From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6028C455181 for ; Wed, 23 Sep 2026 07:40:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.158.5 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790149218; cv=none; b=cyo8UGKkWJ6hVsr8WprPHHTWEVQgvcqSIxguW3uoitJAdb7467g6u0+oB8EOIoZg0YKuF2NZACUDtllR8149ff6cQSvmvYqAgSojqfH9xkYoKI7MeVOVOSsmp7wAjo9D5JWsaQJTUTIj0ebyeHtaZ5mauU+DJUm2ef+8r0i98fw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790149218; c=relaxed/simple; bh=6tkfvwvhV206T9WzF//fvA1D2jl7ot9szRK3Ode3etM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=kKYMU4RLU82E0ANF62uEV/fLKuOM0SFm5N8mb7ubXG6CDXPcxq3UigeBQmaNc5HgaPWpsStzHhZqMAfFPJwEfc45b705X5ft5q8Hia0qMFes/AWUzFprwFzBzrJlUyBSslR74hHu0lcczBPyscA//NLlfcIoH1INnSS3Sg1P+S0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=PF7U1gzU; arc=none smtp.client-ip=148.163.158.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="PF7U1gzU" Received: from pps.filterd (m0360072.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 68N77YLP2759764 for ; Wed, 23 Sep 2026 07:40:13 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:message-id:mime-version :subject:to; s=pp1; bh=vkL/ejhZusl03xFDdQIekadPwdjay726AMNL36b5h 3g=; b=PF7U1gzUqdy+lqjLGIKlTvm5IZTquP7uNkocKFpZw+vuubUD3UbY0QLnG P0aNVYr0Sw2OG2x5UeOM003RC3s7412f4XxNXHem13Ov2ZK+j5HexcwK4lEPxZdW N0geCI2sw0q7bR7qtDnupQAtg3O6Fot/UXxbi9pWDp4h2QdZfHwe9UAPGseZXhsz qlthop0FuH9gkHsQlL8nVPxj1nv5djLXfsReKmMrwCMl7YNFscMXhAwdLcuIvcAn qEGdfDQJFH7ci71QNS/HImk1mmIpsppHMNRoB5IeaK6YcA9WGzX4SRHAHuoWH2ir cybr/4yyj+Mc569hijpf6rgHkAy+w== Received: from ppma22.wdc07v.mail.ibm.com (5c.69.3da9.ip4.static.sl-reverse.com [169.61.105.92]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4gskdv9feh-1 (version=TLSv1.3 cipher=TLS_AES_256_GCM_SHA384 bits=256 verify=NOT) for ; Wed, 23 Sep 2026 07:40:12 +0000 (GMT) Received: from pps.filterd (ppma22.wdc07v.mail.ibm.com [127.0.0.1]) by ppma22.wdc07v.mail.ibm.com (8.18.1.11/8.18.1.11) with ESMTP id 68N7HWa04066140 for ; Wed, 23 Sep 2026 07:40:12 GMT Received: from smtprelay01.fra02v.mail.ibm.com ([9.218.2.227]) by ppma22.wdc07v.mail.ibm.com (PPS) with ESMTPS id 4gt53vncej-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 23 Sep 2026 07:40:12 +0000 (GMT) Received: from smtpav01.fra02v.mail.ibm.com (smtpav01.fra02v.mail.ibm.com [10.20.54.100]) by smtprelay01.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 68N7e6Tr44368230 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 23 Sep 2026 07:40:07 GMT Received: from smtpav01.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D76742004D; Wed, 23 Sep 2026 07:40:06 +0000 (GMT) Received: from smtpav01.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B338E2004B; Wed, 23 Sep 2026 07:40:06 +0000 (GMT) Received: from tuxmaker.lnxne.boe (unknown [9.87.85.9]) by smtpav01.fra02v.mail.ibm.com (Postfix) with ESMTP; Wed, 23 Sep 2026 07:40:06 +0000 (GMT) From: Alexander Egorenkov To: oberpar@linux.ibm.com Cc: gor@linux.ibm.com, hca@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, linux390-list@tuxmaker.boeblingen.de.ibm.com, linux-s390@vger.kernel.org Subject: [PATCH v7 0/5] s390/sclp: Misc fixes Date: Wed, 23 Sep 2026 09:40:01 +0200 Message-ID: <20260923074006.3962077-1-egorenar@linux.ibm.com> X-Mailer: git-send-email 2.53.0 Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: dppS_124hTU3UYnvs7h0XzRFgzaIxhkS X-Proofpoint-Spam-Info: AW1haW4tMjYwOTIzMDAzMCBTYWx0ZWRfXyUYHm5IoZ3cT xJZU5VBxOlLGCQ9sgqGrGR/ig3fNOfkU9pX9MpiRlhDJ4yW2RAGqpf2QrH4T9xG6ULNyzBC3E2o 3EgzhYskW0z6wgOqRJWLIT8CyhKBHcI= X-Authority-Analysis: v=2.4 cv=FLiOVOos c=1 sm=1 tr=0 ts=6ab3825c cx=c_pps a=5BHTudwdYE3Te8bg5FgnPg==:117 a=5BHTudwdYE3Te8bg5FgnPg==:17 a=VdqzKS8jKosA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=RzCfie-kr_QcCd8fBx8p:22 a=E0fA2fgX6Qsn16Cr5gUA:9 X-Proofpoint-GUID: dppS_124hTU3UYnvs7h0XzRFgzaIxhkS X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwOTIzMDAzMCBTYWx0ZWRfXzqbp6MZD8QNi K3jSzhiHhkp4Hju66Nx1hNh7ehchk1XWvGzyz5QGeMvFj0i6Y9pVX7L3JWgsYUHQRycj95OhmtC eLTaNkgEE/mJ6hvi5YD4bwPJM/yeAD1L+lUbwFOqbXZSKdhHhuY726Ezn65HWaqhWm2dzDWsNFY QaTYm36xVMXC0tKNARccLe6AUQpY+K8WpCeYJ7w/W0qwE3kKDIeyLUFH4IPBRqJhm0rxHLljMZC YZ//YUHJIGUvhW0y2KVif+Vi2025BdCkQWpq8Ayl0EwCMvZYMEYpUx+WNKL2cZ6VtXdMRmrt/oj kFcVPTSiBE9PwQTOiQXVQ9cgHddDbIlGdELAfYj90myk1kPbMIaa0rlKBbeFlUHd5dlgVy1F7C9 fkRSeW/B9EWDlen9fNkvsz5/IlrbudBhVfV4bqpvnVI959RAN7VM1owGXpOVC2ZyMKLVqEqNsVs U3MGfzbC567OIK9U96A== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-09-23_03,2026-09-21_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 impostorscore=0 phishscore=0 spamscore=0 clxscore=1015 suspectscore=0 bulkscore=0 lowpriorityscore=0 priorityscore=1501 malwarescore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2609040000 definitions=main-2609230030 This series consists of several fixes for the s390 SCLP driver. * The first patch makes sclp_dispatch_evbufs() more safe while parsing event buffers contained in a received SCCB buffer. * The second patch introduces the macro sclp_gds_for_each() to safely iterate over GDS {sub}vectors and serves to improve error handling in sclp_find_gds_{sub}vector() to prevent out-of-range memory read and potential infinite loops when a malformed event buffer is received from SCLP. * The third patch reuses the macro sclp_gds_for_each() in SCLP TTY introduced in the first patch to replace manual and error-prone iteration over entries of a GDS {sub}vector to fix the same issues addressed in the first patch. * The fourth patch fixes 2 potential illegal memory accesses when reading the value from a GDS subvector in SCLP event buffers sent by OCF. * The fifth patch fixes race situations with in-flight callbacks and sclp_unregister() calls. Changes since v6 ---------------- - Rework the patch "s390/sclp: Make parsing of received event buffers more robust" - Move event buffer header checks into the parsing loop to make code more readable as suggested by Peter - Add check for SCCB buffer length as suggested by Peter - Return with -EINVAL from sclp_dispatch_evbufs() if SCCB or event buffer checks fail - Improved commit message Changes since v5 ---------------- - Added patch "s390/sclp: Make parsing of received event buffers more robust" - Reported by Sashiko - Rework the patch "s390/sclp: Introduce macro sclp_gds_for_each()" - Explicit cast of start and end parameters to void* removing the need for the caller to use extra void* variables for start and end, and also protecting from mistakes when using non-void* variables when calculating n - Rework the patch "s390/sclp_ocf: Fix computation of length of GDS values" - Improved commit description as suggested by Peter Changes since v4 ---------------- - Drop patch "s390/sclp: Drop volatile type class from SCLP state variables" - There are several doubts to it being correct in all situations - Introduce the macro sclp_gds_for_each() - Reusable and safe iteration over GDS {sub}vectors - Make use of sclp_gds_for_each() in SCLP TTY - Rework the patch "s390/sclp: Ensure no callback gets called after sclp_{un}register() returns" - Remove waiting for SCLP mask and reading states to become idle from sclp_register() on sclp_init_mask() failure - First, it is incorrect to sleep in sclp_register() which is called from atomic context - sclp_console_init() -> sclp_rw_init() -> sclp_register() - sclp_vt220_con_init() -> __sclp_vt220_init() -> sclp_register() - Second, it is redundant because no race situation can occur if sclp_init_mask() fails because in that case no events can be received from SCLP due to SCLP receive event mask update performed in sclp_init_mask() having failed - Add might_sleep() to sclp_unregister() to indicate that the function could potentially sleep - Adjust coding style of function sclp_unregister() - Add "Fixes" tag where necessary Changes since v3 ---------------- - Rework the patch "s390/sclp: Ensure no callback gets called after sclp_{un}register() returns" - Shorten and reword the commit description - Replace wake_up_all_locked() with wake_up_all() - Replace sclp_init_state with sclp_mask_state in wait queue condition - Call wake_up_all() unconditionally - Add call to wake_up_call() in sclp_init_mask() after updating sclp_mask_state Changes since v2 ---------------- - Add 2 new patches: - s390/sclp: Drop volatile type class from SCLP state variables - s390/sclp: Improve robustness of sclp_find_gds_{sub}vector() - Rework the patch "s390/sclp: Ensure no callback gets called after sclp_unregister() returns" to implement Peter Oberparleiter's suggestion with a global wait queue and checking the state variables as its condition. It turns out the implementation with a single completion per struct sclp_register is inadequate because theoretically the callback state_change_fn() and receive_fn() could get invoked in parallel, however unlikely. Furthermore, the same race situation might happen with sclp_register() too. Changes since v1 ---------------- - Drop redundant empty lines in sclp.c - Make commit message more verbose for the fix in sclp.c Alexander Egorenkov (5): s390/sclp: Make parsing of received event buffers more robust s390/sclp: Introduce macro sclp_gds_for_each() s390/sclp_tty: Make use of sclp_gds_for_each() s390/sclp_ocf: Fix computation of length of GDS values s390/sclp: Ensure no callback gets called after sclp_unregister() returns drivers/s390/char/sclp.c | 42 +++++++++++++++++++++++++++--------- drivers/s390/char/sclp.h | 24 ++++++++++++++------- drivers/s390/char/sclp_ocf.c | 4 ++-- drivers/s390/char/sclp_tty.c | 24 ++++++++------------- 4 files changed, 59 insertions(+), 35 deletions(-) -- 2.53.0