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From: Cyril Hrubis <chrubis@suse.cz>
To: ltp@lists.linux.it
Subject: [LTP] [PATCH v2] tst_test: using SIGTERM to terminate process
Date: Fri, 17 Sep 2021 10:50:52 +0200	[thread overview]
Message-ID: <YURW7NKNSSr0J6pL@yuki> (raw)
In-Reply-To: <YUJ7SC/FoA8wTaf2@pevik>

Hi!
> setup()
> {
> 	tst_brk TCONF "quit now!"
> }
> 
> do_test()
> {
> 	tst_res TPASS "pass :)"
> }
> 
> tst_run
> EOF
> 
> # while true; do ./debug.sh; done

I managed to reproduce this in dash. I bet that this is a bug where
signal handler inside dash is temporarily disabled when we install the
trap and if we manage to hit that window the signal is discarded. At
least that is my working theory. After I've installed debug prints, in
the cases where it hangs the signal was sent just before have installed
the trap. And in some cases when the signal arrives the timer process is
killed but the trap is not invoked. So it really looks like signal
handling in dash is simply broken. Not sure what we can do about bugs
like this apart from switching to a real programming language.

-- 
Cyril Hrubis
chrubis@suse.cz

WARNING: multiple messages have this Message-ID (diff)
From: Cyril Hrubis <chrubis@suse.cz>
To: Petr Vorel <pvorel@suse.cz>
Cc: ltp@lists.linux.it, Joerg Vehlow <joerg.vehlow@aox-tech.de>
Subject: Re: [LTP] [PATCH v2] tst_test: using SIGTERM to terminate process
Date: Fri, 17 Sep 2021 10:50:52 +0200	[thread overview]
Message-ID: <YURW7NKNSSr0J6pL@yuki> (raw)
Message-ID: <20210917085052.fKdcS5fkC4BjlgsTL7zj8xDkMeZOsoOLRJK_Wxjokco@z> (raw)
In-Reply-To: <YUJ7SC/FoA8wTaf2@pevik>

Hi!
> setup()
> {
> 	tst_brk TCONF "quit now!"
> }
> 
> do_test()
> {
> 	tst_res TPASS "pass :)"
> }
> 
> tst_run
> EOF
> 
> # while true; do ./debug.sh; done

I managed to reproduce this in dash. I bet that this is a bug where
signal handler inside dash is temporarily disabled when we install the
trap and if we manage to hit that window the signal is discarded. At
least that is my working theory. After I've installed debug prints, in
the cases where it hangs the signal was sent just before have installed
the trap. And in some cases when the signal arrives the timer process is
killed but the trap is not invoked. So it really looks like signal
handling in dash is simply broken. Not sure what we can do about bugs
like this apart from switching to a real programming language.

-- 
Cyril Hrubis
chrubis@suse.cz

-- 
Mailing list info: https://lists.linux.it/listinfo/ltp

  reply	other threads:[~2021-09-17  8:50 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-19  8:58 [LTP] [PATCH v2] tst_test: using SIGTERM to terminate process Li Wang
2021-05-19  9:21 ` Joerg Vehlow
2021-05-27  4:11   ` Li Wang
2021-05-31  9:25 ` Li Wang
2021-09-15 22:40 ` Petr Vorel
2021-09-15 22:40   ` Petr Vorel
2021-09-15 23:01   ` Petr Vorel
2021-09-15 23:01     ` Petr Vorel
2021-09-17  8:50     ` Cyril Hrubis [this message]
2021-09-17  8:50       ` Cyril Hrubis
2021-09-17  9:17       ` Petr Vorel
2021-09-17  9:17         ` Petr Vorel
2021-09-17 10:18         ` Petr Vorel
2021-09-17 10:18           ` Petr Vorel
2021-09-17 10:59           ` Cyril Hrubis
2021-09-17 10:59             ` Cyril Hrubis
2021-09-17 11:03             ` Petr Vorel
2021-09-17 11:03               ` Petr Vorel

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