From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59429) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fIaAW-0004k0-Ll for qemu-devel@nongnu.org; Tue, 15 May 2018 09:39:09 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fIaAQ-0001ir-Dq for qemu-devel@nongnu.org; Tue, 15 May 2018 09:39:08 -0400 References: <20180515055949.6446-1-olaf@aepfle.de> <87mux1jrf7.fsf@dusky.pond.sub.org> <7c3cb275-1568-ee34-314e-c3400b8148c2@redhat.com> From: Thomas Huth Message-ID: <27f1e01f-4f06-4cd7-d546-f9654c706be4@redhat.com> Date: Tue, 15 May 2018 15:38:53 +0200 MIME-Version: 1.0 In-Reply-To: <7c3cb275-1568-ee34-314e-c3400b8148c2@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] replace functions which are only available in glib-2.24 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini , Markus Armbruster , Olaf Hering Cc: qemu-trivial@nongnu.org, Fam Zheng , "open list:All patches CC here" , Stefan Hajnoczi On 15.05.2018 10:41, Paolo Bonzini wrote: > On 15/05/2018 09:42, Markus Armbruster wrote: >> Olaf Hering writes: >> >>> Currently the minimal supported version of glib is 2.22. >>> Since testing is done with a glib that claims to be 2.22, but in fact >>> has APIs from newer version of glib, this bug was not caught during >>> submit of the patch referenced below. >>> >>> Replace g_realloc_n, which is available only since 2.24, with g_renew. >> >> We're about to bump our required GLib version to 2.34. See >> https://lists.gnu.org/archive/html/qemu-devel/2018-05/msg02562.html >> Message-ID: <751a3b4f-55ef-dec0-aec9-6b48922b7843@redhat.com> >> >> However, the patch may make sense for stable anyway. > > It's a good idea even for non-stable. In the end, g_*alloc*_n are > rarely needed, and almost always g_*new* is better as it provides better > type safety. I'm queuing the patch, and we should consider adding a > checkpatch rule to suggest not using these functions. Please do not queue this version of the patch - Olaf sent a v2 where he fixed the obvious bug with "IOVAMapping *" vs. "IOVAMapping". > Paolo > >>> Fixes commit 418026ca43 ("util: Introduce vfio helpers") >>> >>> Signed-off-by: Olaf Hering >>> --- >>> >>> This must go into stable-2.12. >> >> Please see docs/devel/stable-process.rst for how to get a patch into a >> stable release. >> >>> util/vfio-helpers.c | 6 ++---- >>> 1 file changed, 2 insertions(+), 4 deletions(-) >>> >>> diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c >>> index 006674c916..5fd4f5f212 100644 >>> --- a/util/vfio-helpers.c >>> +++ b/util/vfio-helpers.c >>> @@ -522,8 +522,7 @@ static IOVAMapping *qemu_vfio_add_mapping(QEMUVFIOState *s, >>> >>> assert(index >= 0); >>> s->nr_mappings++; >>> - s->mappings = g_realloc_n(s->mappings, sizeof(s->mappings[0]), >>> - s->nr_mappings); >>> + s->mappings = g_renew(IOVAMapping *, s->mappings, s->nr_mappings); >> >> I'm afraid this switches from allocating a bunch of IOVAMapping to a >> bunch of IOVAMapping *. My gcc duly warns. See v2 of the patch where Olaf fixed this already. Thomas