gdb/ppcobsd-nat.c - gdb

Functions defined

Source code

  1. /* Native-dependent code for OpenBSD/powerpc.

  3.    Copyright (C) 2004-2015 Free Software Foundation, Inc.

  5.    This file is part of GDB.

  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.

  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.

  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/>.  */

  20. #include "defs.h"
  21. #include "gdbcore.h"
  22. #include "inferior.h"
  23. #include "regcache.h"

  25. #include <sys/types.h>
  26. #include <sys/ptrace.h>
  27. #include <sys/signal.h>
  28. #include <machine/frame.h>
  29. #include <machine/pcb.h>
  30. #include <machine/reg.h>

  32. #include "ppc-tdep.h"
  33. #include "ppcobsd-tdep.h"
  34. #include "inf-ptrace.h"
  35. #include "obsd-nat.h"
  36. #include "bsd-kvm.h"

  38. /* OpenBSD/powerpc didn't have PT_GETFPREGS/PT_SETFPREGS until release
  39.    4.0.  On older releases the floating-point registers are handled by
  40.    PT_GETREGS/PT_SETREGS, but fpscr wasn't available..  */

  42. #ifdef PT_GETFPREGS

  44. /* Returns true if PT_GETFPREGS fetches this register.  */

  46. static int
  47. ‌getfpregs_supplies (struct gdbarch *gdbarch, int regnum)
  48. {
  49.   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  51.   /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
  52.      point registers.  Traditionally, GDB's register set has still
  53.      listed the floating point registers for such machines, so this
  54.      code is harmless.  However, the new E500 port actually omits the
  55.      floating point registers entirely from the register set --- they
  56.      don't even have register numbers assigned to them.

  58.      It's not clear to me how best to update this code, so this assert
  59.      will alert the first person to encounter the NetBSD/E500
  60.      combination to the problem.  */
  61.   gdb_assert (ppc_floating_point_unit_p (gdbarch));

  63.   return ((regnum >= tdep->ppc_fp0_regnum
  64.            && regnum < tdep->ppc_fp0_regnum + ppc_num_fprs)
  65.           || regnum == tdep->ppc_fpscr_regnum);
  66. }

  68. #endif /* PT_GETFPREGS */

  70. /* Fetch register REGNUM from the inferior.  If REGNUM is -1, do this
  71.    for all registers.  */

  73. static void
  74. ‌ppcobsd_fetch_registers (struct target_ops *ops,
  75.                          struct regcache *regcache, int regnum)
  76. {
  77.   struct reg regs;

  79.   if (ptrace (PT_GETREGS, ptid_get_pid (inferior_ptid),
  80.               (PTRACE_TYPE_ARG3) &regs, 0) == -1)
  81.     perror_with_name (_("Couldn't get registers"));

  83.   ppc_supply_gregset (&ppcobsd_gregset, regcache, -1,
  84.                       &regs, sizeof regs);
  85. #ifndef PT_GETFPREGS
  86.   ppc_supply_fpregset (&ppcobsd_gregset, regcache, -1,
  87.                        &regs, sizeof regs);
  88. #endif

  90. #ifdef PT_GETFPREGS
  91.   if (regnum == -1
  92.       || getfpregs_supplies (get_regcache_arch (regcache), regnum))
  93.     {
  94.       struct fpreg fpregs;

  96.       if (ptrace (PT_GETFPREGS, ptid_get_pid (inferior_ptid),
  97.                   (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
  98.         perror_with_name (_("Couldn't get floating point status"));

  100.       ppc_supply_fpregset (&ppcobsd_fpregset, regcache, -1,
  101.                            &fpregs, sizeof fpregs);
  102.     }
  103. #endif
  104. }

  106. /* Store register REGNUM back into the inferior.  If REGNUM is -1, do
  107.    this for all registers.  */

  109. static void
  110. ‌ppcobsd_store_registers (struct target_ops *ops,
  111.                          struct regcache *regcache, int regnum)
  112. {
  113.   struct reg regs;

  115.   if (ptrace (PT_GETREGS, ptid_get_pid (inferior_ptid),
  116.               (PTRACE_TYPE_ARG3) &regs, 0) == -1)
  117.     perror_with_name (_("Couldn't get registers"));

  119.   ppc_collect_gregset (&ppcobsd_gregset, regcache,
  120.                        regnum, &regs, sizeof regs);
  121. #ifndef PT_GETFPREGS
  122.   ppc_collect_fpregset (&ppcobsd_gregset, regcache,
  123.                         regnum, &regs, sizeof regs);
  124. #endif

  126.   if (ptrace (PT_SETREGS, ptid_get_pid (inferior_ptid),
  127.               (PTRACE_TYPE_ARG3) &regs, 0) == -1)
  128.     perror_with_name (_("Couldn't write registers"));

  130. #ifdef PT_GETFPREGS
  131.   if (regnum == -1
  132.       || getfpregs_supplies (get_regcache_arch (regcache), regnum))
  133.     {
  134.       struct fpreg fpregs;

  136.       if (ptrace (PT_GETFPREGS, ptid_get_pid (inferior_ptid),
  137.                   (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
  138.         perror_with_name (_("Couldn't get floating point status"));

  140.       ppc_collect_fpregset (&ppcobsd_fpregset, regcache,
  141.                             regnum, &fpregs, sizeof fpregs);

  143.       if (ptrace (PT_SETFPREGS, ptid_get_pid (inferior_ptid),
  144.                   (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
  145.         perror_with_name (_("Couldn't write floating point status"));
  146.     }
  147. #endif
  148. }


  151. static int
  152. ‌ppcobsd_supply_pcb (struct regcache *regcache, struct pcb *pcb)
  153. {
  154.   struct gdbarch *gdbarch = get_regcache_arch (regcache);
  155.   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  156.   struct switchframe sf;
  157.   struct callframe cf;
  158.   int i, regnum;

  160.   /* The following is true for OpenBSD 3.7:

  162.      The pcb contains %r1 (the stack pointer) at the point of the
  163.      context switch in cpu_switch().  At that point we have a stack
  164.      frame as described by `struct switchframe', and below that a call
  165.      frame as described by `struct callframe'.  From this information
  166.      we reconstruct the register state as it would look when we are in
  167.      cpu_switch().  */

  169.   /* The stack pointer shouldn't be zero.  */
  170.   if (pcb->pcb_sp == 0)
  171.     return 0;

  173.   read_memory (pcb->pcb_sp, (gdb_byte *)&sf, sizeof sf);
  174.   regcache_raw_supply (regcache, gdbarch_sp_regnum (gdbarch), &sf.sp);
  175.   regcache_raw_supply (regcache, tdep->ppc_cr_regnum, &sf.cr);
  176.   regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 2, &sf.fixreg2);
  177.   for (i = 0, regnum = tdep->ppc_gp0_regnum + 13; i < 19; i++, regnum++)
  178.     regcache_raw_supply (regcache, regnum, &sf.fixreg[i]);

  180.   read_memory (sf.sp, (gdb_byte *)&cf, sizeof cf);
  181.   regcache_raw_supply (regcache, gdbarch_pc_regnum (gdbarch), &cf.lr);
  182.   regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 30, &cf.r30);
  183.   regcache_raw_supply (regcache, tdep->ppc_gp0_regnum + 31, &cf.r31);

  185.   return 1;
  186. }


  189. /* Provide a prototype to silence -Wmissing-prototypes.  */
  190. void _initialize_ppcobsd_nat (void);

  192. void
  193. ‌_initialize_ppcobsd_nat (void)
  194. {
  195.   struct target_ops *t;

  197.   /* Add in local overrides.  */
  198.   t = inf_ptrace_target ();
  199.   t->to_fetch_registers = ppcobsd_fetch_registers;
  200.   t->to_store_registers = ppcobsd_store_registers;
  201.   obsd_add_target (t);

  203.   /* General-purpose registers.  */
  204.   ppcobsd_reg_offsets.r0_offset = offsetof (struct reg, gpr);
  205.   ppcobsd_reg_offsets.gpr_size = 4;
  206.   ppcobsd_reg_offsets.xr_size = 4;
  207.   ppcobsd_reg_offsets.pc_offset = offsetof (struct reg, pc);
  208.   ppcobsd_reg_offsets.ps_offset = offsetof (struct reg, ps);
  209.   ppcobsd_reg_offsets.cr_offset = offsetof (struct reg, cnd);
  210.   ppcobsd_reg_offsets.lr_offset = offsetof (struct reg, lr);
  211.   ppcobsd_reg_offsets.ctr_offset = offsetof (struct reg, cnt);
  212.   ppcobsd_reg_offsets.xer_offset = offsetof (struct reg, xer);
  213.   ppcobsd_reg_offsets.mq_offset = offsetof (struct reg, mq);

  215.   /* Floating-point registers.  */
  216.   ppcobsd_reg_offsets.f0_offset = offsetof (struct reg, fpr);
  217.   ppcobsd_reg_offsets.fpscr_offset = -1;
  218. #ifdef PT_GETFPREGS
  219.   ppcobsd_fpreg_offsets.f0_offset = offsetof (struct fpreg, fpr);
  220.   ppcobsd_fpreg_offsets.fpscr_offset = offsetof (struct fpreg, fpscr);
  221.   ppcobsd_fpreg_offsets.fpscr_size = 4;
  222. #endif

  224.   /* AltiVec registers.  */
  225.   ppcobsd_reg_offsets.vr0_offset = offsetof (struct vreg, vreg);
  226.   ppcobsd_reg_offsets.vscr_offset = offsetof (struct vreg, vscr);
  227.   ppcobsd_reg_offsets.vrsave_offset = offsetof (struct vreg, vrsave);

  229.   /* Support debugging kernel virtual memory images.  */
  230.   bsd_kvm_add_target (ppcobsd_supply_pcb);
  231. }