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      1 /* libunwind - a platform-independent unwind library
      2    Copyright (C) 2008 CodeSourcery
      3    Copyright 2011 Linaro Limited
      4 
      5 This file is part of libunwind.
      6 
      7 Permission is hereby granted, free of charge, to any person obtaining
      8 a copy of this software and associated documentation files (the
      9 "Software"), to deal in the Software without restriction, including
     10 without limitation the rights to use, copy, modify, merge, publish,
     11 distribute, sublicense, and/or sell copies of the Software, and to
     12 permit persons to whom the Software is furnished to do so, subject to
     13 the following conditions:
     14 
     15 The above copyright notice and this permission notice shall be
     16 included in all copies or substantial portions of the Software.
     17 
     18 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
     19 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     20 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
     21 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
     22 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
     23 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
     24 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
     25 
     26 #include <stdio.h>
     27 #include "unwind_i.h"
     28 
     29 #ifdef __linux__
     30 #define ARM_NR_sigreturn 119
     31 #define ARM_NR_rt_sigreturn 173
     32 #define ARM_NR_OABI_SYSCALL_BASE 0x900000
     33 
     34 /* ARM EABI sigreturn (the syscall number is loaded into r7) */
     35 #define MOV_R7_SIGRETURN (0xe3a07000UL | ARM_NR_sigreturn)
     36 #define MOV_R7_RT_SIGRETURN (0xe3a07000UL | ARM_NR_rt_sigreturn)
     37 
     38 /* ARM OABI sigreturn (using SWI) */
     39 #define ARM_SIGRETURN \
     40   (0xef000000UL | ARM_NR_sigreturn | ARM_NR_OABI_SYSCALL_BASE)
     41 #define ARM_RT_SIGRETURN \
     42   (0xef000000UL | ARM_NR_rt_sigreturn | ARM_NR_OABI_SYSCALL_BASE)
     43 
     44 /* Thumb sigreturn (two insns, syscall number is loaded into r7) */
     45 #define THUMB_SIGRETURN (0xdf00UL << 16 | 0x2700 | ARM_NR_sigreturn)
     46 #define THUMB_RT_SIGRETURN (0xdf00UL << 16 | 0x2700 | ARM_NR_rt_sigreturn)
     47 #endif /* __linux__ */
     48 
     49 /* Returns 1 in case of a non-RT signal frame and 2 in case of a RT signal
     50    frame. */
     51 PROTECTED int
     52 unw_is_signal_frame (unw_cursor_t *cursor)
     53 {
     54 #ifdef __linux__
     55   struct cursor *c = (struct cursor *) cursor;
     56   unw_word_t w0, ip;
     57   unw_addr_space_t as;
     58   unw_accessors_t *a;
     59   void *arg;
     60   int ret;
     61 
     62   as = c->dwarf.as;
     63   a = unw_get_accessors (as);
     64   arg = c->dwarf.as_arg;
     65 
     66   ip = c->dwarf.ip;
     67 
     68   if ((ret = (*a->access_mem) (as, ip, &w0, 0, arg)) < 0)
     69   /* ANDROID support update. */
     70     return 0;
     71   /* End ANDROID update. */
     72 
     73   /* Return 1 if the IP points to a non-RT sigreturn sequence.  */
     74   if (w0 == MOV_R7_SIGRETURN || w0 == ARM_SIGRETURN || w0 == THUMB_SIGRETURN)
     75     return 1;
     76   /* Return 2 if the IP points to a RT sigreturn sequence.  */
     77   else if (w0 == MOV_R7_RT_SIGRETURN || w0 == ARM_RT_SIGRETURN
     78            || w0 == THUMB_RT_SIGRETURN)
     79     return 2;
     80 
     81   return 0;
     82 #elif defined(__QNX__)
     83   /* Not supported yet */
     84   return 0;
     85 #else
     86   printf ("%s: implement me\n", __FUNCTION__);
     87   return -UNW_ENOINFO;
     88 #endif
     89 }
     90