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Marchesi" , Beau Belgrave , Linus Torvalds , Andrew Morton , Jens Axboe , Florian Weimer , Sam James , Heiko Carstens , Vasily Gorbik References: <20250708012239.268642741@kernel.org> <20250708012357.982692711@kernel.org> <20250710112147.41585f6a@batman.local.home> <155f22cb-b986-4d22-a853-6de49a1c2e03@linux.ibm.com> <20250710130859.41f3d5d0@batman.local.home> Content-Language: en-US From: Jens Remus Organization: IBM Deutschland Research & Development GmbH In-Reply-To: <20250710130859.41f3d5d0@batman.local.home> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Authority-Analysis: v=2.4 cv=Je68rVKV c=1 sm=1 tr=0 ts=6874fd84 cx=c_pps a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17 a=IkcTkHD0fZMA:10 a=Wb1JkmetP80A:10 a=VnNF1IyMAAAA:8 a=0MvmVg10__VCTnNSAJcA:9 a=3ZKOabzyN94A:10 a=QEXdDO2ut3YA:10 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUwNzE0MDA3MiBTYWx0ZWRfX0GmA12MjXPl0 mBleebw0c2P9DZSyzdVI/rFwyNpnKJuNwnipHu0cbHFskKcidiy6ktJrwTumFiA1pla+/R9Kkg8 ExFHZVn7WB4+Ve7gAZZub7bJBNJLq/2RlsS1Xx8H/nb02b+0/+cIuqonSJJf/1+3OqFuVQHF8kg 6DmWruXn4r8mxIm3n2rvEg64x0SYfhh48L5clhqbjjjJDNqjaW8bPJxidrfJKqEXLQalez1kBTE RHOZLgfa/I1ON24ruFHu88Bp8sPdxK3V6lM8I+MCuBWEW14hehWKJ9Fczb0Lq3PgVVbO4qNcXjk oBPCVzaPB3JwXG39TH2uHqsBCpsleaCU5ospb4AjU+ZqIVgWvN2AFJs9HAXm676t5Avv1N7gEh/ 09VYeV53/4d29g21i51TT+ddWkVB3qJblodQp0HbdZ+ErmqMYZr/uKkHSTFiahhXixBX50P/ X-Proofpoint-GUID: Oh6bCUxjZdZRr-S4SJxqEUAcMtwALGGj X-Proofpoint-ORIG-GUID: Oh6bCUxjZdZRr-S4SJxqEUAcMtwALGGj X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1099,Hydra:6.1.7,FMLib:17.12.80.40 definitions=2025-07-14_01,2025-07-14_01,2025-03-28_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 malwarescore=0 lowpriorityscore=0 suspectscore=0 adultscore=0 priorityscore=1501 clxscore=1015 bulkscore=0 phishscore=0 spamscore=0 mlxlogscore=999 mlxscore=0 classifier=spam authscore=0 authtc=n/a authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.19.0-2505280000 definitions=main-2507140072 On 10.07.2025 19:08, Steven Rostedt wrote: > On Thu, 10 Jul 2025 17:41:36 +0200 > Jens Remus wrote: > >> cfa + frame->ra_off could be aligned by chance. So could >> cfa + frame->fp_off be as well of course. >> >> On s390 the CFA must be aligned (as the SP must be aligned) and the >> FP and RA offsets from CFA must be aligned, as pointer / 64-bit integers >> (such as 64-bit register values) must be aligned as well. >> >> So the CFA (and/or offset), FP offset, and RA offset could be validated >> individually. Not sure if that would be over engineering though. > > I wonder if we should just validate that cfa is aligned? Would that work? > > I would think that ra_off and fp_off should be aligned as well and if > cfa is aligned then it would still be aligned when adding those offsets. Makes sense, if the base assumption is that the SFrame information is valid and the primary intend is to check that the used CFA base register (i.e. SP or FP) was aligned. Regards, Jens -- Jens Remus Linux on Z Development (D3303) +49-7031-16-1128 Office jremus@de.ibm.com IBM IBM Deutschland Research & Development GmbH; Vorsitzender des Aufsichtsrats: Wolfgang Wendt; Geschäftsführung: David Faller; Sitz der Gesellschaft: Böblingen; Registergericht: Amtsgericht Stuttgart, HRB 243294 IBM Data Privacy Statement: https://www.ibm.com/privacy/