gdb/ppcfbsd-tdep.c

   1 /* Target-dependent code for PowerPC systems running FreeBSD.
   2
   3    Copyright (C) 2013-2014 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 "gdb_assert.h"
  34 #include <string.h>
  35
  36 #include "ppc-tdep.h"
  37 #include "ppc64-tdep.h"
  38 #include "ppcfbsd-tdep.h"
  39 #include "solib-svr4.h"
  40
  41
  42 /* 32-bit regset descriptions.  */
  43
  44 static const struct ppc_reg_offsets ppc32_fbsd_reg_offsets =
  45   {
  46         /* General-purpose registers.  */
  47         /* .r0_offset = */     0,
  48         /* .gpr_size = */      4,
  49         /* .xr_size = */       4,
  50         /* .pc_offset = */     144,
  51         /* .ps_offset = */     -1,
  52         /* .cr_offset = */     132,
  53         /* .lr_offset = */     128,
  54         /* .ctr_offset = */    140,
  55         /* .xer_offset = */    136,
  56         /* .mq_offset = */     -1,
  57
  58         /* Floating-point registers.  */
  59         /* .f0_offset = */     0,
  60         /* .fpscr_offset = */  256,
  61         /* .fpscr_size = */    8,
  62 #ifdef NOTYET
  63         /* AltiVec registers.  */
  64         /* .vr0_offset = */    0,
  65         /* .vscr_offset = */   512 + 12,
  66         /* .vrsave_offset = */ 512
  67 #endif
  68   };
  69
  70 /* 64-bit regset descriptions.  */
  71
  72 static const struct ppc_reg_offsets ppc64_fbsd_reg_offsets =
  73   {
  74         /* General-purpose registers.  */
  75         /* .r0_offset = */     0,
  76         /* .gpr_size = */      8,
  77         /* .xr_size = */       8,
  78         /* .pc_offset = */     288,
  79         /* .ps_offset = */     -1,
  80         /* .cr_offset = */     264,
  81         /* .lr_offset = */     256,
  82         /* .ctr_offset = */    280,
  83         /* .xer_offset = */    272,
  84         /* .mq_offset = */     -1,
  85
  86         /* Floating-point registers.  */
  87         /* .f0_offset = */     0,
  88         /* .fpscr_offset = */  256,
  89         /* .fpscr_size = */    8,
  90 #ifdef NOYET
  91         /* AltiVec registers.  */
  92         /* .vr0_offset = */    0,
  93         /* .vscr_offset = */   512 + 12,
  94         /* .vrsave_offset = */ 528
  95 #endif
  96   };
  97
  98 /* 32-bit general-purpose register set.  */
  99
 100 static const struct regset ppc32_fbsd_gregset = {
 101   &ppc32_fbsd_reg_offsets,
 102   ppc_supply_gregset,
 103   ppc_collect_gregset
 104 };
 105
 106 /* 64-bit general-purpose register set.  */
 107
 108 static const struct regset ppc64_fbsd_gregset = {
 109   &ppc64_fbsd_reg_offsets,
 110   ppc_supply_gregset,
 111   ppc_collect_gregset
 112 };
 113
 114 /* 32-/64-bit floating-point register set.  */
 115
 116 static const struct regset ppc32_fbsd_fpregset = {
 117   &ppc32_fbsd_reg_offsets,
 118   ppc_supply_fpregset,
 119   ppc_collect_fpregset
 120 };
 121
 122 const struct regset *
 123 ppc_fbsd_gregset (int wordsize)
 124 {
 125   return wordsize == 8 ? &ppc64_fbsd_gregset : &ppc32_fbsd_gregset;
 126 }
 127
 128 const struct regset *
 129 ppc_fbsd_fpregset (void)
 130 {
 131   return &ppc32_fbsd_fpregset;
 132 }
 133
 134 /* Return the appropriate register set for the core section identified
 135    by SECT_NAME and SECT_SIZE.  */
 136
 137 static const struct regset *
 138 ppcfbsd_regset_from_core_section (struct gdbarch *gdbarch,
 139                                   const char *sect_name, size_t sect_size)
 140 {
 141   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 142   if (strcmp (sect_name, ".reg") == 0 && sect_size >= 148)
 143     {
 144       if (tdep->wordsize == 4)
 145         return &ppc32_fbsd_gregset;
 146       else
 147         return &ppc64_fbsd_gregset;
 148     }
 149   if (strcmp (sect_name, ".reg2") == 0 && sect_size >= 264)
 150     return &ppc32_fbsd_fpregset;
 151   return NULL;
 152 }
 153
 154 /* Default page size.  */
 155
 156 static const int ppcfbsd_page_size = 4096;
 157
 158 /* Offset for sigreturn(2).  */
 159
 160 static const int ppcfbsd_sigreturn_offset[] = {
 161   0xc,                          /* FreeBSD 32-bit  */
 162   -1
 163 };
 164
 165 /* Signal trampolines.  */
 166
 167 static int
 168 ppcfbsd_sigtramp_frame_sniffer (const struct frame_unwind *self,
 169                                 struct frame_info *this_frame,
 170                                 void **this_cache)
 171 {
 172   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 173   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 174   CORE_ADDR pc = get_frame_pc (this_frame);
 175   CORE_ADDR start_pc = (pc & ~(ppcfbsd_page_size - 1));
 176   const int *offset;
 177   const char *name;
 178
 179   /* A stack trampoline is detected if no name is associated
 180    to the current pc and if it points inside a trampoline
 181    sequence.  */
 182
 183   find_pc_partial_function (pc, &name, NULL, NULL);
 184
 185   /* If we have a name, we have no trampoline, return.  */
 186   if (name)
 187     return 0;
 188
 189   for (offset = ppcfbsd_sigreturn_offset; *offset != -1; offset++)
 190     {
 191       gdb_byte buf[2 * PPC_INSN_SIZE];
 192       unsigned long insn;
 193
 194       if (!safe_frame_unwind_memory (this_frame, start_pc + *offset,
 195                                      buf, sizeof buf))
 196         continue;
 197
 198       /* Check for "li r0,SYS_sigreturn".  */
 199       insn = extract_unsigned_integer (buf, PPC_INSN_SIZE, byte_order);
 200       if (insn != 0x380001a1)
 201         continue;
 202
 203       /* Check for "sc".  */
 204       insn = extract_unsigned_integer (buf + PPC_INSN_SIZE,
 205                                        PPC_INSN_SIZE, byte_order);
 206       if (insn != 0x44000002)
 207         continue;
 208
 209       return 1;
 210     }
 211
 212   return 0;
 213 }
 214
 215 static struct trad_frame_cache *
 216 ppcfbsd_sigtramp_frame_cache (struct frame_info *this_frame, void **this_cache)
 217 {
 218   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 219   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 220   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
 221   struct trad_frame_cache *cache;
 222   CORE_ADDR addr, base, func;
 223   gdb_byte buf[PPC_INSN_SIZE];
 224   int i;
 225
 226   if (*this_cache)
 227     return *this_cache;
 228
 229   cache = trad_frame_cache_zalloc (this_frame);
 230   *this_cache = cache;
 231
 232   func = get_frame_pc (this_frame);
 233   func &= ~(ppcfbsd_page_size - 1);
 234   if (!safe_frame_unwind_memory (this_frame, func, buf, sizeof buf))
 235     return cache;
 236
 237   base = get_frame_register_unsigned (this_frame, gdbarch_sp_regnum (gdbarch));
 238   addr = base + 0x10 + 2 * tdep->wordsize;
 239   for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
 240     {
 241       int regnum = i + tdep->ppc_gp0_regnum;
 242       trad_frame_set_reg_addr (cache, regnum, addr);
 243     }
 244   trad_frame_set_reg_addr (cache, tdep->ppc_lr_regnum, addr);
 245   addr += tdep->wordsize;
 246   trad_frame_set_reg_addr (cache, tdep->ppc_cr_regnum, addr);
 247   addr += tdep->wordsize;
 248   trad_frame_set_reg_addr (cache, tdep->ppc_xer_regnum, addr);
 249   addr += tdep->wordsize;
 250   trad_frame_set_reg_addr (cache, tdep->ppc_ctr_regnum, addr);
 251   addr += tdep->wordsize;
 252   trad_frame_set_reg_addr (cache, gdbarch_pc_regnum (gdbarch), addr);
 253   /* SRR0?  */
 254   addr += tdep->wordsize;
 255
 256   /* Construct the frame ID using the function start.  */
 257   trad_frame_set_id (cache, frame_id_build (base, func));
 258
 259   return cache;
 260 }
 261
 262 static void
 263 ppcfbsd_sigtramp_frame_this_id (struct frame_info *this_frame,
 264                                 void **this_cache, struct frame_id *this_id)
 265 {
 266   struct trad_frame_cache *cache =
 267     ppcfbsd_sigtramp_frame_cache (this_frame, this_cache);
 268
 269   trad_frame_get_id (cache, this_id);
 270 }
 271
 272 static struct value *
 273 ppcfbsd_sigtramp_frame_prev_register (struct frame_info *this_frame,
 274                                       void **this_cache, int regnum)
 275 {
 276   struct trad_frame_cache *cache =
 277     ppcfbsd_sigtramp_frame_cache (this_frame, this_cache);
 278
 279   return trad_frame_get_register (cache, this_frame, regnum);
 280 }
 281
 282 static const struct frame_unwind ppcfbsd_sigtramp_frame_unwind = {
 283   SIGTRAMP_FRAME,
 284   default_frame_unwind_stop_reason,
 285   ppcfbsd_sigtramp_frame_this_id,
 286   ppcfbsd_sigtramp_frame_prev_register,
 287   NULL,
 288   ppcfbsd_sigtramp_frame_sniffer
 289 };
 290
 291 static enum return_value_convention
 292 ppcfbsd_return_value (struct gdbarch *gdbarch, struct value *function,
 293                       struct type *valtype, struct regcache *regcache,
 294                       gdb_byte *readbuf, const gdb_byte *writebuf)
 295 {
 296   return ppc_sysv_abi_broken_return_value (gdbarch, function, valtype,
 297                                            regcache, readbuf, writebuf);
 298 }
 299
 300
 301 static void
 302 ppcfbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 303 {
 304   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 305
 306   /* FreeBSD doesn't support the 128-bit `long double' from the psABI.  */
 307   set_gdbarch_long_double_bit (gdbarch, 64);
 308   set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
 309
 310   if (tdep->wordsize == 4)
 311     {
 312       set_gdbarch_return_value (gdbarch, ppcfbsd_return_value);
 313
 314       set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 315       set_solib_svr4_fetch_link_map_offsets (gdbarch,
 316                                              svr4_ilp32_fetch_link_map_offsets);
 317
 318       frame_unwind_append_unwinder (gdbarch, &ppcfbsd_sigtramp_frame_unwind);
 319       set_gdbarch_gcore_bfd_target (gdbarch, "elf32-powerpc");
 320     }
 321
 322   if (tdep->wordsize == 8)
 323     {
 324       set_gdbarch_convert_from_func_ptr_addr
 325         (gdbarch, ppc64_convert_from_func_ptr_addr);
 326       set_gdbarch_elf_make_msymbol_special (gdbarch,
 327                                             ppc64_elf_make_msymbol_special);
 328
 329       set_gdbarch_skip_trampoline_code (gdbarch, ppc64_skip_trampoline_code);
 330       set_solib_svr4_fetch_link_map_offsets (gdbarch,
 331                                              svr4_lp64_fetch_link_map_offsets);
 332       set_gdbarch_gcore_bfd_target (gdbarch, "elf64-powerpc");
 333     }
 334
 335   set_gdbarch_regset_from_core_section
 336     (gdbarch, ppcfbsd_regset_from_core_section);
 337
 338   set_gdbarch_fetch_tls_load_module_address (gdbarch,
 339                                              svr4_fetch_objfile_link_map);
 340 }
 341
 342 /* Provide a prototype to silence -Wmissing-prototypes.  */
 343
 344 void _initialize_ppcfbsd_tdep (void);
 345
 346 void
 347 _initialize_ppcfbsd_tdep (void)
 348 {
 349   gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc, GDB_OSABI_FREEBSD_ELF,
 350                           ppcfbsd_init_abi);
 351   gdbarch_register_osabi (bfd_arch_powerpc, bfd_mach_ppc64,
 352                           GDB_OSABI_FREEBSD_ELF,
 353                           ppcfbsd_init_abi);
 354   gdbarch_register_osabi (bfd_arch_rs6000, 0, GDB_OSABI_FREEBSD_ELF,
 355                           ppcfbsd_init_abi);
 356 }