1 
2 /*--------------------------------------------------------------------*/
3 /*--- Address space manager.                  pub_tool_aspacemgr.h ---*/
4 /*--------------------------------------------------------------------*/
5 
6 /*
7    This file is part of Valgrind, a dynamic binary instrumentation
8    framework.
9 
10    Copyright (C) 2000-2017 Julian Seward
11       jseward@acm.org
12 
13    This program is free software; you can redistribute it and/or
14    modify it under the terms of the GNU General Public License as
15    published by the Free Software Foundation; either version 2 of the
16    License, or (at your option) any later version.
17 
18    This program is distributed in the hope that it will be useful, but
19    WITHOUT ANY WARRANTY; without even the implied warranty of
20    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
21    General Public License for more details.
22 
23    You should have received a copy of the GNU General Public License
24    along with this program; if not, write to the Free Software
25    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
26    02111-1307, USA.
27 
28    The GNU General Public License is contained in the file COPYING.
29 */
30 
31 #ifndef __PUB_TOOL_ASPACEMGR_H
32 #define __PUB_TOOL_ASPACEMGR_H
33 
34 #include "pub_tool_basics.h"   // VG_ macro
35 
36 //--------------------------------------------------------------
37 // Definition of address-space segments
38 
39 /* Describes segment kinds. Enumerators are one-hot encoded so they
40    can be or'ed together. */
41 typedef
42    enum {
43       SkFree  = 0x01,  // unmapped space
44       SkAnonC = 0x02,  // anonymous mapping belonging to the client
45       SkAnonV = 0x04,  // anonymous mapping belonging to valgrind
46       SkFileC = 0x08,  // file mapping belonging to the client
47       SkFileV = 0x10,  // file mapping belonging to valgrind
48       SkShmC  = 0x20,  // shared memory segment belonging to the client
49       SkResvn = 0x40   // reservation
50    }
51    SegKind;
52 
53 /* Describes how a reservation segment can be resized. */
54 typedef
55    enum {
56       SmLower,  // lower end can move up
57       SmFixed,  // cannot be shrunk
58       SmUpper   // upper end can move down
59    }
60    ShrinkMode;
61 
62 /* Describes a segment.  Invariants:
63 
64      kind == SkFree:
65         // the only meaningful fields are .start and .end
66 
67      kind == SkAnon{C,V}:
68         // smode==SmFixed
69         // there's no associated file:
70         dev==ino==foff = 0, fnidx == -1
71         // segment may have permissions
72 
73      kind == SkFile{C,V}:
74         // smode==SmFixed
75         // there is an associated file
76         // segment may have permissions
77 
78      kind == SkShmC:
79         // smode==SmFixed
80         // there's no associated file:
81         dev==ino==foff = 0, fnidx == -1
82         // segment may have permissions
83 
84      kind == SkResvn
85         // the segment may be resized if required
86         // there's no associated file:
87         dev==ino==foff = 0, fnidx == -1
88         // segment has no permissions
89         hasR==hasW==hasX == False
90 
91      Also: hasT==True is only allowed in SkFileC, SkAnonC, and SkShmC
92            (viz, not allowed to make translations from non-client areas)
93 */
94 typedef
95    struct {
96       SegKind kind;
97       /* Extent */
98       Addr    start;    // lowest address in range
99       Addr    end;      // highest address in range
100       /* Shrinkable? (SkResvn only) */
101       ShrinkMode smode;
102       /* Associated file (SkFile{C,V} only) */
103       ULong   dev;
104       ULong   ino;
105       Off64T  offset;
106       UInt    mode;
107       Int     fnIdx;    // file name table index, if name is known
108       /* Permissions (SkAnon{C,V}, SkFile{C,V} only) */
109       Bool    hasR;
110       Bool    hasW;
111       Bool    hasX;
112       Bool    hasT;     // True --> translations have (or MAY have)
113                         // been taken from this segment
114       Bool    isCH;     // True --> is client heap (SkAnonC ONLY)
115    }
116    NSegment;
117 
118 
119 /* Collect up the start addresses of segments whose kind matches one of
120    the kinds specified in kind_mask.
121    The interface is a bit strange in order to avoid potential
122    segment-creation races caused by dynamic allocation of the result
123    buffer *starts.
124 
125    The function first computes how many entries in the result
126    buffer *starts will be needed.  If this number <= nStarts,
127    they are placed in starts[0..], and the number is returned.
128    If nStarts is not large enough, nothing is written to
129    starts[0..], and the negation of the size is returned.
130 
131    Correct use of this function may mean calling it multiple times in
132    order to establish a suitably-sized buffer. */
133 extern Int VG_(am_get_segment_starts)( UInt kind_mask, Addr* starts,
134                                        Int nStarts );
135 
136 /* Finds the segment containing 'a'.  Only returns file/anon/resvn
137    segments.  This returns a 'NSegment const *' - a pointer to
138    readonly data. */
139 extern NSegment const * VG_(am_find_nsegment) ( Addr a );
140 
141 /* Get the filename corresponding to this segment, if known and if it
142    has one. The function may return NULL if the file name is not known. */
143 extern const HChar* VG_(am_get_filename)( NSegment const * );
144 
145 /* Is the area [start .. start+len-1] validly accessible by the
146    client with at least the permissions 'prot' ?  To find out
147    simply if said area merely belongs to the client, pass
148    VKI_PROT_NONE as 'prot'.  Will return False if any part of the
149    area does not belong to the client or does not have at least
150    the stated permissions. */
151 extern Bool VG_(am_is_valid_for_client) ( Addr start, SizeT len,
152                                           UInt prot );
153 
154 /* Really just a wrapper around VG_(am_mmap_anon_float_valgrind). */
155 extern void* VG_(am_shadow_alloc)(SizeT size);
156 
157 /* Unmap the given address range and update the segment array
158    accordingly.  This fails if the range isn't valid for valgrind. */
159 extern SysRes VG_(am_munmap_valgrind)( Addr start, SizeT length );
160 
161 #endif   // __PUB_TOOL_ASPACEMGR_H
162 
163 /*--------------------------------------------------------------------*/
164 /*--- end                                                          ---*/
165 /*--------------------------------------------------------------------*/
166