re: printer not present causes fatal read error!
Sunday, February 23, 2003 at 3:17 pm
Windows 2000 Annoyances Discussion Forum
Posted by Jeremy
(10 messages posted)
Kevin,
Let's talk about read/write errors, pointers and drwatson:
I'm not sure if you're having printer issues, but these read/write errors which specify
two 32-bit addresses are actually quite generic, only indicating a general type of
error and not necessarily the cause. This could be a problem with drivers, application/system
dlls or the application exe (in this case, Netscape).
The basic cause of an access (more properly --> addressing) exception is a pointer
"run amock" so that it is pointing at some invalid address (i.e. outside its allowed
area) *or* it is a null pointer (all zeros) that is being interpretted by the application
as a valid memory location when it is not! In your case, "0x077319bc" is the address
which Netscape is attempting to write to ... likely the 1st address is a valid instruction
in the executable, but the second is protected, and *maybe* not valid for the executable
to be writing.
This is academic, so let's get down to debugging, using my problem and its drwatson
dump as an illustrative example.
Win2k includes drwatson, which can be started as your debugger. It sounds like you
do not have it running by default, so type "drwtsn32 -i" (sin quotes) at the command
line or from the run box.
Now start your application in question (in your case, Netscape) and cause the error
(or just wait for it to occur if this is a startup error). This should cause a dump
file to be created, usually drwtsn.log, instead of that unhelpful pop-up error message.
You will receive a mesg. that drwatson is creating a dump -- mine go in "Docs and
Settings\All Users\Documents" (yours may differ). The dump name is drwtsn32.log
and will be appended to if it already exists. Just search for drwtsn32.log on your
system partition (C:\) after you've gotten the mesg. that drwatson created a dump
for you.
(I've included portions of my own dump for illustrative purposes.)
My dump indicates an "access violation" ("0005") in Ultra Edit 32, which means the
application in question attempted to read from memory outside its designated area,
in this case from "0x00000000". Incidentally, this is the same as the IBM SOC5 addressing
exception, which indicates that the memory location is protected from reading/writing
by this program.
I can tell that Windows crashed when executing DrvConvertDevMode ("function:").
My theory is that a null pointer was encountered, but this was not checked in the
code. The applications (Photoshop, Visio and Ultra Edit) were assuming a printer
driver existed where it didn't and attempted to read from this null pointer location
(aka 0x00000000). This was the cause of the access violation. Furthermore, a more
specific diagnosis might target NtReplyWaitReceivePortEx which is also dumped as
a relavent function. Perhaps it was the returner of the null pointer. I really
don't care now that this whole problem is "fixed".
Taking a look at the Microsoft doc page for the function DrvConvertDevMode, http://msdn.microsoft.com/library/default.asp?url=/library/en-us/graphics/hh/graphics/drvrfnc_8s6f.asp,
I see "The function should verify that both pdmIn and pdmOut" exist. This is a Microsoft
SDK function (indicated at the top). It was looking for a valid data structure for
my Windows 2000 driver (pdmIn) and Windows 98 (pdfmOut, server). One was not found,
yet the function did not check for this and return a reasonable error message. Instead,
it assumed a null pointer was actually the address of a valid DEVMODEW structure
for the Windows 98 printer driver.
I find it asinine that Microsoft did not follow their own error-checking guidelines
in this system function and output a more informative error message after testing
and trapping for the null pointer.
You can also see on the task list that "1196 UEDIT32.exe" was the application that
caused the crash (appears just before drwatsn itself). I'm thinking that Ultra Edit
was not the real culprit, and it was a dll loaded in UE's application space containing
this printer conversion function, though I could be totally off here and be blaming
MS when it is this application's fault. Oh, well, I like bashing Microsoft because
it is so easy. :)
The function which caused the error was
DrvConvertDevMode
and the faulting instruction ...
FAULT ->6061fdc3 f3a5 rep movsd ds:00000000=???????? es:00162c28=00000000
Though I'm no PC assembler guru (hehe, IBM assembler is another matter!) this shows
me that several key memory locations (i.e. function arguments) were zero, i.e. null
pointers. Since the Windows 98 printer driver was not present, this DrvConvertDevMode
function received null pointers which were probably not trapped. Thus, the application
attempted to read from 0x00000000 (null pointer), most certainly an invalid address
to mess with (probably containing essential OS instructions) and crashed.
Now, this is all rather circuitous and somewhat involved. You might have better
luck searching google for the specific error mesg. you're receiving, which should
be in Event Viewer -> Application Messages (I didn't find anything on groups or web
using portions of your error mesg.).
Sorry, I couldn't give more specific help for your Netscape error.
Why don't you get drwtsn32 running as your debugger and post a full dump here? I'll
take a look at it for you and see if I can pinpoint the exact function/instruction
causing the error. That will give you something specific to gripe about to Netscape/Microsoft/annoyances.org.
Here is the dump from the example above ...
----start drwatson dump----
Application exception occurred:
App: (pid=1112)
When: 2/13/2003 @ 13:26:21.840
Exception number: c0000005 (access violation)
*----> System Information <----*
Computer Name: MACHINE
User Name: jeremy
Number of Processors: 1
Processor Type: x86 Family 6 Model 4 Stepping 4
Windows 2000 Version: 5.0
Current Build: 2195
Service Pack: 3
Current Type: Uniprocessor Free
Registered Organization: none
Registered Owner: Jeremy McCormick
*----> Task List <----*
...
1112 UEDIT32.exe
1228 DRWTSN32.exe
0 _Total.exe
...
State Dump for Thread Id 0x41c
eax=00000844 ebx=00000000 ecx=00000211 edx=00000000 esi=00000000 edi=0016a008
eip=6061fdc3 esp=0012ed60 ebp=0012ed68 iopl=0 nv up ei pl nz ac po nc
cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00000216
function: DrvConvertDevMode
6061fda4 3bfe cmp edi,esi
6061fda6 7608 jbe DrvConvertDevMode+0x80c4 (606238b0)
6061fda8 3bf8 cmp edi,eax
6061fdaa 0f8278010000 jb DrvConvertDevMode+0x473c (6061ff28)
6061fdb0 f7c703000000 test edi,0x3
6061fdb6 7514 jnz DrvDocumentEvent+0xef1 (6062becc)
6061fdb8 c1e902 shr ecx,0x2
6061fdbb 83e203 and edx,0x3
6061fdbe 83f908 cmp ecx,0x8
6061fdc1 7229 jb 6062f0ec
FAULT ->6061fdc3 f3a5 rep movsd ds:00000000=???????? es:0016a008=00000000
6061fdc5 ff2495d8fe6160 ds:00000000=????????
jmp dword ptr [DrvConvertDevMode+0x46ec (6061fed8)+edx*4]
6061fdcc 8bc7 mov eax,edi
6061fdce ba03000000 mov edx,0x3
6061fdd3 83e904 sub ecx,0x4
6061fdd6 720c jb DrvConvertDevMode+0xc8f8 (606280e4)
6061fdd8 83e003 and eax,0x3
6061fddb 03c8 add ecx,eax
6061fddd ff2485f0fd6160 ds:00000844=????????
jmp dword ptr [DrvConvertDevMode+0x4604 (6061fdf0)+eax*4]
6061fde4 ff248de8fe6160 ds:00000211=????????
jmp dword ptr [DrvConvertDevMode+0x46fc (6061fee8)+ecx*4]
6061fdeb 90 nop
6061fdec ff248d6cfe6160 ds:00000211=????????
jmp dword ptr [DrvConvertDevMode+0x4680 (6061fe6c)+ecx*4]
...
function: NtReplyWaitReceivePortEx
77f83bad b8ac000000 mov eax,0xac
77f83bb2 8d542404 lea edx,[esp+0x4] ss:021ad3fb=????????
77f83bb6 cd2e int 2e
77f83bb8 c21400 ret 0x14
----end drwatson dump----
Cheers!
Jeremy
On Thursday, February 20, 2003 at 4:23 pm, Kevin Riley wrote:
>Jeremy,
>I don't have an answer but I have a simular problem in Win2K:
>_____________________________________________
>Application popup: XPCOM:EventReceiver: NETSCP.EXE - Application Error : The instruction
>at "0x0789e7a4" referenced memory at "0x077319bc". The memory could not be "written".
>
>Click on OK to terminate the program
>_________________________________________________
>
>I'm writing to request if you find an answer I would greatly appreciate a post.
Likwise
>If I find anything I'm post t you.
>
>Regards
>Kevin
>
>
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