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 /* Each offset is multiplied by 8, because of the register size.
  46    These offsets apply to the buffer sent/filled by ptrace.
  47    Additionally, the array elements order corresponds to the .dat file, and the
  48    gdb's registers enumeration order.  */
  49
  50 static int sparc_regmap[] = {
  51   /* These offsets correspond to GET/SETREGSET.  */
  52         -1,  0*8,  1*8,  2*8,  3*8,  4*8,  5*8,  6*8,    /* g0 .. g7 */
  53         7*8,  8*8,  9*8, 10*8, 11*8, 12*8, 13*8, 14*8,   /* o0 .. o5, sp, o7 */
  54         -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,    /* l0 .. l7 */
  55         -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,    /* i0 .. i5, fp, i7 */
  56
  57   /* Floating point registers offsets correspond to GET/SETFPREGSET.  */
  58     0*4,  1*4,  2*4,  3*4,  4*4,  5*4,  6*4,  7*4,         /*  f0 ..  f7 */
  59     8*4,  9*4, 10*4, 11*4, 12*4, 13*4, 14*4, 15*4,         /*  f8 .. f15 */
  60    16*4, 17*4, 18*4, 19*4, 20*4, 21*4, 22*4, 23*4,         /* f16 .. f23 */
  61    24*4, 25*4, 26*4, 27*4, 28*4, 29*4, 30*4, 31*4,         /* f24 .. f31 */
  62
  63   /* F32 offset starts next to f31: 31*4+4 = 16 * 8.  */
  64    16*8, 17*8, 18*8, 19*8, 20*8, 21*8, 22*8, 23*8,         /* f32 .. f46 */
  65    24*8, 25*8, 26*8, 27*8, 28*8, 29*8, 30*8, 31*8,         /* f48 .. f62 */
  66
  67    17 *8, /*    pc */
  68    18 *8, /*   npc */
  69    16 *8, /* state */
  70   /* FSR offset also corresponds to GET/SETFPREGSET, ans is placed
  71      next to f62.  */
  72    32 *8, /*   fsr */
  73       -1, /*  fprs */
  74   /* Y register is 32-bits length, but gdb takes care of that.  */
  75    19 *8, /*     y */
  76
  77 };
  78
  79
  80 struct regs_range_t
  81 {
  82   int regno_start;
  83   int regno_end;
  84 };
  85
  86 static const struct regs_range_t gregs_ranges[] = {
  87  {  0, 31 }, /*   g0 .. i7  */
  88  { 80, 82 }, /*   pc .. state */
  89  { 84, 85 }  /* fprs .. y */
  90 };
  91
  92 #define N_GREGS_RANGES (sizeof (gregs_ranges) / sizeof (struct regs_range_t))
  93
  94 static const struct regs_range_t fpregs_ranges[] = {
  95  { 32, 79 }, /* f0 .. f62  */
  96  { 83, 83 }  /* fsr */
  97 };
  98
  99 #define N_FPREGS_RANGES (sizeof (fpregs_ranges) / sizeof (struct regs_range_t))
 100
 101 /* Defined in auto-generated file reg-sparc64.c.  */
 102 void init_registers_sparc64 (void);
 103 extern const struct target_desc *tdesc_sparc64;
 104
 105 static int
 106 sparc_cannot_store_register (int regno)
 107 {
 108   return (regno >= sparc_num_regs || sparc_regmap[regno] == -1);
 109 }
 110
 111 static int
 112 sparc_cannot_fetch_register (int regno)
 113 {
 114   return (regno >= sparc_num_regs || sparc_regmap[regno] == -1);
 115 }
 116
 117 static void
 118 sparc_fill_gregset_to_stack (struct regcache *regcache, const void *buf)
 119 {
 120   int i;
 121   CORE_ADDR addr = 0;
 122   unsigned char tmp_reg_buf[8];
 123   const int l0_regno = find_regno (regcache->tdesc, "l0");
 124   const int i7_regno = l0_regno + 15;
 125
 126   /* These registers have to be stored in the stack.  */
 127   memcpy (&addr,
 128           ((char *) buf) + sparc_regmap[find_regno (regcache->tdesc, "sp")],
 129           sizeof (addr));
 130
 131   addr += BIAS;
 132
 133   for (i = l0_regno; i <= i7_regno; i++)
 134     {
 135       collect_register (regcache, i, tmp_reg_buf);
 136       the_target->pt->write_memory (addr, tmp_reg_buf, sizeof (tmp_reg_buf));
 137       addr += sizeof (tmp_reg_buf);
 138     }
 139 }
 140
 141 static void
 142 sparc_fill_gregset (struct regcache *regcache, void *buf)
 143 {
 144   int i;
 145   int range;
 146
 147   for (range = 0; range < N_GREGS_RANGES; range++)
 148     for (i = gregs_ranges[range].regno_start;
 149          i <= gregs_ranges[range].regno_end; i++)
 150       if (sparc_regmap[i] != -1)
 151         collect_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
 152
 153   sparc_fill_gregset_to_stack (regcache, buf);
 154 }
 155
 156 static void
 157 sparc_fill_fpregset (struct regcache *regcache, void *buf)
 158 {
 159   int i;
 160   int range;
 161
 162   for (range = 0; range < N_FPREGS_RANGES; range++)
 163     for (i = fpregs_ranges[range].regno_start;
 164          i <= fpregs_ranges[range].regno_end; i++)
 165       collect_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
 166
 167 }
 168
 169 static void
 170 sparc_store_gregset_from_stack (struct regcache *regcache, const void *buf)
 171 {
 172   int i;
 173   CORE_ADDR addr = 0;
 174   unsigned char tmp_reg_buf[8];
 175   const int l0_regno = find_regno (regcache->tdesc, "l0");
 176   const int i7_regno = l0_regno + 15;
 177
 178   /* These registers have to be obtained from the stack.  */
 179   memcpy (&addr,
 180           ((char *) buf) + sparc_regmap[find_regno (regcache->tdesc, "sp")],
 181           sizeof (addr));
 182
 183   addr += BIAS;
 184
 185   for (i = l0_regno; i <= i7_regno; i++)
 186     {
 187       the_target->pt->read_memory (addr, tmp_reg_buf, sizeof (tmp_reg_buf));
 188       supply_register (regcache, i, tmp_reg_buf);
 189       addr += sizeof (tmp_reg_buf);
 190     }
 191 }
 192
 193 static void
 194 sparc_store_gregset (struct regcache *regcache, const void *buf)
 195 {
 196   int i;
 197   char zerobuf[8];
 198   int range;
 199
 200   memset (zerobuf, 0, sizeof (zerobuf));
 201
 202   for (range = 0; range < N_GREGS_RANGES; range++)
 203     for (i = gregs_ranges[range].regno_start;
 204          i <= gregs_ranges[range].regno_end; i++)
 205       if (sparc_regmap[i] != -1)
 206         supply_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
 207       else
 208         supply_register (regcache, i, zerobuf);
 209
 210   sparc_store_gregset_from_stack (regcache, buf);
 211 }
 212
 213 static void
 214 sparc_store_fpregset (struct regcache *regcache, const void *buf)
 215 {
 216   int i;
 217   int range;
 218
 219   for (range = 0; range < N_FPREGS_RANGES; range++)
 220     for (i = fpregs_ranges[range].regno_start;
 221          i <= fpregs_ranges[range].regno_end;
 222          i++)
 223       supply_register (regcache, i, ((char *) buf) + sparc_regmap[i]);
 224 }
 225
 226 static const gdb_byte sparc_breakpoint[INSN_SIZE] = {
 227   0x91, 0xd0, 0x20, 0x01
 228 };
 229 #define sparc_breakpoint_len INSN_SIZE
 230
 231 /* Implementation of linux_target_ops method "sw_breakpoint_from_kind".  */
 232
 233 static const unsigned char *
 234 sparc_sw_breakpoint_from_kind (int kind, int *size)
 235 {
 236   *size = sparc_breakpoint_len;
 237   return sparc_breakpoint;
 238 }
 239
 240 static int
 241 sparc_breakpoint_at (CORE_ADDR where)
 242 {
 243   unsigned char insn[INSN_SIZE];
 244
 245   the_target->pt->read_memory (where, (unsigned char *) insn, sizeof (insn));
 246
 247   if (memcmp (sparc_breakpoint, insn, sizeof (insn)) == 0)
 248     return 1;
 249
 250   /* If necessary, recognize more trap instructions here.  GDB only
 251      uses TRAP Always.  */
 252
 253   return 0;
 254 }
 255
 256 static void
 257 sparc_arch_setup (void)
 258 {
 259   current_process ()->tdesc = tdesc_sparc64;
 260 }
 261
 262 static struct regset_info sparc_regsets[] = {
 263   { PTRACE_GETREGS, PTRACE_SETREGS, 0, sizeof (elf_gregset_t),
 264     GENERAL_REGS,
 265     sparc_fill_gregset, sparc_store_gregset },
 266   { PTRACE_GETFPREGS, PTRACE_SETFPREGS, 0, sizeof (fpregset_t),
 267     FP_REGS,
 268     sparc_fill_fpregset, sparc_store_fpregset },
 269   NULL_REGSET
 270 };
 271
 272 static struct regsets_info sparc_regsets_info =
 273   {
 274     sparc_regsets, /* regsets */
 275     0, /* num_regsets */
 276     NULL, /* disabled_regsets */
 277   };
 278
 279 static struct usrregs_info sparc_usrregs_info =
 280   {
 281     sparc_num_regs,
 282     /* No regmap needs to be provided since this impl. doesn't use
 283        USRREGS.  */
 284     NULL
 285   };
 286
 287 static struct regs_info regs_info =
 288   {
 289     NULL, /* regset_bitmap */
 290     &sparc_usrregs_info,
 291     &sparc_regsets_info
 292   };
 293
 294 static const struct regs_info *
 295 sparc_regs_info (void)
 296 {
 297   return &regs_info;
 298 }
 299
 300 struct linux_target_ops the_low_target = {
 301   sparc_arch_setup,
 302   sparc_regs_info,
 303   sparc_cannot_fetch_register,
 304   sparc_cannot_store_register,
 305   NULL, /* fetch_register */
 306   linux_get_pc_64bit,
 307   /* No sparc_set_pc is needed.  */
 308   NULL,
 309   NULL, /* breakpoint_kind_from_pc */
 310   sparc_sw_breakpoint_from_kind,
 311   NULL, /* get_next_pcs */
 312   0,
 313   sparc_breakpoint_at,
 314   NULL,  /* supports_z_point_type */
 315   NULL, NULL, NULL, NULL,
 316   NULL, NULL
 317 };
 318
 319 void
 320 initialize_low_arch (void)
 321 {
 322   /* Initialize the Linux target descriptions.  */
 323   init_registers_sparc64 ();
 324
 325   initialize_regsets_info (&sparc_regsets_info);
 326 }