gdb/xtensa-linux-nat.c

   1 /* Xtensa GNU/Linux native support.
   2
   3    Copyright (C) 2007-2020 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "frame.h"
  22 #include "inferior.h"
  23 #include "gdbcore.h"
  24 #include "regcache.h"
  25 #include "target.h"
  26 #include "linux-nat.h"
  27 #include <sys/types.h>
  28 #include <signal.h>
  29 #include <sys/user.h>
  30 #include <sys/ioctl.h>
  31 #include "gdbsupport/gdb_wait.h"
  32 #include <fcntl.h>
  33 #include <sys/procfs.h>
  34 #include "nat/gdb_ptrace.h"
  35 #include <asm/ptrace.h>
  36
  37 #include "gregset.h"
  38 #include "xtensa-tdep.h"
  39
  40 /* Defines ps_err_e, struct ps_prochandle.  */
  41 #include "gdb_proc_service.h"
  42
  43 /* Extended register set depends on hardware configs.
  44    Keeping these definitions separately allows to introduce
  45    hardware-specific overlays.  */
  46 #include "xtensa-xtregs.c"
  47
  48 class xtensa_linux_nat_target final : public linux_nat_target
  49 {
  50 public:
  51   /* Add our register access methods.  */
  52   void fetch_registers (struct regcache *, int) override;
  53   void store_registers (struct regcache *, int) override;
  54 };
  55
  56 static xtensa_linux_nat_target the_xtensa_linux_nat_target;
  57
  58 void
  59 fill_gregset (const struct regcache *regcache,
  60               gdb_gregset_t *gregsetp, int regnum)
  61 {
  62   int i;
  63   xtensa_elf_gregset_t *regs = (xtensa_elf_gregset_t *) gregsetp;
  64   struct gdbarch *gdbarch = regcache->arch ();
  65
  66   if (regnum == gdbarch_pc_regnum (gdbarch) || regnum == -1)
  67     regcache->raw_collect (gdbarch_pc_regnum (gdbarch), &regs->pc);
  68   if (regnum == gdbarch_ps_regnum (gdbarch) || regnum == -1)
  69     regcache->raw_collect (gdbarch_ps_regnum (gdbarch), &regs->ps);
  70
  71   if (regnum == gdbarch_tdep (gdbarch)->wb_regnum || regnum == -1)
  72     regcache->raw_collect (gdbarch_tdep (gdbarch)->wb_regnum,
  73                            &regs->windowbase);
  74   if (regnum == gdbarch_tdep (gdbarch)->ws_regnum || regnum == -1)
  75     regcache->raw_collect (gdbarch_tdep (gdbarch)->ws_regnum,
  76                            &regs->windowstart);
  77   if (regnum == gdbarch_tdep (gdbarch)->lbeg_regnum || regnum == -1)
  78     regcache->raw_collect (gdbarch_tdep (gdbarch)->lbeg_regnum,
  79                            &regs->lbeg);
  80   if (regnum == gdbarch_tdep (gdbarch)->lend_regnum || regnum == -1)
  81     regcache->raw_collect (gdbarch_tdep (gdbarch)->lend_regnum,
  82                            &regs->lend);
  83   if (regnum == gdbarch_tdep (gdbarch)->lcount_regnum || regnum == -1)
  84     regcache->raw_collect (gdbarch_tdep (gdbarch)->lcount_regnum,
  85                            &regs->lcount);
  86   if (regnum == gdbarch_tdep (gdbarch)->sar_regnum || regnum == -1)
  87     regcache->raw_collect (gdbarch_tdep (gdbarch)->sar_regnum,
  88                            &regs->sar);
  89   if (regnum == gdbarch_tdep (gdbarch)->threadptr_regnum || regnum == -1)
  90     regcache->raw_collect (gdbarch_tdep (gdbarch)->threadptr_regnum,
  91                            &regs->threadptr);
  92   if (regnum >=gdbarch_tdep (gdbarch)->ar_base
  93       && regnum < gdbarch_tdep (gdbarch)->ar_base
  94                     + gdbarch_tdep (gdbarch)->num_aregs)
  95     regcache->raw_collect (regnum,
  96                            &regs->ar[regnum - gdbarch_tdep (gdbarch)->ar_base]);
  97   else if (regnum == -1)
  98     {
  99       for (i = 0; i < gdbarch_tdep (gdbarch)->num_aregs; ++i)
 100         regcache->raw_collect (gdbarch_tdep (gdbarch)->ar_base + i,
 101                                &regs->ar[i]);
 102     }
 103   if (regnum >= gdbarch_tdep (gdbarch)->a0_base
 104       && regnum < gdbarch_tdep (gdbarch)->a0_base + C0_NREGS)
 105     regcache->raw_collect (regnum,
 106                            &regs->ar[(4 * regs->windowbase + regnum
 107                                       - gdbarch_tdep (gdbarch)->a0_base)
 108                           % gdbarch_tdep (gdbarch)->num_aregs]);
 109   else if (regnum == -1)
 110     {
 111       for (i = 0; i < C0_NREGS; ++i)
 112         regcache->raw_collect (gdbarch_tdep (gdbarch)->a0_base + i,
 113                                (&regs->ar[(4 * regs->windowbase + i)
 114                                 % gdbarch_tdep (gdbarch)->num_aregs]));
 115     }
 116 }
 117
 118 static void
 119 supply_gregset_reg (struct regcache *regcache,
 120                     const gdb_gregset_t *gregsetp, int regnum)
 121 {
 122   int i;
 123   xtensa_elf_gregset_t *regs = (xtensa_elf_gregset_t *) gregsetp;
 124
 125   struct gdbarch *gdbarch = regcache->arch ();
 126
 127   if (regnum == gdbarch_pc_regnum (gdbarch) || regnum == -1)
 128     regcache->raw_supply (gdbarch_pc_regnum (gdbarch), &regs->pc);
 129   if (regnum == gdbarch_ps_regnum (gdbarch) || regnum == -1)
 130     regcache->raw_supply (gdbarch_ps_regnum (gdbarch), &regs->ps);
 131
 132   if (regnum == gdbarch_tdep (gdbarch)->wb_regnum || regnum == -1)
 133     regcache->raw_supply (gdbarch_tdep (gdbarch)->wb_regnum,
 134                           &regs->windowbase);
 135   if (regnum == gdbarch_tdep (gdbarch)->ws_regnum || regnum == -1)
 136     regcache->raw_supply (gdbarch_tdep (gdbarch)->ws_regnum,
 137                           &regs->windowstart);
 138   if (regnum == gdbarch_tdep (gdbarch)->lbeg_regnum || regnum == -1)
 139     regcache->raw_supply (gdbarch_tdep (gdbarch)->lbeg_regnum,
 140                           &regs->lbeg);
 141   if (regnum == gdbarch_tdep (gdbarch)->lend_regnum || regnum == -1)
 142     regcache->raw_supply (gdbarch_tdep (gdbarch)->lend_regnum,
 143                           &regs->lend);
 144   if (regnum == gdbarch_tdep (gdbarch)->lcount_regnum || regnum == -1)
 145     regcache->raw_supply (gdbarch_tdep (gdbarch)->lcount_regnum,
 146                           &regs->lcount);
 147   if (regnum == gdbarch_tdep (gdbarch)->sar_regnum || regnum == -1)
 148     regcache->raw_supply (gdbarch_tdep (gdbarch)->sar_regnum,
 149                           &regs->sar);
 150   if (regnum == gdbarch_tdep (gdbarch)->threadptr_regnum || regnum == -1)
 151     regcache->raw_supply (gdbarch_tdep (gdbarch)->threadptr_regnum,
 152                           &regs->threadptr);
 153   if (regnum >=gdbarch_tdep (gdbarch)->ar_base
 154       && regnum < gdbarch_tdep (gdbarch)->ar_base
 155                     + gdbarch_tdep (gdbarch)->num_aregs)
 156     regcache->raw_supply (regnum,
 157                           &regs->ar[regnum - gdbarch_tdep (gdbarch)->ar_base]);
 158   else if (regnum == -1)
 159     {
 160       for (i = 0; i < gdbarch_tdep (gdbarch)->num_aregs; ++i)
 161         regcache->raw_supply (gdbarch_tdep (gdbarch)->ar_base + i,
 162                               &regs->ar[i]);
 163     }
 164   if (regnum >= gdbarch_tdep (gdbarch)->a0_base
 165       && regnum < gdbarch_tdep (gdbarch)->a0_base + C0_NREGS)
 166     regcache->raw_supply (regnum,
 167                           &regs->ar[(4 * regs->windowbase + regnum
 168                                      - gdbarch_tdep (gdbarch)->a0_base)
 169                          % gdbarch_tdep (gdbarch)->num_aregs]);
 170   else if (regnum == -1)
 171     {
 172       for (i = 0; i < C0_NREGS; ++i)
 173         regcache->raw_supply (gdbarch_tdep (gdbarch)->a0_base + i,
 174                               &regs->ar[(4 * regs->windowbase + i)
 175                                         % gdbarch_tdep (gdbarch)->num_aregs]);
 176     }
 177 }
 178
 179 void
 180 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregsetp)
 181 {
 182   supply_gregset_reg (regcache, gregsetp, -1);
 183 }
 184
 185 void
 186 fill_fpregset (const struct regcache *regcache,
 187                gdb_fpregset_t *fpregsetp, int regnum)
 188 {
 189   return;
 190 }
 191
 192 void
 193 supply_fpregset (struct regcache *regcache,
 194                  const gdb_fpregset_t *fpregsetp)
 195 {
 196   return;
 197 }
 198
 199 /* Fetch greg-register(s) from process/thread TID
 200    and store value(s) in GDB's register array.  */
 201
 202 static void
 203 fetch_gregs (struct regcache *regcache, int regnum)
 204 {
 205   int tid = regcache->ptid ().lwp ();
 206   gdb_gregset_t regs;
 207   int areg;
 208
 209   if (ptrace (PTRACE_GETREGS, tid, 0, (long) &regs) < 0)
 210     {
 211       perror_with_name (_("Couldn't get registers"));
 212       return;
 213     }
 214
 215   supply_gregset_reg (regcache, &regs, regnum);
 216 }
 217
 218 /* Store greg-register(s) in GDB's register
 219    array into the process/thread specified by TID.  */
 220
 221 static void
 222 store_gregs (struct regcache *regcache, int regnum)
 223 {
 224   int tid = regcache->ptid ().lwp ();
 225   gdb_gregset_t regs;
 226   int areg;
 227
 228   if (ptrace (PTRACE_GETREGS, tid, 0, (long) &regs) < 0)
 229     {
 230       perror_with_name (_("Couldn't get registers"));
 231       return;
 232     }
 233
 234   fill_gregset (regcache, &regs, regnum);
 235
 236   if (ptrace (PTRACE_SETREGS, tid, 0, (long) &regs) < 0)
 237     {
 238       perror_with_name (_("Couldn't write registers"));
 239       return;
 240     }
 241 }
 242
 243 static int xtreg_lo;
 244 static int xtreg_high;
 245
 246 /* Fetch/Store Xtensa TIE registers.  Xtensa GNU/Linux PTRACE
 247    interface provides special requests for this.  */
 248
 249 static void
 250 fetch_xtregs (struct regcache *regcache, int regnum)
 251 {
 252   int tid = regcache->ptid ().lwp ();
 253   const xtensa_regtable_t *ptr;
 254   char xtregs [XTENSA_ELF_XTREG_SIZE];
 255
 256   if (ptrace (PTRACE_GETXTREGS, tid, 0, (long)&xtregs) < 0)
 257     perror_with_name (_("Couldn't get extended registers"));
 258
 259   for (ptr = xtensa_regmap_table; ptr->name; ptr++)
 260     if (regnum == ptr->gdb_regnum || regnum == -1)
 261       regcache->raw_supply (ptr->gdb_regnum, xtregs + ptr->ptrace_offset);
 262 }
 263
 264 static void
 265 store_xtregs (struct regcache *regcache, int regnum)
 266 {
 267   int tid = regcache->ptid ().lwp ();
 268   const xtensa_regtable_t *ptr;
 269   char xtregs [XTENSA_ELF_XTREG_SIZE];
 270
 271   if (ptrace (PTRACE_GETXTREGS, tid, 0, (long)&xtregs) < 0)
 272     perror_with_name (_("Couldn't get extended registers"));
 273
 274   for (ptr = xtensa_regmap_table; ptr->name; ptr++)
 275     if (regnum == ptr->gdb_regnum || regnum == -1)
 276       regcache->raw_collect (ptr->gdb_regnum, xtregs + ptr->ptrace_offset);
 277
 278   if (ptrace (PTRACE_SETXTREGS, tid, 0, (long)&xtregs) < 0)
 279     perror_with_name (_("Couldn't write extended registers"));
 280 }
 281
 282 void
 283 xtensa_linux_nat_target::fetch_registers (struct regcache *regcache,
 284                                           int regnum)
 285 {
 286   if (regnum == -1)
 287     {
 288       fetch_gregs (regcache, regnum);
 289       fetch_xtregs (regcache, regnum);
 290     }
 291   else if ((regnum < xtreg_lo) || (regnum > xtreg_high))
 292     fetch_gregs (regcache, regnum);
 293   else
 294     fetch_xtregs (regcache, regnum);
 295 }
 296
 297 void
 298 xtensa_linux_nat_target::store_registers (struct regcache *regcache,
 299                                           int regnum)
 300 {
 301   if (regnum == -1)
 302     {
 303       store_gregs (regcache, regnum);
 304       store_xtregs (regcache, regnum);
 305     }
 306   else if ((regnum < xtreg_lo) || (regnum > xtreg_high))
 307     store_gregs (regcache, regnum);
 308   else
 309     store_xtregs (regcache, regnum);
 310 }
 311
 312 /* Called by libthread_db.  */
 313
 314 ps_err_e
 315 ps_get_thread_area (struct ps_prochandle *ph,
 316                     lwpid_t lwpid, int idx, void **base)
 317 {
 318   xtensa_elf_gregset_t regs;
 319
 320   if (ptrace (PTRACE_GETREGS, lwpid, NULL, &regs) != 0)
 321     return PS_ERR;
 322
 323   /* IDX is the bias from the thread pointer to the beginning of the
 324      thread descriptor.  It has to be subtracted due to implementation
 325      quirks in libthread_db.  */
 326   *base = (void *) ((char *) regs.threadptr - idx);
 327
 328   return PS_OK;
 329 }
 330
 331 void _initialize_xtensa_linux_nat ();
 332 void
 333 _initialize_xtensa_linux_nat ()
 334 {
 335   const xtensa_regtable_t *ptr;
 336
 337   /* Calculate the number range for extended registers.  */
 338   xtreg_lo = 1000000000;
 339   xtreg_high = -1;
 340   for (ptr = xtensa_regmap_table; ptr->name; ptr++)
 341     {
 342       if (ptr->gdb_regnum < xtreg_lo)
 343         xtreg_lo = ptr->gdb_regnum;
 344       if (ptr->gdb_regnum > xtreg_high)
 345         xtreg_high = ptr->gdb_regnum;
 346     }
 347
 348   linux_target = &the_xtensa_linux_nat_target;
 349   add_inf_child_target (&the_xtensa_linux_nat_target);
 350 }