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