1/* KeyMgr backwards-compatibility support for Darwin.
2   Copyright (C) 2001-2020 Free Software Foundation, Inc.
3
4This file is part of GCC.
5
6GCC is free software; you can redistribute it and/or modify it under
7the terms of the GNU General Public License as published by the Free
8Software Foundation; either version 3, or (at your option) any later
9version.
10
11GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12WARRANTY; without even the implied warranty of MERCHANTABILITY or
13FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14for more details.
15
16Under Section 7 of GPL version 3, you are granted additional
17permissions described in the GCC Runtime Library Exception, version
183.1, as published by the Free Software Foundation.
19
20You should have received a copy of the GNU General Public License and
21a copy of the GCC Runtime Library Exception along with this program;
22see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23<http://www.gnu.org/licenses/>.  */
24
25/* It is incorrect to include config.h here, because this file is being
26   compiled for the target, and hence definitions concerning only the host
27   do not apply.  */
28
29#include "tconfig.h"
30#include "tsystem.h"
31
32/* This file doesn't do anything useful on non-powerpc targets, since they
33   don't have backwards compatibility anyway.  */
34
35#ifdef __ppc__
36
37/* Homemade decls substituting for getsect.h and dyld.h, so cross
38   compilation works.  */
39struct mach_header;
40extern char *getsectdatafromheader (struct mach_header *, const char *,
41				    const char *, unsigned long *);
42extern void _dyld_register_func_for_add_image
43  (void (*) (struct mach_header *, unsigned long));
44extern void _dyld_register_func_for_remove_image
45  (void (*) (struct mach_header *, unsigned long));
46
47extern void __darwin_gcc3_preregister_frame_info (void);
48
49/* These are from "keymgr.h".  */
50extern void _init_keymgr (void);
51extern void *_keymgr_get_and_lock_processwide_ptr (unsigned key);
52extern void _keymgr_set_and_unlock_processwide_ptr (unsigned key, void *ptr);
53
54extern void *__keymgr_global[];
55typedef struct _Sinfo_Node {
56        unsigned int size ;             /*size of this node*/
57        unsigned short major_version ;  /*API major version.*/
58        unsigned short minor_version ;  /*API minor version.*/
59        } _Tinfo_Node ;
60
61/* KeyMgr 3.x is the first one supporting GCC3 stuff natively.  */
62#define KEYMGR_API_MAJOR_GCC3           3
63/* ... with these keys.  */
64#define KEYMGR_GCC3_LIVE_IMAGE_LIST	301     /* loaded images  */
65#define KEYMGR_GCC3_DW2_OBJ_LIST	302     /* Dwarf2 object list  */
66
67/* Node of KEYMGR_GCC3_LIVE_IMAGE_LIST.  Info about each resident image.  */
68struct live_images {
69  unsigned long this_size;                      /* sizeof (live_images)  */
70  struct mach_header *mh;                       /* the image info  */
71  unsigned long vm_slide;
72  void (*destructor)(struct live_images *);     /* destructor for this  */
73  struct live_images *next;
74  unsigned int examined_p;
75  void *fde;
76  void *object_info;
77  unsigned long info[2];                        /* Future use.  */
78};
79
80
81/* These routines are used only on Darwin versions before 10.2.
82   Later versions have equivalent code in the system.
83   Eventually, they might go away, although it might be a long time...  */
84
85static void darwin_unwind_dyld_remove_image_hook
86  (struct mach_header *m, unsigned long s);
87static void darwin_unwind_dyld_remove_image_hook
88  (struct mach_header *m, unsigned long s);
89extern void __darwin_gcc3_preregister_frame_info (void);
90
91static void
92darwin_unwind_dyld_add_image_hook (struct mach_header *mh, unsigned long slide)
93{
94  struct live_images *l = (struct live_images *)calloc (1, sizeof (*l));
95  l->mh = mh;
96  l->vm_slide = slide;
97  l->this_size = sizeof (*l);
98  l->next = (struct live_images *)
99	_keymgr_get_and_lock_processwide_ptr (KEYMGR_GCC3_LIVE_IMAGE_LIST);
100  _keymgr_set_and_unlock_processwide_ptr (KEYMGR_GCC3_LIVE_IMAGE_LIST, l);
101}
102
103static void
104darwin_unwind_dyld_remove_image_hook (struct mach_header *m, unsigned long s)
105{
106  struct live_images *top, **lip, *destroy = NULL;
107
108  /* Look for it in the list of live images and delete it.  */
109
110  top = (struct live_images *)
111	   _keymgr_get_and_lock_processwide_ptr (KEYMGR_GCC3_LIVE_IMAGE_LIST);
112  for (lip = &top; *lip != NULL; lip = &(*lip)->next)
113    {
114      if ((*lip)->mh == m && (*lip)->vm_slide == s)
115        {
116          destroy = *lip;
117          *lip = destroy->next;			/* unlink DESTROY  */
118
119          if (destroy->this_size != sizeof (*destroy))	/* sanity check  */
120            abort ();
121
122          break;
123        }
124    }
125  _keymgr_set_and_unlock_processwide_ptr (KEYMGR_GCC3_LIVE_IMAGE_LIST, top);
126
127  /* Now that we have unlinked this from the image list, toss it.  */
128  if (destroy != NULL)
129    {
130      if (destroy->destructor != NULL)
131	(*destroy->destructor) (destroy);
132      free (destroy);
133    }
134}
135
136void
137__darwin_gcc3_preregister_frame_info (void)
138{
139  const _Tinfo_Node *info;
140  _init_keymgr ();
141  info = (_Tinfo_Node *)__keymgr_global[2];
142  if (info != NULL)
143    {
144      if (info->major_version >= KEYMGR_API_MAJOR_GCC3)
145	return;
146      /* Otherwise, use our own add_image_hooks.  */
147    }
148
149  _dyld_register_func_for_add_image (darwin_unwind_dyld_add_image_hook);
150  _dyld_register_func_for_remove_image (darwin_unwind_dyld_remove_image_hook);
151}
152
153#endif  /* __ppc__ */
154