Red Hat Bugzilla – Bug 230423
ptrace causing SIGSEGV in debugged process when sending SIGKILL to it.
Last modified: 2007-11-30 17:11:58 EST
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User-Agent: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; .NET CLR 1.1.4322; .NET CLR 2.0.50727; .NET CLR 3.0.04506.30)
Description of problem:
I have written a small program to demonstrate this bug. It causes ptrace to trace /bin/ls. After the first waitpid, the parent sends a SIGKILL to ls and ls performs a segmentation fault. /bin/ls is only used as an example. Any traced process has the same problem. I have traced xterm, firefox, and gnome-cd as well and seen the bug.
The code will be attached to this bug report.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Compile and run the attached code.
The message "GOT SIGSEGV" should appear because the traced program performs a segmentation fault.
The traced program should not perform a segmentation fault and no message should appear.
Created attachment 148952 [details]
A test c program that demonstrates the bug.
A pure 126.96.36.199 kernel does not show the problem at all. I even tried adding
sched_yield in various places to see if scheduling order would affect things.
This is probably a utrace bug.
I reproduced this on 2.6.19-1.2911.fc6 but not on 2.6.20-1.2925.fc6.
Please try the latest fc6 update kernel and verify that the problem is gone for you.
It looks to be fixed in 2.6.20-1.2925.fc6.