TCMD 21.0.25 Integer divide-by-zero - code c0000094

[jaltman]

The following exception is generated periodically on Windows 7 64-bit.

0:000> .ecxr
*** ERROR: Symbol file could not be found. Defaulted to export symbols for tcmd.exe -
rax=0000000000000000 rbx=000000013f8da740 rcx=000000fb9e802cc6
rdx=0000000000000000 rsi=00000000017d6be0 rdi=000000013fd98360
rip=000000013f8e33f1 rsp=000000000148e5a0 rbp=000000000148e720
r8=00000000100046d0 r9=00003027cab385dc r10=00002e554ab7cbdc
r11=0000000000000000 r12=00000000017d6be0 r13=0000000000000000
r14=0000000000000001 r15=0000000000000001
iopl=0 nv up ei pl zr na po nc
cs=0033 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00010246
tcmd!CPUUsage+0x91:
00000001`3f8e33f1 49f7f3 div rax,r11


0:000> kb
*** Stack trace for last set context - .thread/.cxr resets it
RetAddr : Args to Child : Call Site
00000001`3f8da7a7 : 00000000`00003618 00000000`000037d8 00000000`00000000 00000000`00000030 : tcmd!CPUUsage+0x91
00000001`3f91719a : 00000000`00000591 00000001`3f8da740 00000001`3f8c0000 00000001`3fd98360 : tcmd+0x1a7a7
00000001`3f8e2b66 : 00000000`017d6be0 00000000`00000000 00000000`00000001 00000000`00000000 : tcmd!CPUUsage+0x33e3a
00000001`3f918f8e : 00000001`3f8e2ae0 00000000`00000001 00000000`00000000 00000000`017d6be0 : tcmd+0x22b66
00000001`3f911e3d : 00000000`00000000 00000001`3f918f40 00000000`00000001 00000000`0eb5c704 : tcmd!CPUUsage+0x35c2e
00000001`3f912954 : 00000000`00000229 00000000`7751228c 00000000`0148f884 00000001`3f912900 : tcmd!CPUUsage+0x2eadd
00000000`774e9bbd : 00000001`3f912900 00000000`00000001 00000000`00000000 00000000`00000000 : tcmd!CPUUsage+0x2f5f4
00000000`774e3b94 : 00000000`0006079a 00000001`3f912900 00000000`00000113 00000000`00000000 : user32!UserCallWinProcCheckWow+0x1ad
00000000`774e3b10 : 00000000`01625808 00000001`3f912900 00000000`00000113 00000000`00000000 : user32!CallWindowProcAorW+0xdc
00000001`3fb687b7 : 00000000`01625808 00000001`3f912900 00000000`00000113 00000000`00000113 : user32!CallWindowProcW+0x18
00000000`774e9bbd : 00000000`00000000 00000000`00000000 00000000`00000001 00000000`00000000 : tcmd!CPUUsage+0x285457
00000000`774e98c2 : 00000000`016257c8 00000001`3fb686b0 00000000`01625770 00000000`020a93b0 : user32!UserCallWinProcCheckWow+0x1ad
00000001`3f92ee7e : 00000000`016257c8 00000000`016257c8 00000001`3fb686b0 00000000`00000001 : user32!DispatchMessageWorker+0x3b5
00000001`3f92f5f3 : 00000001`3f92f560 00000000`00000000 00000000`00000001 00002d46`d7090965 : tcmd!CPUUsage+0x4bb1e
00000001`3fc8e99a : 00000001`3f9322f0 00000001`3f8c0000 00000000`00000000 00000000`00000000 : tcmd!CPUUsage+0x4c293
00000001`3fade5e3 : 00000000`0000000a 00000000`00000000 00000000`00000000 00000000`00000000 : tcmd!CPUUsage+0x3ab63a
00000000`775e59cd : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : tcmd!CPUUsage+0x1fb283
00000000`7771a561 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : kernel32!BaseThreadInitThunk+0xd
00000000`00000000 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : ntdll!RtlUserThreadStart+0x21

 

[rconn]

What is " .ecxr"?

And is this a TCMD or TCC/LE issue? (You posted it in the TCC/LE forum).

 

[JohnQSmith]

What is " .ecxr"?

www.google.com/search?q=.excr ==> .excr (Display Exception Context Record)

 

[rconn]

What are you doing when you get the error?

TCC doesn't do any divides (unless requested), and the address isn't in the TCMD / TCC code.

Are you running any plugins or third party apps that are injecting code into TCMD or TCC?

 

[jaltman]

My apologies for posting to the wrong forum.

.excr is the command entered into WinDbg to display the exception record stored withing a dump file.

The exception is taking place in TCMD code, in particular at offset 0x91 from the beginning of function tcmd!CPUUsage.

Does tcmd.exe not have a function called CPUUsage()? strings tcmd.exe includes

?CPUUsage@@YAHXZ

 

[jaltman]

tcmd is often in the background and idle when it crashes. I have a minidump if you are interested.

 

[rconn]

The only way that CPUUsage could fail is if the Windows GetSystemTimes API fails. And the only way that can fail is if you either:

1) Have a busted Windows installation, or
2) Have broken hardware, or
3) Have another app that's intercepting (and breaking) the API.

I made a change in build 28 (already uploaded) that wraps the API call in an exception handler; try that version and let me know if it changes the behavior.