg2", 264, 264, &ppc32_fbsd_fpregset, NULL, cb_data);
 135 }
 136
 137 /* Default page size.  */
 138
 139 static const int ppcfbsd_page_size = 4096;
 140
 141 /* Offset for sigreturn(2).  */
 142
 143 static const int ppcfbsd_sigreturn_offset[] = {
 144   0xc,                          /* FreeBSD 32-bit  */
 145   -1
 146 };
 147
 148 /* Signal trampolines.  */
 149
 150 static int
 151 ppcfbsd_sigtramp_frame_sniffer (const struct frame_unwind *self,
 152                                 struct frame_info *this_frame,
 153                                 void **this_cache)
 154 {
 155   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 156   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 157   CORE_ADDR pc = get_frame_pc (this_frame);
 158   CORE_ADDR start_pc = (pc & ~(ppcfbsd_page_size - 1));
 159   const int *offset;
 160   const char *name;
 161
 162   /* A stack trampoline is detected if no name is associated
 163    to the current pc and if it points inside a trampoline
 164    sequence.  */
 165
 166   find_pc_partial_function (pc, &name, NULL, NULL);
 167
 168   /* If we have a name, we have no trampoline, return.  */
 169   if (name)
 170     return 0;
 171
 172   for (offset = ppcfbsd_sigreturn_offset; *offset != -1; offset++)
 173     {
 174       gdb_byte buf[2 * PPC_INSN_SIZE];
 175       unsigned long insn;
 176
 177       if (!safe_frame_unwind_memory (this_frame, start_pc + *offset,
 178                                      buf, sizeof buf))
 179         continue;
 180
 181       /* Check for "li r0,SYS_sigreturn".  */
 182       insn = extract_unsigned_integer (buf, PPC_INSN_SIZE, byte_order);
 183       if (insn != 0x380001a1)
 184         continue;
 185
 186       /* Check for "sc".  */
 187       insn = extract_unsigned_integer (buf + PPC_INSN_SIZE,
 188                                        PPC_INSN_SIZE, byte_order);
 189       if (insn != 0x44000002)
 190         continue;
 191
 192       return 1;
 193     }
 194
 195   return 0;
 196 }
 197
 198 static struct trad_frame_cache *
 199 ppcfbsd_sigtramp_frame_cache (struct frame_info *this_frame, void **this_cache)
 200 {
 201   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 202   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 203   struct trad_frame_cache *cache;
 204   CORE_ADDR addr, base, func;
 205   gdb_byte buf[PPC_INSN_SIZE];
 206   int i;
 207
 208   if (*this_cache)
 209     return (struct trad_frame_cache *) *this_cache;
 210
 211   cache = trad_frame_cache_zalloc (this_frame);
 212   *this_cache = cache;
 213
 214   func = get_frame_pc (this_frame);
 215   func &= ~(ppcfbsd_page_size - 1);
 216   if (!safe_frame_unwind_memory (this_frame, func, buf, sizeof buf))
 217     return cache;
 218
 219   base = get_frame_register_unsigned (this_frame, gdbarch_sp_regnum (gdbarch));
 220   addr = base + 0x10 + 2 * tdep->wordsize;
 221   for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
 222     {
 223       int regnum = i + tdep->ppc_gp0_regnum;
 224       trad_frame_set_reg_addr (cache, regnum, addr);
 225     }
 226   trad_frame_set_reg_addr (cache, tdep->ppc_lr_regnum, addr);
 227   addr += tdep->wordsize;
 228   trad_frame_set_reg_addr (cache, tdep->ppc_cr_regnum, addr);
 229   addr += tdep->wordsize;
 230   trad_frame_set_reg_addr (cache, tdep->ppc_xer_regnum, addr);
 231   addr += tdep->wordsize;
 232   trad_frame_set_reg_addr (cache, tdep->ppc_ctr_regnum, addr);
 233   addr += tdep->wordsize;
 234   trad_frame_set_reg_addr (cache, gdbarch_pc_regnum (gdbarch), addr);
 235   /* SRR0?  */
 236   addr += tdep->wordsize;
 237
 238   /* Construct the frame ID using the function start.  */
 239   trad_frame_set_id (cache, frame_id_build (base, func));
 240
 241   return cache;
 242 }
 243
 244 static void
 245 ppcfbsd_sigtramp_frame_this_id (struct frame_info *this_frame,
 246                                 void **this_cache, struct frame_id *this_id)
 247 {
 248   struct trad_frame_cache *cache =
 249     ppcfbsd_sigtramp_frame_cache (this_frame, this_cache);
 250
 251   trad_frame_get_id (cache, this_id);
 252 }
 253
 254 static struct value *
 255 ppcfbsd_sigtramp_frame_prev_register (struct frame_info *this_frame,
 256                                       void **this_cache, int regnum)
 257 {
 258   struct trad_frame_cache *cache =
 259     ppcfbsd_sigtramp_frame_cache (this_frame, this_cache);
 260
 261   return trad_frame_get_register (cache, this_frame, regnum);
 262 }
 263
 264 static const struct frame_unwind ppcfbsd_sigtramp_frame_unwind = {
 265   SIGTRAMP_FRAME,
 266   default_frame_unwind_stop_reason,
 267   ppcfbsd_sigtramp_frame_this_id,
 268   ppcfbsd_sigtramp_frame_prev_register,
 269   NULL,
 270   ppcfbsd_sigtramp_frame_sniffer
 271 };
 272
 273 static enum return_value_convention
 274 ppcfbsd_return_value (struct gdbarch *gdbarch, struct value *function,
 275                       struct type *valtype, struct regcache *regcache,
 276                       gdb_byte *readbuf, const gdb_byte *writebuf)
 277 {
 278   return ppc_sysv_abi_broken_return_value (gdbarch, function, valtype,
 279                                            regcache, readbuf, writebuf);
 280 }
 281
 282 /* Implement the "get_thread_local_address" gdbarch method.  */
 283
 284 static CORE_ADDR
 285 ppcfbsd_get_thread_local_address (struct gdbarch *gdbarch, ptid_t ptid,
 286                                   CORE_ADDR lm_addr, CORE_ADDR offset)
 287 {
 288   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 289   struct regcache *regcache;
 290   int tp_offset, tp_regnum;
 291
 292   regcache = get_thread_arch_regcache (ptid, gdbarch);
 293
 294   if (tdep->wordsize == 4)
 295     {
 296       tp_offset = 0x7008;
 297       tp_regnum = PPC_R0_REGNUM + 2;
 298     }
 299   else
 300     {
 301       tp_offset = 0x7010;
 302       tp_regnum = PPC_R0_REGNUM + 13;
 303     }
 304   target_fetch_registers (regcache, tp_regnum);
 305
 306   ULONGEST tp;
 307   if (regcache->cooked_read (tp_regnum, &tp) != REG_VALID)
 308     error (_("Unable to fetch tcb pointer"));
 309
 310   /* tp points to the end of the TCB block.  The first member of the
 311      TCB is the pointer to the DTV array.  */
 312   CORE_ADDR dtv_addr = tp - tp_offset;
 313   return fbsd_get_thread_local_address (gdbarch, dtv_addr, lm_addr, offset);
 314 }
 315
 316 static void
 317 ppcfbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 318 {
 319   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 320
 321   /* Generic FreeBSD support. */
 322   fbsd_init_abi (info, gdbarch);
 323
 324   /* FreeBSD doesn't support the 128-bit `long double' from the psABI.  */
 325   set_gdbarch_long_double_bit (gdbarch, 64);
 326   set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
 327
 328   if (tdep->wordsize == 4)
 329     {
 330       set_gdbarch_return_value (gdbarch, ppcfbsd_return_value);
 331
 332       set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 333       set_solib_svr4_fetch_link_map_offsets (gdbarch,
 334                                              svr4_ilp32_fetch_link_map_offsets);
 335
 336       frame_unwind_append_unwinder (gdbarch, &ppcfbsd_sigtramp_frame_unwind);
 337       set_gdbarch_gcore_bfd_target (gdbarch, "elf32-powerpc");
 338     }
 339
 340   if (tdep->wordsize == 8)
 341     {
 342       set_gdbarch_convert_from_func_ptr_addr
 343         (gdbarch, ppc64_convert_from_func_ptr_addr);
 344       set_gdbarch_elf_make_msymbol_special (gdbarch,
 345                                             ppc64_elf_make_msymbol_special);
 346
 347       set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code);
 348       set_solib_svr4_fetch_link_map_offsets (gdbarch,
 349                                              svr4_lp64_fetch_link_map_offsets);
 350       set_gdbarch_gcore_bfd_target (gdbarch, "elf64-powerpc");
 351     }
 352
 353   set_gdbarch_iterate_over_regset_sections
 354     (gdbarch, ppcfbsd_iterate_over_regset_sections);
 355
 356   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 357                                              svr4_fetch_objfile_link_map);
 358   set_gdbarch_get_thread_local_address (gdbarch,
 359                                         ppcfbsd_get_thread_local_address);
 360 }
 361
 362 void
 363 _initialize_ppcfbsd_tdep (void)
 364 {
 365   gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc, GDB_OSABI_FREEBSD,
 366                           ppcfbsd_init_abi);
 367   gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc64, GDB_OSABI_FREEBSD,
 368                           ppcfbsd_init_abi);
 369   gdbarch_register_osabi (bfd_arch_rs6000, 0, GDB_OSABI_FREEBSD,
 370                           ppcfbsd_init_abi);
 371 }