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