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 protected:
  52
  53   void low_arch_setup () override;
  54 };
  55
  56 /* The singleton target ops object.  */
  57
  58 static sparc_target the_sparc_target;
  59
  60 /* Each offset is multiplied by 8, because of the register size.
  61    These offsets apply to the buffer sent/filled by ptrace.
  62    Additionally, the array elements order corresponds to the .dat file, and the
  63    gdb's registers enumeration order.  */
  64
  65 static int sparc_regmap[] = {
  66   /* These offsets correspond to GET/SETREGSET.  */
  67         -1,  0*8,  1*8,  2*8,  3*8,  4*8,  5*8,  6*8,    /* g0 .. g7 */
  68         7*8,  8*8,  9*8, 10*8, 11*8, 12*8, 13*8, 14*8,   /* o0 .. o5, sp, o7 */
  69         -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,    /* l0 .. l7 */
  70         -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,    /* i0 .. i5, fp, i7 */
  71
  72   /* Floating point registers offsets correspond to GET/SETFPREGSET.  */
  73     0*4,  1*4,  2*4,  3*4,  4*4,  5*4,  6*4,  7*4,         /*  f0 ..  f7 */
  74     8*4,  9*4, 10*4, 11*4, 12*4, 13*4, 14*4, 15*4,         /*  f8 .. f15 */
  75    16*4, 17*4, 18*4, 19*4, 20*4, 21*4, 22*4, 23*4,         /* f16 .. f23 */
  76    24*4, 25*4, 26*4, 27*4, 28*4, 29*4, 30*4, 31*4,         /* f24 .. f31 */
  77
  78   /* F32 offset starts next to f31: 31*4+4 = 16 * 8.  */
  79    16*8, 17*8, 18*8, 19*8, 20*8, 21*8, 22*8, 23*8,         /* f32 .. f46 */
  80    24*8, 25*8, 26*8, 27*8, 28*8, 29*8, 30*8, 31*8,         /* f48 .. f62 */
  81
  82    17 *8, /*    pc */
  83    18 *8, /*   npc */
  84    16 *8, /* state */
  85   /* FSR offset also corresponds to GET/SETFPREGSET, ans is placed
  86      next to f62.  */
  87    32 *8, /*   fsr */
  88       -1, /*  fprs */
  89   /* Y register is 32-bits length, but gdb takes care of that.  */
  90    19 *8, /*     y */
  91
  92 };
  93
  94
  95 struct regs_range_t
  96 {
  97   int regno_start;
  98   int regno_end;
  99 };
 100
 101 static const struct regs_range_t gregs_ranges[] = {
 102  {  0, 31 }, /*   g0 .. i7  */
 103  { 80, 82 }, /*   pc .. state */
 104  { 84, 85 }  /* fprs .. y */
 105 };
 106
 107 #define N_GREGS_RANGES (sizeof (gregs_ranges) / sizeof (struct regs_range_t))
 108
 109 static const struct regs_range_t fpregs_ranges[] = {
 110  { 32, 79 }, /* f0 .. f62  */
 111  { 83, 83 }  /* fsr */
 112 };
 113
 114 #define N_FPREGS_RANGES (sizeof (fpregs_ranges) / sizeof (struct regs_range_t))
 115
 116 /* Defined in auto-generated file reg-sparc64.c.  */
 117 void init_registers_sparc64 (void);
 118 extern const struct target_desc *tdesc_sparc64;
 119
 120 static int
 121 sparc_cannot_store_register (int regno)
 122 {
 123   return (regno >= sparc_num_regs || sparc_regmap[regno] == -1);
 124 }
 125
 126 static int
 127 sparc_cannot_fetch_register (int regno)
 128 {
 129   return (regno >= sparc_num_regs || sparc_regmap[regno] == -1);
 130 }
 131
 132 static void
 133 sparc_fill_gregset_to_stack (struct regcache *regcache, const void *buf)
 134 {
 135   int i;
 136   CORE_ADDR addr = 0;
 137   unsigned char tmp_reg_buf[8];
 138   const int l0_regno = find_regno (regcache->tdesc, "l0");
 139   const int i7_regno = l0_regno + 15;
 140
 141   /* These registers have to be stored in the stack.  */
 142   memcpy (&addr,
 143           ((char *) buf) + sparc_regmap[find_regno (regcache->tdesc, "sp")],
 144           sizeof (addr));
 145
 146   addr += BIAS;
 147
 148   for (i = l0_regno; i <= i7_regno; i++)
 149     {
 150       collect_register (regcache, i, tmp_reg_buf);
 151       the_target->write_memory (addr, tmp_reg_buf, sizeof (tmp_reg_buf));
 152       addr += sizeof (tmp_reg_buf);
 153     }
 154 }
 155
 156 static void
 157 sparc_fill_gregset (struct regcache *regcache, void *buf)
 158 {
 159   int i;
 160   int range;
 161
 162   for (range = 0; range < N_GREGS_RANGES; range++)
 163     for (i = gregs_ranges[range].regno_start;
 164          i <= gregs_ranges[range].regno_end; i++)
 165       if (sparc_regmap[i] != -1)
 166         collect_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
 167
 168   sparc_fill_gregset_to_stack (regcache, buf);
 169 }
 170
 171 static void
 172 sparc_fill_fpregset (struct regcache *regcache, void *buf)
 173 {
 174   int i;
 175   int range;
 176
 177   for (range = 0; range < N_FPREGS_RANGES; range++)
 178     for (i = fpregs_ranges[range].regno_start;
 179          i <= fpregs_ranges[range].regno_end; i++)
 180       collect_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
 181
 182 }
 183
 184 static void
 185 sparc_store_gregset_from_stack (struct regcache *regcache, const void *buf)
 186 {
 187   int i;
 188   CORE_ADDR addr = 0;
 189   unsigned char tmp_reg_buf[8];
 190   const int l0_regno = find_regno (regcache->tdesc, "l0");
 191   const int i7_regno = l0_regno + 15;
 192
 193   /* These registers have to be obtained from the stack.  */
 194   memcpy (&addr,
 195           ((char *) buf) + sparc_regmap[find_regno (regcache->tdesc, "sp")],
 196           sizeof (addr));
 197
 198   addr += BIAS;
 199
 200   for (i = l0_regno; i <= i7_regno; i++)
 201     {
 202       the_target->read_memory (addr, tmp_reg_buf, sizeof (tmp_reg_buf));
 203       supply_register (regcache, i, tmp_reg_buf);
 204       addr += sizeof (tmp_reg_buf);
 205     }
 206 }
 207
 208 static void
 209 sparc_store_gregset (struct regcache *regcache, const void *buf)
 210 {
 211   int i;
 212   char zerobuf[8];
 213   int range;
 214
 215   memset (zerobuf, 0, sizeof (zerobuf));
 216
 217   for (range = 0; range < N_GREGS_RANGES; range++)
 218     for (i = gregs_ranges[range].regno_start;
 219          i <= gregs_ranges[range].regno_end; i++)
 220       if (sparc_regmap[i] != -1)
 221         supply_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
 222       else
 223         supply_register (regcache, i, zerobuf);
 224
 225   sparc_store_gregset_from_stack (regcache, buf);
 226 }
 227
 228 static void
 229 sparc_store_fpregset (struct regcache *regcache, const void *buf)
 230 {
 231   int i;
 232   int range;
 233
 234   for (range = 0; range < N_FPREGS_RANGES; range++)
 235     for (i = fpregs_ranges[range].regno_start;
 236          i <= fpregs_ranges[range].regno_end;
 237          i++)
 238       supply_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
 239 }
 240
 241 static const gdb_byte sparc_breakpoint[INSN_SIZE] = {
 242   0x91, 0xd0, 0x20, 0x01
 243 };
 244 #define sparc_breakpoint_len INSN_SIZE
 245
 246 /* Implementation of linux_target_ops method "sw_breakpoint_from_kind".  */
 247
 248 static const unsigned char *
 249 sparc_sw_breakpoint_from_kind (int kind, int *size)
 250 {
 251   *size = sparc_breakpoint_len;
 252   return sparc_breakpoint;
 253 }
 254
 255 static int
 256 sparc_breakpoint_at (CORE_ADDR where)
 257 {
 258   unsigned char insn[INSN_SIZE];
 259
 260   the_target->read_memory (where, (unsigned char *) insn, sizeof (insn));
 261
 262   if (memcmp (sparc_breakpoint, insn, sizeof (insn)) == 0)
 263     return 1;
 264
 265   /* If necessary, recognize more trap instructions here.  GDB only
 266      uses TRAP Always.  */
 267
 268   return 0;
 269 }
 270
 271 void
 272 sparc_target::low_arch_setup ()
 273 {
 274   current_process ()->tdesc = tdesc_sparc64;
 275 }
 276
 277 static struct regset_info sparc_regsets[] = {
 278   { PTRACE_GETREGS, PTRACE_SETREGS, 0, sizeof (elf_gregset_t),
 279     GENERAL_REGS,
 280     sparc_fill_gregset, sparc_store_gregset },
 281   { PTRACE_GETFPREGS, PTRACE_SETFPREGS, 0, sizeof (fpregset_t),
 282     FP_REGS,
 283     sparc_fill_fpregset, sparc_store_fpregset },
 284   NULL_REGSET
 285 };
 286
 287 static struct regsets_info sparc_regsets_info =
 288   {
 289     sparc_regsets, /* regsets */
 290     0, /* num_regsets */
 291     NULL, /* disabled_regsets */
 292   };
 293
 294 static struct usrregs_info sparc_usrregs_info =
 295   {
 296     sparc_num_regs,
 297     /* No regmap needs to be provided since this impl. doesn't use
 298        USRREGS.  */
 299     NULL
 300   };
 301
 302 static struct regs_info regs_info =
 303   {
 304     NULL, /* regset_bitmap */
 305     &sparc_usrregs_info,
 306     &sparc_regsets_info
 307   };
 308
 309 static const struct regs_info *
 310 sparc_regs_info (void)
 311 {
 312   return &regs_info;
 313 }
 314
 315 struct linux_target_ops the_low_target = {
 316   sparc_regs_info,
 317   sparc_cannot_fetch_register,
 318   sparc_cannot_store_register,
 319   NULL, /* fetch_register */
 320   linux_get_pc_64bit,
 321   /* No sparc_set_pc is needed.  */
 322   NULL,
 323   NULL, /* breakpoint_kind_from_pc */
 324   sparc_sw_breakpoint_from_kind,
 325   NULL, /* get_next_pcs */
 326   0,
 327   sparc_breakpoint_at,
 328   NULL,  /* supports_z_point_type */
 329   NULL, NULL, NULL, NULL,
 330   NULL, NULL
 331 };
 332
 333 /* The linux target ops object.  */
 334
 335 linux_process_target *the_linux_target = &the_sparc_target;
 336
 337 void
 338 initialize_low_arch (void)
 339 {
 340   /* Initialize the Linux target descriptions.  */
 341   init_registers_sparc64 ();
 342
 343   initialize_regsets_info (&sparc_regsets_info);
 344 }