linux-mips
[Top] [All Lists]

Re: a method to distinguish between syscall-enter/exit-stop

To: Kees Cook <keescook@chromium.org>
Subject: Re: a method to distinguish between syscall-enter/exit-stop
From: "Dmitry V. Levin" <ldv@altlinux.org>
Date: Sat, 7 Feb 2015 02:17:20 +0300
Cc: Andy Lutomirski <luto@amacapital.net>, LKML <linux-kernel@vger.kernel.org>, Will Drewry <wad@chromium.org>, Oleg Nesterov <oleg@redhat.com>, "x86@kernel.org" <x86@kernel.org>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org>, Linux MIPS Mailing List <linux-mips@linux-mips.org>, linux-arch <linux-arch@vger.kernel.org>, linux-security-module <linux-security-module@vger.kernel.org>, Alexei Starovoitov <ast@plumgrid.com>, "H. Peter Anvin" <hpa@zytor.com>, Frederic Weisbecker <fweisbec@gmail.com>, Michael Kerrisk-manpages <mtk.manpages@gmail.com>
In-reply-to: <CAGXu5jJXspS_34KBJ5VxvyKuj4bA+zg267dNiEkqR1LuvjoA1Q@mail.gmail.com>
List-archive: <http://www.linux-mips.org/archives/linux-mips/>
List-help: <mailto:ecartis@linux-mips.org?Subject=help>
List-id: linux-mips <linux-mips.eddie.linux-mips.org>
List-owner: <mailto:ralf@linux-mips.org>
List-post: <mailto:linux-mips@linux-mips.org>
List-software: Ecartis version 1.0.0
List-subscribe: <mailto:ecartis@linux-mips.org?subject=subscribe%20linux-mips>
List-unsubscribe: <mailto:ecartis@linux-mips.org?subject=unsubscribe%20linux-mips>
Original-recipient: rfc822;linux-mips@linux-mips.org
References: <CALCETrXFzcXngHsX=_72hYZqms32Zf7oFYDBgC3XNw7zOGdDCA@mail.gmail.com> <CAGXu5jJtHT9o8WMoynifN13=uZoARt4G9iVcgZsc9xYOBEwWsg@mail.gmail.com> <20150205233945.GA31540@altlinux.org> <CAGXu5jLTH+mUF0JxeR2qA_r=ocWjPHPSK2OPgE0Fu_JKoQyQ9w@mail.gmail.com> <CALCETrXsCUje+_V=Ud+TB4A2jH2M7yqyoCFMLEyxOD6pd7Di5w@mail.gmail.com> <20150206023249.GB31540@altlinux.org> <CALCETrWTnqKDoatK+5FN=yYDOeENoW5=r5YMToYKhZ8Zfv5wWA@mail.gmail.com> <CAGXu5j+nopAMFukwMu=Cy0GOapziOLTb-ryJhA-aywk_uerg9A@mail.gmail.com> <CALCETrVaF+3ETn5nfcbvyWKUYb71jNXK-zo9V6uOK0cEW4TCNQ@mail.gmail.com> <CAGXu5jJXspS_34KBJ5VxvyKuj4bA+zg267dNiEkqR1LuvjoA1Q@mail.gmail.com>
Sender: linux-mips-bounce@linux-mips.org
On Fri, Feb 06, 2015 at 12:07:03PM -0800, Kees Cook wrote:
> On Fri, Feb 6, 2015 at 11:32 AM, Andy Lutomirski <luto@amacapital.net> wrote:
> > On Fri, Feb 6, 2015 at 11:23 AM, Kees Cook <keescook@chromium.org> wrote:
[...]
> >> And an unrelated thought:
> >>
> >> 3) Can't we find some way to fix the inability of a ptracer to
> >> distinguish between syscall-enter-stop and syscall-exit-stop?
> >
> > Couldn't we add PTRACE_O_TRACESYSENTRY and PTRACE_O_TRACESYSEXIT along
> > the lines of PTRACE_O_TRACESYSGOOD?
> 
> That might be a nice idea. I haven't written a test to see, but what
> does PTRACE_GETEVENTMSG return on syscall-enter/exit-stop?

The value returned by PTRACE_GETEVENTMSG is the value set along with the
latest PTRACE_EVENT_*.
In case of syscall-enter/exit-stop (which is not a PTRACE_EVENT_*),
there is no particular value set for PTRACE_GETEVENTMSG.


-- 
ldv

<Prev in Thread] Current Thread [Next in Thread>