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 protected:
  54
  55   void low_arch_setup () override;
  56
  57   bool low_cannot_fetch_register (int regno) override;
  58
  59   bool low_cannot_store_register (int regno) override;
  60
  61   bool low_supports_breakpoints () override;
  62
  63   CORE_ADDR low_get_pc (regcache *regcache) override;
  64
  65   /* No low_set_pc is needed.  */
  66 };
  67
  68 /* The singleton target ops object.  */
  69
  70 static sparc_target the_sparc_target;
  71
  72 bool
  73 sparc_target::low_supports_breakpoints ()
  74 {
  75   return true;
  76 }
  77
  78 CORE_ADDR
  79 sparc_target::low_get_pc (regcache *regcache)
  80 {
  81   return linux_get_pc_64bit (regcache);
  82 }
  83
  84 /* Each offset is multiplied by 8, because of the register size.
  85    These offsets apply to the buffer sent/filled by ptrace.
  86    Additionally, the array elements order corresponds to the .dat file, and the
  87    gdb's registers enumeration order.  */
  88
  89 static int sparc_regmap[] = {
  90   /* These offsets correspond to GET/SETREGSET.  */
  91         -1,  0*8,  1*8,  2*8,  3*8,  4*8,  5*8,  6*8,    /* g0 .. g7 */
  92         7*8,  8*8,  9*8, 10*8, 11*8, 12*8, 13*8, 14*8,   /* o0 .. o5, sp, o7 */
  93         -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,    /* l0 .. l7 */
  94         -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,    /* i0 .. i5, fp, i7 */
  95
  96   /* Floating point registers offsets correspond to GET/SETFPREGSET.  */
  97     0*4,  1*4,  2*4,  3*4,  4*4,  5*4,  6*4,  7*4,         /*  f0 ..  f7 */
  98     8*4,  9*4, 10*4, 11*4, 12*4, 13*4, 14*4, 15*4,         /*  f8 .. f15 */
  99    16*4, 17*4, 18*4, 19*4, 20*4, 21*4, 22*4, 23*4,         /* f16 .. f23 */
 100    24*4, 25*4, 26*4, 27*4, 28*4, 29*4, 30*4, 31*4,         /* f24 .. f31 */
 101
 102   /* F32 offset starts next to f31: 31*4+4 = 16 * 8.  */
 103    16*8, 17*8, 18*8, 19*8, 20*8, 21*8, 22*8, 23*8,         /* f32 .. f46 */
 104    24*8, 25*8, 26*8, 27*8, 28*8, 29*8, 30*8, 31*8,         /* f48 .. f62 */
 105
 106    17 *8, /*    pc */
 107    18 *8, /*   npc */
 108    16 *8, /* state */
 109   /* FSR offset also corresponds to GET/SETFPREGSET, ans is placed
 110      next to f62.  */
 111    32 *8, /*   fsr */
 112       -1, /*  fprs */
 113   /* Y register is 32-bits length, but gdb takes care of that.  */
 114    19 *8, /*     y */
 115
 116 };
 117
 118
 119 struct regs_range_t
 120 {
 121   int regno_start;
 122   int regno_end;
 123 };
 124
 125 static const struct regs_range_t gregs_ranges[] = {
 126  {  0, 31 }, /*   g0 .. i7  */
 127  { 80, 82 }, /*   pc .. state */
 128  { 84, 85 }  /* fprs .. y */
 129 };
 130
 131 #define N_GREGS_RANGES (sizeof (gregs_ranges) / sizeof (struct regs_range_t))
 132
 133 static const struct regs_range_t fpregs_ranges[] = {
 134  { 32, 79 }, /* f0 .. f62  */
 135  { 83, 83 }  /* fsr */
 136 };
 137
 138 #define N_FPREGS_RANGES (sizeof (fpregs_ranges) / sizeof (struct regs_range_t))
 139
 140 /* Defined in auto-generated file reg-sparc64.c.  */
 141 void init_registers_sparc64 (void);
 142 extern const struct target_desc *tdesc_sparc64;
 143
 144 bool
 145 sparc_target::low_cannot_store_register (int regno)
 146 {
 147   return (regno >= sparc_num_regs || sparc_regmap[regno] == -1);
 148 }
 149
 150 bool
 151 sparc_target::low_cannot_fetch_register (int regno)
 152 {
 153   return (regno >= sparc_num_regs || sparc_regmap[regno] == -1);
 154 }
 155
 156 static void
 157 sparc_fill_gregset_to_stack (struct regcache *regcache, const void *buf)
 158 {
 159   int i;
 160   CORE_ADDR addr = 0;
 161   unsigned char tmp_reg_buf[8];
 162   const int l0_regno = find_regno (regcache->tdesc, "l0");
 163   const int i7_regno = l0_regno + 15;
 164
 165   /* These registers have to be stored in the stack.  */
 166   memcpy (&addr,
 167           ((char *) buf) + sparc_regmap[find_regno (regcache->tdesc, "sp")],
 168           sizeof (addr));
 169
 170   addr += BIAS;
 171
 172   for (i = l0_regno; i <= i7_regno; i++)
 173     {
 174       collect_register (regcache, i, tmp_reg_buf);
 175       the_target->write_memory (addr, tmp_reg_buf, sizeof (tmp_reg_buf));
 176       addr += sizeof (tmp_reg_buf);
 177     }
 178 }
 179
 180 static void
 181 sparc_fill_gregset (struct regcache *regcache, void *buf)
 182 {
 183   int i;
 184   int range;
 185
 186   for (range = 0; range < N_GREGS_RANGES; range++)
 187     for (i = gregs_ranges[range].regno_start;
 188          i <= gregs_ranges[range].regno_end; i++)
 189       if (sparc_regmap[i] != -1)
 190         collect_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
 191
 192   sparc_fill_gregset_to_stack (regcache, buf);
 193 }
 194
 195 static void
 196 sparc_fill_fpregset (struct regcache *regcache, void *buf)
 197 {
 198   int i;
 199   int range;
 200
 201   for (range = 0; range < N_FPREGS_RANGES; range++)
 202     for (i = fpregs_ranges[range].regno_start;
 203          i <= fpregs_ranges[range].regno_end; i++)
 204       collect_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
 205
 206 }
 207
 208 static void
 209 sparc_store_gregset_from_stack (struct regcache *regcache, const void *buf)
 210 {
 211   int i;
 212   CORE_ADDR addr = 0;
 213   unsigned char tmp_reg_buf[8];
 214   const int l0_regno = find_regno (regcache->tdesc, "l0");
 215   const int i7_regno = l0_regno + 15;
 216
 217   /* These registers have to be obtained from the stack.  */
 218   memcpy (&addr,
 219           ((char *) buf) + sparc_regmap[find_regno (regcache->tdesc, "sp")],
 220           sizeof (addr));
 221
 222   addr += BIAS;
 223
 224   for (i = l0_regno; i <= i7_regno; i++)
 225     {
 226       the_target->read_memory (addr, tmp_reg_buf, sizeof (tmp_reg_buf));
 227       supply_register (regcache, i, tmp_reg_buf);
 228       addr += sizeof (tmp_reg_buf);
 229     }
 230 }
 231
 232 static void
 233 sparc_store_gregset (struct regcache *regcache, const void *buf)
 234 {
 235   int i;
 236   char zerobuf[8];
 237   int range;
 238
 239   memset (zerobuf, 0, sizeof (zerobuf));
 240
 241   for (range = 0; range < N_GREGS_RANGES; range++)
 242     for (i = gregs_ranges[range].regno_start;
 243          i <= gregs_ranges[range].regno_end; i++)
 244       if (sparc_regmap[i] != -1)
 245         supply_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
 246       else
 247         supply_register (regcache, i, zerobuf);
 248
 249   sparc_store_gregset_from_stack (regcache, buf);
 250 }
 251
 252 static void
 253 sparc_store_fpregset (struct regcache *regcache, const void *buf)
 254 {
 255   int i;
 256   int range;
 257
 258   for (range = 0; range < N_FPREGS_RANGES; range++)
 259     for (i = fpregs_ranges[range].regno_start;
 260          i <= fpregs_ranges[range].regno_end;
 261          i++)
 262       supply_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
 263 }
 264
 265 static const gdb_byte sparc_breakpoint[INSN_SIZE] = {
 266   0x91, 0xd0, 0x20, 0x01
 267 };
 268 #define sparc_breakpoint_len INSN_SIZE
 269
 270 /* Implementation of linux_target_ops method "sw_breakpoint_from_kind".  */
 271
 272 static const unsigned char *
 273 sparc_sw_breakpoint_from_kind (int kind, int *size)
 274 {
 275   *size = sparc_breakpoint_len;
 276   return sparc_breakpoint;
 277 }
 278
 279 static int
 280 sparc_breakpoint_at (CORE_ADDR where)
 281 {
 282   unsigned char insn[INSN_SIZE];
 283
 284   the_target->read_memory (where, (unsigned char *) insn, sizeof (insn));
 285
 286   if (memcmp (sparc_breakpoint, insn, sizeof (insn)) == 0)
 287     return 1;
 288
 289   /* If necessary, recognize more trap instructions here.  GDB only
 290      uses TRAP Always.  */
 291
 292   return 0;
 293 }
 294
 295 void
 296 sparc_target::low_arch_setup ()
 297 {
 298   current_process ()->tdesc = tdesc_sparc64;
 299 }
 300
 301 static struct regset_info sparc_regsets[] = {
 302   { PTRACE_GETREGS, PTRACE_SETREGS, 0, sizeof (elf_gregset_t),
 303     GENERAL_REGS,
 304     sparc_fill_gregset, sparc_store_gregset },
 305   { PTRACE_GETFPREGS, PTRACE_SETFPREGS, 0, sizeof (fpregset_t),
 306     FP_REGS,
 307     sparc_fill_fpregset, sparc_store_fpregset },
 308   NULL_REGSET
 309 };
 310
 311 static struct regsets_info sparc_regsets_info =
 312   {
 313     sparc_regsets, /* regsets */
 314     0, /* num_regsets */
 315     NULL, /* disabled_regsets */
 316   };
 317
 318 static struct usrregs_info sparc_usrregs_info =
 319   {
 320     sparc_num_regs,
 321     /* No regmap needs to be provided since this impl. doesn't use
 322        USRREGS.  */
 323     NULL
 324   };
 325
 326 static struct regs_info myregs_info =
 327   {
 328     NULL, /* regset_bitmap */
 329     &sparc_usrregs_info,
 330     &sparc_regsets_info
 331   };
 332
 333 const regs_info *
 334 sparc_target::get_regs_info ()
 335 {
 336   return &myregs_info;
 337 }
 338
 339 struct linux_target_ops the_low_target = {
 340   NULL, /* breakpoint_kind_from_pc */
 341   sparc_sw_breakpoint_from_kind,
 342   NULL, /* get_next_pcs */
 343   0,
 344   sparc_breakpoint_at,
 345   NULL,  /* supports_z_point_type */
 346   NULL, NULL, NULL, NULL,
 347   NULL, NULL
 348 };
 349
 350 /* The linux target ops object.  */
 351
 352 linux_process_target *the_linux_target = &the_sparc_target;
 353
 354 void
 355 initialize_low_arch (void)
 356 {
 357   /* Initialize the Linux target descriptions.  */
 358   init_registers_sparc64 ();
 359
 360   initialize_regsets_info (&sparc_regsets_info);
 361 }