pub_tool_gdbserver.h revision b32f58018498ea2225959b0ba11c18f0c433deef 
1
2/*--------------------------------------------------------------------*/
3/*--- Handle remote gdb protocol.             pub_tool_gdbserver.h ---*/
4/*--------------------------------------------------------------------*/
5
6/*
7   This file is part of Valgrind, a dynamic binary instrumentation
8   framework.
9
10   Copyright (C) 2011-2011 Philippe Waroquiers
11
12   This program is free software; you can redistribute it and/or
13   modify it under the terms of the GNU General Public License as
14   published by the Free Software Foundation; either version 2 of the
15   License, or (at your option) any later version.
16
17   This program is distributed in the hope that it will be useful, but
18   WITHOUT ANY WARRANTY; without even the implied warranty of
19   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20   General Public License for more details.
21
22   You should have received a copy of the GNU General Public License
23   along with this program; if not, write to the Free Software
24   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
25   02111-1307, USA.
26
27   The GNU General Public License is contained in the file COPYING.
28*/
29
30#ifndef __PUB_TOOL_GDBSERVER_H
31#define __PUB_TOOL_GDBSERVER_H
32
33#include "libvex.h"
34#include "libvex_ir.h"
35
36//--------------------------------------------------------------------
37// PURPOSE: This module provides the support to have a gdb
38// connecting to a valgrind process using remote gdb protocol. It provides
39//  * A function to allow a tool (or the valgrind core) to
40//    wait for a gdb to connect and then handle gdb commands.
41//    Typically, this can be used to let the user debug the process
42//    when valgrind reports an error.
43//  * A function allowing to instrument the code to support gdb breakpoints.
44//  * A function allowing the tool to support watchpoints.
45//  * A utility function to help implementing the processing of the
46//    gdb_monitor_command strings.
47
48
49// Function to be used by tool or coregrind to allow a gdb to connect
50// to this process.
51// Calling VG_(gdbserver) with tid > 0 means to let a debugger attach
52// to the valgrind process. gdbserver will report to gdb that the
53// process stopped in thread tid.
54// tid == 0 indicates to stop gdbserver and report to gdb
55// that the valgrind-ified process has exited.
56//--------------------------------------------------------------------
57extern void VG_(gdbserver) ( ThreadId tid );
58
59/* VG_(dyn_vgdb_error) gets its initial value from
60   VG_(clo_vgdb_error).  It can be changed after initial command
61   processing in order to enable/disable the call to VG_(gdbserver) in
62   m_errormgr.c.  The main reasons to change the below is either
63   because the user updates it via a monitor command or to
64   (temporarily) avoid calling gdbserver for error reporting during
65   monitor command handling.
66*/
67extern Int VG_(dyn_vgdb_error);
68
69/* defines the various kinds of breakpoints that gdbserver
70   might ask to insert/remove. Note that the below matches
71   the gdbserver protocol definition. The level of support
72   of the various breakpoint kinds depends on the tool.
73
74   For the moment, it is unclear how a tool would implement
75   hardware_breakpoint in valgrind  :).
76
77   software_breakpoint implies some (small) specific
78   instrumentation to be done for gdbserver. This instrumentation
79   is implemented for all tools in m_translate.c.
80
81   write/read/access watchpoints can only be done by tools
82   which are maintaining some notion of address accessibility
83   as part of their instrumentation. watchpoints can then
84   be done by marking the watched address(es) as not accessible.
85   But instead of giving back an error (or whatever the tool
86   wants to do with unaccessible mechanism), the tool must then
87   just call gdbserver. See memcheck for an example of reusing
88   accessibility for watchpoint support.
89*/
90typedef
91   enum {
92      software_breakpoint,
93      hardware_breakpoint,
94      write_watchpoint,
95      read_watchpoint,
96      access_watchpoint } PointKind;
97extern char* VG_(ppPointKind) (PointKind kind);
98
99
100/* watchpoint support --------------------------------------*/
101/* True if one or more bytes in [addr, addr+len[ are being watched by
102   gdbserver for write or read or access.
103   In addition, VG_(is_watched) will invoke gdbserver if
104   the access provided by the tool matches the watchpoint kind.
105   For this, the tool must pass the kind of access it has detected:
106      write_watchpoint indicates the tool has detected a write
107      read_watchpoint indicates the tool has detected a read
108      access_watchpoint indicates the tool has detected an access but does
109      not know if this is a read or a write
110*/
111extern Bool VG_(is_watched)(PointKind kind, Addr addr, Int szB);
112
113extern void VG_(needs_watchpoint) (
114   // indicates the given Addr/len is being watched (insert)
115   // or not watched anymore (! insert).
116   // gdbserver will maintain the list of watched addresses.
117   // The tool can use VG_(is_watched) to verify if an
118   // access to an Addr is in one of the watched intervals.
119   // Must return True if the watchpoint has been properly inserted or
120   // removed. False if not supported.
121   // Note that an address can only be watched for a single kind.
122   // The tool must be ready to be called successively with
123   // multiple kinds for the same addr and len and with
124   // different kinds. The last kind must replace the previous values.
125   // Behaviour with multiple watches having overlapping addr+len
126   // is undefined.
127   Bool (*watchpoint) (PointKind kind, Bool insert, Addr addr, SizeT len)
128);
129
130
131// can be used during the processing of the VG_USERREQ__GDB_MONITOR_COMMAND
132// tool client request to output information to gdb or vgdb.
133extern UInt VG_(gdb_printf) ( const HChar *format, ... ) PRINTF_CHECK(1, 2);
134
135/* Utility functions to (e.g.) parse gdb monitor commands.
136
137   keywords is a set of keywords separated by a space
138   keyword_id will search for the keyword starting with the string input_word
139   and return its position.
140   It returns -1 if no keyword matches.
141   It returns -2 if two or more keywords are starting with input_word
142                 and none of these matches exactly input_word
143   Example with keywords = "hello world here is hell" :
144   input_word    result
145   ----------    ------
146   paradise   => -1
147   i          =>  3
148   hell       =>  4
149   hel        => -2
150   ishtar     => -1
151
152   report indicates when to output an error msg with VG_(gdb_printf).
153   kwd_report_none : no error is reported.
154   kwd_report_all : the error msg will show all possible keywords
155   kwd_report_duplicated_matches : the error msg will show only the
156     ambiguous matches.
157*/
158typedef
159   enum {
160      kwd_report_none,
161      kwd_report_all,
162      kwd_report_duplicated_matches } kwd_report_error;
163extern Int VG_(keyword_id) (Char* keywords, Char* input_word,
164                            kwd_report_error report);
165
166/* Extract an address and (optionally) a size from the string
167   currently being parsed by strtok_r (see pub_tool_libcbase.h).
168   If no size in the string, keeps the current value of szB.
169   Returns address 0 and szB 0 if there is an error.  Reports to the
170   user problems via VG_(gdb_printf).  */
171extern void VG_(strtok_get_address_and_size) (Addr* address,
172                                              SizeT* szB,
173                                              Char **ssaveptr);
174
175#endif   // __PUB_TOOL_GDBSERVER_H
176
177/*--------------------------------------------------------------------*/
178/*--- end                                                          ---*/
179/*--------------------------------------------------------------------*/
180