gdb/tilegx-linux-nat.c

   1 /* Native-dependent code for GNU/Linux TILE-Gx.
   2
   3    Copyright (C) 2012-2020 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 "inferior.h"
  22 #include "gdbcore.h"
  23 #include "regcache.h"
  24 #include "linux-nat.h"
  25 #include "inf-ptrace.h"
  26
  27 #include "nat/gdb_ptrace.h"
  28
  29 #include <sys/procfs.h>
  30
  31 /* Defines ps_err_e, struct ps_prochandle.  */
  32 #include "gdb_proc_service.h"
  33
  34 /* Prototypes for supply_gregset etc.  */
  35 #include "gregset.h"
  36
  37 class tilegx_linux_nat_target final : public linux_nat_target
  38 {
  39 public:
  40   /* Add our register access methods.  */
  41   void fetch_registers (struct regcache *, int) override;
  42   void store_registers (struct regcache *, int) override;
  43 };
  44
  45 static tilegx_linux_nat_target the_tilegx_linux_nat_target;
  46
  47 /* The register sets used in GNU/Linux ELF core-dumps are identical to
  48    the register sets in `struct user' that is used for a.out
  49    core-dumps, and is also used by `ptrace'.  The corresponding types
  50    are `elf_gregset_t' for the general-purpose registers (with
  51    `elf_greg_t' the type of a single GP register) and `elf_fpregset_t'
  52    for the floating-point registers.
  53
  54    Those types used to be available under the names `gregset_t' and
  55    `fpregset_t' too, and this file used those names in the past.  But
  56    those names are now used for the register sets used in the
  57    `mcontext_t' type, and have a different size and layout.  */
  58
  59 /* Mapping between the general-purpose registers in `struct user'
  60    format and GDB's register array layout.  Note that we map the
  61    first 56 registers (0 thru 55) one-to-one.  GDB maps the pc to
  62    slot 64, but ptrace returns it in slot 56.  */
  63 static const int regmap[] =
  64 {
  65    0,  1,  2,  3,  4,  5,  6,  7,
  66    8,  9, 10, 11, 12, 13, 14, 15,
  67   16, 17, 18, 19, 20, 21, 22, 23,
  68   24, 25, 26, 27, 28, 29, 30, 31,
  69   32, 33, 34, 35, 36, 37, 38, 39,
  70   40, 41, 42, 43, 44, 45, 46, 47,
  71   48, 49, 50, 51, 52, 53, 54, 55,
  72   -1, -1, -1, -1, -1, -1, -1, -1,
  73   56, 58
  74 };
  75
  76 /* Transfering the general-purpose registers between GDB, inferiors
  77    and core files.  */
  78
  79 /* Fill GDB's register array with the general-purpose register values
  80    in *GREGSETP.  */
  81
  82 void
  83 supply_gregset (struct regcache* regcache,
  84                 const elf_gregset_t *gregsetp)
  85 {
  86   elf_greg_t *regp = (elf_greg_t *) gregsetp;
  87   int i;
  88
  89   for (i = 0; i < sizeof (regmap) / sizeof (regmap[0]); i++)
  90     if (regmap[i] >= 0)
  91       regcache->raw_supply (i, regp + regmap[i]);
  92 }
  93
  94 /* Fill registers in *GREGSETPS with the values in GDB's
  95    register array.  */
  96
  97 void
  98 fill_gregset (const struct regcache* regcache,
  99               elf_gregset_t *gregsetp, int regno)
 100 {
 101   elf_greg_t *regp = (elf_greg_t *) gregsetp;
 102   int i;
 103
 104   for (i = 0; i < sizeof (regmap) / sizeof (regmap[0]); i++)
 105     if (regmap[i] >= 0)
 106       regcache->raw_collect (i, regp + regmap[i]);
 107 }
 108
 109 /* Transfering floating-point registers between GDB, inferiors and cores.  */
 110
 111 /* Fill GDB's register array with the floating-point register values in
 112    *FPREGSETP.  */
 113
 114 void
 115 supply_fpregset (struct regcache *regcache,
 116                  const elf_fpregset_t *fpregsetp)
 117 {
 118   /* NOTE: There are no floating-point registers for TILE-Gx.  */
 119 }
 120
 121 /* Fill register REGNO (if it is a floating-point register) in
 122    *FPREGSETP with the value in GDB's register array.  If REGNO is -1,
 123    do this for all registers.  */
 124
 125 void
 126 fill_fpregset (const struct regcache *regcache,
 127                elf_fpregset_t *fpregsetp, int regno)
 128 {
 129   /* NOTE: There are no floating-point registers for TILE-Gx.  */
 130 }
 131
 132 /* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
 133    for all registers.  */
 134
 135 void
 136 tilegx_linux_nat_target::fetch_registers (struct regcache *regcache,
 137                                           int regnum)
 138 {
 139   elf_gregset_t regs;
 140   pid_t tid = get_ptrace_pid (regcache->ptid ());
 141
 142   if (ptrace (PTRACE_GETREGS, tid, 0, (PTRACE_TYPE_ARG3) &regs) < 0)
 143     perror_with_name (_("Couldn't get registers"));
 144
 145   supply_gregset (regcache, (const elf_gregset_t *)&regs);
 146 }
 147
 148 /* Store register REGNUM back into the inferior.  If REGNUM is -1, do
 149    this for all registers.  */
 150
 151 void
 152 tilegx_linux_nat_target::store_registers (struct regcache *regcache,
 153                                           int regnum)
 154 {
 155   elf_gregset_t regs;
 156   pid_t tid = get_ptrace_pid (regcache->ptid ());
 157
 158   if (ptrace (PTRACE_GETREGS, tid, 0, (PTRACE_TYPE_ARG3) &regs) < 0)
 159     perror_with_name (_("Couldn't get registers"));
 160
 161   fill_gregset (regcache, &regs, regnum);
 162
 163   if (ptrace (PTRACE_SETREGS, tid, 0, (PTRACE_TYPE_ARG3) &regs) < 0)
 164     perror_with_name (_("Couldn't write registers"));
 165 }
 166
 167 void
 168 _initialize_tile_linux_nat (void)
 169 {
 170   linux_target = &the_tilegx_linux_nat_target;
 171   add_inf_child_target (&the_tilegx_linux_nat_target);
 172 }