1 /* Internal interfaces for the Windows code
2 Copyright (C) 1995-2020 Free Software Foundation, Inc.
4 This file is part of GDB.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>. */
19 #include "gdbsupport/common-defs.h"
20 #include "nat/windows-nat.h"
21 #include "gdbsupport/common-debug.h"
26 HANDLE current_process_handle
;
27 DWORD current_process_id
;
29 enum gdb_signal last_sig
= GDB_SIGNAL_0
;
30 DEBUG_EVENT current_event
;
32 /* The most recent event from WaitForDebugEvent. Unlike
33 current_event, this is guaranteed never to come from a pending
34 stop. This is important because only data from the most recent
35 event from WaitForDebugEvent can be used when calling
36 ContinueDebugEvent. */
37 static DEBUG_EVENT last_wait_event
;
39 DWORD desired_stop_thread_id
= -1;
40 std::vector
<pending_stop
> pending_stops
;
41 EXCEPTION_RECORD siginfo_er
;
44 bool ignore_first_breakpoint
= false;
47 /* Note that 'debug_events' must be locally defined in the relevant
49 #define DEBUG_EVENTS(x) if (debug_events) debug_printf x
51 windows_thread_info::~windows_thread_info ()
56 windows_thread_info::suspend ()
61 if (SuspendThread (h
) == (DWORD
) -1)
63 DWORD err
= GetLastError ();
65 /* We get Access Denied (5) when trying to suspend
66 threads that Windows started on behalf of the
67 debuggee, usually when those threads are just
69 We can get Invalid Handle (6) if the main thread
71 if (err
!= ERROR_INVALID_HANDLE
&& err
!= ERROR_ACCESS_DENIED
)
72 warning (_("SuspendThread (tid=0x%x) failed. (winerr %u)"),
73 (unsigned) tid
, (unsigned) err
);
81 windows_thread_info::resume ()
85 stopped_at_software_breakpoint
= false;
87 if (ResumeThread (h
) == (DWORD
) -1)
89 DWORD err
= GetLastError ();
90 warning (_("warning: ResumeThread (tid=0x%x) failed. (winerr %u)"),
91 (unsigned) tid
, (unsigned) err
);
98 get_image_name (HANDLE h
, void *address
, int unicode
)
101 static char buf
[MAX_PATH
];
103 static char buf
[(2 * MAX_PATH
) + 1];
105 DWORD size
= unicode
? sizeof (WCHAR
) : sizeof (char);
111 /* Attempt to read the name of the dll that was detected.
112 This is documented to work only when actively debugging
113 a program. It will not work for attached processes. */
118 /* Windows CE reports the address of the image name,
119 instead of an address of a pointer into the image name. */
120 address_ptr
= address
;
122 /* See if we could read the address of a string, and that the
123 address isn't null. */
124 if (!ReadProcessMemory (h
, address
, &address_ptr
,
125 sizeof (address_ptr
), &done
)
126 || done
!= sizeof (address_ptr
)
131 /* Find the length of the string. */
132 while (ReadProcessMemory (h
, address_ptr
+ len
++ * size
, &b
, size
, &done
)
133 && (b
[0] != 0 || b
[size
- 1] != 0) && done
== size
)
137 ReadProcessMemory (h
, address_ptr
, buf
, len
, &done
);
140 WCHAR
*unicode_address
= (WCHAR
*) alloca (len
* sizeof (WCHAR
));
141 ReadProcessMemory (h
, address_ptr
, unicode_address
, len
* sizeof (WCHAR
),
144 wcstombs (buf
, unicode_address
, MAX_PATH
);
146 WideCharToMultiByte (CP_ACP
, 0, unicode_address
, len
, buf
, sizeof buf
,
154 /* The exception thrown by a program to tell the debugger the name of
155 a thread. The exception record contains an ID of a thread and a
156 name to give it. This exception has no documented name, but MSDN
157 dubs it "MS_VC_EXCEPTION" in one code example. */
158 #define MS_VC_EXCEPTION 0x406d1388
160 handle_exception_result
161 handle_exception (struct target_waitstatus
*ourstatus
, bool debug_exceptions
)
163 #define DEBUG_EXCEPTION_SIMPLE(x) if (debug_exceptions) \
164 debug_printf ("gdb: Target exception %s at %s\n", x, \
165 host_address_to_string (\
166 current_event.u.Exception.ExceptionRecord.ExceptionAddress))
168 EXCEPTION_RECORD
*rec
= ¤t_event
.u
.Exception
.ExceptionRecord
;
169 DWORD code
= rec
->ExceptionCode
;
170 handle_exception_result result
= HANDLE_EXCEPTION_HANDLED
;
172 memcpy (&siginfo_er
, rec
, sizeof siginfo_er
);
174 ourstatus
->kind
= TARGET_WAITKIND_STOPPED
;
176 /* Record the context of the current thread. */
177 thread_rec (ptid_t (current_event
.dwProcessId
, current_event
.dwThreadId
, 0),
182 case EXCEPTION_ACCESS_VIOLATION
:
183 DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_ACCESS_VIOLATION");
184 ourstatus
->value
.sig
= GDB_SIGNAL_SEGV
;
185 if (handle_access_violation (rec
))
186 return HANDLE_EXCEPTION_UNHANDLED
;
188 case STATUS_STACK_OVERFLOW
:
189 DEBUG_EXCEPTION_SIMPLE ("STATUS_STACK_OVERFLOW");
190 ourstatus
->value
.sig
= GDB_SIGNAL_SEGV
;
192 case STATUS_FLOAT_DENORMAL_OPERAND
:
193 DEBUG_EXCEPTION_SIMPLE ("STATUS_FLOAT_DENORMAL_OPERAND");
194 ourstatus
->value
.sig
= GDB_SIGNAL_FPE
;
196 case EXCEPTION_ARRAY_BOUNDS_EXCEEDED
:
197 DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_ARRAY_BOUNDS_EXCEEDED");
198 ourstatus
->value
.sig
= GDB_SIGNAL_FPE
;
200 case STATUS_FLOAT_INEXACT_RESULT
:
201 DEBUG_EXCEPTION_SIMPLE ("STATUS_FLOAT_INEXACT_RESULT");
202 ourstatus
->value
.sig
= GDB_SIGNAL_FPE
;
204 case STATUS_FLOAT_INVALID_OPERATION
:
205 DEBUG_EXCEPTION_SIMPLE ("STATUS_FLOAT_INVALID_OPERATION");
206 ourstatus
->value
.sig
= GDB_SIGNAL_FPE
;
208 case STATUS_FLOAT_OVERFLOW
:
209 DEBUG_EXCEPTION_SIMPLE ("STATUS_FLOAT_OVERFLOW");
210 ourstatus
->value
.sig
= GDB_SIGNAL_FPE
;
212 case STATUS_FLOAT_STACK_CHECK
:
213 DEBUG_EXCEPTION_SIMPLE ("STATUS_FLOAT_STACK_CHECK");
214 ourstatus
->value
.sig
= GDB_SIGNAL_FPE
;
216 case STATUS_FLOAT_UNDERFLOW
:
217 DEBUG_EXCEPTION_SIMPLE ("STATUS_FLOAT_UNDERFLOW");
218 ourstatus
->value
.sig
= GDB_SIGNAL_FPE
;
220 case STATUS_FLOAT_DIVIDE_BY_ZERO
:
221 DEBUG_EXCEPTION_SIMPLE ("STATUS_FLOAT_DIVIDE_BY_ZERO");
222 ourstatus
->value
.sig
= GDB_SIGNAL_FPE
;
224 case STATUS_INTEGER_DIVIDE_BY_ZERO
:
225 DEBUG_EXCEPTION_SIMPLE ("STATUS_INTEGER_DIVIDE_BY_ZERO");
226 ourstatus
->value
.sig
= GDB_SIGNAL_FPE
;
228 case STATUS_INTEGER_OVERFLOW
:
229 DEBUG_EXCEPTION_SIMPLE ("STATUS_INTEGER_OVERFLOW");
230 ourstatus
->value
.sig
= GDB_SIGNAL_FPE
;
232 case EXCEPTION_BREAKPOINT
:
234 if (ignore_first_breakpoint
)
236 /* For WOW64 processes, there are always 2 breakpoint exceptions
237 on startup, first a BREAKPOINT for the 64bit ntdll.dll,
238 then a WX86_BREAKPOINT for the 32bit ntdll.dll.
239 Here we only care about the WX86_BREAKPOINT's. */
240 ourstatus
->kind
= TARGET_WAITKIND_SPURIOUS
;
241 ignore_first_breakpoint
= false;
245 case STATUS_WX86_BREAKPOINT
:
246 DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_BREAKPOINT");
247 ourstatus
->value
.sig
= GDB_SIGNAL_TRAP
;
249 /* Remove the initial breakpoint. */
250 check_breakpoints ((CORE_ADDR
) (long) current_event
251 .u
.Exception
.ExceptionRecord
.ExceptionAddress
);
255 DEBUG_EXCEPTION_SIMPLE ("DBG_CONTROL_C");
256 ourstatus
->value
.sig
= GDB_SIGNAL_INT
;
258 case DBG_CONTROL_BREAK
:
259 DEBUG_EXCEPTION_SIMPLE ("DBG_CONTROL_BREAK");
260 ourstatus
->value
.sig
= GDB_SIGNAL_INT
;
262 case EXCEPTION_SINGLE_STEP
:
263 case STATUS_WX86_SINGLE_STEP
:
264 DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_SINGLE_STEP");
265 ourstatus
->value
.sig
= GDB_SIGNAL_TRAP
;
267 case EXCEPTION_ILLEGAL_INSTRUCTION
:
268 DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_ILLEGAL_INSTRUCTION");
269 ourstatus
->value
.sig
= GDB_SIGNAL_ILL
;
271 case EXCEPTION_PRIV_INSTRUCTION
:
272 DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_PRIV_INSTRUCTION");
273 ourstatus
->value
.sig
= GDB_SIGNAL_ILL
;
275 case EXCEPTION_NONCONTINUABLE_EXCEPTION
:
276 DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_NONCONTINUABLE_EXCEPTION");
277 ourstatus
->value
.sig
= GDB_SIGNAL_ILL
;
279 case MS_VC_EXCEPTION
:
280 DEBUG_EXCEPTION_SIMPLE ("MS_VC_EXCEPTION");
281 if (handle_ms_vc_exception (rec
))
283 ourstatus
->value
.sig
= GDB_SIGNAL_TRAP
;
284 result
= HANDLE_EXCEPTION_IGNORED
;
287 /* treat improperly formed exception as unknown */
290 /* Treat unhandled first chance exceptions specially. */
291 if (current_event
.u
.Exception
.dwFirstChance
)
292 return HANDLE_EXCEPTION_UNHANDLED
;
293 debug_printf ("gdb: unknown target exception 0x%08x at %s\n",
294 (unsigned) current_event
.u
.Exception
.ExceptionRecord
.ExceptionCode
,
295 host_address_to_string (
296 current_event
.u
.Exception
.ExceptionRecord
.ExceptionAddress
));
297 ourstatus
->value
.sig
= GDB_SIGNAL_UNKNOWN
;
301 last_sig
= ourstatus
->value
.sig
;
304 #undef DEBUG_EXCEPTION_SIMPLE
307 /* See nat/windows-nat.h. */
310 matching_pending_stop (bool debug_events
)
312 /* If there are pending stops, and we might plausibly hit one of
313 them, we don't want to actually continue the inferior -- we just
314 want to report the stop. In this case, we just pretend to
315 continue. See the comment by the definition of "pending_stops"
316 for details on why this is needed. */
317 for (const auto &item
: pending_stops
)
319 if (desired_stop_thread_id
== -1
320 || desired_stop_thread_id
== item
.thread_id
)
322 DEBUG_EVENTS (("windows_continue - pending stop anticipated, "
323 "desired=0x%x, item=0x%x\n",
324 desired_stop_thread_id
, item
.thread_id
));
332 /* See nat/windows-nat.h. */
334 gdb::optional
<pending_stop
>
335 fetch_pending_stop (bool debug_events
)
337 gdb::optional
<pending_stop
> result
;
338 for (auto iter
= pending_stops
.begin ();
339 iter
!= pending_stops
.end ();
342 if (desired_stop_thread_id
== -1
343 || desired_stop_thread_id
== iter
->thread_id
)
346 current_event
= iter
->event
;
348 DEBUG_EVENTS (("get_windows_debug_event - "
349 "pending stop found in 0x%x (desired=0x%x)\n",
350 iter
->thread_id
, desired_stop_thread_id
));
352 pending_stops
.erase (iter
);
360 /* See nat/windows-nat.h. */
363 continue_last_debug_event (DWORD continue_status
, bool debug_events
)
365 DEBUG_EVENTS (("ContinueDebugEvent (cpid=%d, ctid=0x%x, %s);\n",
366 (unsigned) last_wait_event
.dwProcessId
,
367 (unsigned) last_wait_event
.dwThreadId
,
368 continue_status
== DBG_CONTINUE
?
369 "DBG_CONTINUE" : "DBG_EXCEPTION_NOT_HANDLED"));
371 return ContinueDebugEvent (last_wait_event
.dwProcessId
,
372 last_wait_event
.dwThreadId
,
376 /* See nat/windows-nat.h. */
379 wait_for_debug_event (DEBUG_EVENT
*event
, DWORD timeout
)
381 BOOL result
= WaitForDebugEvent (event
, timeout
);
383 last_wait_event
= *event
;