gdb/ppc-fbsd-nat.c

   1 /* Native-dependent code for PowerPC's running FreeBSD, for GDB.
   2
   3    Copyright (C) 2013-2017 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 "gdbcore.h"
  22 #include "inferior.h"
  23 #include "regcache.h"
  24
  25 #include <sys/types.h>
  26 #include <sys/procfs.h>
  27 #include <sys/ptrace.h>
  28 #include <sys/signal.h>
  29 #include <machine/frame.h>
  30 #include <machine/pcb.h>
  31 #include <machine/reg.h>
  32
  33 #include "fbsd-nat.h"
  34 #include "gregset.h"
  35 #include "ppc-tdep.h"
  36 #include "ppc-fbsd-tdep.h"
  37 #include "inf-ptrace.h"
  38 #include "bsd-kvm.h"
  39
  40 /* Fill GDB's register array with the general-purpose register values
  41    in *GREGSETP.  */
  42
  43 void
  44 supply_gregset (struct regcache *regcache, const gdb_gregset_t *gregsetp)
  45 {
  46   const struct regset *regset = ppc_fbsd_gregset (sizeof (long));
  47
  48   ppc_supply_gregset (regset, regcache, -1, gregsetp, sizeof (*gregsetp));
  49 }
  50
  51 /* Fill register REGNO (if a gpr) in *GREGSETP with the value in GDB's
  52    register array. If REGNO is -1 do it for all registers.  */
  53
  54 void
  55 fill_gregset (const struct regcache *regcache,
  56               gdb_gregset_t *gregsetp, int regno)
  57 {
  58   const struct regset *regset = ppc_fbsd_gregset (sizeof (long));
  59
  60   if (regno == -1)
  61     memset (gregsetp, 0, sizeof (*gregsetp));
  62   ppc_collect_gregset (regset, regcache, regno, gregsetp, sizeof (*gregsetp));
  63 }
  64
  65 /* Fill GDB's register array with the floating-point register values
  66    in *FPREGSETP.  */
  67
  68 void
  69 supply_fpregset (struct regcache *regcache, const gdb_fpregset_t * fpregsetp)
  70 {
  71   const struct regset *regset = ppc_fbsd_fpregset ();
  72
  73   ppc_supply_fpregset (regset, regcache, -1,
  74                        fpregsetp, sizeof (*fpregsetp));
  75 }
  76
  77 /* Fill register REGNO in *FGREGSETP with the value in GDB's
  78    register array. If REGNO is -1 do it for all registers.  */
  79
  80 void
  81 fill_fpregset (const struct regcache *regcache,
  82                gdb_fpregset_t *fpregsetp, int regno)
  83 {
  84   const struct regset *regset = ppc_fbsd_fpregset ();
  85
  86   ppc_collect_fpregset (regset, regcache, regno,
  87                         fpregsetp, sizeof (*fpregsetp));
  88 }
  89
  90 /* Returns true if PT_GETFPREGS fetches this register.  */
  91
  92 static int
  93 getfpregs_supplies (struct gdbarch *gdbarch, int regno)
  94 {
  95   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  96
  97   /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
  98          point registers.  Traditionally, GDB's register set has still
  99          listed the floating point registers for such machines, so this
 100          code is harmless.  However, the new E500 port actually omits the
 101          floating point registers entirely from the register set --- they
 102          don't even have register numbers assigned to them.
 103
 104          It's not clear to me how best to update this code, so this assert
 105          will alert the first person to encounter the NetBSD/E500
 106          combination to the problem.  */
 107
 108   gdb_assert (ppc_floating_point_unit_p (gdbarch));
 109
 110   return ((regno >= tdep->ppc_fp0_regnum
 111            && regno < tdep->ppc_fp0_regnum + ppc_num_fprs)
 112           || regno == tdep->ppc_fpscr_regnum);
 113 }
 114
 115 /* Fetch register REGNO from the child process. If REGNO is -1, do it
 116    for all registers.  */
 117
 118 static void
 119 ppcfbsd_fetch_inferior_registers (struct target_ops *ops,
 120                                   struct regcache *regcache, int regno)
 121 {
 122   gdb_gregset_t regs;
 123
 124   if (ptrace (PT_GETREGS, ptid_get_lwp (inferior_ptid),
 125               (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 126     perror_with_name (_("Couldn't get registers"));
 127
 128   supply_gregset (regcache, &regs);
 129
 130   if (regno == -1 || getfpregs_supplies (get_regcache_arch (regcache), regno))
 131     {
 132       const struct regset *fpregset = ppc_fbsd_fpregset ();
 133       gdb_fpregset_t fpregs;
 134
 135       if (ptrace (PT_GETFPREGS, ptid_get_lwp (inferior_ptid),
 136                   (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 137         perror_with_name (_("Couldn't get FP registers"));
 138
 139       ppc_supply_fpregset (fpregset, regcache, regno, &fpregs, sizeof fpregs);
 140     }
 141 }
 142
 143 /* Store register REGNO back into the child process. If REGNO is -1,
 144    do this for all registers.  */
 145
 146 static void
 147 ppcfbsd_store_inferior_registers (struct target_ops *ops,
 148                                   struct regcache *regcache, int regno)
 149 {
 150   gdb_gregset_t regs;
 151
 152   if (ptrace (PT_GETREGS, ptid_get_lwp (inferior_ptid),
 153               (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 154     perror_with_name (_("Couldn't get registers"));
 155
 156   fill_gregset (regcache, &regs, regno);
 157
 158   if (ptrace (PT_SETREGS, ptid_get_lwp (inferior_ptid),
 159               (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 160     perror_with_name (_("Couldn't write registers"));
 161
 162   if (regno == -1 || getfpregs_supplies (get_regcache_arch (regcache), regno))
 163     {
 164       gdb_fpregset_t fpregs;
 165
 166       if (ptrace (PT_GETFPREGS, ptid_get_lwp (inferior_ptid),
 167                   (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 168         perror_with_name (_("Couldn't get FP registers"));
 169
 170       fill_fpregset (regcache, &fpregs, regno);
 171
 172       if (ptrace (PT_SETFPREGS, ptid_get_lwp (inferior_ptid),
 173                   (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 174         perror_with_name (_("Couldn't set FP registers"));
 175     }
 176 }
 177
 178 /* Architecture specific function that reconstructs the
 179    register state from PCB (Process Control Block) and supplies it
 180    to REGCACHE.  */
 181
 182 static int
 183 ppcfbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 184 {
 185   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 186   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 187   int i, regnum;
 188
 189   /* The stack pointer shouldn't be zero.  */
 190   if (pcb->pcb_sp == 0)
 191     return 0;
 192
 193   regcache_raw_supply (regcache, gdbarch_sp_regnum (gdbarch), &pcb->pcb_sp);
 194   regcache_raw_supply (regcache, tdep->ppc_cr_regnum, &pcb->pcb_cr);
 195   regcache_raw_supply (regcache, tdep->ppc_lr_regnum, &pcb->pcb_lr);
 196   for (i = 0, regnum = tdep->ppc_gp0_regnum + 14; i < 20; i++, regnum++)
 197     regcache_raw_supply (regcache, regnum, &pcb->pcb_context[i]);
 198
 199   return 1;
 200 }
 201
 202 /* Provide a prototype to silence -Wmissing-prototypes.  */
 203
 204 void _initialize_ppcfbsd_nat (void);
 205
 206 void
 207 _initialize_ppcfbsd_nat (void)
 208 {
 209   struct target_ops *t;
 210
 211   /* Add in local overrides.  */
 212   t = inf_ptrace_target ();
 213   t->to_fetch_registers = ppcfbsd_fetch_inferior_registers;
 214   t->to_store_registers = ppcfbsd_store_inferior_registers;
 215   fbsd_nat_add_target (t);
 216
 217   /* Support debugging kernel virtual memory images.  */
 218   bsd_kvm_add_target (ppcfbsd_supply_pcb);
 219 }