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bh=f4i8LPcqHMF5a7sL3hplt26szteTPb3nGOf4sc/9mYY=; b=I5itVw8AJTxYaIW+IWcAFv9vJnVIFC1cJqDy1AxQwOwIo8oc1GRx5dGCzLR5lT/vi+88uY N54KPmQ1eMXpUDwuQBSJyzfBXUnH4bGidRW5yvY9bjH0d3vIiROlvCgmQjpKbijurD9qTE SUzRUIHSDhl2w3h2m4TbLxDQZJP3U7Q= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-232-6ZR_jTPFOZ64TohmUz8g7w-1; Thu, 22 Apr 2021 07:48:50 -0400 X-MC-Unique: 6ZR_jTPFOZ64TohmUz8g7w-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6574D8CC352; Thu, 22 Apr 2021 11:48:40 +0000 (UTC) Received: from redhat.com (ovpn-112-200.ams2.redhat.com [10.36.112.200]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0A47160BE5; Thu, 22 Apr 2021 11:48:37 +0000 (UTC) Date: Thu, 22 Apr 2021 12:48:35 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Philippe =?utf-8?Q?Mathieu-Daud=C3=A9?= Subject: Re: s390-ccw: warning: writing 1 byte into a region of size 0 [-Wstringop-overflow=] Message-ID: References: <4e327c80-8f5d-c848-b524-7f2c75255da4@redhat.com> <485773db-fca2-03ca-c6e8-90ef313fb8f1@redhat.com> <089df242-8788-a162-4a75-4c9c9e04a64e@redhat.com> MIME-Version: 1.0 In-Reply-To: <089df242-8788-a162-4a75-4c9c9e04a64e@redhat.com> User-Agent: Mutt/2.0.5 (2021-01-21) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 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: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Peter Maydell , Thomas Huth , Janosch Frank , Cornelia Huck , Richard Henderson , qemu-devel , Christian Borntraeger , qemu-s390x , Stefano Garzarella Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Apr 22, 2021 at 01:24:30PM +0200, Philippe Mathieu-Daudé wrote: > This silents the warning however: > > -- >8 -- > diff --git a/pc-bios/s390-ccw/libc.h b/pc-bios/s390-ccw/libc.h > index bcdc45732d..2dea399904 100644 > --- a/pc-bios/s390-ccw/libc.h > +++ b/pc-bios/s390-ccw/libc.h > @@ -19,6 +19,8 @@ typedef unsigned short uint16_t; > typedef unsigned int uint32_t; > typedef unsigned long long uint64_t; > > +#pragma GCC diagnostic push > +#pragma GCC diagnostic ignored "-Wstringop-overflow" > static inline void *memset(void *s, int c, size_t n) > { > size_t i; > @@ -30,6 +32,7 @@ static inline void *memset(void *s, int c, size_t n) > > return s; > } > +#pragma GCC diagnostic pop I wonder if it works if you put the pragma around the specific caller, as that would make the scope more limited so we can still see valid bugs elsewhere > > static inline void *memcpy(void *s1, const void *s2, size_t n) > { > --- > > Oddly this code doesn't emit any warning: Let me correct that for you s/doesn't emit any warning/doesn't emit any warning *yet*/ compilers get more strict all the time. The memcmp is just a memory read, however, while memset is a write, so less severe > if (!memcmp((char *)S390EP, "S390EP", 6)) { > ... 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 :|