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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id 7F209C4332F for ; Fri, 17 Dec 2021 15:22:11 +0000 (UTC) Received: from localhost ([::1]:42590 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1myF3i-0001Gw-GG for qemu-devel@archiver.kernel.org; Fri, 17 Dec 2021 10:22:10 -0500 Received: from eggs.gnu.org ([209.51.188.92]:46758) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1myEkK-0002Pd-5f for qemu-devel@nongnu.org; Fri, 17 Dec 2021 10:02:08 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:47889) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1myEkB-00017l-8p for qemu-devel@nongnu.org; Fri, 17 Dec 2021 10:02:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1639753318; h=from:from:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=Fxu2JLKFuvBEujjfrNcMVtqnapkgvTnQJsuF/0zfQok=; b=a0EHAoTrWFIAlOIV9CvSoqQ45ybIE7FEamWjVqckvESUtHuMBP7aZ3TIeZwzbU2ACqXpgj UOSsaCcdylQFmN6vQhfwSqo+SsQTR2Fk2C4vB+S6UEZ+Mtt9eSOXWvWapCJB5LcPZK2A78 toAsucz5i926hONbsx1kDLdLIXdZCCs= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-508-nby7Sj3QMcizNUNA3mB3Lg-1; Fri, 17 Dec 2021 10:01:48 -0500 X-MC-Unique: nby7Sj3QMcizNUNA3mB3Lg-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EB2FD801AAB; Fri, 17 Dec 2021 15:01:46 +0000 (UTC) Received: from redhat.com (unknown [10.22.32.60]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 4BBD5E2F0; Fri, 17 Dec 2021 15:01:41 +0000 (UTC) Date: Fri, 17 Dec 2021 15:01:38 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Alex =?utf-8?Q?Benn=C3=A9e?= Subject: Re: [PATCH v3 02/28] glib-compat: Introduce g_memdup2() wrapper Message-ID: References: <20210903174510.751630-1-philmd@redhat.com> <20210903174510.751630-3-philmd@redhat.com> <875yrofxki.fsf@linaro.org> <87ilvne0x2.fsf@linaro.org> MIME-Version: 1.0 In-Reply-To: <87ilvne0x2.fsf@linaro.org> User-Agent: Mutt/2.1.3 (2021-09-10) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -34 X-Spam_score: -3.5 X-Spam_bar: --- X-Spam_report: (-3.5 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.718, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Peter Maydell , "Michael S. Tsirkin" , Jason Wang , Christian Schoenebeck , qemu-devel@nongnu.org, Gerd Hoffmann , Eric Blake , qemu-block@nongnu.org, David Hildenbrand , Markus Armbruster , Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= , Laurent Vivier , Thomas Huth , Eduardo Habkost , Richard Henderson , qemu-arm@nongnu.org, John Snow , David Gibson , Kevin Wolf , Vladimir Sementsov-Ogievskiy , Hanna Reitz , qemu-ppc@nongnu.org, Paolo Bonzini Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Fri, Dec 17, 2021 at 02:53:05PM +0000, Alex Bennée wrote: > > Daniel P. Berrangé writes: > > > On Thu, Dec 16, 2021 at 02:11:37PM +0000, Alex Bennée wrote: > >> > >> Philippe Mathieu-Daudé writes: > >> > >> > When experimenting raising GLIB_VERSION_MIN_REQUIRED to 2.68 > >> > (Fedora 34 provides GLib 2.68.1) we get: > >> > > >> > hw/virtio/virtio-crypto.c:245:24: error: 'g_memdup' is deprecated: Use 'g_memdup2' instead [-Werror,-Wdeprecated-declarations] > >> > ... > >> > > >> > g_memdup() has been updated by g_memdup2() to fix eventual security > >> > issues (size argument is 32-bit and could be truncated / wrapping). > >> > GLib recommends to copy their static inline version of g_memdup2(): > >> > https://discourse.gnome.org/t/port-your-module-from-g-memdup-to-g-memdup2-now/5538 > >> > > >> > Our glib-compat.h provides a comment explaining how to deal with > >> > these deprecated declarations (see commit e71e8cc0355 > >> > "glib: enforce the minimum required version and warn about old APIs"). > >> > > >> > Following this comment suggestion, implement the g_memdup2_qemu() > >> > wrapper to g_memdup2(), and use the safer equivalent inlined when > >> > we are using pre-2.68 GLib. > >> > > >> > Reported-by: Eric Blake > >> > Signed-off-by: Philippe Mathieu-Daudé > >> > --- > >> > include/glib-compat.h | 37 +++++++++++++++++++++++++++++++++++++ > >> > 1 file changed, 37 insertions(+) > >> > > >> > diff --git a/include/glib-compat.h b/include/glib-compat.h > >> > index 9e95c888f54..8d01a8c01fb 100644 > >> > --- a/include/glib-compat.h > >> > +++ b/include/glib-compat.h > >> > @@ -68,6 +68,43 @@ > >> > * without generating warnings. > >> > */ > >> > > >> > +/* > >> > + * g_memdup2_qemu: > >> > + * @mem: (nullable): the memory to copy. > >> > + * @byte_size: the number of bytes to copy. > >> > + * > >> > + * Allocates @byte_size bytes of memory, and copies @byte_size bytes into it > >> > + * from @mem. If @mem is %NULL it returns %NULL. > >> > + * > >> > + * This replaces g_memdup(), which was prone to integer overflows when > >> > + * converting the argument from a #gsize to a #guint. > >> > + * > >> > + * This static inline version is a backport of the new public API from > >> > + * GLib 2.68, kept internal to GLib for backport to older stable releases. > >> > + * See https://gitlab.gnome.org/GNOME/glib/-/issues/2319. > >> > + * > >> > + * Returns: (nullable): a pointer to the newly-allocated copy of the memory, > >> > + * or %NULL if @mem is %NULL. > >> > + */ > >> > +static inline gpointer g_memdup2_qemu(gconstpointer mem, gsize byte_size) > >> > +{ > >> > +#if GLIB_CHECK_VERSION(2, 68, 0) > >> > + return g_memdup2(mem, byte_size); > >> > +#else > >> > + gpointer new_mem; > >> > + > >> > + if (mem && byte_size != 0) { > >> > + new_mem = g_malloc(byte_size); > >> > + memcpy(new_mem, mem, byte_size); > >> > + } else { > >> > + new_mem = NULL; > >> > + } > >> > + > >> > + return new_mem; > >> > +#endif > >> > +} > >> > +#define g_memdup2(m, s) g_memdup2_qemu(m, s) > >> > + > >> > >> As per our style wouldn't it make sense to just call it qemu_memdup(m, > >> s)? > > > > Not in this case. We use suffix as we don't want people calling this > > directly with the suffix. > > > > In the glibcompat.h header we're attempting to transparently/secretly > > replace/wrap standard glib APIs. All the callers should remain using > > the plain glib API name, never call the method with the suffix at > > all. This lets us delete the wrapper later and not have to update > > any callers. The suffix is basically just a hack of the impl we use > > for transparent replacement. > > Right - at the risk of bike shedding names maybe we should choose a > suffix the better reflects the purpose like _alt or _internal rather > than overloading qemu? Sure, I'm fine with that. Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|