Home | History | Annotate | Download | only in backends 
      1 /* Fetch live process registers from TID.
      2    Copyright (C) 2013 Red Hat, Inc.
      3    This file is part of elfutils.
      4 
      5    This file is free software; you can redistribute it and/or modify
      6    it under the terms of either
      7 
      8      * the GNU Lesser General Public License as published by the Free
      9        Software Foundation; either version 3 of the License, or (at
     10        your option) any later version
     11 
     12    or
     13 
     14      * the GNU General Public License as published by the Free
     15        Software Foundation; either version 2 of the License, or (at
     16        your option) any later version
     17 
     18    or both in parallel, as here.
     19 
     20    elfutils is distributed in the hope that it will be useful, but
     21    WITHOUT ANY WARRANTY; without even the implied warranty of
     22    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     23    General Public License for more details.
     24 
     25    You should have received copies of the GNU General Public License and
     26    the GNU Lesser General Public License along with this program.  If
     27    not, see <http://www.gnu.org/licenses/>.  */
     28 
     29 #ifdef HAVE_CONFIG_H
     30 # include <config.h>
     31 #endif
     32 
     33 #include "system.h"
     34 #include <stdlib.h>
     35 #ifdef __powerpc__
     36 # include <sys/user.h>
     37 # include <sys/ptrace.h>
     38 #endif
     39 
     40 #define BACKEND ppc_
     41 #include "libebl_CPU.h"
     42 
     43 bool
     44 ppc_dwarf_to_regno (Ebl *ebl __attribute__ ((unused)), unsigned *regno)
     45 {
     46   switch (*regno)
     47   {
     48     case 108:
     49       // LR uses both 65 and 108 numbers, there is no consistency for it.
     50       *regno = 65;
     51       return true;
     52     case 0 ... 107:
     53     case 109 ... (114 - 1) -1:
     54       return true;
     55     case 1200 ... 1231:
     56       *regno = *regno - 1200 + (114 - 1);
     57       return true;
     58     default:
     59       return false;
     60   }
     61   abort ();
     62 }
     63 
     64 __typeof (ppc_dwarf_to_regno)
     65      ppc64_dwarf_to_regno
     66      __attribute__ ((alias ("ppc_dwarf_to_regno")));
     67 
     68 bool
     69 ppc_set_initial_registers_tid (pid_t tid __attribute__ ((unused)),
     70 			  ebl_tid_registers_t *setfunc __attribute__ ((unused)),
     71 			       void *arg __attribute__ ((unused)))
     72 {
     73 #ifndef __powerpc__
     74   return false;
     75 #else /* __powerpc__ */
     76   union
     77     {
     78       struct pt_regs r;
     79       long l[sizeof (struct pt_regs) / sizeof (long)];
     80     }
     81   user_regs;
     82   eu_static_assert (sizeof (struct pt_regs) % sizeof (long) == 0);
     83   /* PTRACE_GETREGS is EIO on kernel-2.6.18-308.el5.ppc64.  */
     84   errno = 0;
     85   for (unsigned regno = 0; regno < sizeof (user_regs) / sizeof (long);
     86        regno++)
     87     {
     88       user_regs.l[regno] = ptrace (PTRACE_PEEKUSER, tid,
     89 				   (void *) (uintptr_t) (regno
     90 							 * sizeof (long)),
     91 				   NULL);
     92       if (errno != 0)
     93 	return false;
     94     }
     95   const size_t gprs = sizeof (user_regs.r.gpr) / sizeof (*user_regs.r.gpr);
     96   Dwarf_Word dwarf_regs[gprs];
     97   for (unsigned gpr = 0; gpr < gprs; gpr++)
     98     dwarf_regs[gpr] = user_regs.r.gpr[gpr];
     99   if (! setfunc (0, gprs, dwarf_regs, arg))
    100     return false;
    101   dwarf_regs[0] = user_regs.r.link;
    102   // LR uses both 65 and 108 numbers, there is no consistency for it.
    103   if (! setfunc (65, 1, dwarf_regs, arg))
    104     return false;
    105   /* Registers like msr, ctr, xer, dar, dsisr etc. are probably irrelevant
    106      for CFI.  */
    107   dwarf_regs[0] = user_regs.r.nip;
    108   return setfunc (-1, 1, dwarf_regs, arg);
    109 #endif /* __powerpc__ */
    110 }
    111 
    112 __typeof (ppc_set_initial_registers_tid)
    113      ppc64_set_initial_registers_tid
    114      __attribute__ ((alias ("ppc_set_initial_registers_tid")));
    115