1 /* libunwind - a platform-independent unwind library
2    Copyright (c) 2002-2004 Hewlett-Packard Development Company, L.P.
3 	Contributed by David Mosberger-Tang <davidm@hpl.hp.com>
4 
5    Modified for x86_64 by Max Asbock <masbock@us.ibm.com>
6 
7 This file is part of libunwind.
8 
9 Permission is hereby granted, free of charge, to any person obtaining
10 a copy of this software and associated documentation files (the
11 "Software"), to deal in the Software without restriction, including
12 without limitation the rights to use, copy, modify, merge, publish,
13 distribute, sublicense, and/or sell copies of the Software, and to
14 permit persons to whom the Software is furnished to do so, subject to
15 the following conditions:
16 
17 The above copyright notice and this permission notice shall be
18 included in all copies or substantial portions of the Software.
19 
20 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
23 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
24 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
25 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
26 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
27 
28 #include <stdlib.h>
29 
30 #include "offsets.h"
31 #include "unwind_i.h"
32 
33 #ifndef UNW_REMOTE_ONLY
34 
35 HIDDEN inline int
x86_64_local_resume(unw_addr_space_t as,unw_cursor_t * cursor,void * arg)36 x86_64_local_resume (unw_addr_space_t as, unw_cursor_t *cursor, void *arg)
37 {
38   struct cursor *c = (struct cursor *) cursor;
39   ucontext_t *uc = c->uc;
40 
41   /* Ensure c->pi is up-to-date.  On x86-64, it's relatively common to
42      be missing DWARF unwind info.  We don't want to fail in that
43      case, because the frame-chain still would let us do a backtrace
44      at least.  */
45   dwarf_make_proc_info (&c->dwarf);
46 
47   if (unlikely (c->sigcontext_format != X86_64_SCF_NONE))
48     {
49       x86_64_sigreturn(cursor);
50       abort();
51     }
52   else
53     {
54       Debug (8, "resuming at ip=%llx via setcontext()\n",
55 	     (unsigned long long) c->dwarf.ip);
56       setcontext (uc);
57     }
58   return -UNW_EINVAL;
59 }
60 
61 #endif /* !UNW_REMOTE_ONLY */
62 
63 /* This routine is responsible for copying the register values in
64    cursor C and establishing them as the current machine state. */
65 
66 static inline int
establish_machine_state(struct cursor * c)67 establish_machine_state (struct cursor *c)
68 {
69   int (*access_reg) (unw_addr_space_t, unw_regnum_t, unw_word_t *,
70 		     int write, void *);
71   int (*access_fpreg) (unw_addr_space_t, unw_regnum_t, unw_fpreg_t *,
72 		       int write, void *);
73   unw_addr_space_t as = c->dwarf.as;
74   void *arg = c->dwarf.as_arg;
75   unw_fpreg_t fpval;
76   unw_word_t val;
77   int reg;
78 
79   access_reg = as->acc.access_reg;
80   access_fpreg = as->acc.access_fpreg;
81 
82   Debug (8, "copying out cursor state\n");
83 
84   for (reg = 0; reg <= UNW_REG_LAST; ++reg)
85     {
86       Debug (16, "copying %s %d\n", unw_regname (reg), reg);
87       if (unw_is_fpreg (reg))
88 	{
89 	  if (tdep_access_fpreg (c, reg, &fpval, 0) >= 0)
90 	    (*access_fpreg) (as, reg, &fpval, 1, arg);
91 	}
92       else
93 	{
94 	  if (tdep_access_reg (c, reg, &val, 0) >= 0)
95 	    (*access_reg) (as, reg, &val, 1, arg);
96 	}
97     }
98   return 0;
99 }
100 
101 PROTECTED int
unw_resume(unw_cursor_t * cursor)102 unw_resume (unw_cursor_t *cursor)
103 {
104   struct cursor *c = (struct cursor *) cursor;
105   int ret;
106 
107   Debug (1, "(cursor=%p)\n", c);
108 
109   if ((ret = establish_machine_state (c)) < 0)
110     return ret;
111 
112   return (*c->dwarf.as->acc.resume) (c->dwarf.as, (unw_cursor_t *) c,
113 				     c->dwarf.as_arg);
114 }
115