Gresume.c revision 31440e9796bb34146372df52ed59c4f68ea5839d 
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
7This file is part of libunwind.
8
9Permission is hereby granted, free of charge, to any person obtaining
10a copy of this software and associated documentation files (the
11"Software"), to deal in the Software without restriction, including
12without limitation the rights to use, copy, modify, merge, publish,
13distribute, sublicense, and/or sell copies of the Software, and to
14permit persons to whom the Software is furnished to do so, subject to
15the following conditions:
16
17The above copyright notice and this permission notice shall be
18included in all copies or substantial portions of the Software.
19
20THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
23NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
24LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
25OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
26WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.  */
27
28#include <stdlib.h>
29
30#include "unwind_i.h"
31
32#ifndef UNW_REMOTE_ONLY
33
34#include <sys/syscall.h>
35
36/* sigreturn() is a no-op on x86_64 glibc.  */
37
38static NORETURN inline long
39my_rt_sigreturn (void *new_sp)
40{
41  __asm__ __volatile__ ("mov %0, %%rsp;"
42			"mov %1, %%rax;"
43			"syscall"
44			:: "r"(new_sp), "i"(SYS_rt_sigreturn)
45			: "memory");
46  abort ();
47}
48
49HIDDEN inline int
50x86_64_local_resume (unw_addr_space_t as, unw_cursor_t *cursor, void *arg)
51{
52#if defined(__linux)
53  struct cursor *c = (struct cursor *) cursor;
54  ucontext_t *uc = c->dwarf.as_arg;
55
56  /* Ensure c->pi is up-to-date.  On x86-64, it's relatively common to
57     be missing DWARF unwind info.  We don't want to fail in that
58     case, because the frame-chain still would let us do a backtrace
59     at least.  */
60  dwarf_make_proc_info (&c->dwarf);
61
62  if (unlikely (c->sigcontext_format != X86_64_SCF_NONE))
63    {
64      struct sigcontext *sc = (struct sigcontext *) c->sigcontext_addr;
65
66      Debug (8, "resuming at ip=%llx via sigreturn(%p)\n",
67	     (unsigned long long) c->dwarf.ip, sc);
68      my_rt_sigreturn (sc);
69    }
70  else
71    {
72      Debug (8, "resuming at ip=%llx via setcontext()\n",
73	     (unsigned long long) c->dwarf.ip);
74      _x86_64_setcontext (uc);
75    }
76#else
77# warning Implement me!
78#endif
79  return -UNW_EINVAL;
80}
81
82#endif /* !UNW_REMOTE_ONLY */
83
84/* This routine is responsible for copying the register values in
85   cursor C and establishing them as the current machine state. */
86
87static inline int
88establish_machine_state (struct cursor *c)
89{
90  int (*access_reg) (unw_addr_space_t, unw_regnum_t, unw_word_t *,
91		     int write, void *);
92  int (*access_fpreg) (unw_addr_space_t, unw_regnum_t, unw_fpreg_t *,
93		       int write, void *);
94  unw_addr_space_t as = c->dwarf.as;
95  void *arg = c->dwarf.as_arg;
96  unw_fpreg_t fpval;
97  unw_word_t val;
98  int reg;
99
100  access_reg = as->acc.access_reg;
101  access_fpreg = as->acc.access_fpreg;
102
103  Debug (8, "copying out cursor state\n");
104
105  for (reg = 0; reg <= UNW_REG_LAST; ++reg)
106    {
107      Debug (16, "copying %s %d\n", unw_regname (reg), reg);
108      if (unw_is_fpreg (reg))
109	{
110	  if (tdep_access_fpreg (c, reg, &fpval, 0) >= 0)
111	    (*access_fpreg) (as, reg, &fpval, 1, arg);
112	}
113      else
114	{
115	  if (tdep_access_reg (c, reg, &val, 0) >= 0)
116	    (*access_reg) (as, reg, &val, 1, arg);
117	}
118    }
119  return 0;
120}
121
122PROTECTED int
123unw_resume (unw_cursor_t *cursor)
124{
125  struct cursor *c = (struct cursor *) cursor;
126  int ret;
127
128  Debug (1, "(cursor=%p)\n", c);
129
130  if ((ret = establish_machine_state (c)) < 0)
131    return ret;
132
133  return (*c->dwarf.as->acc.resume) (c->dwarf.as, (unw_cursor_t *) c,
134				     c->dwarf.as_arg);
135}
136