From owner-cvs-all  Tue Mar 11  3:21:55 2003
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Date: Tue, 11 Mar 2003 22:21:48 +1100 (EST)
From: Bruce Evans <bde@zeta.org.au>
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To: David Xu <davidxu@freebsd.org>
Cc: src-committers@freebsd.org, "" <cvs-src@freebsd.org>,
	"" <cvs-all@freebsd.org>
Subject: Re: cvs commit: src/usr.bin/su su.c
In-Reply-To: <000501c2e7ad$48ab2790$f001a8c0@davidw2k>
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References: <200303110010.h2B0ANe3061768@repoman.freebsd.org>
 <20030311180357.E23929@gamplex.bde.org> <000501c2e7ad$48ab2790$f001a8c0@davidw2k>
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On Tue, 11 Mar 2003, David Xu wrote:

> Unfortunately I had ignored code for child process :(
> BTW, The SIGTSTP handler will be reset by execsigs() in kernel,
> The garbage sa_tstp is only effective in very short time.

execsigs() only resets caught signals, so the garbage lives at least a
little longer if happened to set to SIG_IGN.  For the same reason, we
can't depend on execsigs() changing SIG_IGN to SIG_DFL for the parent.

I think the stack garbage is always 0 on i386 (since we're in main()
and have barely used the stack), and SIG_DFL happens to be 0, so the
contents of the garbage is probably correct for setting the signal to
SIG_DFL except it doesn't have SA_RESTART set.

Bruce

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