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Thu, 14 May 2026 05:24:08 +0000 (GMT) Received: from [9.123.5.233] (unknown [9.123.5.233]) by smtpav02.fra02v.mail.ibm.com (Postfix) with ESMTP; Thu, 14 May 2026 05:24:07 +0000 (GMT) Message-ID: <60e44383-0791-4d0a-8c16-41fb4f436e0b@linux.ibm.com> Date: Thu, 14 May 2026 10:54:07 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] powerpc/hv-gpci: fix preempt count leak in sysfs show paths To: "Ritesh Harjani (IBM)" Cc: Christophe Leroy , Kajol Jain , linux-kernel@vger.kernel.org, Aboorva Devarajan , Madhavan Srinivasan , Athira Rajeev , linuxppc-dev@lists.ozlabs.org References: <20260508041256.3447113-1-aboorvad@linux.ibm.com> <5x4usp43.ritesh.list@gmail.com> Content-Language: en-US From: Shrikanth Hegde In-Reply-To: <5x4usp43.ritesh.list@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Proofpoint-ORIG-GUID: b3bY_LRIoNQYJfxqWEZsIfjD8xGmUG4G X-Proofpoint-GUID: btCnoQHbR8Ir3FPBUq5nUDUqdjiQ9i0o X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNTE0MDA0OCBTYWx0ZWRfX8P+RDdsXryx9 1xHtpc18CahqNG7kPLtXaWu+YMKxJ+4nDO+HofPWgqAzzBdaJVOjmzZKyDUUlW1SzwsHBMbBGUW pT3uAAyqjw+Jn6eihSV7Ku7qjJBrwIFS0QnWiLjZsMqVQJiO1i+QZCJM85KyjqkBlbWN4hmFkMs vrKNitfAPykQNr8p2r7Qyi0f4f6vZkqnjLq9XYCOW+AYjKbQVUcvr39Qg4hAxxEPKYXHRLlan5E 6XClwu/2RiAIYeEDhZPa7OIT4G9UHLaVO4X96NhZQaU3EiQ7TXKGerYrpTYTAH2iik3yjiVJOqx Obq8/P3ZzyZg2e0Ic/D6HI8LMtRBwl/CWj6gjpDXdvwrOMogbbW9ZSK2y9pxwYQgFLufjwTKdIo VaEWgXIGky06m4ijAQJrayO45iT8ohSCr51Q8wpvg0v5AevtPfz+vnFYM3aovFkzspZESkQet2v PJiTto1i435RZ2giNsQ== X-Authority-Analysis: v=2.4 cv=P8UKQCAu c=1 sm=1 tr=0 ts=6a055c7e cx=c_pps a=3Bg1Hr4SwmMryq2xdFQyZA==:117 a=3Bg1Hr4SwmMryq2xdFQyZA==:17 a=IkcTkHD0fZMA:10 a=NGcC8JguVDcA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=RzCfie-kr_QcCd8fBx8p:22 a=0vG1zSKhuiwHglsLdNIA:9 a=QEXdDO2ut3YA:10 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-05-14_01,2026-05-13_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 priorityscore=1501 phishscore=0 bulkscore=0 clxscore=1015 malwarescore=0 spamscore=0 lowpriorityscore=0 suspectscore=0 impostorscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2605050000 definitions=main-2605140048 Hi Ritesh. > I guess, these would be the other kind of issues which might show up now, > since powerpc is moved to CONFIG_PREEMPTION=y with lazy preempt as the > default preemption mode. It will be nice to have some mechanism to catch > these error handling paths where preempt counts might be getting leaked. > There is CONFIG_DEBUG_PREEMPT=y which helps you to catch these issue where count leak happens. Otherwise we only see end result, but not the culprit. That said, we do have issues of not nesting with get_cpu/put_cpu in few places and preempt_disable/preempt_enable in few return paths still.