gdb/xtensa-linux-nat.c

   1 /* Xtensa GNU/Linux native support.
   2
   3    Copyright (C) 2007-2024 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 "frame.h"
  21 #include "inferior.h"
  22 #include "gdbcore.h"
  23 #include "regcache.h"
  24 #include "target.h"
  25 #include "linux-nat.h"
  26 #include <sys/types.h>
  27 #include <signal.h>
  28 #include <sys/user.h>
  29 #include <sys/ioctl.h>
  30 #include "gdbsupport/gdb_wait.h"
  31 #include <fcntl.h>
  32 #include <sys/procfs.h>
  33 #include "nat/gdb_ptrace.h"
  34 #include <asm/ptrace.h>
  35
  36 #include "gregset.h"
  37 #include "xtensa-tdep.h"
  38
  39 /* Defines ps_err_e, struct ps_prochandle.  */
  40 #include "gdb_proc_service.h"
  41
  42 /* Extended register set depends on hardware configs.
  43    Keeping these definitions separately allows to introduce
  44    hardware-specific overlays.  */
  45 #include "xtensa-xtregs.c"
  46
  47 class xtensa_linux_nat_target final : public linux_nat_target
  48 {
  49 public:
  50   /* Add our register access methods.  */
  51   void fetch_registers (struct regcache *, int) override;
  52   void store_registers (struct regcache *, int) override;
  53 };
  54
  55 static xtensa_linux_nat_target the_xtensa_linux_nat_target;
  56
  57 void
  58 fill_gregset (const struct regcache *regcache,
  59               gdb_gregset_t *gregsetp, int regnum)
  60 {
  61   int i;
  62   xtensa_elf_gregset_t *regs = (xtensa_elf_gregset_t *) gregsetp;
  63   struct gdbarch *gdbarch = regcache->arch ();
  64   xtensa_gdbarch_tdep *tdep = gdbarch_tdep<xtensa_gdbarch_tdep> (gdbarch);
  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 == tdep->wb_regnum || regnum == -1)
  72     regcache->raw_collect (tdep->wb_regnum,
  73                            &regs->windowbase);
  74   if (regnum == tdep->ws_regnum || regnum == -1)
  75     regcache->raw_collect (tdep->ws_regnum,
  76                            &regs->windowstart);
  77   if (regnum == tdep->lbeg_regnum || regnum == -1)
  78     regcache->raw_collect (tdep->lbeg_regnum,
  79                            &regs->lbeg);
  80   if (regnum == tdep->lend_regnum || regnum == -1)
  81     regcache->raw_collect (tdep->lend_regnum,
  82                            &regs->lend);
  83   if (regnum == tdep->lcount_regnum || regnum == -1)
  84     regcache->raw_collect (tdep->lcount_regnum,
  85                            &regs->lcount);
  86   if (regnum == tdep->sar_regnum || regnum == -1)
  87     regcache->raw_collect (tdep->sar_regnum,
  88                            &regs->sar);
  89   if (regnum == tdep->threadptr_regnum || regnum == -1)
  90     regcache->raw_collect (tdep->threadptr_regnum,
  91                            &regs->threadptr);
  92   if (regnum >=tdep->ar_base
  93       && regnum < tdep->ar_base
  94                     + tdep->num_aregs)
  95     regcache->raw_collect (regnum,
  96                            &regs->ar[regnum - tdep->ar_base]);
  97   else if (regnum == -1)
  98     {
  99       for (i = 0; i < tdep->num_aregs; ++i)
 100         regcache->raw_collect (tdep->ar_base + i,
 101                                &regs->ar[i]);
 102     }
 103   if (regnum >= tdep->a0_base
 104       && regnum < tdep->a0_base + C0_NREGS)
 105     regcache->raw_collect (regnum,
 106                            &regs->ar[(4 * regs->windowbase + regnum
 107                                       - tdep->a0_base)
 108                           % tdep->num_aregs]);
 109   else if (regnum == -1)
 110     {
 111       for (i = 0; i < C0_NREGS; ++i)
 112         regcache->raw_collect (tdep->a0_base + i,
 113                                (&regs->ar[(4 * regs->windowbase + i)
 114                                 % tdep->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   xtensa_gdbarch_tdep *tdep = gdbarch_tdep<xtensa_gdbarch_tdep> (gdbarch);
 127
 128   if (regnum == gdbarch_pc_regnum (gdbarch) || regnum == -1)
 129     regcache->raw_supply (gdbarch_pc_regnum (gdbarch), &regs->pc);
 130   if (regnum == gdbarch_ps_regnum (gdbarch) || regnum == -1)
 131     regcache->raw_supply (gdbarch_ps_regnum (gdbarch), &regs->ps);
 132
 133   if (regnum == tdep->wb_regnum || regnum == -1)
 134     regcache->raw_supply (tdep->wb_regnum,
 135                           &regs->windowbase);
 136   if (regnum == tdep->ws_regnum || regnum == -1)
 137     regcache->raw_supply (tdep->ws_regnum,
 138                           &regs->windowstart);
 139   if (regnum == tdep->lbeg_regnum || regnum == -1)
 140     regcache->raw_supply (tdep->lbeg_regnum,
 141                           &regs->lbeg);
 142   if (regnum == tdep->lend_regnum || regnum == -1)
 143     regcache->raw_supply (tdep->lend_regnum,
 144                           &regs->lend);
 145   if (regnum == tdep->lcount_regnum || regnum == -1)
 146     regcache->raw_supply (tdep->lcount_regnum,
 147                           &regs->lcount);
 148   if (regnum == tdep->sar_regnum || regnum == -1)
 149     regcache->raw_supply (tdep->sar_regnum,
 150                           &regs->sar);
 151   if (regnum == tdep->threadptr_regnum || regnum == -1)
 152     regcache->raw_supply (tdep->threadptr_regnum,
 153                           &regs->threadptr);
 154   if (regnum >=tdep->ar_base
 155       && regnum < tdep->ar_base
 156                     + tdep->num_aregs)
 157     regcache->raw_supply (regnum,
 158                           &regs->ar[regnum - tdep->ar_base]);
 159   else if (regnum == -1)
 160     {
 161       for (i = 0; i < tdep->num_aregs; ++i)
 162         regcache->raw_supply (tdep->ar_base + i,
 163                               &regs->ar[i]);
 164     }
 165   if (regnum >= tdep->a0_base
 166       && regnum < tdep->a0_base + C0_NREGS)
 167     regcache->raw_supply (regnum,
 168                           &regs->ar[(4 * regs->windowbase + regnum
 169                                      - tdep->a0_base)
 170                          % tdep->num_aregs]);
 171   else if (regnum == -1)
 172     {
 173       for (i = 0; i < C0_NREGS; ++i)
 174         regcache->raw_supply (tdep->a0_base + i,
 175                               &regs->ar[(4 * regs->windowbase + i)
 176                                         % tdep->num_aregs]);
 177     }
 178 }
 179
 180 void
 181 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregsetp)
 182 {
 183   supply_gregset_reg (regcache, gregsetp, -1);
 184 }
 185
 186 void
 187 fill_fpregset (const struct regcache *regcache,
 188                gdb_fpregset_t *fpregsetp, int regnum)
 189 {
 190   return;
 191 }
 192
 193 void
 194 supply_fpregset (struct regcache *regcache,
 195                  const gdb_fpregset_t *fpregsetp)
 196 {
 197   return;
 198 }
 199
 200 /* Fetch greg-register(s) from process/thread TID
 201    and store value(s) in GDB's register array.  */
 202
 203 static void
 204 fetch_gregs (struct regcache *regcache, int regnum)
 205 {
 206   int tid = regcache->ptid ().lwp ();
 207   gdb_gregset_t regs;
 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
 227   if (ptrace (PTRACE_GETREGS, tid, 0, (long) &regs) < 0)
 228     {
 229       perror_with_name (_("Couldn't get registers"));
 230       return;
 231     }
 232
 233   fill_gregset (regcache, &regs, regnum);
 234
 235   if (ptrace (PTRACE_SETREGS, tid, 0, (long) &regs) < 0)
 236     {
 237       perror_with_name (_("Couldn't write registers"));
 238       return;
 239     }
 240 }
 241
 242 static int xtreg_lo;
 243 static int xtreg_high;
 244
 245 /* Fetch/Store Xtensa TIE registers.  Xtensa GNU/Linux PTRACE
 246    interface provides special requests for this.  */
 247
 248 static void
 249 fetch_xtregs (struct regcache *regcache, int regnum)
 250 {
 251   int tid = regcache->ptid ().lwp ();
 252   const xtensa_regtable_t *ptr;
 253   char xtregs [XTENSA_ELF_XTREG_SIZE];
 254
 255   if (ptrace (PTRACE_GETXTREGS, tid, 0, (long)&xtregs) < 0)
 256     perror_with_name (_("Couldn't get extended registers"));
 257
 258   for (ptr = xtensa_regmap_table; ptr->name; ptr++)
 259     if (regnum == ptr->gdb_regnum || regnum == -1)
 260       regcache->raw_supply (ptr->gdb_regnum, xtregs + ptr->ptrace_offset);
 261 }
 262
 263 static void
 264 store_xtregs (struct regcache *regcache, int regnum)
 265 {
 266   int tid = regcache->ptid ().lwp ();
 267   const xtensa_regtable_t *ptr;
 268   char xtregs [XTENSA_ELF_XTREG_SIZE];
 269
 270   if (ptrace (PTRACE_GETXTREGS, tid, 0, (long)&xtregs) < 0)
 271     perror_with_name (_("Couldn't get extended registers"));
 272
 273   for (ptr = xtensa_regmap_table; ptr->name; ptr++)
 274     if (regnum == ptr->gdb_regnum || regnum == -1)
 275       regcache->raw_collect (ptr->gdb_regnum, xtregs + ptr->ptrace_offset);
 276
 277   if (ptrace (PTRACE_SETXTREGS, tid, 0, (long)&xtregs) < 0)
 278     perror_with_name (_("Couldn't write extended registers"));
 279 }
 280
 281 void
 282 xtensa_linux_nat_target::fetch_registers (struct regcache *regcache,
 283                                           int regnum)
 284 {
 285   if (regnum == -1)
 286     {
 287       fetch_gregs (regcache, regnum);
 288       fetch_xtregs (regcache, regnum);
 289     }
 290   else if ((regnum < xtreg_lo) || (regnum > xtreg_high))
 291     fetch_gregs (regcache, regnum);
 292   else
 293     fetch_xtregs (regcache, regnum);
 294 }
 295
 296 void
 297 xtensa_linux_nat_target::store_registers (struct regcache *regcache,
 298                                           int regnum)
 299 {
 300   if (regnum == -1)
 301     {
 302       store_gregs (regcache, regnum);
 303       store_xtregs (regcache, regnum);
 304     }
 305   else if ((regnum < xtreg_lo) || (regnum > xtreg_high))
 306     store_gregs (regcache, regnum);
 307   else
 308     store_xtregs (regcache, regnum);
 309 }
 310
 311 /* Called by libthread_db.  */
 312
 313 ps_err_e
 314 ps_get_thread_area (struct ps_prochandle *ph,
 315                     lwpid_t lwpid, int idx, void **base)
 316 {
 317   xtensa_elf_gregset_t regs;
 318
 319   if (ptrace (PTRACE_GETREGS, lwpid, NULL, &regs) != 0)
 320     return PS_ERR;
 321
 322   /* IDX is the bias from the thread pointer to the beginning of the
 323      thread descriptor.  It has to be subtracted due to implementation
 324      quirks in libthread_db.  */
 325   *base = (void *) ((char *) regs.threadptr - idx);
 326
 327   return PS_OK;
 328 }
 329
 330 void _initialize_xtensa_linux_nat ();
 331 void
 332 _initialize_xtensa_linux_nat ()
 333 {
 334   const xtensa_regtable_t *ptr;
 335
 336   /* Calculate the number range for extended registers.  */
 337   xtreg_lo = 1000000000;
 338   xtreg_high = -1;
 339   for (ptr = xtensa_regmap_table; ptr->name; ptr++)
 340     {
 341       if (ptr->gdb_regnum < xtreg_lo)
 342         xtreg_lo = ptr->gdb_regnum;
 343       if (ptr->gdb_regnum > xtreg_high)
 344         xtreg_high = ptr->gdb_regnum;
 345     }
 346
 347   linux_target = &the_xtensa_linux_nat_target;
 348   add_inf_child_target (&the_xtensa_linux_nat_target);
 349 }