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   pid_t pid = ptid_get_lwp (regcache_get_ptid (regcache));
 124
 125   if (ptrace (PT_GETREGS, pid, (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 (regcache->arch (), regno))
 131     {
 132       const struct regset *fpregset = ppc_fbsd_fpregset ();
 133       gdb_fpregset_t fpregs;
 134
 135       if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 136         perror_with_name (_("Couldn't get FP registers"));
 137
 138       ppc_supply_fpregset (fpregset, regcache, regno, &fpregs, sizeof fpregs);
 139     }
 140 }
 141
 142 /* Store register REGNO back into the child process. If REGNO is -1,
 143    do this for all registers.  */
 144
 145 static void
 146 ppcfbsd_store_inferior_registers (struct target_ops *ops,
 147                                   struct regcache *regcache, int regno)
 148 {
 149   gdb_gregset_t regs;
 150   pid_t pid = ptid_get_lwp (regcache_get_ptid (regcache));
 151
 152   if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 153     perror_with_name (_("Couldn't get registers"));
 154
 155   fill_gregset (regcache, &regs, regno);
 156
 157   if (ptrace (PT_SETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 158     perror_with_name (_("Couldn't write registers"));
 159
 160   if (regno == -1 || getfpregs_supplies (regcache->arch (), regno))
 161     {
 162       gdb_fpregset_t fpregs;
 163
 164       if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 165         perror_with_name (_("Couldn't get FP registers"));
 166
 167       fill_fpregset (regcache, &fpregs, regno);
 168
 169       if (ptrace (PT_SETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 170         perror_with_name (_("Couldn't set FP registers"));
 171     }
 172 }
 173
 174 /* Architecture specific function that reconstructs the
 175    register state from PCB (Process Control Block) and supplies it
 176    to REGCACHE.  */
 177
 178 static int
 179 ppcfbsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
 180 {
 181   struct gdbarch *gdbarch = regcache->arch ();
 182   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 183   int i, regnum;
 184
 185   /* The stack pointer shouldn't be zero.  */
 186   if (pcb->pcb_sp == 0)
 187     return 0;
 188
 189   regcache_raw_supply (regcache, gdbarch_sp_regnum (gdbarch), &pcb->pcb_sp);
 190   regcache_raw_supply (regcache, tdep->ppc_cr_regnum, &pcb->pcb_cr);
 191   regcache_raw_supply (regcache, tdep->ppc_lr_regnum, &pcb->pcb_lr);
 192   for (i = 0, regnum = tdep->ppc_gp0_regnum + 14; i < 20; i++, regnum++)
 193     regcache_raw_supply (regcache, regnum, &pcb->pcb_context[i]);
 194
 195   return 1;
 196 }
 197
 198 void
 199 _initialize_ppcfbsd_nat (void)
 200 {
 201   struct target_ops *t;
 202
 203   /* Add in local overrides.  */
 204   t = inf_ptrace_target ();
 205   t->to_fetch_registers = ppcfbsd_fetch_inferior_registers;
 206   t->to_store_registers = ppcfbsd_store_inferior_registers;
 207   fbsd_nat_add_target (t);
 208
 209   /* Support debugging kernel virtual memory images.  */
 210   bsd_kvm_add_target (ppcfbsd_supply_pcb);
 211 }