From: Oleg Nesterov <oleg@redhat.com>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org
Subject: Re: [RFC] semantics of singlestepping vs. tracer exiting
Date: Tue, 4 Sep 2012 18:58:23 +0200 [thread overview]
Message-ID: <20120904165823.GA11332@redhat.com> (raw)
In-Reply-To: <20120904160824.GI23464@ZenIV.linux.org.uk>
On 09/04, Al Viro wrote:
>
> On Tue, Sep 04, 2012 at 05:39:38PM +0200, Oleg Nesterov wrote:
>
> > > BTW, speaking of alpha, what about PTRACE_SINGLESTEP when the task is stopped
> > > on syscall entry/exit after previous PTRACE_SYSCALL, BTW? Looks like it will
> > > be like PTRACE_CONT until we hit the first signal, at which point it converts
> > > to singlesteping mode; unless I'm seriously misreading that code, we rely
> > > on ptrace_set_bpt() done shortly after returning from get_signal_to_deliver()
> > > if we found that we'd been singlestepping. Fine, but in this case we
> > > had been resumed *not* in get_signal_to_deliver()...
> >
> > Again, "single_stepping |= ptrace_cancel_bpt()" after get_signal_to_deliver()
> > should work I think... Not sure.
>
> Umm... What would get us anywhere near get_signal_to_deliver() in this
> case?
Yes, I misread this code...
> so we happily proceed
> to run the process until a signal arrives, same as we would with PTRACE_CONT.
> What am I missing here?
Looks like, you are right.
Oleg.
prev parent reply other threads:[~2012-09-04 16:56 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20120903001436.GG23464@ZenIV.linux.org.uk>
2012-09-03 16:05 ` [RFC] semantics of singlestepping vs. tracer exiting Oleg Nesterov
2012-09-03 17:02 ` Oleg Nesterov
2012-09-03 17:31 ` Al Viro
2012-09-04 15:39 ` Oleg Nesterov
2012-09-04 16:08 ` Al Viro
2012-09-04 16:58 ` Oleg Nesterov [this message]
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