gdb/sparcnbsd-tdep.c

   1 /* Target-dependent code for NetBSD/sparc.
   2
   3    Copyright (C) 2002-2004, 2006-2012 Free Software Foundation, Inc.
   4    Contributed by Wasabi Systems, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "frame.h"
  23 #include "frame-unwind.h"
  24 #include "gdbcore.h"
  25 #include "gdbtypes.h"
  26 #include "osabi.h"
  27 #include "regcache.h"
  28 #include "regset.h"
  29 #include "solib-svr4.h"
  30 #include "symtab.h"
  31 #include "trad-frame.h"
  32
  33 #include "gdb_assert.h"
  34 #include "gdb_string.h"
  35
  36 #include "sparc-tdep.h"
  37 #include "nbsd-tdep.h"
  38
  39 /* Macros to extract fields from SPARC instructions.  */
  40 #define X_RS1(i) (((i) >> 14) & 0x1f)
  41 #define X_RS2(i) ((i) & 0x1f)
  42 #define X_I(i) (((i) >> 13) & 1)
  43
  44 const struct sparc_gregset sparc32nbsd_gregset =
  45 {
  46   0 * 4,                        /* %psr */
  47   1 * 4,                        /* %pc */
  48   2 * 4,                        /* %npc */
  49   3 * 4,                        /* %y */
  50   -1,                           /* %wim */
  51   -1,                           /* %tbr */
  52   5 * 4,                        /* %g1 */
  53   -1                            /* %l0 */
  54 };
  55
  56 static void
  57 sparc32nbsd_supply_gregset (const struct regset *regset,
  58                             struct regcache *regcache,
  59                             int regnum, const void *gregs, size_t len)
  60 {
  61   sparc32_supply_gregset (&sparc32nbsd_gregset, regcache, regnum, gregs);
  62
  63   /* Traditional NetBSD core files don't use multiple register sets.
  64      Instead, the general-purpose and floating-point registers are
  65      lumped together in a single section.  */
  66   if (len >= 212)
  67     sparc32_supply_fpregset (regcache, regnum, (const char *) gregs + 80);
  68 }
  69
  70 static void
  71 sparc32nbsd_supply_fpregset (const struct regset *regset,
  72                              struct regcache *regcache,
  73                              int regnum, const void *fpregs, size_t len)
  74 {
  75   sparc32_supply_fpregset (regcache, regnum, fpregs);
  76 }
  77
  78 \f
  79 /* Signal trampolines.  */
  80
  81 /* The following variables describe the location of an on-stack signal
  82    trampoline.  The current values correspond to the memory layout for
  83    NetBSD 1.3 and up.  These shouldn't be necessary for NetBSD 2.0 and
  84    up, since NetBSD uses signal trampolines provided by libc now.  */
  85
  86 static const CORE_ADDR sparc32nbsd_sigtramp_start = 0xeffffef0;
  87 static const CORE_ADDR sparc32nbsd_sigtramp_end = 0xeffffff0;
  88
  89 static int
  90 sparc32nbsd_pc_in_sigtramp (CORE_ADDR pc, const char *name)
  91 {
  92   if (pc >= sparc32nbsd_sigtramp_start && pc < sparc32nbsd_sigtramp_end)
  93     return 1;
  94
  95   return nbsd_pc_in_sigtramp (pc, name);
  96 }
  97
  98 struct trad_frame_saved_reg *
  99 sparc32nbsd_sigcontext_saved_regs (struct frame_info *this_frame)
 100 {
 101   struct gdbarch *gdbarch = get_frame_arch (this_frame);
 102   struct trad_frame_saved_reg *saved_regs;
 103   CORE_ADDR addr, sigcontext_addr;
 104   int regnum, delta;
 105   ULONGEST psr;
 106
 107   saved_regs = trad_frame_alloc_saved_regs (this_frame);
 108
 109   /* We find the appropriate instance of `struct sigcontext' at a
 110      fixed offset in the signal frame.  */
 111   addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM);
 112   sigcontext_addr = addr + 64 + 16;
 113
 114   /* The registers are saved in bits and pieces scattered all over the
 115      place.  The code below records their location on the assumption
 116      that the part of the signal trampoline that saves the state has
 117      been executed.  */
 118
 119   saved_regs[SPARC_SP_REGNUM].addr = sigcontext_addr + 8;
 120   saved_regs[SPARC32_PC_REGNUM].addr = sigcontext_addr + 12;
 121   saved_regs[SPARC32_NPC_REGNUM].addr = sigcontext_addr + 16;
 122   saved_regs[SPARC32_PSR_REGNUM].addr = sigcontext_addr + 20;
 123   saved_regs[SPARC_G1_REGNUM].addr = sigcontext_addr + 24;
 124   saved_regs[SPARC_O0_REGNUM].addr = sigcontext_addr + 28;
 125
 126   /* The remaining `global' registers and %y are saved in the `local'
 127      registers.  */
 128   delta = SPARC_L0_REGNUM - SPARC_G0_REGNUM;
 129   for (regnum = SPARC_G2_REGNUM; regnum <= SPARC_G7_REGNUM; regnum++)
 130     saved_regs[regnum].realreg = regnum + delta;
 131   saved_regs[SPARC32_Y_REGNUM].realreg = SPARC_L1_REGNUM;
 132
 133   /* The remaining `out' registers can be found in the current frame's
 134      `in' registers.  */
 135   delta = SPARC_I0_REGNUM - SPARC_O0_REGNUM;
 136   for (regnum = SPARC_O1_REGNUM; regnum <= SPARC_O5_REGNUM; regnum++)
 137     saved_regs[regnum].realreg = regnum + delta;
 138   saved_regs[SPARC_O7_REGNUM].realreg = SPARC_I7_REGNUM;
 139
 140   /* The `local' and `in' registers have been saved in the register
 141      save area.  */
 142   addr = saved_regs[SPARC_SP_REGNUM].addr;
 143   addr = get_frame_memory_unsigned (this_frame, addr, 4);
 144   for (regnum = SPARC_L0_REGNUM;
 145        regnum <= SPARC_I7_REGNUM; regnum++, addr += 4)
 146     saved_regs[regnum].addr = addr;
 147
 148   /* Handle StackGhost.  */
 149   {
 150     ULONGEST wcookie = sparc_fetch_wcookie (gdbarch);
 151
 152     if (wcookie != 0)
 153       {
 154         ULONGEST i7;
 155
 156         addr = saved_regs[SPARC_I7_REGNUM].addr;
 157         i7 = get_frame_memory_unsigned (this_frame, addr, 4);
 158         trad_frame_set_value (saved_regs, SPARC_I7_REGNUM, i7 ^ wcookie);
 159       }
 160   }
 161
 162   /* The floating-point registers are only saved if the EF bit in %prs
 163      has been set.  */
 164
 165 #define PSR_EF  0x00001000
 166
 167   addr = saved_regs[SPARC32_PSR_REGNUM].addr;
 168   psr = get_frame_memory_unsigned (this_frame, addr, 4);
 169   if (psr & PSR_EF)
 170     {
 171       CORE_ADDR sp;
 172
 173       sp = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM);
 174       saved_regs[SPARC32_FSR_REGNUM].addr = sp + 96;
 175       for (regnum = SPARC_F0_REGNUM, addr = sp + 96 + 8;
 176            regnum <= SPARC_F31_REGNUM; regnum++, addr += 4)
 177         saved_regs[regnum].addr = addr;
 178     }
 179
 180   return saved_regs;
 181 }
 182
 183 static struct sparc_frame_cache *
 184 sparc32nbsd_sigcontext_frame_cache (struct frame_info *this_frame,
 185                                     void **this_cache)
 186 {
 187   struct sparc_frame_cache *cache;
 188   CORE_ADDR addr;
 189
 190   if (*this_cache)
 191     return *this_cache;
 192
 193   cache = sparc_frame_cache (this_frame, this_cache);
 194   gdb_assert (cache == *this_cache);
 195
 196   /* If we couldn't find the frame's function, we're probably dealing
 197      with an on-stack signal trampoline.  */
 198   if (cache->pc == 0)
 199     {
 200       cache->pc = sparc32nbsd_sigtramp_start;
 201
 202       /* Since we couldn't find the frame's function, the cache was
 203          initialized under the assumption that we're frameless.  */
 204       sparc_record_save_insn (cache);
 205       addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM);
 206       cache->base = addr;
 207     }
 208
 209   cache->saved_regs = sparc32nbsd_sigcontext_saved_regs (this_frame);
 210
 211   return cache;
 212 }
 213
 214 static void
 215 sparc32nbsd_sigcontext_frame_this_id (struct frame_info *this_frame,
 216                                       void **this_cache,
 217                                       struct frame_id *this_id)
 218 {
 219   struct sparc_frame_cache *cache =
 220     sparc32nbsd_sigcontext_frame_cache (this_frame, this_cache);
 221
 222   (*this_id) = frame_id_build (cache->base, cache->pc);
 223 }
 224
 225 static struct value *
 226 sparc32nbsd_sigcontext_frame_prev_register (struct frame_info *this_frame,
 227                                             void **this_cache, int regnum)
 228 {
 229   struct sparc_frame_cache *cache =
 230     sparc32nbsd_sigcontext_frame_cache (this_frame, this_cache);
 231
 232   return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum);
 233 }
 234
 235 static int
 236 sparc32nbsd_sigcontext_frame_sniffer (const struct frame_unwind *self,
 237                                       struct frame_info *this_frame,
 238                                       void **this_cache)
 239 {
 240   CORE_ADDR pc = get_frame_pc (this_frame);
 241   const char *name;
 242
 243   find_pc_partial_function (pc, &name, NULL, NULL);
 244   if (sparc32nbsd_pc_in_sigtramp (pc, name))
 245     {
 246       if (name == NULL || strncmp (name, "__sigtramp_sigcontext", 21))
 247         return 1;
 248     }
 249
 250   return 0;
 251 }
 252
 253 static const struct frame_unwind sparc32nbsd_sigcontext_frame_unwind =
 254 {
 255   SIGTRAMP_FRAME,
 256   default_frame_unwind_stop_reason,
 257   sparc32nbsd_sigcontext_frame_this_id,
 258   sparc32nbsd_sigcontext_frame_prev_register,
 259   NULL,
 260   sparc32nbsd_sigcontext_frame_sniffer
 261 };
 262 \f
 263 /* Return the address of a system call's alternative return
 264    address.  */
 265
 266 CORE_ADDR
 267 sparcnbsd_step_trap (struct frame_info *frame, unsigned long insn)
 268 {
 269   if ((X_I (insn) == 0 && X_RS1 (insn) == 0 && X_RS2 (insn) == 0)
 270       || (X_I (insn) == 1 && X_RS1 (insn) == 0 && (insn & 0x7f) == 0))
 271     {
 272       /* "New" system call.  */
 273       ULONGEST number = get_frame_register_unsigned (frame, SPARC_G1_REGNUM);
 274
 275       if (number & 0x400)
 276         return get_frame_register_unsigned (frame, SPARC_G2_REGNUM);
 277       if (number & 0x800)
 278         return get_frame_register_unsigned (frame, SPARC_G7_REGNUM);
 279     }
 280
 281   return 0;
 282 }
 283 \f
 284
 285 static void
 286 sparc32nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 287 {
 288   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 289
 290   /* NetBSD doesn't support the 128-bit `long double' from the psABI.  */
 291   set_gdbarch_long_double_bit (gdbarch, 64);
 292   set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
 293
 294   tdep->gregset = regset_alloc (gdbarch, sparc32nbsd_supply_gregset, NULL);
 295   tdep->sizeof_gregset = 20 * 4;
 296
 297   tdep->fpregset = regset_alloc (gdbarch, sparc32nbsd_supply_fpregset, NULL);
 298   tdep->sizeof_fpregset = 33 * 4;
 299
 300   /* Make sure we can single-step "new" syscalls.  */
 301   tdep->step_trap = sparcnbsd_step_trap;
 302
 303   frame_unwind_append_unwinder (gdbarch, &sparc32nbsd_sigcontext_frame_unwind);
 304 }
 305
 306 static void
 307 sparc32nbsd_aout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 308 {
 309   sparc32nbsd_init_abi (info, gdbarch);
 310 }
 311
 312 void
 313 sparc32nbsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 314 {
 315   sparc32nbsd_init_abi (info, gdbarch);
 316
 317   set_solib_svr4_fetch_link_map_offsets
 318     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 319 }
 320
 321 static enum gdb_osabi
 322 sparcnbsd_aout_osabi_sniffer (bfd *abfd)
 323 {
 324   if (strcmp (bfd_get_target (abfd), "a.out-sparc-netbsd") == 0)
 325     return GDB_OSABI_NETBSD_AOUT;
 326
 327   return GDB_OSABI_UNKNOWN;
 328 }
 329
 330 /* OpenBSD uses the traditional NetBSD core file format, even for
 331    ports that use ELF.  Therefore, if the default OS ABI is OpenBSD
 332    ELF, we return that instead of NetBSD a.out.  This is mainly for
 333    the benfit of OpenBSD/sparc64, which inherits the sniffer below
 334    since we include this file for an OpenBSD/sparc64 target.  For
 335    OpenBSD/sparc, the NetBSD a.out OS ABI is probably similar enough
 336    to both the OpenBSD a.out and the OpenBSD ELF OS ABI.  */
 337 #if defined (GDB_OSABI_DEFAULT) && (GDB_OSABI_DEFAULT == GDB_OSABI_OPENBSD_ELF)
 338 #define GDB_OSABI_NETBSD_CORE GDB_OSABI_OPENBSD_ELF
 339 #else
 340 #define GDB_OSABI_NETBSD_CORE GDB_OSABI_NETBSD_AOUT
 341 #endif
 342
 343 static enum gdb_osabi
 344 sparcnbsd_core_osabi_sniffer (bfd *abfd)
 345 {
 346   if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
 347     return GDB_OSABI_NETBSD_CORE;
 348
 349   return GDB_OSABI_UNKNOWN;
 350 }
 351
 352 \f
 353 /* Provide a prototype to silence -Wmissing-prototypes.  */
 354 void _initialize_sparcnbsd_tdep (void);
 355
 356 void
 357 _initialize_sparcnbsd_tdep (void)
 358 {
 359   gdbarch_register_osabi_sniffer (bfd_arch_sparc, bfd_target_aout_flavour,
 360                                   sparcnbsd_aout_osabi_sniffer);
 361
 362   /* BFD doesn't set a flavour for NetBSD style a.out core files.  */
 363   gdbarch_register_osabi_sniffer (bfd_arch_sparc, bfd_target_unknown_flavour,
 364                                   sparcnbsd_core_osabi_sniffer);
 365
 366   gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_NETBSD_AOUT,
 367                           sparc32nbsd_aout_init_abi);
 368   gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_NETBSD_ELF,
 369                           sparc32nbsd_elf_init_abi);
 370 }