gdbserver/linux-sparc-low.cc

   1 /* Low level interface to ptrace, for the remote server for GDB.
   2    Copyright (C) 1995-2020 Free Software Foundation, Inc.
   3
   4    This file is part of GDB.
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include "server.h"
  20 #include "linux-low.h"
  21
  22 #include "nat/gdb_ptrace.h"
  23
  24 #include "gdb_proc_service.h"
  25
  26 /* The stack pointer is offset from the stack frame by a BIAS of 2047
  27    (0x7ff) for 64-bit code.  BIAS is likely to be defined on SPARC
  28    hosts, so undefine it first.  */
  29 #undef BIAS
  30 #define BIAS 2047
  31
  32 #ifdef HAVE_SYS_REG_H
  33 #include <sys/reg.h>
  34 #endif
  35
  36 #define INSN_SIZE 4
  37
  38 #define SPARC_R_REGS_NUM 32
  39 #define SPARC_F_REGS_NUM 48
  40 #define SPARC_CONTROL_REGS_NUM 6
  41
  42 #define sparc_num_regs \
  43   (SPARC_R_REGS_NUM + SPARC_F_REGS_NUM + SPARC_CONTROL_REGS_NUM)
  44
  45 /* Linux target op definitions for the SPARC architecture.  */
  46
  47 class sparc_target : public linux_process_target
  48 {
  49 public:
  50
  51   const regs_info *get_regs_info () override;
  52
  53   const gdb_byte *sw_breakpoint_from_kind (int kind, int *size) override;
  54
  55 protected:
  56
  57   void low_arch_setup () override;
  58
  59   bool low_cannot_fetch_register (int regno) override;
  60
  61   bool low_cannot_store_register (int regno) override;
  62
  63   bool low_supports_breakpoints () override;
  64
  65   CORE_ADDR low_get_pc (regcache *regcache) override;
  66
  67   /* No low_set_pc is needed.  */
  68 };
  69
  70 /* The singleton target ops object.  */
  71
  72 static sparc_target the_sparc_target;
  73
  74 bool
  75 sparc_target::low_supports_breakpoints ()
  76 {
  77   return true;
  78 }
  79
  80 CORE_ADDR
  81 sparc_target::low_get_pc (regcache *regcache)
  82 {
  83   return linux_get_pc_64bit (regcache);
  84 }
  85
  86 /* Each offset is multiplied by 8, because of the register size.
  87    These offsets apply to the buffer sent/filled by ptrace.
  88    Additionally, the array elements order corresponds to the .dat file, and the
  89    gdb's registers enumeration order.  */
  90
  91 static int sparc_regmap[] = {
  92   /* These offsets correspond to GET/SETREGSET.  */
  93         -1,  0*8,  1*8,  2*8,  3*8,  4*8,  5*8,  6*8,    /* g0 .. g7 */
  94         7*8,  8*8,  9*8, 10*8, 11*8, 12*8, 13*8, 14*8,   /* o0 .. o5, sp, o7 */
  95         -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,    /* l0 .. l7 */
  96         -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,    /* i0 .. i5, fp, i7 */
  97
  98   /* Floating point registers offsets correspond to GET/SETFPREGSET.  */
  99     0*4,  1*4,  2*4,  3*4,  4*4,  5*4,  6*4,  7*4,         /*  f0 ..  f7 */
 100     8*4,  9*4, 10*4, 11*4, 12*4, 13*4, 14*4, 15*4,         /*  f8 .. f15 */
 101    16*4, 17*4, 18*4, 19*4, 20*4, 21*4, 22*4, 23*4,         /* f16 .. f23 */
 102    24*4, 25*4, 26*4, 27*4, 28*4, 29*4, 30*4, 31*4,         /* f24 .. f31 */
 103
 104   /* F32 offset starts next to f31: 31*4+4 = 16 * 8.  */
 105    16*8, 17*8, 18*8, 19*8, 20*8, 21*8, 22*8, 23*8,         /* f32 .. f46 */
 106    24*8, 25*8, 26*8, 27*8, 28*8, 29*8, 30*8, 31*8,         /* f48 .. f62 */
 107
 108    17 *8, /*    pc */
 109    18 *8, /*   npc */
 110    16 *8, /* state */
 111   /* FSR offset also corresponds to GET/SETFPREGSET, ans is placed
 112      next to f62.  */
 113    32 *8, /*   fsr */
 114       -1, /*  fprs */
 115   /* Y register is 32-bits length, but gdb takes care of that.  */
 116    19 *8, /*     y */
 117
 118 };
 119
 120
 121 struct regs_range_t
 122 {
 123   int regno_start;
 124   int regno_end;
 125 };
 126
 127 static const struct regs_range_t gregs_ranges[] = {
 128  {  0, 31 }, /*   g0 .. i7  */
 129  { 80, 82 }, /*   pc .. state */
 130  { 84, 85 }  /* fprs .. y */
 131 };
 132
 133 #define N_GREGS_RANGES (sizeof (gregs_ranges) / sizeof (struct regs_range_t))
 134
 135 static const struct regs_range_t fpregs_ranges[] = {
 136  { 32, 79 }, /* f0 .. f62  */
 137  { 83, 83 }  /* fsr */
 138 };
 139
 140 #define N_FPREGS_RANGES (sizeof (fpregs_ranges) / sizeof (struct regs_range_t))
 141
 142 /* Defined in auto-generated file reg-sparc64.c.  */
 143 void init_registers_sparc64 (void);
 144 extern const struct target_desc *tdesc_sparc64;
 145
 146 bool
 147 sparc_target::low_cannot_store_register (int regno)
 148 {
 149   return (regno >= sparc_num_regs || sparc_regmap[regno] == -1);
 150 }
 151
 152 bool
 153 sparc_target::low_cannot_fetch_register (int regno)
 154 {
 155   return (regno >= sparc_num_regs || sparc_regmap[regno] == -1);
 156 }
 157
 158 static void
 159 sparc_fill_gregset_to_stack (struct regcache *regcache, const void *buf)
 160 {
 161   int i;
 162   CORE_ADDR addr = 0;
 163   unsigned char tmp_reg_buf[8];
 164   const int l0_regno = find_regno (regcache->tdesc, "l0");
 165   const int i7_regno = l0_regno + 15;
 166
 167   /* These registers have to be stored in the stack.  */
 168   memcpy (&addr,
 169           ((char *) buf) + sparc_regmap[find_regno (regcache->tdesc, "sp")],
 170           sizeof (addr));
 171
 172   addr += BIAS;
 173
 174   for (i = l0_regno; i <= i7_regno; i++)
 175     {
 176       collect_register (regcache, i, tmp_reg_buf);
 177       the_target->write_memory (addr, tmp_reg_buf, sizeof (tmp_reg_buf));
 178       addr += sizeof (tmp_reg_buf);
 179     }
 180 }
 181
 182 static void
 183 sparc_fill_gregset (struct regcache *regcache, void *buf)
 184 {
 185   int i;
 186   int range;
 187
 188   for (range = 0; range < N_GREGS_RANGES; range++)
 189     for (i = gregs_ranges[range].regno_start;
 190          i <= gregs_ranges[range].regno_end; i++)
 191       if (sparc_regmap[i] != -1)
 192         collect_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
 193
 194   sparc_fill_gregset_to_stack (regcache, buf);
 195 }
 196
 197 static void
 198 sparc_fill_fpregset (struct regcache *regcache, void *buf)
 199 {
 200   int i;
 201   int range;
 202
 203   for (range = 0; range < N_FPREGS_RANGES; range++)
 204     for (i = fpregs_ranges[range].regno_start;
 205          i <= fpregs_ranges[range].regno_end; i++)
 206       collect_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
 207
 208 }
 209
 210 static void
 211 sparc_store_gregset_from_stack (struct regcache *regcache, const void *buf)
 212 {
 213   int i;
 214   CORE_ADDR addr = 0;
 215   unsigned char tmp_reg_buf[8];
 216   const int l0_regno = find_regno (regcache->tdesc, "l0");
 217   const int i7_regno = l0_regno + 15;
 218
 219   /* These registers have to be obtained from the stack.  */
 220   memcpy (&addr,
 221           ((char *) buf) + sparc_regmap[find_regno (regcache->tdesc, "sp")],
 222           sizeof (addr));
 223
 224   addr += BIAS;
 225
 226   for (i = l0_regno; i <= i7_regno; i++)
 227     {
 228       the_target->read_memory (addr, tmp_reg_buf, sizeof (tmp_reg_buf));
 229       supply_register (regcache, i, tmp_reg_buf);
 230       addr += sizeof (tmp_reg_buf);
 231     }
 232 }
 233
 234 static void
 235 sparc_store_gregset (struct regcache *regcache, const void *buf)
 236 {
 237   int i;
 238   char zerobuf[8];
 239   int range;
 240
 241   memset (zerobuf, 0, sizeof (zerobuf));
 242
 243   for (range = 0; range < N_GREGS_RANGES; range++)
 244     for (i = gregs_ranges[range].regno_start;
 245          i <= gregs_ranges[range].regno_end; i++)
 246       if (sparc_regmap[i] != -1)
 247         supply_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
 248       else
 249         supply_register (regcache, i, zerobuf);
 250
 251   sparc_store_gregset_from_stack (regcache, buf);
 252 }
 253
 254 static void
 255 sparc_store_fpregset (struct regcache *regcache, const void *buf)
 256 {
 257   int i;
 258   int range;
 259
 260   for (range = 0; range < N_FPREGS_RANGES; range++)
 261     for (i = fpregs_ranges[range].regno_start;
 262          i <= fpregs_ranges[range].regno_end;
 263          i++)
 264       supply_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
 265 }
 266
 267 static const gdb_byte sparc_breakpoint[INSN_SIZE] = {
 268   0x91, 0xd0, 0x20, 0x01
 269 };
 270 #define sparc_breakpoint_len INSN_SIZE
 271
 272 /* Implementation of target ops method "sw_breakpoint_from_kind".  */
 273
 274 const gdb_byte *
 275 sparc_target::sw_breakpoint_from_kind (int kind, int *size)
 276 {
 277   *size = sparc_breakpoint_len;
 278   return sparc_breakpoint;
 279 }
 280
 281 static int
 282 sparc_breakpoint_at (CORE_ADDR where)
 283 {
 284   unsigned char insn[INSN_SIZE];
 285
 286   the_target->read_memory (where, (unsigned char *) insn, sizeof (insn));
 287
 288   if (memcmp (sparc_breakpoint, insn, sizeof (insn)) == 0)
 289     return 1;
 290
 291   /* If necessary, recognize more trap instructions here.  GDB only
 292      uses TRAP Always.  */
 293
 294   return 0;
 295 }
 296
 297 void
 298 sparc_target::low_arch_setup ()
 299 {
 300   current_process ()->tdesc = tdesc_sparc64;
 301 }
 302
 303 static struct regset_info sparc_regsets[] = {
 304   { PTRACE_GETREGS, PTRACE_SETREGS, 0, sizeof (elf_gregset_t),
 305     GENERAL_REGS,
 306     sparc_fill_gregset, sparc_store_gregset },
 307   { PTRACE_GETFPREGS, PTRACE_SETFPREGS, 0, sizeof (fpregset_t),
 308     FP_REGS,
 309     sparc_fill_fpregset, sparc_store_fpregset },
 310   NULL_REGSET
 311 };
 312
 313 static struct regsets_info sparc_regsets_info =
 314   {
 315     sparc_regsets, /* regsets */
 316     0, /* num_regsets */
 317     NULL, /* disabled_regsets */
 318   };
 319
 320 static struct usrregs_info sparc_usrregs_info =
 321   {
 322     sparc_num_regs,
 323     /* No regmap needs to be provided since this impl. doesn't use
 324        USRREGS.  */
 325     NULL
 326   };
 327
 328 static struct regs_info myregs_info =
 329   {
 330     NULL, /* regset_bitmap */
 331     &sparc_usrregs_info,
 332     &sparc_regsets_info
 333   };
 334
 335 const regs_info *
 336 sparc_target::get_regs_info ()
 337 {
 338   return &myregs_info;
 339 }
 340
 341 struct linux_target_ops the_low_target = {
 342   0,
 343   sparc_breakpoint_at,
 344   NULL,  /* supports_z_point_type */
 345   NULL, NULL, NULL, NULL,
 346   NULL, NULL
 347 };
 348
 349 /* The linux target ops object.  */
 350
 351 linux_process_target *the_linux_target = &the_sparc_target;
 352
 353 void
 354 initialize_low_arch (void)
 355 {
 356   /* Initialize the Linux target descriptions.  */
 357   init_registers_sparc64 ();
 358
 359   initialize_regsets_info (&sparc_regsets_info);
 360 }