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Date:   Wed, 13 Jun 2018 13:48:11 +0200
From:   Heiko Carstens <heiko.carstens@de.ibm.com>
To:     Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc:     "Carlos O'Donell" <carlos@redhat.com>,
        Florian Weimer <fweimer@redhat.com>,
        Peter Zijlstra <peterz@infradead.org>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
        Boqun Feng <boqun.feng@gmail.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        libc-alpha <libc-alpha@sourceware.org>
Subject: Re: Restartable Sequences system call merged into Linux
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On Mon, Jun 11, 2018 at 03:49:18PM -0400, Mathieu Desnoyers wrote:
> Hi!
> 
> Good news! The restartable sequences (rseq) system call is now merged into the master
> branch of the Linux kernel within the 4.18 merge window:
> 
> https://github.com/torvalds/linux/commit/d82991a8688ad128b46db1b42d5d84396487a508
> 
> It would be important to discuss how we should proceed to integrate the library part
> of rseq (see tools/testing/selftests/rseq/rseq*.{ch}) into glibc, or if it should
> live in a standalone project.

Is there any documentation available of what is the exact semantics of the
functions that have to be implemented for additional architectures?

I could look at rseq-skip.h and e.g. rseq-x86.h and try to figure out what
would be the correct implementation for s390. But having that somewhere
written down, e.g. as comments in one of the implementations, would be very
helpful.