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Mon, 27 Jul 2026 13:52:31 +0000 (GMT) Received: from osiris (unknown [9.111.92.67]) by smtpav06.fra02v.mail.ibm.com (Postfix) with ESMTPS; Mon, 27 Jul 2026 13:52:31 +0000 (GMT) Date: Mon, 27 Jul 2026 15:52:29 +0200 From: Heiko Carstens To: Nathan Chancellor Cc: Stefan Schulze Frielinghaus , Juergen Christ , Ilya Leoshkevich , Dominik Steenken , Alexander Gordeev , Sven Schnelle , Vasily Gorbik , Christian Borntraeger , Maxim Khmelevskii , Jens Remus , Sami Tolvanen , Kees Cook , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Kumar Kartikeya Dwivedi , llvm@lists.linux.dev, bpf@vger.kernel.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 5/6] s390/Kconfig: Select ARCH_SUPPORTS_CFI Message-ID: <20260727135229.11274A39-hca@linux.ibm.com> References: <20260724141318.1037434-1-hca@linux.ibm.com> <20260724141318.1037434-6-hca@linux.ibm.com> <20260725010004.GA1686739@ax162> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260725010004.GA1686739@ax162> X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Proofpoint-Spam-Info: AW1haW4tMjYwNzI3MDEzMiBTYWx0ZWRfXybABj6qeuKlq shpLduYRncpd2UDnOjgFrADssQ01ntj3sIQNao7HJyYKjPSF2/KJFtFdxwkhIm/nTN+B6Iz5Xt5 eGrLSZTrtZ97u92pbyAuA4jR1WP/rA8= X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNzI3MDEzMiBTYWx0ZWRfX/xmonw2aZNvm sWViXLldaOrWPftEAlEa1UxHcnVk1skOzfGuxSSKAcPS8v4Y3RcwEm7PgD3vngC/1q9xYjW87RM jHkI9lETLEBuPVVNI7PgSrePCv4w8oggHJiUScCXg4Yjwl8YZtMcIImn2cFHdTV6GOuoaO3un57 ozYUJiiiQiRIq3S0uG8O5SKlvZPexBeSJ6w/mC2wZp/F9ty87QRqgQseEeREsZKutxnSSiZqbMN nzGKYnJuZ+aY1zbI4wXeKx7Yx34Lcaj1Tbp+hgqgLcaG3toBHmpKo79ynmSWkbcbhQFevyGAX9E Cgh95LNUo+ZiWmEva+IDYITwR7RiRtOkTGiUHCbbfn44V3hs5dI31EIFD3rkzB67iFkmigixGd4 M48phmsXV2dnVmgC4BGwPcfGgiVHrd881cbUw8w9fqgBMxDeBtoceBI5+F6/4/0VbxpF6bh9y6g SeJweFeE927OAqcNxZw== X-Authority-Analysis: v=2.4 cv=b5WCJNGx c=1 sm=1 tr=0 ts=6a67685f cx=c_pps a=aDMHemPKRhS1OARIsFnwRA==:117 a=aDMHemPKRhS1OARIsFnwRA==:17 a=kj9zAlcOel0A:10 a=RAioF0-LDSMA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=V8glGbnc2Ofi9Qvn3v5h:22 a=QUYGkz1GEY4_jyd1gQUA:9 a=CjuIK1q_8ugA:10 X-Proofpoint-GUID: vMhr7Ox03rhvdv6QrXTkbcxHn9IpPdex X-Proofpoint-ORIG-GUID: nuXJq4p0HBEtzkdiDKBObrq_O90kCWkP X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-07-27_04,2026-07-24_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 spamscore=0 adultscore=0 malwarescore=0 impostorscore=0 bulkscore=0 phishscore=0 suspectscore=0 clxscore=1015 lowpriorityscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2607270132 On Fri, Jul 24, 2026 at 06:00:04PM -0700, Nathan Chancellor wrote: > Hi Heiko, > > On Fri, Jul 24, 2026 at 04:13:17PM +0200, Heiko Carstens wrote: > > With all prerequisites in place select ARCH_SUPPORTS_CFI. > > > > Note that this support is supposed to work with the generic kcfi support > > which is provided by clang. This comes with a couple of limitations: > > Consider adding > > select ARCH_USES_CFI_GENERIC_LLVM_PASS if CC_IS_CLANG > > to this change in case there are problems such as the one worked around > by commit c57f5fee54df ("libeth: xdp: Disable generic kCFI pass for > libeth_xdp_tx_xmit_bulk()"). Whenever clang grows an s390 backend > expansion for kCFI, that can be version gated pretty easily. Thanks, I'll add that. > I will test this series fully next week. Highly appreciated! I'm going to send a v2 soon, which addresses your feedback, and hopefully all AI findings too.