From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-out.m-online.net (mail-out.m-online.net [212.18.0.9]) by sourceware.org (Postfix) with ESMTPS id A0B5A386F440 for ; Fri, 2 Oct 2020 12:15:21 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org A0B5A386F440 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=denx.de Authentication-Results: sourceware.org; spf=none smtp.mailfrom=lukma@denx.de Received: from frontend01.mail.m-online.net (unknown [192.168.8.182]) by mail-out.m-online.net (Postfix) with ESMTP id 4C2ppt6rS2z1qrfB; Fri, 2 Oct 2020 14:15:18 +0200 (CEST) Received: from localhost (dynscan1.mnet-online.de [192.168.6.70]) by mail.m-online.net (Postfix) with ESMTP id 4C2ppt5QLGz1qtYN; Fri, 2 Oct 2020 14:15:18 +0200 (CEST) X-Virus-Scanned: amavisd-new at mnet-online.de Received: from mail.mnet-online.de ([192.168.8.182]) by localhost (dynscan1.mail.m-online.net [192.168.6.70]) (amavisd-new, port 10024) with ESMTP id i4czEK5nrDJH; Fri, 2 Oct 2020 14:15:16 +0200 (CEST) X-Auth-Info: CcHg5lDqCS8MFVX0NIYPL0tlhdjLLY0epqoMoG97FBE= Received: from jawa (85-222-111-42.dynamic.chello.pl [85.222.111.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.mnet-online.de (Postfix) with ESMTPSA; Fri, 2 Oct 2020 14:15:16 +0200 (CEST) Date: Fri, 2 Oct 2020 14:15:08 +0200 From: Lukasz Majewski To: Adhemerval Zanella Cc: Joseph Myers , Paul Eggert , Alistair Francis , Arnd Bergmann , Alistair Francis , GNU C Library , Florian Weimer , Carlos O'Donell , Stepan Golosunov , Andreas Schwab , Zack Weinberg , Jeff Law Subject: Re: [PATCH v2 3/3] y2038: nptl: Convert pthread_rwlock_{clock|timed}{rd|wr}lock to support 64 bit time Message-ID: <20201002141508.23f06238@jawa> In-Reply-To: <9e934743-7a8f-36ce-7a9d-45808e647b02@linaro.org> References: <20200919130759.31916-1-lukma@denx.de> <20200919130759.31916-3-lukma@denx.de> <55d2e158-d3df-2c3e-757c-5673d436d4a2@linaro.org> <20200930151201.19522e3b@jawa> <9e934743-7a8f-36ce-7a9d-45808e647b02@linaro.org> Organization: denx.de X-Mailer: Claws Mail 3.17.4 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; boundary="Sig_/vxHQZH2Rig72tf+p7xShs=3"; protocol="application/pgp-signature" X-Spam-Status: No, score=-16.3 required=5.0 tests=BAYES_00, GIT_PATCH_0, KAM_DMARC_STATUS, KAM_LAZY_DOMAIN_SECURITY, RCVD_IN_BARRACUDACENTRAL, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 02 Oct 2020 12:15:23 -0000 --Sig_/vxHQZH2Rig72tf+p7xShs=3 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Hi Adhemerval, > On 30/09/2020 10:12, Lukasz Majewski wrote: > >>> diff --git a/nptl/pthread_rwlock_rdlock.c > >>> b/nptl/pthread_rwlock_rdlock.c index 04cecad395..2b8509a49c 100644 > >>> --- a/nptl/pthread_rwlock_rdlock.c > >>> +++ b/nptl/pthread_rwlock_rdlock.c > >>> @@ -24,7 +24,7 @@ __pthread_rwlock_rdlock (pthread_rwlock_t > >>> *rwlock) { > >>> LIBC_PROBE (rdlock_entry, 1, rwlock); =20 > >> > >> We need to move the systemtap probe to the 64-bit variant, so the > >> 64-bit time will still trigger it. =20 > >=20 > > Those are syscalls, which don't require timespec time. =20 >=20 > These are in fact systemtap markers [1] and they are not related to=20 > syscalls. Ok. Thanks for the info (and link). >=20 > >=20 > > The LIBC_PROBE() macros were there before, so I left them as is and > > only changed __pthread_rwlock_rdlock_full() to > > __pthread_rwlock_rdlock_full64(). > >=20 > >=20 > > On the other hand - for example: > > __pthread_rwlock_clockwrlock() and __pthread_rwlock_clockwrlock64() > > are only calling __pthread_rwlock_wrlock_full64(), and there were no > > LIBC_PROBE() macros before. > >=20 > > Do I understand correctly that you propose to add LIBC_PROBE() > > macros to e.g. __pthread_rwlock_clockwrlock64() ? =20 >=20 > The idea of the LIBC_PROBE is to trigger an systemtap even when the > function is called so systemtap can act accordingly (and the markers > are enable only if --enable-systemtap is used on configure). >=20 Ok. > Without moving the LIBC_PROBE, 64-bit time architectures won't see > the probes anymore since they will call the 64-bit time version > instead. Please correct me if I'm wrong, but it seems to me that you are concerned if=20 - __pthread_rwlock_rdlock_full64=20 - __pthread_rwlock_wrlock_full64 would be called as aliased (for e.g. x86-64) and redirected (for e.g. arm)? This is not the case as above functions are local (i.e. helpers) ones defined in ./nptl/pthread_rwlock_common.c (and are not exported). For them, the only change was to add '64' suffix. The LIBC_PROBE() calls have been left untouched, surrounding them, so I think that we don't need to move them. Or maybe I do miss something important here? Thanks in advance for your help and explanation. >=20 > [1] https://sourceware.org/systemtap/wiki/glibcMarkers Best regards, Lukasz Majewski -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-59 Fax: (+49)-8142-66989-80 Email: lukma@denx.de --Sig_/vxHQZH2Rig72tf+p7xShs=3 Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQEzBAEBCgAdFiEEgAyFJ+N6uu6+XupJAR8vZIA0zr0FAl93GcwACgkQAR8vZIA0 zr3YEwgAhxlXDGkUHZsGHjQDD+yeC1DoscPe2QRm+lM3ws7csGkvLItedn8xbX18 glDazi2RLqYnnRKjmkAf9ujE1YQ7OMfr/++SC4sBk+j76USZSYwUrrnyaRlHvGtv LKw9YOcWFNqoryYNs+zubCxFr/zI3QpH4SJzlHzjRGOmzrwRq5L1LhZMnMXqx4nj eb6u0ck0con69kwPMjCNe8udrYYPvBjuQEZP0yOCEibjTassfDpjsxGFI+Ic5qwM n1gHxlx1LIu6bZtR0U4R1ntVwfuZU/4TnWmGHAKeuBljX58JXrnk7HseIA1vJpIQ em6NpypzDKpt338j5Y1rlOjtLPPBtw== =W6xP -----END PGP SIGNATURE----- --Sig_/vxHQZH2Rig72tf+p7xShs=3--