gdb/arch/arm-linux.c

   1 /* Common target dependent code for GNU/Linux on ARM systems.
   2
   3    Copyright (C) 1999-2016 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 "common-defs.h"
  21 #include "arch/arm.h"
  22 #include "arm-linux.h"
  23
  24 /* Calculate the offset from stack pointer of the pc register on the stack
  25    in the case of a sigreturn or sigreturn_rt syscall.  */
  26 int
  27 arm_linux_sigreturn_next_pc_offset (unsigned long sp,
  28                                     unsigned long sp_data,
  29                                     unsigned long svc_number,
  30                                     int is_sigreturn)
  31 {
  32   /* Offset of R0 register.  */
  33   int r0_offset = 0;
  34   /* Offset of PC register.  */
  35   int pc_offset = 0;
  36
  37   if (is_sigreturn)
  38     {
  39       if (sp_data == ARM_NEW_SIGFRAME_MAGIC)
  40         r0_offset = ARM_UCONTEXT_SIGCONTEXT + ARM_SIGCONTEXT_R0;
  41       else
  42         r0_offset = ARM_SIGCONTEXT_R0;
  43     }
  44   else
  45     {
  46       if (sp_data == sp + ARM_OLD_RT_SIGFRAME_SIGINFO)
  47         r0_offset = ARM_OLD_RT_SIGFRAME_UCONTEXT;
  48       else
  49         r0_offset = ARM_NEW_RT_SIGFRAME_UCONTEXT;
  50
  51       r0_offset += ARM_UCONTEXT_SIGCONTEXT + ARM_SIGCONTEXT_R0;
  52     }
  53
  54   pc_offset = r0_offset + INT_REGISTER_SIZE * ARM_PC_REGNUM;
  55
  56   return pc_offset;
  57 }