Date: Tue, 22 Nov 2016 14:07:38 +0100
From: Szabolcs Nagy <nsz@port70.net>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: syzkaller <syzkaller@googlegroups.com>, linux-api@vger.kernel.org,
        LKML <linux-kernel@vger.kernel.org>,
        Michael Kerrisk-manpages <mtk.manpages@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Sasha Levin <levinsasha928@gmail.com>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>, scientist@fb.com,
        Steven Rostedt <rostedt@goodmis.org>, Arnd Bergmann <arnd@arndb.de>,
        carlos@redhat.com, Kostya Serebryany <kcc@google.com>,
        Mike Frysinger <vapier@google.com>,
        Dave Jones <davej@codemonkey.org.uk>,
        Tavis Ormandy <taviso@google.com>
Subject: Re: Formal description of system call interface
Message-ID: <20161122130738.GT5749@port70.net>
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* Dmitry Vyukov <dvyukov@google.com> [2016-11-21 16:03:04 +0100]:
> On Mon, Nov 7, 2016 at 1:28 AM, Szabolcs Nagy <nsz@port70.net> wrote:
> > * Dmitry Vyukov <dvyukov@google.com> [2016-11-06 14:39:28 -0800]:
> >> For the reference, current syzkaller descriptions are in txt files here:
> >> https://github.com/google/syzkaller/tree/master/sys
> > ...
> >> Taking the opportunity, if you see that something is missing/wrong
> >> in the descriptions of the subsystem you care about, or if it is not
> >> described at all, fixes are welcome.
> >
> > abi variants are missing (abi variation makes a lot of
> > syscall interface related work painful).
> 
> 
> What exactly do you mean by "abi variants"? Is it architecture?
> What exactly needs to be added to the descriptions support "abi variants?
> 

abi variant is a supported syscall abi
(linux supports several abis on the same arch:
e.g. x86 has i386,x86_64,x32 one might also
call different endianness a different abi, but
i'd expect le/be to be handled together.)

available syscalls, argument types and ordering
can be different across abis

i may be wrong, but i did not see those handled
in sys.txt, looking at it now i see missing
paddings in ipc structs (*_ds) so it may not
work the way i assumed (these are types which
have some abi variation).