gdb/xtensa-linux-nat.c

   1 /* Xtensa GNU/Linux native support.
   2
   3    Copyright (C) 2007-2023 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   xtensa_gdbarch_tdep *tdep = gdbarch_tdep<xtensa_gdbarch_tdep> (gdbarch);
  66
  67   if (regnum == gdbarch_pc_regnum (gdbarch) || regnum == -1)
  68     regcache->raw_collect (gdbarch_pc_regnum (gdbarch), &regs->pc);
  69   if (regnum == gdbarch_ps_regnum (gdbarch) || regnum == -1)
  70     regcache->raw_collect (gdbarch_ps_regnum (gdbarch), &regs->ps);
  71
  72   if (regnum == tdep->wb_regnum || regnum == -1)
  73     regcache->raw_collect (tdep->wb_regnum,
  74                            &regs->windowbase);
  75   if (regnum == tdep->ws_regnum || regnum == -1)
  76     regcache->raw_collect (tdep->ws_regnum,
  77                            &regs->windowstart);
  78   if (regnum == tdep->lbeg_regnum || regnum == -1)
  79     regcache->raw_collect (tdep->lbeg_regnum,
  80                            &regs->lbeg);
  81   if (regnum == tdep->lend_regnum || regnum == -1)
  82     regcache->raw_collect (tdep->lend_regnum,
  83                            &regs->lend);
  84   if (regnum == tdep->lcount_regnum || regnum == -1)
  85     regcache->raw_collect (tdep->lcount_regnum,
  86                            &regs->lcount);
  87   if (regnum == tdep->sar_regnum || regnum == -1)
  88     regcache->raw_collect (tdep->sar_regnum,
  89                            &regs->sar);
  90   if (regnum == tdep->threadptr_regnum || regnum == -1)
  91     regcache->raw_collect (tdep->threadptr_regnum,
  92                            &regs->threadptr);
  93   if (regnum >=tdep->ar_base
  94       && regnum < tdep->ar_base
  95                     + tdep->num_aregs)
  96     regcache->raw_collect (regnum,
  97                            &regs->ar[regnum - tdep->ar_base]);
  98   else if (regnum == -1)
  99     {
 100       for (i = 0; i < tdep->num_aregs; ++i)
 101         regcache->raw_collect (tdep->ar_base + i,
 102                                &regs->ar[i]);
 103     }
 104   if (regnum >= tdep->a0_base
 105       && regnum < tdep->a0_base + C0_NREGS)
 106     regcache->raw_collect (regnum,
 107                            &regs->ar[(4 * regs->windowbase + regnum
 108                                       - tdep->a0_base)
 109                           % tdep->num_aregs]);
 110   else if (regnum == -1)
 111     {
 112       for (i = 0; i < C0_NREGS; ++i)
 113         regcache->raw_collect (tdep->a0_base + i,
 114                                (&regs->ar[(4 * regs->windowbase + i)
 115                                 % tdep->num_aregs]));
 116     }
 117 }
 118
 119 static void
 120 supply_gregset_reg (struct regcache *regcache,
 121                     const gdb_gregset_t *gregsetp, int regnum)
 122 {
 123   int i;
 124   xtensa_elf_gregset_t *regs = (xtensa_elf_gregset_t *) gregsetp;
 125
 126   struct gdbarch *gdbarch = regcache->arch ();
 127   xtensa_gdbarch_tdep *tdep = gdbarch_tdep<xtensa_gdbarch_tdep> (gdbarch);
 128
 129   if (regnum == gdbarch_pc_regnum (gdbarch) || regnum == -1)
 130     regcache->raw_supply (gdbarch_pc_regnum (gdbarch), &regs->pc);
 131   if (regnum == gdbarch_ps_regnum (gdbarch) || regnum == -1)
 132     regcache->raw_supply (gdbarch_ps_regnum (gdbarch), &regs->ps);
 133
 134   if (regnum == tdep->wb_regnum || regnum == -1)
 135     regcache->raw_supply (tdep->wb_regnum,
 136                           &regs->windowbase);
 137   if (regnum == tdep->ws_regnum || regnum == -1)
 138     regcache->raw_supply (tdep->ws_regnum,
 139                           &regs->windowstart);
 140   if (regnum == tdep->lbeg_regnum || regnum == -1)
 141     regcache->raw_supply (tdep->lbeg_regnum,
 142                           &regs->lbeg);
 143   if (regnum == tdep->lend_regnum || regnum == -1)
 144     regcache->raw_supply (tdep->lend_regnum,
 145                           &regs->lend);
 146   if (regnum == tdep->lcount_regnum || regnum == -1)
 147     regcache->raw_supply (tdep->lcount_regnum,
 148                           &regs->lcount);
 149   if (regnum == tdep->sar_regnum || regnum == -1)
 150     regcache->raw_supply (tdep->sar_regnum,
 151                           &regs->sar);
 152   if (regnum == tdep->threadptr_regnum || regnum == -1)
 153     regcache->raw_supply (tdep->threadptr_regnum,
 154                           &regs->threadptr);
 155   if (regnum >=tdep->ar_base
 156       && regnum < tdep->ar_base
 157                     + tdep->num_aregs)
 158     regcache->raw_supply (regnum,
 159                           &regs->ar[regnum - tdep->ar_base]);
 160   else if (regnum == -1)
 161     {
 162       for (i = 0; i < tdep->num_aregs; ++i)
 163         regcache->raw_supply (tdep->ar_base + i,
 164                               &regs->ar[i]);
 165     }
 166   if (regnum >= tdep->a0_base
 167       && regnum < tdep->a0_base + C0_NREGS)
 168     regcache->raw_supply (regnum,
 169                           &regs->ar[(4 * regs->windowbase + regnum
 170                                      - tdep->a0_base)
 171                          % tdep->num_aregs]);
 172   else if (regnum == -1)
 173     {
 174       for (i = 0; i < C0_NREGS; ++i)
 175         regcache->raw_supply (tdep->a0_base + i,
 176                               &regs->ar[(4 * regs->windowbase + i)
 177                                         % tdep->num_aregs]);
 178     }
 179 }
 180
 181 void
 182 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregsetp)
 183 {
 184   supply_gregset_reg (regcache, gregsetp, -1);
 185 }
 186
 187 void
 188 fill_fpregset (const struct regcache *regcache,
 189                gdb_fpregset_t *fpregsetp, int regnum)
 190 {
 191   return;
 192 }
 193
 194 void
 195 supply_fpregset (struct regcache *regcache,
 196                  const gdb_fpregset_t *fpregsetp)
 197 {
 198   return;
 199 }
 200
 201 /* Fetch greg-register(s) from process/thread TID
 202    and store value(s) in GDB's register array.  */
 203
 204 static void
 205 fetch_gregs (struct regcache *regcache, int regnum)
 206 {
 207   int tid = regcache->ptid ().lwp ();
 208   gdb_gregset_t regs;
 209
 210   if (ptrace (PTRACE_GETREGS, tid, 0, (long) &regs) < 0)
 211     {
 212       perror_with_name (_("Couldn't get registers"));
 213       return;
 214     }
 215
 216   supply_gregset_reg (regcache, &regs, regnum);
 217 }
 218
 219 /* Store greg-register(s) in GDB's register
 220    array into the process/thread specified by TID.  */
 221
 222 static void
 223 store_gregs (struct regcache *regcache, int regnum)
 224 {
 225   int tid = regcache->ptid ().lwp ();
 226   gdb_gregset_t regs;
 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 }