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1 /* Target operations for the Valgrind remote server for GDB.
2    Copyright (C) 2002, 2003, 2004, 2005, 2012
3    Free Software Foundation, Inc.
4    Philippe Waroquiers.
5 
6    Contributed by MontaVista Software.
7 
8    This file is part of GDB.
9    It has been modified to integrate it in valgrind
10 
11    This program is free software; you can redistribute it and/or modify
12    it under the terms of the GNU General Public License as published by
13    the Free Software Foundation; either version 2 of the License, or
14    (at your option) any later version.
15 
16    This program is distributed in the hope that it will be useful,
17    but WITHOUT ANY WARRANTY; without even the implied warranty of
18    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19    GNU General Public License for more details.
20 
21    You should have received a copy of the GNU General Public License
22    along with this program; if not, write to the Free Software
23    Foundation, Inc., 51 Franklin Street, Fifth Floor,
24    Boston, MA 02110-1301, USA.  */
25 
26 #ifndef TARGET_H
27 #define TARGET_H
28 
29 /* This file defines the architecture independent Valgrind gdbserver
30    high level operations such as read memory, get/set registers, ...
31 
32    These high level operations are called by the gdbserver
33    protocol implementation (e.g. typically server.c).
34 
35    For some of these high level operations, target.c will call
36    low level operations dependent on the architecture.
37 
38    For example, getting or setting the registers will work on a
39    register cache. The exact details of the registers (how much,
40    their size, etc) is not defined by target.c or the register cache.
41 
42    Such architecture dependent information is defined by
43    valgrind_low.h/valgrind-low-xxxxx.c providing 'low level operations'
44    specific to the xxxxx architecture (for example,
45    valgrind-low-x86.c, valgrind-low-armc.c). */
46 
47 /* -------------------------------------------------------------------------- */
48 /* ------------------------ Initialisation ---------------------------------- */
49 /* -------------------------------------------------------------------------- */
50 
51 /* Initialize the Valgrind high target. This will in turn
52    initialise the low (architecture specific) target. */
53 extern void valgrind_initialize_target(void);
54 
55 /* initialize or re-initialize the register set of the low target.
56    if shadow_mode, then (re-)define the normal and valgrind shadow registers
57    else (re-)define only the normal registers. */
58 extern void initialize_shadow_low (Bool shadow_mode);
59 
60 /* Returns the name of the xml target description file.
61    returns NULL if no xml target description available.
62    if shadow_mode, then returns the xml target description
63    with the shadow registers
64    else returns the xml target description only for
65    the normal registers. */
66 extern char* valgrind_target_xml (Bool shadow_mode);
67 
68 
69 /* -------------------------------------------------------------------------- */
70 /* --------------------------- Execution control ---------------------------- */
71 /* -------------------------------------------------------------------------- */
72 
73 /* This structure describes how to resume the execution.
74    Currently, there is no way to resume only a specific thread.  */
75 struct thread_resume
76 {
77   /* If non-zero, we want to single-step.  */
78   int step;
79 
80   /* If non-zero, send this signal when we resume.  */
81   int sig;
82 };
83 
84 /* Prepare to Resume (i.e. restart) the guest.
85    The resume info indicates how the resume will be done.
86    In case GDB has changed the program counter, valgrind_resume
87    will also ensure that the execution will be resumed at this
88    new program counter.
89    The Resume is really only executed once the gdbserver
90    returns (giving back the control to Valgrind). */
91 extern void valgrind_resume (struct thread_resume *resume_info);
92 
93 /* When Valgrind gets the control, it will execute the guest
94    process till there is a reason to call the gdbserver
95    again (e.g. because a breakpoint is encountered or the
96    tool reports an error).
97    In such case, the executionof guest code  stops, and the
98    control is given to gdbserver. Gdbserver will send a resume
99    reply packet to GDB.
100 
101    valgrind_wait gets from Valgrind data structures the
102    information needed produce the resume reply for GDB:
103    a.o. OURSTATUS will be filled in with a response code to send to GDB.
104 
105    Returns the signal which caused the process to stop, in the
106    remote protocol numbering (e.g. TARGET_SIGNAL_STOP), or the
107    exit code as an integer if *OURSTATUS is 'W'.  */
108 extern unsigned char valgrind_wait (char *outstatus);
109 
110 /* When execution is stopped and gdbserver has control, more
111    info about the stop reason can be retrieved using the following
112    functions. */
113 
114 /* gets the addr at which a (possible) break must be ignored once.
115    If there is no such break to be ignored once, 0 is returned.
116    This is needed for the following case:
117    The user sets a break at address AAA.
118    The break is encountered. Then the user does stepi
119    (i.e. step one instruction).
120    In such a case, the already encountered break must be ignored
121    to ensure the stepi will advance by one instruction: a "break"
122    is implemented in valgrind by some helper code just after the
123    instruction mark at which the break is set. This helper code
124    verifies if either there is a break at the current PC
125    or if we are in stepping mode. If we are in stepping mode,
126    the already encountered break must be ignored once to advance
127    to the next instruction.
128    ??? need to check if this is *really* needed. */
129 extern Addr valgrind_get_ignore_break_once(void);
130 
131 /* When addr > 0, ensures the next resume reply packet informs
132    gdb about the encountered watchpoint.
133    valgrind_stopped_by_watchpoint() will return 1 till reset.
134    Use addr 0x0 to reset. */
135 extern void VG_(set_watchpoint_stop_address) (Addr addr);
136 
137 /* Returns 1 if target was stopped due to a watchpoint hit, 0 otherwise.  */
138 extern int valgrind_stopped_by_watchpoint (void);
139 
140 /* Returns the address associated with the watchpoint that hit, if any;
141    returns 0 otherwise.  */
142 extern CORE_ADDR valgrind_stopped_data_address (void);
143 
144 /* True if gdbserver is single stepping the valgrind process */
145 extern Bool valgrind_single_stepping(void);
146 
147 /* Set Valgrind in single stepping mode or not according to Bool. */
148 extern void valgrind_set_single_stepping(Bool);
149 
150 /* -------------------------------------------------------------------------- */
151 /* ----------------- Examining/modifying data while stopped ----------------- */
152 /* -------------------------------------------------------------------------- */
153 
154 /* Return 1 iff the thread with ID tid is alive.  */
155 extern int valgrind_thread_alive (unsigned long tid);
156 
157 /* Allows to controls the thread (current_inferior) used for following
158    valgrind_(fetch|store)_registers calls.
159    If USE_GENERAL,
160      current_inferior is set to general_thread
161    else
162      current_inferior is set to step_thread or else cont_thread.
163    If the above gives no valid thread, then current_inferior is
164    set to the first valid thread. */
165 extern void set_desired_inferior (int use_general);
166 
167 /* Fetch registers from the current_inferior thread.
168    If REGNO is -1, fetch all registers; otherwise, fetch at least REGNO.  */
169 extern void valgrind_fetch_registers (int regno);
170 
171 /* Store registers to the current_inferior thread.
172    If REGNO is -1, store all registers; otherwise, store at least REGNO.  */
173 extern void valgrind_store_registers (int regno);
174 
175 
176 
177 /* Read memory from the inferior process.
178    Read LEN bytes at MEMADDR into a buffer at MYADDR.
179    Returns 0 on success and errno on failure.  */
180 extern int valgrind_read_memory (CORE_ADDR memaddr,
181                                  unsigned char *myaddr, int len);
182 
183 /* Write memory to the inferior process.
184    Write LEN bytes from the buffer at MYADDR to MEMADDR.
185    Returns 0 on success and errno on failure.  */
186 extern int valgrind_write_memory (CORE_ADDR memaddr,
187                                   const unsigned char *myaddr, int len);
188 
189 
190 /* Insert and remove a hardware watchpoint.
191    Returns 0 on success, -1 on failure and 1 on unsupported.
192    The type is coded as follows:
193    2 = write watchpoint
194    3 = read watchpoint
195    4 = access watchpoint
196 */
197 extern int valgrind_insert_watchpoint (char type, CORE_ADDR addr, int len);
198 extern int valgrind_remove_watchpoint (char type, CORE_ADDR addr, int len);
199 
200 
201 /* -------------------------------------------------------------------------- */
202 /* ----------- Utils functions for low level arch specific files ------------ */
203 /* -------------------------------------------------------------------------- */
204 
205 /* returns a pointer to the architecture state corresponding to
206    the provided register set: 0 => normal guest registers,
207                               1 => shadow1
208                               2 => shadow2
209 */
210 extern VexGuestArchState* get_arch (int set, ThreadState* tst);
211 
212 /* like memcpy but first check if content of destination and source
213    differs. If no difference, no copy is done, *mod set to False.
214    If different; copy is done, *mod set to True. */
215 extern void* VG_(dmemcpy) ( void *d, const void *s, SizeT sz, Bool *mod );
216 
217 typedef
218    enum {
219       valgrind_to_gdbserver,
220       gdbserver_to_valgrind} transfer_direction;
221 
222 // According to dir, calls VG_(dmemcpy)
223 // to copy data from/to valgrind to/from gdbserver.
224 // If the transferred data differs from what is currently stored,
225 // sets *mod to True otherwise set *mod to False.
226 extern void  VG_(transfer) (void *valgrind,
227                             void *gdbserver,
228                             transfer_direction dir,
229                             SizeT sz,
230                             Bool *mod);
231 
232 
233 
234 #endif /* TARGET_H */
235