[Qemu-devel] Segfault installing Windows XP 32 Bit guest on Linux 64Bit host

[Qemu-devel] Segfault installing Windows XP 32 Bit guest on Linux 64Bit host

[Brad Campbell]

(gdb) run
Starting program: /home/brad/bin/qemu -fda /tmp/fd.img -hda /home/brad/qemu/xptest.img -cdrom 
/raid3/isos/XP-corp-sp2.iso -localtime -m 256 -usb -usbdevice tablet -std-vga -no-acpi -vnc :2 -boot 
d -no-reboot -no-kqemu
Failed to read a valid object file image from memory.
[Thread debugging using libthread_db enabled]
[New Thread 139849118447312 (LWP 9558)]
[New Thread 1098533216 (LWP 9561)]

Program received signal SIGUSR2, User defined signal 2.
[Switching to Thread 139849118447312 (LWP 9558)]
temp_save (s=0x3, temp=11050592, allocated_regs=16404)
     at /home/brad/src/qemu/tcg/tcg.c:1334
1334	    ts = &s->temps[temp];
(gdb) bt
#0  temp_save (s=0x3, temp=11050592, allocated_regs=16404)
     at /home/brad/src/qemu/tcg/tcg.c:1334
#1  0x00000000004defc2 in save_globals (s=0xa89e60, allocated_regs=16404)
     at /home/brad/src/qemu/tcg/tcg.c:1368
#2  0x00000000004dfd22 in tcg_reg_alloc_op (s=0xa89e60, def=0x687200, opc=69,
     args=0xa7ecf8, dead_iargs=1) at /home/brad/src/qemu/tcg/tcg.c:1586
#3  0x00000000004ead88 in dyngen_code (s=0xa89e60,
     gen_code_buf=0x431640b0 "1?A\211>1?A\211v\004A\213v H\213?I\211?\230")
     at /home/brad/src/qemu/tcg/tcg.c:1960
#4  0x000000000048ca51 in cpu_x86_gen_code (env=0xb07980, tb=0x7f31139fdfe0,
     gen_code_size_ptr=0x7fff3107c6bc)
     at /home/brad/src/qemu/translate-all.c:121
#5  0x000000000048d1e2 in cpu_x86_exec (env1=0xa89e60)
     at /home/brad/src/qemu/cpu-exec.c:144
#6  0x000000000040f96c in main (argc=21, argv=0x0)
     at /home/brad/src/qemu/vl.c:7076

Does this mean anything to the tcg wizards ?

Regards,
Brad
-- 
"Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so." -- Douglas Adams

Re: [Qemu-devel] Segfault installing Windows XP 32 Bit guest on Linux 64Bit host

[andrzej zaborowski]

On 30/05/2008, Brad Campbell <brad@wasp.net.au> wrote:
> (gdb) run
>  Starting program: /home/brad/bin/qemu -fda /tmp/fd.img -hda
> /home/brad/qemu/xptest.img -cdrom /raid3/isos/XP-corp-sp2.iso -localtime -m
> 256 -usb -usbdevice tablet -std-vga -no-acpi -vnc :2 -boot d -no-reboot
> -no-kqemu
>  Failed to read a valid object file image from memory.
>  [Thread debugging using libthread_db enabled]
>  [New Thread 139849118447312 (LWP 9558)]
>  [New Thread 1098533216 (LWP 9561)]
>
>  Program received signal SIGUSR2, User defined signal 2.

I'm afraid this is not the backtrace you want.  You need to ignore
SIGUSR2 and continue until the SIGSEGV:

(gdb) handle SIGUSR2 nostop noprint pass
(gdb) c
(gdb) bt

HTH
-- 
Please do not print this email unless absolutely necessary. Spread
environmental awareness.

Re: [Qemu-devel] Segfault installing Windows XP 32 Bit guest on Linux 64Bit host

[Brad Campbell]

andrzej zaborowski wrote:
> On 30/05/2008, Brad Campbell <brad@wasp.net.au> wrote:
>> (gdb) run
>>  Starting program: /home/brad/bin/qemu -fda /tmp/fd.img -hda
>> /home/brad/qemu/xptest.img -cdrom /raid3/isos/XP-corp-sp2.iso -localtime -m
>> 256 -usb -usbdevice tablet -std-vga -no-acpi -vnc :2 -boot d -no-reboot
>> -no-kqemu
>>  Failed to read a valid object file image from memory.
>>  [Thread debugging using libthread_db enabled]
>>  [New Thread 139849118447312 (LWP 9558)]
>>  [New Thread 1098533216 (LWP 9561)]
>>
>>  Program received signal SIGUSR2, User defined signal 2.
> 
> I'm afraid this is not the backtrace you want.  You need to ignore
> SIGUSR2 and continue until the SIGSEGV:
> 
> (gdb) handle SIGUSR2 nostop noprint pass
> (gdb) c
> (gdb) bt
> 
> HTH

Thanks Paul, that helped greatly!

Program received signal SIGUSR2, User defined signal 2.
[Switching to Thread 140040879920848 (LWP 15924)]
0x00007f5dce73cffd in __lll_mutex_unlock_wake () from /lib/libpthread.so.0
(gdb) handle SIGUSR2 nostop noprint pass
Signal        Stop	Print	Pass to program	Description
SIGUSR2       No	No	Yes		User defined signal 2
(gdb) c
Continuing.

Program received signal SIGSEGV, Segmentation fault.
0x000000000046d5a5 in vnc_update_client (opaque=0x7f5db8e99000) at vnc.c:536
536			    if (memcmp(old_ptr, ptr, 16 * vs->depth) == 0) {
(gdb) bt
#0  0x000000000046d5a5 in vnc_update_client (opaque=0x7f5db8e99000)
     at vnc.c:536
#1  0x000000000040668c in qemu_run_timers (ptimer_head=0x688cc0,
     current_time=9750412) at /home/brad/src/qemu/vl.c:1077
#2  0x000000000040ca0c in main_loop_wait (timeout=0)
     at /home/brad/src/qemu/vl.c:7043
#3  0x000000000040fa15 in main (argc=21, argv=0x0)
     at /home/brad/src/qemu/vl.c:7133


I'm running this on a headless machine and don't have libSDL installed (compiled with 
--disable-gfx-check) and I'll lay odds it's something weird here..
I'm getting this with Ubuntu guest also now, so it's easier for me to track down!

Regards,
Brad
-- 
"Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so." -- Douglas Adams

Re: [Qemu-devel] Segfault installing Windows XP 32 Bit guest on Linux 64Bit host

[Brad Campbell]

Brad Campbell wrote:
> andrzej zaborowski wrote:
>> On 30/05/2008, Brad Campbell <brad@wasp.net.au> wrote:
>>> (gdb) run
>>>  Starting program: /home/brad/bin/qemu -fda /tmp/fd.img -hda
>>> /home/brad/qemu/xptest.img -cdrom /raid3/isos/XP-corp-sp2.iso 
>>> -localtime -m
>>> 256 -usb -usbdevice tablet -std-vga -no-acpi -vnc :2 -boot d -no-reboot
>>> -no-kqemu
>>>  Failed to read a valid object file image from memory.
>>>  [Thread debugging using libthread_db enabled]
>>>  [New Thread 139849118447312 (LWP 9558)]
>>>  [New Thread 1098533216 (LWP 9561)]
>>>
>>>  Program received signal SIGUSR2, User defined signal 2.
>>
>> I'm afraid this is not the backtrace you want.  You need to ignore
>> SIGUSR2 and continue until the SIGSEGV:
>>
>> (gdb) handle SIGUSR2 nostop noprint pass
>> (gdb) c
>> (gdb) bt
>>
>> HTH
> 
> Thanks Paul, that helped greatly!

My sincerest apologies Andrzej, I'm not sure where my brain was when I wrote that!

Brad
-- 
"Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so." -- Douglas Adams

[Qemu-devel] VNC Segfault : was Re: Segfault installing Windows XP 32 Bit guest on Linux 64Bit host

[Brad Campbell]

Brad Campbell wrote:
> Program received signal SIGSEGV, Segmentation fault.
> 0x000000000046d5a5 in vnc_update_client (opaque=0x7f5db8e99000) at 
> vnc.c:536
> 536                if (memcmp(old_ptr, ptr, 16 * vs->depth) == 0) {
> (gdb) bt
> #0  0x000000000046d5a5 in vnc_update_client (opaque=0x7f5db8e99000)
>     at vnc.c:536
> #1  0x000000000040668c in qemu_run_timers (ptimer_head=0x688cc0,
>     current_time=9750412) at /home/brad/src/qemu/vl.c:1077
> #2  0x000000000040ca0c in main_loop_wait (timeout=0)
>     at /home/brad/src/qemu/vl.c:7043
> #3  0x000000000040fa15 in main (argc=21, argv=0x0)
>     at /home/brad/src/qemu/vl.c:7133
> 
> 
> I'm running this on a headless machine and don't have libSDL installed 
> (compiled with --disable-gfx-check) and I'll lay odds it's something 
> weird here..
> I'm getting this with Ubuntu guest also now, so it's easier for me to 
> track down!

Ok, this is a general VNC explosion. If I compile it with libSDL and run a standard SDL window over 
X then it works fine. As soon as I add -vnc :2 to the command line it blows up in the same place.

Brad
-- 
"Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so." -- Douglas Adams

Re: [Qemu-devel] VNC Segfault : was Re: Segfault installing Windows XP 32 Bit guest on Linux 64Bit host

[Anthony Liguori]

Brad Campbell wrote:
> Brad Campbell wrote:
>> Program received signal SIGSEGV, Segmentation fault.
>> 0x000000000046d5a5 in vnc_update_client (opaque=0x7f5db8e99000) at 
>> vnc.c:536
>> 536                if (memcmp(old_ptr, ptr, 16 * vs->depth) == 0) {
>> (gdb) bt
>> #0  0x000000000046d5a5 in vnc_update_client (opaque=0x7f5db8e99000)
>>     at vnc.c:536
>> #1  0x000000000040668c in qemu_run_timers (ptimer_head=0x688cc0,
>>     current_time=9750412) at /home/brad/src/qemu/vl.c:1077
>> #2  0x000000000040ca0c in main_loop_wait (timeout=0)
>>     at /home/brad/src/qemu/vl.c:7043
>> #3  0x000000000040fa15 in main (argc=21, argv=0x0)
>>     at /home/brad/src/qemu/vl.c:7133
>>
>>
>> I'm running this on a headless machine and don't have libSDL 
>> installed (compiled with --disable-gfx-check) and I'll lay odds it's 
>> something weird here..
>> I'm getting this with Ubuntu guest also now, so it's easier for me to 
>> track down!
>
> Ok, this is a general VNC explosion. If I compile it with libSDL and 
> run a standard SDL window over X then it works fine. As soon as I add 
> -vnc :2 to the command line it blows up in the same place.

Is this the latest SVN?  There was a recent SEGV fix for VNC.

Regards

Anthony Liguori

> Brad

Re: [Qemu-devel] VNC Segfault : was Re: Segfault installing Windows XP 32 Bit guest on Linux 64Bit host

[Brad Campbell]

Anthony Liguori wrote:

>> Ok, this is a general VNC explosion. If I compile it with libSDL and 
>> run a standard SDL window over X then it works fine. As soon as I add 
>> -vnc :2 to the command line it blows up in the same place.
> 
> Is this the latest SVN?  There was a recent SEGV fix for VNC.

Yep
brad@srv-64:~/src/qemu$ svn up
At revision 4622.

It's very easily reproducible here, I'll have some time tomorrow to look at it closer and see if I 
can fix it.

Regards,
Brad
-- 
"Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so." -- Douglas Adams

Re: [Qemu-devel] VNC Segfault : was Re: Segfault installing Windows XP 32 Bit guest on Linux 64Bit host

[Anthony Liguori]

Brad Campbell wrote:
> Anthony Liguori wrote:
>
>>> Ok, this is a general VNC explosion. If I compile it with libSDL and 
>>> run a standard SDL window over X then it works fine. As soon as I 
>>> add -vnc :2 to the command line it blows up in the same place.
>>
>> Is this the latest SVN?  There was a recent SEGV fix for VNC.
>
> Yep
> brad@srv-64:~/src/qemu$ svn up
> At revision 4622.
>
> It's very easily reproducible here, I'll have some time tomorrow to 
> look at it closer and see if I can fix it.

How are you reproducing it?  With what client?

Regards,

Anthony Liguori

> Regards,
> Brad

Re: [Qemu-devel] VNC Segfault : was Re: Segfault installing Windows XP 32 Bit guest on Linux 64Bit host

[Eduardo Felipe]

[-- Attachment #1: Type: text/plain, Size: 1041 bytes --]

2008/5/30 Anthony Liguori <anthony@codemonkey.ws>:

> Brad Campbell wrote:
>
>> Anthony Liguori wrote:
>>
>>  Ok, this is a general VNC explosion. If I compile it with libSDL and run
>>>> a standard SDL window over X then it works fine. As soon as I add -vnc :2 to
>>>> the command line it blows up in the same place.
>>>>
>>>
>>> Is this the latest SVN?  There was a recent SEGV fix for VNC.
>>>
>>
>> Yep
>> brad@srv-64:~/src/qemu$ svn up
>> At revision 4622.
>>
>> It's very easily reproducible here, I'll have some time tomorrow to look
>> at it closer and see if I can fix it.
>>
>
> How are you reproducing it?  With what client?
>
>
This seems related to a problem discussed here some time ago:

http://lists.gnu.org/archive/html/qemu-devel/2007-10/msg00104.html

If it is so, to reproduce it just use a client without DesktopSize
pseudoencoding and tell the guest OS to scale down his window. A segfault
will follow in the next SetPixelFormat received by qemu.

Regards,
Edu

P.S. (I don't know if my original patch already applies)

[-- Attachment #2: Type: text/html, Size: 1860 bytes --]

Re: [Qemu-devel] VNC Segfault : was Re: Segfault installing Windows XP 32 Bit guest on Linux 64Bit host

[Anthony Liguori]

Eduardo Felipe wrote:
>
>
> 2008/5/30 Anthony Liguori <anthony@codemonkey.ws 
> <mailto:anthony@codemonkey.ws>>:
>
>     Brad Campbell wrote:
>
>         Anthony Liguori wrote:
>
>                 Ok, this is a general VNC explosion. If I compile it
>                 with libSDL and run a standard SDL window over X then
>                 it works fine. As soon as I add -vnc :2 to the command
>                 line it blows up in the same place.
>
>
>             Is this the latest SVN?  There was a recent SEGV fix for VNC.
>
>
>         Yep
>         brad@srv-64:~/src/qemu$ svn up
>         At revision 4622.
>
>         It's very easily reproducible here, I'll have some time
>         tomorrow to look at it closer and see if I can fix it.
>
>
>     How are you reproducing it?  With what client?
>
>
> This seems related to a problem discussed here some time ago:
>
> http://lists.gnu.org/archive/html/qemu-devel/2007-10/msg00104.html
>
> If it is so, to reproduce it just use a client without DesktopSize 
> pseudoencoding and tell the guest OS to scale down his window. A 
> segfault will follow in the next SetPixelFormat received by qemu.

That shoudl be fixed in SVN.

Regards,

Anthony Liguori

> Regards,
> Edu
>
> P.S. (I don't know if my original patch already applies) 

Re: [Qemu-devel] VNC Segfault : was Re: Segfault installing Windows XP 32 Bit guest on Linux 64Bit host

[Brad Campbell]

Anthony Liguori wrote:
> Brad Campbell wrote:
>> Anthony Liguori wrote:
>>
>>>> Ok, this is a general VNC explosion. If I compile it with libSDL and 
>>>> run a standard SDL window over X then it works fine. As soon as I 
>>>> add -vnc :2 to the command line it blows up in the same place.
>>>
>>> Is this the latest SVN?  There was a recent SEGV fix for VNC.
>>
>> Yep
>> brad@srv-64:~/src/qemu$ svn up
>> At revision 4622.
>>
>> It's very easily reproducible here, I'll have some time tomorrow to 
>> look at it closer and see if I can fix it.
> 
> How are you reproducing it?  With what client?

Great question. I tried the realvnc based xvncviewer and the problem did not occur.

brad@bklaptop2:~$ xvnc4viewer --version

VNC Viewer Free Edition 4.1.1 for X - built Apr 16 2008 13:02:40
Copyright (C) 2002-2005 RealVNC Ltd.
See http://www.realvnc.com for information on VNC.


This one dies horribly. Apparently on resolution change, but not certainly.. It does always die on a 
screen mode change though.

brad@bklaptop2:~$ vncviewer --version
TightVNC viewer version 1.2.9
Ubuntu package : xtightvncviewer from 8.04

I'm just building the latest tightvnc from source to see if the issue is fixed there, but 
xtightvncviewer from Ubuntu 8.04 will certainly kill it.

Brad
-- 
"Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so." -- Douglas Adams

Re: [Qemu-devel] VNC Segfault : was Re: Segfault installing Windows XP 32 Bit guest on Linux 64Bit host

[Brad Campbell]

Anthony Liguori wrote:
>> Yep
>> brad@srv-64:~/src/qemu$ svn up
>> At revision 4622.
>>
>> It's very easily reproducible here, I'll have some time tomorrow to 
>> look at it closer and see if I can fix it.
> 
> How are you reproducing it?  With what client?
> 
Ok, this is compiled from source and still kills it dead.
http://downloads.sourceforge.net/vnc-tight/tightvnc-1.3.9_unixsrc.tar.bz2

brad@bklaptop2:~/temp/vnc_unixsrc/vncviewer$ ./vncviewer --version
TightVNC Viewer version 1.3.9

Brad
-- 
"Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so." -- Douglas Adams

Re: [Qemu-devel] VNC Segfault : was Re: Segfault installing Windows XP 32 Bit guest on Linux 64Bit host

[Brad Campbell]

[-- Attachment #1: Type: text/plain, Size: 747 bytes --]

Eduardo Felipe wrote:
> This seems related to a problem discussed here some time ago:

Yep!

> http://lists.gnu.org/archive/html/qemu-devel/2007-10/msg00104.html
> 
> If it is so, to reproduce it just use a client without DesktopSize 
> pseudoencoding and tell the guest OS to scale down his window. A 
> segfault will follow in the next SetPixelFormat received by qemu.
> 
> Regards,
> Edu
> 
> P.S. (I don't know if my original patch already applies)

It was already sorta integrated by the looks of it.. but not completely.

Patch attached.

Thanks all!
Brad
-- 
"Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so." -- Douglas Adams

[-- Attachment #2: patch --]
[-- Type: text/plain, Size: 842 bytes --]

Index: vnc.c
===================================================================
--- vnc.c	(revision 4632)
+++ vnc.c	(working copy)
@@ -307,12 +307,14 @@
     ds->width = w;
     ds->height = h;
     ds->linesize = w * vs->depth;
-    if (vs->csock != -1 && vs->has_resize && size_changed) {
-	vnc_write_u8(vs, 0);  /* msg id */
-	vnc_write_u8(vs, 0);
-	vnc_write_u16(vs, 1); /* number of rects */
-	vnc_framebuffer_update(vs, 0, 0, ds->width, ds->height, -223);
-	vnc_flush(vs);
+    if (size_changed) {
+        if (vs->csock != -1 && vs->has_resize && size_changed) {
+	    vnc_write_u8(vs, 0);  /* msg id */
+	    vnc_write_u8(vs, 0);
+	    vnc_write_u16(vs, 1); /* number of rects */
+	    vnc_framebuffer_update(vs, 0, 0, ds->width, ds->height, -223);
+	    vnc_flush(vs);
+	}
 	vs->width = ds->width;
 	vs->height = ds->height;
     }

[PATCH] Re: [Qemu-devel] VNC Segfault : was Re: Segfault installing Windows XP 32 Bit guest on Linux 64Bit host

[Brad Campbell]

[-- Attachment #1: Type: text/plain, Size: 267 bytes --]

Brad Campbell wrote:

> Patch attached.
> 

*fixed* patch attached.. <sigh>

Brad
-- 
"Human beings, who are almost unique in having the ability
to learn from the experience of others, are also remarkable
for their apparent disinclination to do so." -- Douglas Adams

[-- Attachment #2: patch --]
[-- Type: text/plain, Size: 826 bytes --]

Index: vnc.c
===================================================================
--- vnc.c	(revision 4632)
+++ vnc.c	(working copy)
@@ -307,12 +307,14 @@
     ds->width = w;
     ds->height = h;
     ds->linesize = w * vs->depth;
-    if (vs->csock != -1 && vs->has_resize && size_changed) {
-	vnc_write_u8(vs, 0);  /* msg id */
-	vnc_write_u8(vs, 0);
-	vnc_write_u16(vs, 1); /* number of rects */
-	vnc_framebuffer_update(vs, 0, 0, ds->width, ds->height, -223);
-	vnc_flush(vs);
+    if (size_changed) {
+        if (vs->csock != -1 && vs->has_resize) {
+	    vnc_write_u8(vs, 0);  /* msg id */
+	    vnc_write_u8(vs, 0);
+	    vnc_write_u16(vs, 1); /* number of rects */
+	    vnc_framebuffer_update(vs, 0, 0, ds->width, ds->height, -223);
+	    vnc_flush(vs);
+	}
 	vs->width = ds->width;
 	vs->height = ds->height;
     }