Messages in this thread | | | Date | Wed, 04 Jun 2008 11:16:12 +0200 | From | Petr Tesarik <> | Subject | Re: [RFC PATCH] set TASK_TRACED before arch_ptrace code to fix a race |
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Luming Yu wrote: >> It's definitely a bug in strace. For some reason (I don't care about) >> the execve() syscall produces an extra notification. However, this >> notification message is suppressed when SIGTRAP is blocked. This >> explains why the test case fails only when SIGTRAP is blocked. > > This is exact problem I suspected and I was trying to address in my hack.. > Since there are several processes involved in the pretty complex > ptrace scenario., > I need to capture all processes context with kdump to confirm this is > exact root-cause > for the problem. But kdump doesn't work for me..I'm trying to solve it now.. > > I'm also in doubt about the semantic correctness of the test case.. > Since SIGTRAP is so necessary to get ptrace work, is it legitimate to > block it in test case? > > One more thing I need to say is: > Same strace works for utrace enabled kernel on IA64.. If the bug is in > strace, how could it happen?
No idea, but send me the strace.log file from running
strace -o strace.log strace -f -o log.txt ./test1
and I may be able to tell.
Petr Tesarik
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