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