gdb/ppc-fbsd-tdep.c

   1 /* Target-dependent code for PowerPC systems running FreeBSD.
   2
   3    Copyright (C) 2013-2017 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 #ifdef NOTYET
  61         /* AltiVec registers.  */
  62         /* .vr0_offset = */    0,
  63         /* .vscr_offset = */   512 + 12,
  64         /* .vrsave_offset = */ 512
  65 #endif
  66   };
  67
  68 /* 64-bit regset descriptions.  */
  69
  70 static const struct ppc_reg_offsets ppc64_fbsd_reg_offsets =
  71   {
  72         /* General-purpose registers.  */
  73         /* .r0_offset = */     0,
  74         /* .gpr_size = */      8,
  75         /* .xr_size = */       8,
  76         /* .pc_offset = */     288,
  77         /* .ps_offset = */     -1,
  78         /* .cr_offset = */     264,
  79         /* .lr_offset = */     256,
  80         /* .ctr_offset = */    280,
  81         /* .xer_offset = */    272,
  82         /* .mq_offset = */     -1,
  83
  84         /* Floating-point registers.  */
  85         /* .f0_offset = */     0,
  86         /* .fpscr_offset = */  256,
  87         /* .fpscr_size = */    8,
  88 #ifdef NOYET
  89         /* AltiVec registers.  */
  90         /* .vr0_offset = */    0,
  91         /* .vscr_offset = */   512 + 12,
  92         /* .vrsave_offset = */ 528
  93 #endif
  94   };
  95
  96 /* 32-bit general-purpose register set.  */
  97
  98 static const struct regset ppc32_fbsd_gregset = {
  99   &ppc32_fbsd_reg_offsets,
 100   ppc_supply_gregset,
 101   ppc_collect_gregset
 102 };
 103
 104 /* 64-bit general-purpose register set.  */
 105
 106 static const struct regset ppc64_fbsd_gregset = {
 107   &ppc64_fbsd_reg_offsets,
 108   ppc_supply_gregset,
 109   ppc_collect_gregset
 110 };
 111
 112 /* 32-/64-bit floating-point register set.  */
 113
 114 static const struct regset ppc32_fbsd_fpregset = {
 115   &ppc32_fbsd_reg_offsets,
 116   ppc_supply_fpregset,
 117   ppc_collect_fpregset
 118 };
 119
 120 const struct regset *
 121 ppc_fbsd_gregset (int wordsize)
 122 {
 123   return wordsize == 8 ? &ppc64_fbsd_gregset : &ppc32_fbsd_gregset;
 124 }
 125
 126 const struct regset *
 127 ppc_fbsd_fpregset (void)
 128 {
 129   return &ppc32_fbsd_fpregset;
 130 }
 131
 132 /* Iterate over core file register note sections.  */
 133
 134 static void
 135 ppcfbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
 136                                       iterate_over_regset_sections_cb *cb,
 137                                       void *cb_data,
 138                                       const struct regcache *regcache)
 139 {
 140   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 141
 142   if (tdep->wordsize == 4)
 143     cb (".reg", 148, &ppc32_fbsd_gregset, NULL, cb_data);
 144   else
 145     cb (".reg", 296, &ppc64_fbsd_gregset, NULL, cb_data);
 146   cb (".reg2", 264, &ppc32_fbsd_fpregset, NULL, cb_data);
 147 }
 148
 149 /* Default page size.  */
 150
 151 static const int ppcfbsd_page_size = 4096;
 152
 153 /* Offset for sigreturn(2).  */
 154
 155 static const int ppcfbsd_sigreturn_offset[] = {
 156   0xc,                          /* FreeBSD 32-bit  */
 157   -1
 158 };
 159
 160 /* Signal trampolines.  */
 161
 162 static int
 163 ppcfbsd_sigtramp_frame_sniffer (const struct frame_unwind *self,
 164                                 struct frame_info *this_frame,
 165                                 void **this_cache)
 166 {
 167   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 168   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 169   CORE_ADDR pc = get_frame_pc (this_frame);
 170   CORE_ADDR start_pc = (pc & ~(ppcfbsd_page_size - 1));
 171   const int *offset;
 172   const char *name;
 173
 174   /* A stack trampoline is detected if no name is associated
 175    to the current pc and if it points inside a trampoline
 176    sequence.  */
 177
 178   find_pc_partial_function (pc, &name, NULL, NULL);
 179
 180   /* If we have a name, we have no trampoline, return.  */
 181   if (name)
 182     return 0;
 183
 184   for (offset = ppcfbsd_sigreturn_offset; *offset != -1; offset++)
 185     {
 186       gdb_byte buf[2 * PPC_INSN_SIZE];
 187       unsigned long insn;
 188
 189       if (!safe_frame_unwind_memory (this_frame, start_pc + *offset,
 190                                      buf, sizeof buf))
 191         continue;
 192
 193       /* Check for "li r0,SYS_sigreturn".  */
 194       insn = extract_unsigned_integer (buf, PPC_INSN_SIZE, byte_order);
 195       if (insn != 0x380001a1)
 196         continue;
 197
 198       /* Check for "sc".  */
 199       insn = extract_unsigned_integer (buf + PPC_INSN_SIZE,
 200                                        PPC_INSN_SIZE, byte_order);
 201       if (insn != 0x44000002)
 202         continue;
 203
 204       return 1;
 205     }
 206
 207   return 0;
 208 }
 209
 210 static struct trad_frame_cache *
 211 ppcfbsd_sigtramp_frame_cache (struct frame_info *this_frame, void **this_cache)
 212 {
 213   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 214   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 215   struct trad_frame_cache *cache;
 216   CORE_ADDR addr, base, func;
 217   gdb_byte buf[PPC_INSN_SIZE];
 218   int i;
 219
 220   if (*this_cache)
 221     return (struct trad_frame_cache *) *this_cache;
 222
 223   cache = trad_frame_cache_zalloc (this_frame);
 224   *this_cache = cache;
 225
 226   func = get_frame_pc (this_frame);
 227   func &= ~(ppcfbsd_page_size - 1);
 228   if (!safe_frame_unwind_memory (this_frame, func, buf, sizeof buf))
 229     return cache;
 230
 231   base = get_frame_register_unsigned (this_frame, gdbarch_sp_regnum (gdbarch));
 232   addr = base + 0x10 + 2 * tdep->wordsize;
 233   for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
 234     {
 235       int regnum = i + tdep->ppc_gp0_regnum;
 236       trad_frame_set_reg_addr (cache, regnum, addr);
 237     }
 238   trad_frame_set_reg_addr (cache, tdep->ppc_lr_regnum, addr);
 239   addr += tdep->wordsize;
 240   trad_frame_set_reg_addr (cache, tdep->ppc_cr_regnum, addr);
 241   addr += tdep->wordsize;
 242   trad_frame_set_reg_addr (cache, tdep->ppc_xer_regnum, addr);
 243   addr += tdep->wordsize;
 244   trad_frame_set_reg_addr (cache, tdep->ppc_ctr_regnum, addr);
 245   addr += tdep->wordsize;
 246   trad_frame_set_reg_addr (cache, gdbarch_pc_regnum (gdbarch), addr);
 247   /* SRR0?  */
 248   addr += tdep->wordsize;
 249
 250   /* Construct the frame ID using the function start.  */
 251   trad_frame_set_id (cache, frame_id_build (base, func));
 252
 253   return cache;
 254 }
 255
 256 static void
 257 ppcfbsd_sigtramp_frame_this_id (struct frame_info *this_frame,
 258                                 void **this_cache, struct frame_id *this_id)
 259 {
 260   struct trad_frame_cache *cache =
 261     ppcfbsd_sigtramp_frame_cache (this_frame, this_cache);
 262
 263   trad_frame_get_id (cache, this_id);
 264 }
 265
 266 static struct value *
 267 ppcfbsd_sigtramp_frame_prev_register (struct frame_info *this_frame,
 268                                       void **this_cache, int regnum)
 269 {
 270   struct trad_frame_cache *cache =
 271     ppcfbsd_sigtramp_frame_cache (this_frame, this_cache);
 272
 273   return trad_frame_get_register (cache, this_frame, regnum);
 274 }
 275
 276 static const struct frame_unwind ppcfbsd_sigtramp_frame_unwind = {
 277   SIGTRAMP_FRAME,
 278   default_frame_unwind_stop_reason,
 279   ppcfbsd_sigtramp_frame_this_id,
 280   ppcfbsd_sigtramp_frame_prev_register,
 281   NULL,
 282   ppcfbsd_sigtramp_frame_sniffer
 283 };
 284
 285 static enum return_value_convention
 286 ppcfbsd_return_value (struct gdbarch *gdbarch, struct value *function,
 287                       struct type *valtype, struct regcache *regcache,
 288                       gdb_byte *readbuf, const gdb_byte *writebuf)
 289 {
 290   return ppc_sysv_abi_broken_return_value (gdbarch, function, valtype,
 291                                            regcache, readbuf, writebuf);
 292 }
 293
 294
 295 static void
 296 ppcfbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 297 {
 298   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 299
 300   /* Generic FreeBSD support. */
 301   fbsd_init_abi (info, gdbarch);
 302
 303   /* FreeBSD doesn't support the 128-bit `long double' from the psABI.  */
 304   set_gdbarch_long_double_bit (gdbarch, 64);
 305   set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
 306
 307   if (tdep->wordsize == 4)
 308     {
 309       set_gdbarch_return_value (gdbarch, ppcfbsd_return_value);
 310
 311       set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 312       set_solib_svr4_fetch_link_map_offsets (gdbarch,
 313                                              svr4_ilp32_fetch_link_map_offsets);
 314
 315       frame_unwind_append_unwinder (gdbarch, &ppcfbsd_sigtramp_frame_unwind);
 316       set_gdbarch_gcore_bfd_target (gdbarch, "elf32-powerpc");
 317     }
 318
 319   if (tdep->wordsize == 8)
 320     {
 321       set_gdbarch_convert_from_func_ptr_addr
 322         (gdbarch, ppc64_convert_from_func_ptr_addr);
 323       set_gdbarch_elf_make_msymbol_special (gdbarch,
 324                                             ppc64_elf_make_msymbol_special);
 325
 326       set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code);
 327       set_solib_svr4_fetch_link_map_offsets (gdbarch,
 328                                              svr4_lp64_fetch_link_map_offsets);
 329       set_gdbarch_gcore_bfd_target (gdbarch, "elf64-powerpc");
 330     }
 331
 332   set_gdbarch_iterate_over_regset_sections
 333     (gdbarch, ppcfbsd_iterate_over_regset_sections);
 334
 335   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 336                                              svr4_fetch_objfile_link_map);
 337 }
 338
 339 /* Provide a prototype to silence -Wmissing-prototypes.  */
 340
 341 void _initialize_ppcfbsd_tdep (void);
 342
 343 void
 344 _initialize_ppcfbsd_tdep (void)
 345 {
 346   gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc, GDB_OSABI_FREEBSD,
 347                           ppcfbsd_init_abi);
 348   gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc64, GDB_OSABI_FREEBSD,
 349                           ppcfbsd_init_abi);
 350   gdbarch_register_osabi (bfd_arch_rs6000, 0, GDB_OSABI_FREEBSD,
 351                           ppcfbsd_init_abi);
 352 }