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 #include "inferior.h"
  39
  40
  41 /* 32-bit regset descriptions.  */
  42
  43 static const struct ppc_reg_offsets ppc32_fbsd_reg_offsets =
  44   {
  45         /* General-purpose registers.  */
  46         /* .r0_offset = */     0,
  47         /* .gpr_size = */      4,
  48         /* .xr_size = */       4,
  49         /* .pc_offset = */     144,
  50         /* .ps_offset = */     -1,
  51         /* .cr_offset = */     132,
  52         /* .lr_offset = */     128,
  53         /* .ctr_offset = */    140,
  54         /* .xer_offset = */    136,
  55         /* .mq_offset = */     -1,
  56
  57         /* Floating-point registers.  */
  58         /* .f0_offset = */     0,
  59         /* .fpscr_offset = */  256,
  60         /* .fpscr_size = */    8
  61   };
  62
  63 /* 64-bit regset descriptions.  */
  64
  65 static const struct ppc_reg_offsets ppc64_fbsd_reg_offsets =
  66   {
  67         /* General-purpose registers.  */
  68         /* .r0_offset = */     0,
  69         /* .gpr_size = */      8,
  70         /* .xr_size = */       8,
  71         /* .pc_offset = */     288,
  72         /* .ps_offset = */     -1,
  73         /* .cr_offset = */     264,
  74         /* .lr_offset = */     256,
  75         /* .ctr_offset = */    280,
  76         /* .xer_offset = */    272,
  77         /* .mq_offset = */     -1,
  78
  79         /* Floating-point registers.  */
  80         /* .f0_offset = */     0,
  81         /* .fpscr_offset = */  256,
  82         /* .fpscr_size = */    8
  83   };
  84
  85 /* 32-bit general-purpose register set.  */
  86
  87 static const struct regset ppc32_fbsd_gregset = {
  88   &ppc32_fbsd_reg_offsets,
  89   ppc_supply_gregset,
  90   ppc_collect_gregset
  91 };
  92
  93 /* 64-bit general-purpose register set.  */
  94
  95 static const struct regset ppc64_fbsd_gregset = {
  96   &ppc64_fbsd_reg_offsets,
  97   ppc_supply_gregset,
  98   ppc_collect_gregset
  99 };
 100
 101 /* 32-/64-bit floating-point register set.  */
 102
 103 static const struct regset ppc32_fbsd_fpregset = {
 104   &ppc32_fbsd_reg_offsets,
 105   ppc_supply_fpregset,
 106   ppc_collect_fpregset
 107 };
 108
 109 const struct regset *
 110 ppc_fbsd_gregset (int wordsize)
 111 {
 112   return wordsize == 8 ? &ppc64_fbsd_gregset : &ppc32_fbsd_gregset;
 113 }
 114
 115 const struct regset *
 116 ppc_fbsd_fpregset (void)
 117 {
 118   return &ppc32_fbsd_fpregset;
 119 }
 120
 121 /* Iterate over core file register note sections.  */
 122
 123 static void
 124 ppcfbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
 125                                       iterate_over_regset_sections_cb *cb,
 126                                       void *cb_data,
 127                                       const struct regcache *regcache)
 128 {
 129   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 130
 131   if (tdep->wordsize == 4)
 132     cb (".reg", 148, 148, &ppc32_fbsd_gregset, NULL, cb_data);
 133   else
 134     cb (".reg", 296, 296, &ppc64_fbsd_gregset, NULL, cb_data);
 135   cb (".reg2", 264, 264, &ppc32_fbsd_fpregset, NULL, cb_data);
 136 }
 137
 138 /* Default page size.  */
 139
 140 static const int ppcfbsd_page_size = 4096;
 141
 142 /* Offset for sigreturn(2).  */
 143
 144 static const int ppcfbsd_sigreturn_offset[] = {
 145   0xc,                          /* FreeBSD 32-bit  */
 146   -1
 147 };
 148
 149 /* Signal trampolines.  */
 150
 151 static int
 152 ppcfbsd_sigtramp_frame_sniffer (const struct frame_unwind *self,
 153                                 struct frame_info *this_frame,
 154                                 void **this_cache)
 155 {
 156   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 157   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 158   CORE_ADDR pc = get_frame_pc (this_frame);
 159   CORE_ADDR start_pc = (pc & ~(ppcfbsd_page_size - 1));
 160   const int *offset;
 161   const char *name;
 162
 163   /* A stack trampoline is detected if no name is associated
 164    to the current pc and if it points inside a trampoline
 165    sequence.  */
 166
 167   find_pc_partial_function (pc, &name, NULL, NULL);
 168
 169   /* If we have a name, we have no trampoline, return.  */
 170   if (name)
 171     return 0;
 172
 173   for (offset = ppcfbsd_sigreturn_offset; *offset != -1; offset++)
 174     {
 175       gdb_byte buf[2 * PPC_INSN_SIZE];
 176       unsigned long insn;
 177
 178       if (!safe_frame_unwind_memory (this_frame, start_pc + *offset,
 179                                      buf, sizeof buf))
 180         continue;
 181
 182       /* Check for "li r0,SYS_sigreturn".  */
 183       insn = extract_unsigned_integer (buf, PPC_INSN_SIZE, byte_order);
 184       if (insn != 0x380001a1)
 185         continue;
 186
 187       /* Check for "sc".  */
 188       insn = extract_unsigned_integer (buf + PPC_INSN_SIZE,
 189                                        PPC_INSN_SIZE, byte_order);
 190       if (insn != 0x44000002)
 191         continue;
 192
 193       return 1;
 194     }
 195
 196   return 0;
 197 }
 198
 199 static struct trad_frame_cache *
 200 ppcfbsd_sigtramp_frame_cache (struct frame_info *this_frame, void **this_cache)
 201 {
 202   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 203   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 204   struct trad_frame_cache *cache;
 205   CORE_ADDR addr, base, func;
 206   gdb_byte buf[PPC_INSN_SIZE];
 207   int i;
 208
 209   if (*this_cache)
 210     return (struct trad_frame_cache *) *this_cache;
 211
 212   cache = trad_frame_cache_zalloc (this_frame);
 213   *this_cache = cache;
 214
 215   func = get_frame_pc (this_frame);
 216   func &= ~(ppcfbsd_page_size - 1);
 217   if (!safe_frame_unwind_memory (this_frame, func, buf, sizeof buf))
 218     return cache;
 219
 220   base = get_frame_register_unsigned (this_frame, gdbarch_sp_regnum (gdbarch));
 221   addr = base + 0x10 + 2 * tdep->wordsize;
 222   for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
 223     {
 224       int regnum = i + tdep->ppc_gp0_regnum;
 225       trad_frame_set_reg_addr (cache, regnum, addr);
 226     }
 227   trad_frame_set_reg_addr (cache, tdep->ppc_lr_regnum, addr);
 228   addr += tdep->wordsize;
 229   trad_frame_set_reg_addr (cache, tdep->ppc_cr_regnum, addr);
 230   addr += tdep->wordsize;
 231   trad_frame_set_reg_addr (cache, tdep->ppc_xer_regnum, addr);
 232   addr += tdep->wordsize;
 233   trad_frame_set_reg_addr (cache, tdep->ppc_ctr_regnum, addr);
 234   addr += tdep->wordsize;
 235   trad_frame_set_reg_addr (cache, gdbarch_pc_regnum (gdbarch), addr);
 236   /* SRR0?  */
 237   addr += tdep->wordsize;
 238
 239   /* Construct the frame ID using the function start.  */
 240   trad_frame_set_id (cache, frame_id_build (base, func));
 241
 242   return cache;
 243 }
 244
 245 static void
 246 ppcfbsd_sigtramp_frame_this_id (struct frame_info *this_frame,
 247                                 void **this_cache, struct frame_id *this_id)
 248 {
 249   struct trad_frame_cache *cache =
 250     ppcfbsd_sigtramp_frame_cache (this_frame, this_cache);
 251
 252   trad_frame_get_id (cache, this_id);
 253 }
 254
 255 static struct value *
 256 ppcfbsd_sigtramp_frame_prev_register (struct frame_info *this_frame,
 257                                       void **this_cache, int regnum)
 258 {
 259   struct trad_frame_cache *cache =
 260     ppcfbsd_sigtramp_frame_cache (this_frame, this_cache);
 261
 262   return trad_frame_get_register (cache, this_frame, regnum);
 263 }
 264
 265 static const struct frame_unwind ppcfbsd_sigtramp_frame_unwind = {
 266   SIGTRAMP_FRAME,
 267   default_frame_unwind_stop_reason,
 268   ppcfbsd_sigtramp_frame_this_id,
 269   ppcfbsd_sigtramp_frame_prev_register,
 270   NULL,
 271   ppcfbsd_sigtramp_frame_sniffer
 272 };
 273
 274 static enum return_value_convention
 275 ppcfbsd_return_value (struct gdbarch *gdbarch, struct value *function,
 276                       struct type *valtype, struct regcache *regcache,
 277                       gdb_byte *readbuf, const gdb_byte *writebuf)
 278 {
 279   return ppc_sysv_abi_broken_return_value (gdbarch, function, valtype,
 280                                            regcache, readbuf, writebuf);
 281 }
 282
 283 /* Implement the "get_thread_local_address" gdbarch method.  */
 284
 285 static CORE_ADDR
 286 ppcfbsd_get_thread_local_address (struct gdbarch *gdbarch, ptid_t ptid,
 287                                   CORE_ADDR lm_addr, CORE_ADDR offset)
 288 {
 289   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 290   struct regcache *regcache;
 291   int tp_offset, tp_regnum;
 292
 293   regcache = get_thread_arch_regcache (current_inferior ()->process_target (),
 294                                        ptid, gdbarch);
 295
 296   if (tdep->wordsize == 4)
 297     {
 298       tp_offset = 0x7008;
 299       tp_regnum = PPC_R0_REGNUM + 2;
 300     }
 301   else
 302     {
 303       tp_offset = 0x7010;
 304       tp_regnum = PPC_R0_REGNUM + 13;
 305     }
 306   target_fetch_registers (regcache, tp_regnum);
 307
 308   ULONGEST tp;
 309   if (regcache->cooked_read (tp_regnum, &tp) != REG_VALID)
 310     error (_("Unable to fetch tcb pointer"));
 311
 312   /* tp points to the end of the TCB block.  The first member of the
 313      TCB is the pointer to the DTV array.  */
 314   CORE_ADDR dtv_addr = tp - tp_offset;
 315   return fbsd_get_thread_local_address (gdbarch, dtv_addr, lm_addr, offset);
 316 }
 317
 318 static void
 319 ppcfbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 320 {
 321   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 322
 323   /* Generic FreeBSD support. */
 324   fbsd_init_abi (info, gdbarch);
 325
 326   /* FreeBSD doesn't support the 128-bit `long double' from the psABI.  */
 327   set_gdbarch_long_double_bit (gdbarch, 64);
 328   set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
 329
 330   if (tdep->wordsize == 4)
 331     {
 332       set_gdbarch_return_value (gdbarch, ppcfbsd_return_value);
 333
 334       set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 335       set_solib_svr4_fetch_link_map_offsets (gdbarch,
 336                                              svr4_ilp32_fetch_link_map_offsets);
 337
 338       frame_unwind_append_unwinder (gdbarch, &ppcfbsd_sigtramp_frame_unwind);
 339       set_gdbarch_gcore_bfd_target (gdbarch, "elf32-powerpc");
 340     }
 341
 342   if (tdep->wordsize == 8)
 343     {
 344       set_gdbarch_convert_from_func_ptr_addr
 345         (gdbarch, ppc64_convert_from_func_ptr_addr);
 346       set_gdbarch_elf_make_msymbol_special (gdbarch,
 347                                             ppc64_elf_make_msymbol_special);
 348
 349       set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code);
 350       set_solib_svr4_fetch_link_map_offsets (gdbarch,
 351                                              svr4_lp64_fetch_link_map_offsets);
 352       set_gdbarch_gcore_bfd_target (gdbarch, "elf64-powerpc");
 353     }
 354
 355   set_gdbarch_iterate_over_regset_sections
 356     (gdbarch, ppcfbsd_iterate_over_regset_sections);
 357
 358   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 359                                              svr4_fetch_objfile_link_map);
 360   set_gdbarch_get_thread_local_address (gdbarch,
 361                                         ppcfbsd_get_thread_local_address);
 362 }
 363
 364 void
 365 _initialize_ppcfbsd_tdep (void)
 366 {
 367   gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc, GDB_OSABI_FREEBSD,
 368                           ppcfbsd_init_abi);
 369   gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc64, GDB_OSABI_FREEBSD,
 370                           ppcfbsd_init_abi);
 371   gdbarch_register_osabi (bfd_arch_rs6000, 0, GDB_OSABI_FREEBSD,
 372                           ppcfbsd_init_abi);
 373 }