1 This file describes where to start debugging Wine and how to write
7 These usually show up like this:
9 |Unexpected Windows program segfault - opcode = 8b
10 |Segmentation fault in Windows program 1b7:c41.
11 |Loading symbols from ELF file /root/wine/wine...
12 |....more Loading symbols from ...
15 | CS:01b7 SS:016f DS:0287 ES:0000
16 | IP:0c41 SP:878a BP:8796 FLAGS:0246
17 | AX:811e BX:0000 CX:0000 DX:0000 SI:0001 DI:ffff
19 |0x016f:0x878a: 0001 016f ffed 0000 0000 0287 890b 1e5b
20 |0x016f:0x879a: 01b7 0001 000d 1050 08b7 016f 0001 000d
21 |0x016f:0x87aa: 000a 0003 0004 0000 0007 0007 0190 0000
24 |0050: sel=0287 base=40211d30 limit=0b93f (bytes) 16-bit rw-
26 |0 0x01b7:0x0c41 (PXSRV_FONGETFACENAME+0x7c)
27 |1 0x01b7:0x1e5b (PXSRV_FONPUTCATFONT+0x2cd)
29 |3 0x01b7:0x0768 (PXSRV_FONINITFONTS+0x81)
30 |4 0x014f:0x03ed (PDOXWIN_@SQLCURCB$Q6CBTYPEULN8CBSCTYPE+0x1b1)
33 |0x01b7:0x0c41 (PXSRV_FONGETFACENAME+0x7c): movw %es:0x38(%bx),%dx
35 Steps to debug a crash. You may stop at any step, but please report the bug
36 and provide as much of the information gathered to the newsgroup or the
37 relevant developer as feasonable.
39 1. Get the reason for the crash. This is usually an access to an invalid
40 selector, an access to an out of range address in a valid selector,
41 popping a segmentregister from the stack or the like. When reporting a
42 crash, report this WHOLE crashdump even if it doesn't make sense to you.
44 (In this case it is access to an invalid selector, for %es is 0000, as
45 seen in the register dump).
47 2. Determine where the reason came from.
48 Since this is usually a primary/secondary reaction to a failed or
49 misbehaving Wine function, rerun Wine with "-debugmsg +relay" (without ")
50 added to the commandline. This will get rather much output, but usually
51 the reason is located in the last call(s). Those lines usually look like
54 |Call KERNEL.90: LSTRLEN(0227:0692 "text") ret=01e7:2ce7 ds=0227
55 ^^^^^^^^^ ^ ^^^^^^^^^ ^^^^^^ ^^^^^^^^^ ^^^^
56 | | | | | |Datasegment
57 | | | | |Return address
58 | | | |textual parameter
60 | | |Argument(s). This one is a win16 segmented pointer.
62 |The module, the function is called in. In this case it is KERNEL.
64 |Ret KERNEL.90: LSTRLEN() retval=0x0004 ret=01e7:2ce7 ds=0227
66 |Returnvalue is 16 bit and has the value 4.
69 3. If you have found a misbehaving function, try to find out why it
70 misbehaves. Find the function in the source code. Try to make sense of
71 the arguments passed. Usually there is a
72 "dprintf_xyz(stddeb,"Function(...)"...);" at the beginning of the
73 function. Rerun wine with "-debugmsg +xyz,+relay" added to the
76 4. Additional information on how to debug using the internal debugger can be
77 found in debugger/README.
79 5. If those information isn't clear enough or if you want to know more about
80 what's happening in the function itself, try running wine with "-debugmsg
81 +all", which dumps ALL included debug information in wine.
83 6. If that isn't enough add more debug output for yourself into the
84 functions you find relevant.
85 You might also try to run the program in gdb instead of using the
86 WINE-debugger. If you don't use the "-desktop" or "-managed" option,
87 start the WINE process with "-sync", or chances are good to get X into
90 7. You can also set a breakpoint for that function. Start wine with the
91 "-debug" option added to the commandline. After loading the executable
92 wine will enter the internal debugger. Use "break KERNEL_LSTRLEN"
93 (replace by function you want to debug, CASE IS RELEVANT.) to set a
94 breakpoint. Then use "continue" to start normal program-execution. Wine
95 will stop if it reaches the breakpoint. If the program isn't yet at the
96 crashing call of that function, use "continue" again until you are about
97 to enter that function. You may now proceed with single-stepping the
98 function until you reach the point of crash. Use the other debugger
99 commands to print registers and the like.
102 Program hangs, nothing happens
103 ==============================
105 Switch to UNIX shell, get the process-ID using "ps -a|grep wine", and do a
106 "kill -HUP <pid>" (without " and <>). Wine will then enter its internal
107 debugger and you can proceed as explained above. Also, you can use -debug
108 switch and then you can get into internal debugger by pressing Ctrl-C in
109 the terminal where you run Wine.
111 Program reports an error with a Messagebox
112 ==========================================
114 Sometimes programs are reporting failure using a more or less nondescript
115 messageboxes. We can debug this using the same method as Crashes, but there
116 is one problem... For setting up a message box the program also calls Wine
117 producing huge chunks of debug code.
119 Since the failure happens usually directly before setting up the Messagebox
120 you can start wine with "-debug" added to the commandline, set a breakpoint
121 at "MessageBox32A" (called by win16 and win32 programs) and proceed with
122 "continue". With "-debugmsg +all" Wine will now stop directly directly
123 before setting up the Messagebox. Proceed as explained above.
125 You can also run wine using "wine -debugmsg +relay program.exe 2>&1|less -i"
126 and in less search for messagebox.
128 Disassembling programs:
129 =======================
130 You may also try to disassemble the offending program to check for
131 undocumented features and/or use of them.
133 The best, freely available, disassembler for Win16 programs is
134 Windows Codeback, archivename wcbxxx.zip, which usually can be found
135 in the Cica-Mirror subdirectory on the WINE ftpsites. (See ANNOUNCE).
136 Disassembling win32 programs is possible using the Windows Disassembler 32,
137 archivename something like w32dasm.zip on ftp.winsite.com and mirrors.
138 The shareware version does not allow saving of disassembly listings.
140 [It also has a bug, it disassembles the dll and immediately after that
141 crashes, leaving a very large file caled 'winsys' in the directory of the
142 disassembled file. This file contains nothing of value (just the disassembly)
143 and can be safely deleted.]
145 Understanding disassembled code is just a question of exercise.
147 Most code out there uses standard C function entries (for it is usually
148 written in C). Win16 function entries usually look like that:
151 | ... function code ..
152 | retf XXXX <--------- XXXX is number of bytes of arguments
154 This is a FAR function with no local storage. The arguments usually start
155 at [bp+6] with increasing offsets. Note, that [bp+6] belongs to the RIGHTMOST
156 argument, for exported win16 functions use the PASCAL calling convention.
157 So, if we use strcmp(a,b) with a and b both 32 bit variables b would be at
158 [bp+6] and a at [bp+10].
159 Most functions make also use of local storage in the stackframe:
161 | ... function code ...
164 This does mostly the same as above, but also adds 0x86 bytes of
165 stackstorage, which is accessed using [bp-xx].
166 Before calling a function, arguments are pushed on the stack using something
168 | push word ptr [bp-02] <- will be at [bp+8]
169 | push di <- will be at [bp+6]
170 | call KERNEL.LSTRLEN
171 Here first the selector and then the offset to the passed string are pushed.
173 Sample debugging session:
174 =========================
176 Let's debug the infamous Word SHARE.EXE messagebox:
178 |marcus@jet $ wine winword.exe
179 | +---------------------------------------------+
180 | | ! You must leave Windows and load SHARE.EXE|
181 | | before starting Word. |
182 | +---------------------------------------------+
185 |marcus@jet $ wine winword.exe -debugmsg +relay -debug
186 |CallTo32(wndproc=0x40065bc0,hwnd=000001ac,msg=00000081,wp=00000000,lp=00000000)
187 |Win16 task 'winword': Breakpoint 1 at 0x01d7:0x001a
188 |CallTo16(func=0127:0070,ds=0927)
189 |Call WPROCS.24: TASK_RESCHEDULE() ret=00b7:1456 ds=0927
190 |Ret WPROCS.24: TASK_RESCHEDULE() retval=0x8672 ret=00b7:1456 ds=0927
191 |CallTo16(func=01d7:001a,ds=0927)
192 | AX=0000 BX=3cb4 CX=1f40 DX=0000 SI=0000 DI=0927 BP=0000 ES=11f7
193 |Loading symbols: /home/marcus/wine/wine...
194 |Stopped on breakpoint 1 at 0x01d7:0x001a
196 |Wine-dbg>break MessageBox32A <---- Set Breakpoint
197 |Breakpoint 2 at 0x40189100 (MessageBox32A [msgbox.c:190])
198 |Wine-dbg>c <---- Continue
199 |Call KERNEL.91: INITTASK() ret=0157:0022 ds=08a7
200 | AX=0000 BX=3cb4 CX=1f40 DX=0000 SI=0000 DI=08a7 ES=11d7 EFL=00000286
201 |CallTo16(func=090f:085c,ds=0dcf,0x0000,0x0000,0x0000,0x0000,0x0800,0x0000,0x0000,0x0dcf)
202 |... <----- Much debugoutput
203 |Call KERNEL.136: GETDRIVETYPE(0x0000) ret=060f:097b ds=0927
205 |Ret KERNEL.136: GETDRIVETYPE() retval=0x0002 ret=060f:097b ds=0927
206 ^^^^^^ DRIVE_REMOVEABLE
207 (It is a floppy diskdrive.)
209 |Call KERNEL.136: GETDRIVETYPE(0x0001) ret=060f:097b ds=0927
211 |Ret KERNEL.136: GETDRIVETYPE() retval=0x0000 ret=060f:097b ds=0927
212 ^^^^^^ DRIVE_CANNOTDETERMINE
213 (I don't have drive B: assigned)
215 |Call KERNEL.136: GETDRIVETYPE(0x0002) ret=060f:097b ds=0927
217 |Ret KERNEL.136: GETDRIVETYPE() retval=0x0003 ret=060f:097b ds=0927
219 (specified as a harddisk)
221 |Call KERNEL.97: GETTEMPFILENAME(0x00c3,0x09278364"doc",0x0000,0927:8248) ret=060f:09b1 ds=0927
222 ^^^^^^ ^^^^^ ^^^^^^^^^
223 | | |buffer for fname
224 | |temporary name ~docXXXX.tmp
225 |Force use of Drive C:.
227 |Warning: GetTempFileName returns 'C:~doc9281.tmp', which doesn't seem to be writeable.
228 |Please check your configuration file if this generates a failure.
230 Whoops, it even detects that something is wrong!
232 |Ret KERNEL.97: GETTEMPFILENAME() retval=0x9281 ret=060f:09b1 ds=0927
233 ^^^^^^ Temporary storage ID
235 |Call KERNEL.74: OPENFILE(0x09278248"C:~doc9281.tmp",0927:82da,0x1012) ret=060f:09d8 ds=0927
236 ^^^^^^^^^^^^^^^^ ^^^^^^^^^ ^^^^^^^
237 |filename |OFSTRUCT |open mode:
239 OF_CREATE|OF_SHARE_EXCLUSIVE|OF_READWRITE
241 This fails, since my C: drive is in this case mounted readonly.
243 |Ret KERNEL.74: OPENFILE() retval=0xffff ret=060f:09d8 ds=0927
244 ^^^^^^ HFILE_ERROR16, yes, it failed.
246 |Call USER.1: MESSAGEBOX(0x0000,0x09278376"Sie müssen Windows verlassen und SHARE.EXE laden bevor Sie Word starten.",0x00000000,0x1030) ret=060f:084f ds=0927
250 |Stopped on breakpoint 2 at 0x40189100 (MessageBox32A [msgbox.c:190])
251 |190 { <- the sourceline
255 The code seems to find a writeable harddisk and tries to create a file
256 there. To work around this bug, you can define C: as a networkdrive,
257 which is ignored by the code above.
259 Written by Marcus Meissner <msmeissn@cip.informatik.uni-erlangen.de>,