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 542EAC433F5 for ; Fri, 17 Dec 2021 15:28:00 +0000 (UTC) Received: from localhost ([::1]:57636 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1myF9L-0002jG-54 for qemu-devel@archiver.kernel.org; Fri, 17 Dec 2021 10:27:59 -0500 Received: from eggs.gnu.org ([209.51.188.92]:44896) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1myEdr-000116-OB for qemu-devel@nongnu.org; Fri, 17 Dec 2021 09:55:27 -0500 Received: from [2607:f8b0:4864:20::92c] (port=40623 helo=mail-ua1-x92c.google.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1myEdp-0000A6-Pr for qemu-devel@nongnu.org; Fri, 17 Dec 2021 09:55:27 -0500 Received: by mail-ua1-x92c.google.com with SMTP id y23so4797533uay.7 for ; Fri, 17 Dec 2021 06:55:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=references:user-agent:from:to:cc:subject:date:in-reply-to :message-id:mime-version:content-transfer-encoding; bh=caQ+GawRU7q4sumBjAscV7/6W3K191EJqTdNQsMSpcM=; b=tAOzRWin3vQoUZBFvE275fF44cwoxUbodBcihR6nCxVKkLZTa4SgJRjVkySIKFP5EG IOciZjtLZeFgJxYgOgvEfFTLqQEOTAooAqrgxe3Vtw2VswkyNSkrGzWgky/FmueZS0f6 Dcy2egGGVmdQj3l79ZnXyTi82ub1xS3FZW0GOABQGg6wBntiG0mnObXGn2WW6Kp6PgIS FBLWER2t8LEjukKl4QEUoZH30ZnvMJZwm4NJEz2OPvmxCciDCDkTtHOLOnorkDJfe/Ox SsElk0lO1INS7BEKnnscmItMsg/zE6+zCVttvM9j9SKZ0HYn7e304FhHSYrrqz0jpJ4P FlXg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:references:user-agent:from:to:cc:subject:date :in-reply-to:message-id:mime-version:content-transfer-encoding; bh=caQ+GawRU7q4sumBjAscV7/6W3K191EJqTdNQsMSpcM=; b=laaNrHl2wE0Qy425+sjnW4LeK6V6Gxehxu7YhPfGd9gfWGiilJHhWG897kJ7K+8QFv eKLEpdP9MZST4hlS/0fDecLzz4zZ+YKnDiQaWAw7NO/Q9QMbB/t8YVSBII073Q5+GMQZ bBJ9qLuQdngbmSGrPOATdVluLCpYr95pCHUW5gOnZckzOlLt+2RdYWZWXrXxthD1soHa WZo4Ur3uoGnQCLw6vecO0xhXqaSegsUcgy72eGzjMP/mYhph6nHLYArZZYG3RjSWDgjt nE23G/eTx77ZReSbEx8lmf83aqvmSCumrX7htVjPCc7sOWHu60+Ev/NgtDeis77ba3dY +Waw== X-Gm-Message-State: AOAM532GfAypybGGBXpvKw4/Cw11ex9wA92qRArryHI5Gh5wqJ8mbLGZ sfdq5ML1yyGrEN8Binf1fd/9og== X-Google-Smtp-Source: ABdhPJy+wMLxHcbL50E8MCXn3x6NHJOaxLJdpBVskMblx+EkrkXE1Rk9nKgKD29Qval5I3DCDENWtQ== X-Received: by 2002:ab0:b88:: with SMTP id c8mr1122747uak.130.1639752923868; Fri, 17 Dec 2021 06:55:23 -0800 (PST) Received: from zen.linaroharston ([51.148.130.216]) by smtp.gmail.com with ESMTPSA id h7sm1201963vsk.5.2021.12.17.06.55.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Dec 2021 06:55:22 -0800 (PST) Received: from zen (localhost [127.0.0.1]) by zen.linaroharston (Postfix) with ESMTP id 1F0B71FF96; Fri, 17 Dec 2021 14:55:21 +0000 (GMT) References: <20210903174510.751630-1-philmd@redhat.com> <20210903174510.751630-3-philmd@redhat.com> <875yrofxki.fsf@linaro.org> User-agent: mu4e 1.7.5; emacs 28.0.90 From: Alex =?utf-8?Q?Benn=C3=A9e?= To: =?utf-8?Q?Daniel_P=2E_Berrang=C3=A9?= Subject: Re: [PATCH v3 02/28] glib-compat: Introduce g_memdup2() wrapper Date: Fri, 17 Dec 2021 14:53:05 +0000 In-reply-to: Message-ID: <87ilvne0x2.fsf@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Host-Lookup-Failed: Reverse DNS lookup failed for 2607:f8b0:4864:20::92c (failed) Received-SPF: pass client-ip=2607:f8b0:4864:20::92c; envelope-from=alex.bennee@linaro.org; helo=mail-ua1-x92c.google.com X-Spam_score_int: -12 X-Spam_score: -1.3 X-Spam_bar: - X-Spam_report: (-1.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no 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: , 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" Daniel P. Berrang=C3=A9 writes: > On Thu, Dec 16, 2021 at 02:11:37PM +0000, Alex Benn=C3=A9e wrote: >>=20 >> Philippe Mathieu-Daud=C3=A9 writes: >>=20 >> > 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: U= se '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-memd= up2-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-Daud=C3=A9 >> > --- >> > 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. >> > */ >> >=20=20 >> > +/* >> > + * 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 rele= ases. >> > + * 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_s= ize) >> > +{ >> > +#if GLIB_CHECK_VERSION(2, 68, 0) >> > + return g_memdup2(mem, byte_size); >> > +#else >> > + gpointer new_mem; >> > + >> > + if (mem && byte_size !=3D 0) { >> > + new_mem =3D g_malloc(byte_size); >> > + memcpy(new_mem, mem, byte_size); >> > + } else { >> > + new_mem =3D NULL; >> > + } >> > + >> > + return new_mem; >> > +#endif >> > +} >> > +#define g_memdup2(m, s) g_memdup2_qemu(m, s) >> > + >>=20 >> 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? We already document _locked for example. > A method with a 'qemu_' prefix by constrast is something that callers > are explicitly expected to call directly. > > > Regards, > Daniel --=20 Alex Benn=C3=A9e