From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.1 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id EC8A21F463 for ; Tue, 7 Jan 2020 20:44:10 +0000 (UTC) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:date:from:to:cc:message-id:in-reply-to :references:subject:mime-version:content-type :content-transfer-encoding; q=dns; s=default; b=LDAiPvGKuOzKAutP Y+IEZ8vulakVTcd+P58xd6mAF7OpTsbIpMll9+m7hYUtf4Y4cYH6KXfAEj2XgSA4 sajW72NUwZV8/BMUDoaRP+ecGStyjGMKVlYBbI5HDNVwuatvk0sjzPkYWsRH0oKG Oo96se+wK2PLds2vZtgHbpxj1pg= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:date:from:to:cc:message-id:in-reply-to :references:subject:mime-version:content-type :content-transfer-encoding; s=default; bh=k7ZNd0ZRZ8g4UsskyZ0HjX R1reE=; b=dmeGEdBuICvYMBXsyepl6b3osXzxITyojN5ePVQMVuG8950hha7bO5 Cdqwn5pTGENS+4PJJFwOQFxQtkIlmWVB5CN6iwF5TsLAtJKCdcXLifjZjpNvkNgP QDMYFbZZESQpkVqhbUKCH6Y+BpZnQhSpCaEW0+1SD6XLG4z89weyQ= Received: (qmail 51809 invoked by alias); 7 Jan 2020 20:44:06 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 51743 invoked by uid 89); 7 Jan 2020 20:44:05 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: mail.efficios.com DKIM-Filter: OpenDKIM Filter v2.10.3 mail.efficios.com B5CC9695804 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=default; t=1578429840; bh=a7PhLxRLqwPOptIFbATUjStQXS7bfiLqgNZX9c8LwXs=; h=Date:From:To:Message-ID:MIME-Version; b=ZKTM2S5itDu6Awve+O/mF1Z1DX5vlX2ILroe6oGF/dB6a5uk77biDynUJCbg6DwKw CcG9GRdAJUbcjRJxAZKIn1w4voCXUki4k9prXYFNO7xBzlWj0DjkgeKNVfLeMFgqsr MEXM27U+M6YgEKGvnyTsKrRS6f5Owl95uKOkmXLnioDJl4/VxFJqEi+brVtOJMNZdA S8wqlt1Brlo5Sic/hy1ZdLrh0mcLN+u+JC5PnWX0VhmDJwkPXfKvHp1oxr4es6KZFc 2f9+s0YbRXUa0tF+ZQtdeut9RLk2EK8e6NYmAiq/XqrKYVHRBWxICRsgcyJX8C0gCs F87vrxZxFjXaA== Date: Tue, 7 Jan 2020 15:44:00 -0500 (EST) From: Mathieu Desnoyers To: Florian Weimer Cc: carlos , Joseph Myers , Szabolcs Nagy , libc-alpha , Thomas Gleixner , Ben Maurer , Peter Zijlstra , "Paul E. McKenney" , Boqun Feng , Will Deacon , Dave Watson , Paul Turner , Rich Felker , linux-kernel , linux-api Message-ID: <1968185366.4418.1578429840460.JavaMail.zimbra@efficios.com> In-Reply-To: <871rsbv4io.fsf@oldenburg2.str.redhat.com> References: <20200106155713.397-1-mathieu.desnoyers@efficios.com> <20200106155713.397-10-mathieu.desnoyers@efficios.com> <871rsbv4io.fsf@oldenburg2.str.redhat.com> Subject: Re: [RFC PATCH glibc 09/13] glibc: Perform rseq(2) registration at C startup and thread creation (v13) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit ----- On Jan 7, 2020, at 7:23 AM, Florian Weimer fweimer@redhat.com wrote: > * Mathieu Desnoyers: > >> Register rseq(2) TLS for each thread (including main), and unregister >> for each thread (excluding main). "rseq" stands for Restartable >> Sequences. >> >> See the rseq(2) man page proposed here: >> https://lkml.org/lkml/2018/9/19/647 >> >> This patch is based on glibc-2.30. The rseq(2) system call was merged >> into Linux 4.18. > > This patch needs to be updated for some be/le abilist splits. > Big-endian ABI lists for arm, microblaze, sh, appear to be missing. done. > This is something that can be checked with build-many-glibcs.py. OK. > >> diff --git a/manual/threads.texi b/manual/threads.texi >> index 0858ef8f92..059f781120 100644 >> --- a/manual/threads.texi >> +++ b/manual/threads.texi >> @@ -881,3 +881,20 @@ Behaves like @code{pthread_timedjoin_np} except that the >> absolute time in >> @c pthread_spin_unlock >> @c pthread_testcancel >> @c pthread_yield >> + >> +@node Restartable Sequences >> +@section Restartable Sequences >> +@cindex rseq >> + >> +This section describes the @glibcadj{} Restartable Sequences integration. >> + >> +The @glibcadj{} implements a __rseq_abi TLS symbol to interact with the > @Theglibc{} @code{__rseq_abi} > > >> +Restartable Sequences system call (Linux-specific). The layout of this >> +structure is defined by the Linux kernel rseq.h UAPI. Registration of each >> +thread's __rseq_abi is performed by @glibcadj{} at libc initialization and > @theglibc{} > @code{__rseq_abi} >> +pthread creation. > >> +Each supported architecture provide a RSEQ_SIG signature in sys/rseq.h. That > @code{RSEQ_SIG} @file{sys/rseq.h} > >> +signature is expected to be present in the code before each Restartable >> +Sequences abort handler. Failure to provide the expected signature may >> +terminate the process with a Segmentation fault. > > > Two spaces at the end of setences, please. All above done. > > The manual should use @deftypevar to create an index entry etc. for > __rseq_abi. See argp_program_version for an example of how to do this. OK. I've added __rseq_abi as a variable and RSEQ_SIG as a macro. > > I think current policy is to have documentation for at least the minimum > functionality in the manual. I understand that it makes it a lot of > work to write patches which add system call wrappers. Makes sense. Thanks! Mathieu > > Thanks, > Florian -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com