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Date: Fri, 2 Jul 2004 00:22:08 -0400
From: Daniel Jacobowitz <dan@debian.org>
To: Roland McGrath <roland@redhat.com>
Cc: Davide Libenzi <davidel@xmailserver.org>, Andrew Morton <akpm@osdl.org>,
       Linus Torvalds <torvalds@osdl.org>, mingo@redhat.com, cagney@redhat.com,
       Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH] x86 single-step (TF) vs system calls & traps
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On Thu, Jul 01, 2004 at 02:59:20PM -0700, Roland McGrath wrote:
> > I am not the originator of PTRACE_O_TRACESYSGOOD, I just had the bad
> > luck to touch it.
> 
> My apologies.
> 
> > I think reporting the system call using 0x80|SIGTRAP when you
> > PTRACE_SINGLESTEP over the trap instruction makes excellent good sense.
> 
> If you are not concerned about existing users of PTRACE_O_TRACESYSGOOD
> calling PTRACE_SINGLESTEP and then being confused, then I have no objection.
> I consider you to be the authority on any such users there might be.
> 
> In that case, I'm happy to endorse Davide's original patch.
> I will look into extending it to cover x86-64's ia32 support as well.

I don't know of any example users.  I'm sure there are a couple
somewhere, though.  The new behavior seems intuitively useful to me, so
I'd prefer Davide's original patch.

-- 
Daniel Jacobowitz