From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A279BC4CEC4 for ; Mon, 23 Sep 2019 16:39:40 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7610F2089F for ; Mon, 23 Sep 2019 16:39:40 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7610F2089F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=virtuozzo.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:59522 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iCRND-00056F-69 for qemu-devel@archiver.kernel.org; Mon, 23 Sep 2019 12:39:39 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57114) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iCQxP-0002RP-27 for qemu-devel@nongnu.org; Mon, 23 Sep 2019 12:13:00 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iCQxM-0003jP-VF for qemu-devel@nongnu.org; Mon, 23 Sep 2019 12:12:58 -0400 Received: from relay.sw.ru ([185.231.240.75]:39522) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iCQxM-0003aE-IE; Mon, 23 Sep 2019 12:12:56 -0400 Received: from [10.94.3.0] (helo=kvm.qa.sw.ru) by relay.sw.ru with esmtp (Exim 4.92.2) (envelope-from ) id 1iCQwy-0001Fp-8L; Mon, 23 Sep 2019 19:12:32 +0300 From: Vladimir Sementsov-Ogievskiy To: qemu-devel@nongnu.org Subject: [RFC v2 1/9] error: auto propagated local_err Date: Mon, 23 Sep 2019 19:12:23 +0300 Message-Id: <20190923161231.22028-2-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190923161231.22028-1-vsementsov@virtuozzo.com> References: <20190923161231.22028-1-vsementsov@virtuozzo.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 185.231.240.75 X-Mailman-Approved-At: Mon, 23 Sep 2019 12:26:10 -0400 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: stefanha@redhat.com, codyprime@gmail.com, jan.kiszka@siemens.com, berto@igalia.com, zhang.zhanghailiang@huawei.com, qemu-block@nongnu.org, arikalo@wavecomp.com, pasic@linux.ibm.com, hpoussin@reactos.org, anthony.perard@citrix.com, samuel.thibault@ens-lyon.org, philmd@redhat.com, green@moxielogic.com, lvivier@redhat.com, ehabkost@redhat.com, xiechanglong.d@gmail.com, pl@kamp.de, dgilbert@redhat.com, b.galvani@gmail.com, eric.auger@redhat.com, alex.williamson@redhat.com, ronniesahlberg@gmail.com, jsnow@redhat.com, rth@twiddle.net, kwolf@redhat.com, vsementsov@virtuozzo.com, andrew@aj.id.au, crwulff@gmail.com, sundeep.lkml@gmail.com, michael@walle.cc, qemu-ppc@nongnu.org, kbastian@mail.uni-paderborn.de, imammedo@redhat.com, fam@euphon.net, peter.maydell@linaro.org, sheepdog@lists.wpkg.org, david@redhat.com, palmer@sifive.com, thuth@redhat.com, jcmvbkbc@gmail.com, den@openvz.org, hare@suse.com, sstabellini@kernel.org, arei.gonglei@huawei.com, namei.unix@gmail.com, atar4qemu@gmail.com, farman@linux.ibm.com, amit@kernel.org, sw@weilnetz.de, groug@kaod.org, qemu-s390x@nongnu.org, qemu-arm@nongnu.org, peter.chubb@nicta.com.au, clg@kaod.org, shorne@gmail.com, qemu-riscv@nongnu.org, cohuck@redhat.com, amarkovic@wavecomp.com, aurelien@aurel32.net, pburton@wavecomp.com, sagark@eecs.berkeley.edu, jasowang@redhat.com, kraxel@redhat.com, edgar.iglesias@gmail.com, gxt@mprc.pku.edu.cn, ari@tuxera.com, quintela@redhat.com, mdroth@linux.vnet.ibm.com, lersek@redhat.com, borntraeger@de.ibm.com, antonynpavlov@gmail.com, dillaman@redhat.com, joel@jms.id.au, xen-devel@lists.xenproject.org, integration@gluster.org, rjones@redhat.com, Andrew.Baumann@microsoft.com, mreitz@redhat.com, walling@linux.ibm.com, mst@redhat.com, mark.cave-ayland@ilande.co.uk, v.maffione@gmail.com, marex@denx.de, armbru@redhat.com, marcandre.lureau@redhat.com, alistair@alistair23.me, paul.durrant@citrix.com, pavel.dovgaluk@ispras.ru, g.lettieri@iet.unipi.it, rizzo@iet.unipi.it, david@gibson.dropbear.id.au, akrowiak@linux.ibm.com, berrange@redhat.com, xiaoguangrong.eric@gmail.com, pmorel@linux.ibm.com, wencongyang2@huawei.com, jcd@tribudubois.net, pbonzini@redhat.com, stefanb@linux.ibm.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Here is introduced ERRP_FUNCTION_BEGIN macro, to be used at start of any function with errp parameter. It has three goals: 1. Fix issue with error_fatal & error_append_hint: user can't see these hints, because exit() happens in error_setg earlier than hint is appended. [Reported by Greg Kurz] 2. Fix issue with error_abort & error_propagate: when we wrap error_abort by local_err+error_propagate, resulting coredump will refer to error_propagate and not to the place where error happened. (the macro itself don't fix the issue, but it allows to [3.] drop all local_err+error_propagate pattern, which will definitely fix the issue) [Reported by Kevin Wolf] 3. Drop local_err+error_propagate pattern, which is used to workaround void functions with errp parameter, when caller wants to know resulting status. (Note: actually these functions should be merely updated to return int error code). Signed-off-by: Vladimir Sementsov-Ogievskiy --- include/qapi/error.h | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/include/qapi/error.h b/include/qapi/error.h index 3f95141a01..f6f4fa0fac 100644 --- a/include/qapi/error.h +++ b/include/qapi/error.h @@ -322,6 +322,43 @@ void error_set_internal(Error **errp, ErrorClass err_class, const char *fmt, ...) GCC_FMT_ATTR(6, 7); +typedef struct ErrorPropagator { + Error *local_err; + Error **errp; +} ErrorPropagator; + +static inline void error_propagator_cleanup(ErrorPropagator *prop) +{ + error_propagate(prop->errp, prop->local_err); +} + +G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC(ErrorPropagator, error_propagator_cleanup); + +/* + * ERRP_FUNCTION_BEGIN + * + * This macro MUST be the first line of EACH function with Error **errp + * parameter. + * + * If errp is NULL or points to error_fatal, it is rewritten to point to + * local Error object, which will be automatically propagated to original + * errp on function exit (see error_propagator_cleanup). + * + * After invocation of this macro it is always safe to dereference errp + * (as it's not NULL anymore) and to append hint (by error_append_hint) + * (as, if it was error_fatal, we swapped it by local_error to be + * propagated on cleanup). + * + * Note: we don't wrap error_abort case, as we want resulting coredump + * to point to the place where the error happened, not to error_propagate. + */ +#define ERRP_FUNCTION_BEGIN() \ +g_auto(ErrorPropagator) __auto_errp_prop = {.errp = errp}; \ +Error **__local_errp_unused __attribute__ ((unused)) = \ + (errp = (errp == NULL || *errp == error_fatal ? \ + &__auto_errp_prop.local_err : errp)) + + /* * Special error destination to abort on error. * See error_setg() and error_propagate() for details. -- 2.21.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 918D4C4CED4 for ; Mon, 23 Sep 2019 17:16:36 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 6A4262089F for ; 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Mon, 23 Sep 2019 19:12:32 +0300 From: Vladimir Sementsov-Ogievskiy To: qemu-devel@nongnu.org Date: Mon, 23 Sep 2019 19:12:23 +0300 Message-Id: <20190923161231.22028-2-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190923161231.22028-1-vsementsov@virtuozzo.com> References: <20190923161231.22028-1-vsementsov@virtuozzo.com> MIME-Version: 1.0 X-Mailman-Approved-At: Mon, 23 Sep 2019 17:16:12 +0000 Subject: [Xen-devel] [RFC v2 1/9] error: auto propagated local_err X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: stefanha@redhat.com, codyprime@gmail.com, jan.kiszka@siemens.com, eblake@redhat.com, berto@igalia.com, zhang.zhanghailiang@huawei.com, qemu-block@nongnu.org, arikalo@wavecomp.com, pasic@linux.ibm.com, hpoussin@reactos.org, anthony.perard@citrix.com, samuel.thibault@ens-lyon.org, philmd@redhat.com, green@moxielogic.com, lvivier@redhat.com, ehabkost@redhat.com, xiechanglong.d@gmail.com, pl@kamp.de, dgilbert@redhat.com, b.galvani@gmail.com, eric.auger@redhat.com, alex.williamson@redhat.com, ronniesahlberg@gmail.com, jsnow@redhat.com, rth@twiddle.net, kwolf@redhat.com, vsementsov@virtuozzo.com, andrew@aj.id.au, crwulff@gmail.com, sundeep.lkml@gmail.com, michael@walle.cc, qemu-ppc@nongnu.org, kbastian@mail.uni-paderborn.de, imammedo@redhat.com, fam@euphon.net, peter.maydell@linaro.org, sheepdog@lists.wpkg.org, david@redhat.com, palmer@sifive.com, thuth@redhat.com, jcmvbkbc@gmail.com, den@openvz.org, hare@suse.com, sstabellini@kernel.org, arei.gonglei@huawei.com, marcel.apfelbaum@gmail.com, namei.unix@gmail.com, atar4qemu@gmail.com, farman@linux.ibm.com, amit@kernel.org, sw@weilnetz.de, groug@kaod.org, qemu-s390x@nongnu.org, qemu-arm@nongnu.org, peter.chubb@nicta.com.au, clg@kaod.org, shorne@gmail.com, qemu-riscv@nongnu.org, cohuck@redhat.com, amarkovic@wavecomp.com, aurelien@aurel32.net, pburton@wavecomp.com, sagark@eecs.berkeley.edu, jasowang@redhat.com, kraxel@redhat.com, edgar.iglesias@gmail.com, gxt@mprc.pku.edu.cn, ari@tuxera.com, quintela@redhat.com, mdroth@linux.vnet.ibm.com, lersek@redhat.com, borntraeger@de.ibm.com, antonynpavlov@gmail.com, dillaman@redhat.com, joel@jms.id.au, xen-devel@lists.xenproject.org, integration@gluster.org, balrogg@gmail.com, rjones@redhat.com, Andrew.Baumann@microsoft.com, mreitz@redhat.com, walling@linux.ibm.com, mst@redhat.com, mark.cave-ayland@ilande.co.uk, v.maffione@gmail.com, marex@denx.de, armbru@redhat.com, marcandre.lureau@redhat.com, alistair@alistair23.me, paul.durrant@citrix.com, pavel.dovgaluk@ispras.ru, g.lettieri@iet.unipi.it, rizzo@iet.unipi.it, david@gibson.dropbear.id.au, akrowiak@linux.ibm.com, berrange@redhat.com, xiaoguangrong.eric@gmail.com, pmorel@linux.ibm.com, wencongyang2@huawei.com, jcd@tribudubois.net, pbonzini@redhat.com, stefanb@linux.ibm.com Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" SGVyZSBpcyBpbnRyb2R1Y2VkIEVSUlBfRlVOQ1RJT05fQkVHSU4gbWFjcm8sIHRvIGJlIHVzZWQg YXQgc3RhcnQgb2YKYW55IGZ1bmN0aW9uIHdpdGggZXJycCBwYXJhbWV0ZXIuCgpJdCBoYXMgdGhy ZWUgZ29hbHM6CgoxLiBGaXggaXNzdWUgd2l0aCBlcnJvcl9mYXRhbCAmIGVycm9yX2FwcGVuZF9o aW50OiB1c2VyIGNhbid0IHNlZSB0aGVzZQpoaW50cywgYmVjYXVzZSBleGl0KCkgaGFwcGVucyBp biBlcnJvcl9zZXRnIGVhcmxpZXIgdGhhbiBoaW50IGlzCmFwcGVuZGVkLiBbUmVwb3J0ZWQgYnkg R3JlZyBLdXJ6XQoKMi4gRml4IGlzc3VlIHdpdGggZXJyb3JfYWJvcnQgJiBlcnJvcl9wcm9wYWdh dGU6IHdoZW4gd2Ugd3JhcAplcnJvcl9hYm9ydCBieSBsb2NhbF9lcnIrZXJyb3JfcHJvcGFnYXRl LCByZXN1bHRpbmcgY29yZWR1bXAgd2lsbApyZWZlciB0byBlcnJvcl9wcm9wYWdhdGUgYW5kIG5v dCB0byB0aGUgcGxhY2Ugd2hlcmUgZXJyb3IgaGFwcGVuZWQuCih0aGUgbWFjcm8gaXRzZWxmIGRv bid0IGZpeCB0aGUgaXNzdWUsIGJ1dCBpdCBhbGxvd3MgdG8gWzMuXSBkcm9wIGFsbApsb2NhbF9l cnIrZXJyb3JfcHJvcGFnYXRlIHBhdHRlcm4sIHdoaWNoIHdpbGwgZGVmaW5pdGVseSBmaXggdGhl IGlzc3VlKQpbUmVwb3J0ZWQgYnkgS2V2aW4gV29sZl0KCjMuIERyb3AgbG9jYWxfZXJyK2Vycm9y X3Byb3BhZ2F0ZSBwYXR0ZXJuLCB3aGljaCBpcyB1c2VkIHRvIHdvcmthcm91bmQKdm9pZCBmdW5j dGlvbnMgd2l0aCBlcnJwIHBhcmFtZXRlciwgd2hlbiBjYWxsZXIgd2FudHMgdG8ga25vdyByZXN1 bHRpbmcKc3RhdHVzLiAoTm90ZTogYWN0dWFsbHkgdGhlc2UgZnVuY3Rpb25zIHNob3VsZCBiZSBt ZXJlbHkgdXBkYXRlZCB0bwpyZXR1cm4gaW50IGVycm9yIGNvZGUpLgoKU2lnbmVkLW9mZi1ieTog VmxhZGltaXIgU2VtZW50c292LU9naWV2c2tpeSA8dnNlbWVudHNvdkB2aXJ0dW96em8uY29tPgot LS0KIGluY2x1ZGUvcWFwaS9lcnJvci5oIHwgMzcgKysrKysrKysrKysrKysrKysrKysrKysrKysr KysrKysrKysrKwogMSBmaWxlIGNoYW5nZWQsIDM3IGluc2VydGlvbnMoKykKCmRpZmYgLS1naXQg YS9pbmNsdWRlL3FhcGkvZXJyb3IuaCBiL2luY2x1ZGUvcWFwaS9lcnJvci5oCmluZGV4IDNmOTUx NDFhMDEuLmY2ZjRmYTBmYWMgMTAwNjQ0Ci0tLSBhL2luY2x1ZGUvcWFwaS9lcnJvci5oCisrKyBi L2luY2x1ZGUvcWFwaS9lcnJvci5oCkBAIC0zMjIsNiArMzIyLDQzIEBAIHZvaWQgZXJyb3Jfc2V0 X2ludGVybmFsKEVycm9yICoqZXJycCwKICAgICAgICAgICAgICAgICAgICAgICAgIEVycm9yQ2xh c3MgZXJyX2NsYXNzLCBjb25zdCBjaGFyICpmbXQsIC4uLikKICAgICBHQ0NfRk1UX0FUVFIoNiwg Nyk7CiAKK3R5cGVkZWYgc3RydWN0IEVycm9yUHJvcGFnYXRvciB7CisgICAgRXJyb3IgKmxvY2Fs X2VycjsKKyAgICBFcnJvciAqKmVycnA7Cit9IEVycm9yUHJvcGFnYXRvcjsKKworc3RhdGljIGlu bGluZSB2b2lkIGVycm9yX3Byb3BhZ2F0b3JfY2xlYW51cChFcnJvclByb3BhZ2F0b3IgKnByb3Ap Cit7CisgICAgZXJyb3JfcHJvcGFnYXRlKHByb3AtPmVycnAsIHByb3AtPmxvY2FsX2Vycik7Cit9 CisKK0dfREVGSU5FX0FVVE9fQ0xFQU5VUF9DTEVBUl9GVU5DKEVycm9yUHJvcGFnYXRvciwgZXJy b3JfcHJvcGFnYXRvcl9jbGVhbnVwKTsKKworLyoKKyAqIEVSUlBfRlVOQ1RJT05fQkVHSU4KKyAq CisgKiBUaGlzIG1hY3JvIE1VU1QgYmUgdGhlIGZpcnN0IGxpbmUgb2YgRUFDSCBmdW5jdGlvbiB3 aXRoIEVycm9yICoqZXJycAorICogcGFyYW1ldGVyLgorICoKKyAqIElmIGVycnAgaXMgTlVMTCBv ciBwb2ludHMgdG8gZXJyb3JfZmF0YWwsIGl0IGlzIHJld3JpdHRlbiB0byBwb2ludCB0bworICog bG9jYWwgRXJyb3Igb2JqZWN0LCB3aGljaCB3aWxsIGJlIGF1dG9tYXRpY2FsbHkgcHJvcGFnYXRl ZCB0byBvcmlnaW5hbAorICogZXJycCBvbiBmdW5jdGlvbiBleGl0IChzZWUgZXJyb3JfcHJvcGFn YXRvcl9jbGVhbnVwKS4KKyAqCisgKiBBZnRlciBpbnZvY2F0aW9uIG9mIHRoaXMgbWFjcm8gaXQg aXMgYWx3YXlzIHNhZmUgdG8gZGVyZWZlcmVuY2UgZXJycAorICogKGFzIGl0J3Mgbm90IE5VTEwg YW55bW9yZSkgYW5kIHRvIGFwcGVuZCBoaW50IChieSBlcnJvcl9hcHBlbmRfaGludCkKKyAqIChh cywgaWYgaXQgd2FzIGVycm9yX2ZhdGFsLCB3ZSBzd2FwcGVkIGl0IGJ5IGxvY2FsX2Vycm9yIHRv IGJlCisgKiBwcm9wYWdhdGVkIG9uIGNsZWFudXApLgorICoKKyAqIE5vdGU6IHdlIGRvbid0IHdy YXAgZXJyb3JfYWJvcnQgY2FzZSwgYXMgd2Ugd2FudCByZXN1bHRpbmcgY29yZWR1bXAKKyAqIHRv IHBvaW50IHRvIHRoZSBwbGFjZSB3aGVyZSB0aGUgZXJyb3IgaGFwcGVuZWQsIG5vdCB0byBlcnJv cl9wcm9wYWdhdGUuCisgKi8KKyNkZWZpbmUgRVJSUF9GVU5DVElPTl9CRUdJTigpIFwKK2dfYXV0 byhFcnJvclByb3BhZ2F0b3IpIF9fYXV0b19lcnJwX3Byb3AgPSB7LmVycnAgPSBlcnJwfTsgXAor RXJyb3IgKipfX2xvY2FsX2VycnBfdW51c2VkIF9fYXR0cmlidXRlX18gKCh1bnVzZWQpKSA9IFwK KyAgICAoZXJycCA9IChlcnJwID09IE5VTEwgfHwgKmVycnAgPT0gZXJyb3JfZmF0YWwgPyBcCisg ICAgICAgICAgICAgJl9fYXV0b19lcnJwX3Byb3AubG9jYWxfZXJyIDogZXJycCkpCisKKwogLyoK ICAqIFNwZWNpYWwgZXJyb3IgZGVzdGluYXRpb24gdG8gYWJvcnQgb24gZXJyb3IuCiAgKiBTZWUg ZXJyb3Jfc2V0ZygpIGFuZCBlcnJvcl9wcm9wYWdhdGUoKSBmb3IgZGV0YWlscy4KLS0gCjIuMjEu MAoKCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fClhlbi1k ZXZlbCBtYWlsaW5nIGxpc3QKWGVuLWRldmVsQGxpc3RzLnhlbnByb2plY3Qub3JnCmh0dHBzOi8v bGlzdHMueGVucHJvamVjdC5vcmcvbWFpbG1hbi9saXN0aW5mby94ZW4tZGV2ZWw= From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.90_1) id 1iCRAY-0003Qf-CY for mharc-qemu-riscv@gnu.org; Mon, 23 Sep 2019 12:26:34 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:57639) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iCQxq-0002i7-CV for qemu-riscv@nongnu.org; Mon, 23 Sep 2019 12:13:28 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iCQxn-00044O-OM for qemu-riscv@nongnu.org; Mon, 23 Sep 2019 12:13:26 -0400 Received: from relay.sw.ru ([185.231.240.75]:39522) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iCQxM-0003aE-IE; Mon, 23 Sep 2019 12:12:56 -0400 Received: from [10.94.3.0] (helo=kvm.qa.sw.ru) by relay.sw.ru with esmtp (Exim 4.92.2) (envelope-from ) id 1iCQwy-0001Fp-8L; Mon, 23 Sep 2019 19:12:32 +0300 From: Vladimir Sementsov-Ogievskiy To: qemu-devel@nongnu.org Cc: kraxel@redhat.com, berrange@redhat.com, arei.gonglei@huawei.com, ehabkost@redhat.com, imammedo@redhat.com, lvivier@redhat.com, amit@kernel.org, kwolf@redhat.com, mreitz@redhat.com, ari@tuxera.com, pavel.dovgaluk@ispras.ru, pbonzini@redhat.com, stefanha@redhat.com, jsnow@redhat.com, sw@weilnetz.de, fam@euphon.net, ronniesahlberg@gmail.com, pl@kamp.de, eblake@redhat.com, den@openvz.org, armbru@redhat.com, berto@igalia.com, dillaman@redhat.com, wencongyang2@huawei.com, xiechanglong.d@gmail.com, namei.unix@gmail.com, rjones@redhat.com, codyprime@gmail.com, marcandre.lureau@redhat.com, rth@twiddle.net, groug@kaod.org, mst@redhat.com, marcel.apfelbaum@gmail.com, b.galvani@gmail.com, peter.maydell@linaro.org, Andrew.Baumann@microsoft.com, philmd@redhat.com, antonynpavlov@gmail.com, jcd@tribudubois.net, peter.chubb@nicta.com.au, sundeep.lkml@gmail.com, joel@jms.id.au, eric.auger@redhat.com, alistair@alistair23.me, balrogg@gmail.com, edgar.iglesias@gmail.com, sstabellini@kernel.org, anthony.perard@citrix.com, paul.durrant@citrix.com, pburton@wavecomp.com, arikalo@wavecomp.com, clg@kaod.org, andrew@aj.id.au, crwulff@gmail.com, marex@denx.de, david@gibson.dropbear.id.au, pasic@linux.ibm.com, cohuck@redhat.com, borntraeger@de.ibm.com, hpoussin@reactos.org, xiaoguangrong.eric@gmail.com, aurelien@aurel32.net, amarkovic@wavecomp.com, mark.cave-ayland@ilande.co.uk, jasowang@redhat.com, lersek@redhat.com, palmer@sifive.com, sagark@eecs.berkeley.edu, kbastian@mail.uni-paderborn.de, david@redhat.com, thuth@redhat.com, farman@linux.ibm.com, walling@linux.ibm.com, hare@suse.com, michael@walle.cc, atar4qemu@gmail.com, stefanb@linux.ibm.com, samuel.thibault@ens-lyon.org, akrowiak@linux.ibm.com, pmorel@linux.ibm.com, alex.williamson@redhat.com, mdroth@linux.vnet.ibm.com, zhang.zhanghailiang@huawei.com, quintela@redhat.com, dgilbert@redhat.com, rizzo@iet.unipi.it, g.lettieri@iet.unipi.it, v.maffione@gmail.com, jan.kiszka@siemens.com, green@moxielogic.com, shorne@gmail.com, gxt@mprc.pku.edu.cn, jcmvbkbc@gmail.com, qemu-block@nongnu.org, integration@gluster.org, sheepdog@lists.wpkg.org, qemu-arm@nongnu.org, xen-devel@lists.xenproject.org, qemu-ppc@nongnu.org, qemu-s390x@nongnu.org, qemu-riscv@nongnu.org, vsementsov@virtuozzo.com Subject: [RFC v2 1/9] error: auto propagated local_err Date: Mon, 23 Sep 2019 19:12:23 +0300 Message-Id: <20190923161231.22028-2-vsementsov@virtuozzo.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190923161231.22028-1-vsementsov@virtuozzo.com> References: <20190923161231.22028-1-vsementsov@virtuozzo.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 185.231.240.75 X-Mailman-Approved-At: Mon, 23 Sep 2019 12:26:31 -0400 X-BeenThere: qemu-riscv@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 23 Sep 2019 16:13:31 -0000 Here is introduced ERRP_FUNCTION_BEGIN macro, to be used at start of any function with errp parameter. It has three goals: 1. Fix issue with error_fatal & error_append_hint: user can't see these hints, because exit() happens in error_setg earlier than hint is appended. [Reported by Greg Kurz] 2. Fix issue with error_abort & error_propagate: when we wrap error_abort by local_err+error_propagate, resulting coredump will refer to error_propagate and not to the place where error happened. (the macro itself don't fix the issue, but it allows to [3.] drop all local_err+error_propagate pattern, which will definitely fix the issue) [Reported by Kevin Wolf] 3. Drop local_err+error_propagate pattern, which is used to workaround void functions with errp parameter, when caller wants to know resulting status. (Note: actually these functions should be merely updated to return int error code). Signed-off-by: Vladimir Sementsov-Ogievskiy --- include/qapi/error.h | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/include/qapi/error.h b/include/qapi/error.h index 3f95141a01..f6f4fa0fac 100644 --- a/include/qapi/error.h +++ b/include/qapi/error.h @@ -322,6 +322,43 @@ void error_set_internal(Error **errp, ErrorClass err_class, const char *fmt, ...) GCC_FMT_ATTR(6, 7); +typedef struct ErrorPropagator { + Error *local_err; + Error **errp; +} ErrorPropagator; + +static inline void error_propagator_cleanup(ErrorPropagator *prop) +{ + error_propagate(prop->errp, prop->local_err); +} + +G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC(ErrorPropagator, error_propagator_cleanup); + +/* + * ERRP_FUNCTION_BEGIN + * + * This macro MUST be the first line of EACH function with Error **errp + * parameter. + * + * If errp is NULL or points to error_fatal, it is rewritten to point to + * local Error object, which will be automatically propagated to original + * errp on function exit (see error_propagator_cleanup). + * + * After invocation of this macro it is always safe to dereference errp + * (as it's not NULL anymore) and to append hint (by error_append_hint) + * (as, if it was error_fatal, we swapped it by local_error to be + * propagated on cleanup). + * + * Note: we don't wrap error_abort case, as we want resulting coredump + * to point to the place where the error happened, not to error_propagate. + */ +#define ERRP_FUNCTION_BEGIN() \ +g_auto(ErrorPropagator) __auto_errp_prop = {.errp = errp}; \ +Error **__local_errp_unused __attribute__ ((unused)) = \ + (errp = (errp == NULL || *errp == error_fatal ? \ + &__auto_errp_prop.local_err : errp)) + + /* * Special error destination to abort on error. * See error_setg() and error_propagate() for details. -- 2.21.0