gdb/sparc64-nbsd-tdep.c

   1 /* Target-dependent code for NetBSD/sparc64.
   2
   3    Copyright (C) 2002-2020 Free Software Foundation, Inc.
   4    Based on code 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 "osabi.h"
  26 #include "regcache.h"
  27 #include "regset.h"
  28 #include "symtab.h"
  29 #include "objfiles.h"
  30 #include "solib-svr4.h"
  31 #include "trad-frame.h"
  32
  33 #include "sparc64-tdep.h"
  34 #include "nbsd-tdep.h"
  35
  36 /* From <machine/reg.h>.  */
  37 const struct sparc_gregmap sparc64nbsd_gregmap =
  38 {
  39   0 * 8,                        /* "tstate" */
  40   1 * 8,                        /* %pc */
  41   2 * 8,                        /* %npc */
  42   3 * 8,                        /* %y */
  43   -1,                           /* %fprs */
  44   -1,
  45   5 * 8,                        /* %g1 */
  46   -1,                           /* %l0 */
  47   4                             /* sizeof (%y) */
  48 };
  49 \f
  50
  51 static void
  52 sparc64nbsd_supply_gregset (const struct regset *regset,
  53                             struct regcache *regcache,
  54                             int regnum, const void *gregs, size_t len)
  55 {
  56   sparc64_supply_gregset (&sparc64nbsd_gregmap, regcache, regnum, gregs);
  57 }
  58
  59 static void
  60 sparc64nbsd_supply_fpregset (const struct regset *regset,
  61                              struct regcache *regcache,
  62                              int regnum, const void *fpregs, size_t len)
  63 {
  64   sparc64_supply_fpregset (&sparc64_bsd_fpregmap, regcache, regnum, fpregs);
  65 }
  66 \f
  67
  68 /* Signal trampolines.  */
  69
  70 /* The following variables describe the location of an on-stack signal
  71    trampoline.  The current values correspond to the memory layout for
  72    NetBSD 1.3 and up.  These shouldn't be necessary for NetBSD 2.0 and
  73    up, since NetBSD uses signal trampolines provided by libc now.  */
  74
  75 static const CORE_ADDR sparc64nbsd_sigtramp_start = 0xffffffffffffdee4ULL;
  76 static const CORE_ADDR sparc64nbsd_sigtramp_end = 0xffffffffffffe000ULL;
  77
  78 static int
  79 sparc64nbsd_pc_in_sigtramp (CORE_ADDR pc, const char *name)
  80 {
  81   if (pc >= sparc64nbsd_sigtramp_start && pc < sparc64nbsd_sigtramp_end)
  82     return 1;
  83
  84   return nbsd_pc_in_sigtramp (pc, name);
  85 }
  86
  87 struct trad_frame_saved_reg *
  88 sparc64nbsd_sigcontext_saved_regs (CORE_ADDR sigcontext_addr,
  89                                    struct frame_info *this_frame)
  90 {
  91   struct gdbarch *gdbarch = get_frame_arch (this_frame);
  92   struct trad_frame_saved_reg *saved_regs;
  93   CORE_ADDR addr, sp;
  94   int regnum, delta;
  95
  96   saved_regs = trad_frame_alloc_saved_regs (this_frame);
  97
  98   /* The registers are saved in bits and pieces scattered all over the
  99      place.  The code below records their location on the assumption
 100      that the part of the signal trampoline that saves the state has
 101      been executed.  */
 102
 103   saved_regs[SPARC_SP_REGNUM].addr = sigcontext_addr + 8;
 104   saved_regs[SPARC64_PC_REGNUM].addr = sigcontext_addr + 16;
 105   saved_regs[SPARC64_NPC_REGNUM].addr = sigcontext_addr + 24;
 106   saved_regs[SPARC64_STATE_REGNUM].addr = sigcontext_addr + 32;
 107   saved_regs[SPARC_G1_REGNUM].addr = sigcontext_addr + 40;
 108   saved_regs[SPARC_O0_REGNUM].addr = sigcontext_addr + 48;
 109
 110   /* The remaining `global' registers and %y are saved in the `local'
 111      registers.  */
 112   delta = SPARC_L0_REGNUM - SPARC_G0_REGNUM;
 113   for (regnum = SPARC_G2_REGNUM; regnum <= SPARC_G7_REGNUM; regnum++)
 114     saved_regs[regnum].realreg = regnum + delta;
 115   saved_regs[SPARC64_Y_REGNUM].realreg = SPARC_L1_REGNUM;
 116
 117   /* The remaining `out' registers can be found in the current frame's
 118      `in' registers.  */
 119   delta = SPARC_I0_REGNUM - SPARC_O0_REGNUM;
 120   for (regnum = SPARC_O1_REGNUM; regnum <= SPARC_O5_REGNUM; regnum++)
 121     saved_regs[regnum].realreg = regnum + delta;
 122   saved_regs[SPARC_O7_REGNUM].realreg = SPARC_I7_REGNUM;
 123
 124   /* The `local' and `in' registers have been saved in the register
 125      save area.  */
 126   addr = saved_regs[SPARC_SP_REGNUM].addr;
 127   sp = get_frame_memory_unsigned (this_frame, addr, 8);
 128   for (regnum = SPARC_L0_REGNUM, addr = sp + BIAS;
 129        regnum <= SPARC_I7_REGNUM; regnum++, addr += 8)
 130     saved_regs[regnum].addr = addr;
 131
 132   /* Handle StackGhost.  */
 133   {
 134     ULONGEST wcookie = sparc_fetch_wcookie (gdbarch);
 135
 136     if (wcookie != 0)
 137       {
 138         ULONGEST i7;
 139
 140         addr = saved_regs[SPARC_I7_REGNUM].addr;
 141         i7 = get_frame_memory_unsigned (this_frame, addr, 8);
 142         trad_frame_set_value (saved_regs, SPARC_I7_REGNUM, i7 ^ wcookie);
 143       }
 144   }
 145
 146   /* TODO: Handle the floating-point registers.  */
 147
 148   return saved_regs;
 149 }
 150
 151 static struct sparc_frame_cache *
 152 sparc64nbsd_sigcontext_frame_cache (struct frame_info *this_frame,
 153                                     void **this_cache)
 154 {
 155   struct sparc_frame_cache *cache;
 156   CORE_ADDR addr;
 157
 158   if (*this_cache)
 159     return (struct sparc_frame_cache *) *this_cache;
 160
 161   cache = sparc_frame_cache (this_frame, this_cache);
 162   gdb_assert (cache == *this_cache);
 163
 164   /* If we couldn't find the frame's function, we're probably dealing
 165      with an on-stack signal trampoline.  */
 166   if (cache->pc == 0)
 167     {
 168       cache->pc = sparc64nbsd_sigtramp_start;
 169
 170       /* Since we couldn't find the frame's function, the cache was
 171          initialized under the assumption that we're frameless.  */
 172       sparc_record_save_insn (cache);
 173       addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM);
 174       if (addr & 1)
 175         addr += BIAS;
 176       cache->base = addr;
 177     }
 178
 179   /* We find the appropriate instance of `struct sigcontext' at a
 180      fixed offset in the signal frame.  */
 181   addr = cache->base + 128 + 8;
 182   cache->saved_regs = sparc64nbsd_sigcontext_saved_regs (addr, this_frame);
 183
 184   return cache;
 185 }
 186
 187 static void
 188 sparc64nbsd_sigcontext_frame_this_id (struct frame_info *this_frame,
 189                                       void **this_cache,
 190                                       struct frame_id *this_id)
 191 {
 192   struct sparc_frame_cache *cache =
 193     sparc64nbsd_sigcontext_frame_cache (this_frame, this_cache);
 194
 195   (*this_id) = frame_id_build (cache->base, cache->pc);
 196 }
 197
 198 static struct value *
 199 sparc64nbsd_sigcontext_frame_prev_register (struct frame_info *this_frame,
 200                                             void **this_cache, int regnum)
 201 {
 202   struct sparc_frame_cache *cache =
 203     sparc64nbsd_sigcontext_frame_cache (this_frame, this_cache);
 204
 205   return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum);
 206 }
 207
 208 static int
 209 sparc64nbsd_sigtramp_frame_sniffer (const struct frame_unwind *self,
 210                                     struct frame_info *this_frame,
 211                                     void **this_cache)
 212 {
 213   CORE_ADDR pc = get_frame_pc (this_frame);
 214   const char *name;
 215
 216   find_pc_partial_function (pc, &name, NULL, NULL);
 217   if (sparc64nbsd_pc_in_sigtramp (pc, name))
 218     {
 219       if (name == NULL || !startswith (name, "__sigtramp_sigcontext"))
 220         return 1;
 221     }
 222
 223   return 0;
 224 }
 225
 226 static const struct frame_unwind sparc64nbsd_sigcontext_frame_unwind =
 227 {
 228   SIGTRAMP_FRAME,
 229   default_frame_unwind_stop_reason,
 230   sparc64nbsd_sigcontext_frame_this_id,
 231   sparc64nbsd_sigcontext_frame_prev_register,
 232   NULL,
 233   sparc64nbsd_sigtramp_frame_sniffer
 234 };
 235 \f
 236
 237 static const struct regset sparc64nbsd_gregset =
 238   {
 239     NULL, sparc64nbsd_supply_gregset, NULL
 240   };
 241
 242 static const struct regset sparc64nbsd_fpregset =
 243   {
 244     NULL, sparc64nbsd_supply_fpregset, NULL
 245   };
 246
 247 static void
 248 sparc64nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 249 {
 250   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 251
 252   tdep->gregset = &sparc64nbsd_gregset;
 253   tdep->sizeof_gregset = 160;
 254
 255   tdep->fpregset =  &sparc64nbsd_fpregset;
 256   tdep->sizeof_fpregset = 272;
 257
 258   /* Make sure we can single-step "new" syscalls.  */
 259   tdep->step_trap = sparcnbsd_step_trap;
 260
 261   frame_unwind_append_unwinder (gdbarch, &sparc64nbsd_sigcontext_frame_unwind);
 262
 263   sparc64_init_abi (info, gdbarch);
 264
 265   /* NetBSD/sparc64 has SVR4-style shared libraries.  */
 266   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
 267   set_solib_svr4_fetch_link_map_offsets
 268     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 269 }
 270
 271 void
 272 _initialize_sparc64nbsd_tdep (void)
 273 {
 274   gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9,
 275                           GDB_OSABI_NETBSD, sparc64nbsd_init_abi);
 276 }