TITLE: HP Tru64 UNIX - Potential Dead Lock and KMF in tape cam_changer code Copyright (c) Hewlett-Packard Company 2005. All rights reserved. PRODUCT: HP Tru64 UNIX [R] V5.1A PK6 SOURCE: Hewlett-Packard Company ECO INFORMATION: ECO Name: T64KIT0025059-V51AB24-E-20050302 ECO Kit Approximate Size: 3.70MB Kit Applies To: HP Tru64 UNIX V5.1A PK6 ECO Kit CHECKSUMS: /usr/bin/sum results: 27837 3790 /usr/bin/cksum results: 2550077459 3880960 MD5 results: f92ef9d30cecc043573bcec8fa3cfecb SHA1 results: 3665026494b9514e577d31146eaefae545400f6b ECO KIT SUMMARY: A dupatch-based, Early Release Patch kit exists for HP Tru64 UNIX V5.1A PK6 that contains solutions to the following problem(s): Previous cam_changer Early Release Patches (ERPs) have been updated to include an additional correction in cam_changer code. The ERP described here now contains two fixes: - A potential dead lock condition that manifests as an application hang - A potential kernel memory fault (KMF) The fixes are described below. A. Potential Dead Lock A dead lock condition can occur in cam_changer code while a changer application is accessing the media changer. This condition is likely to occur when a previous changer access failed with the error "SCSI device busy," due to a chance that the access lock is not properly released. The dead lock condition manifests as a changer application hang. B. Potential KMF A KMF can occur in the cam_changer code if more than one thread attempts to access the changer at the same time. For example, if a robot is moving tapes and another thread opens the same device the panic event is likely to occur. This panic is more likely occur if the customer is running tape backup software that uses multiple changer threads. When the problem occurs, the customer loses any data written to the tape library before final tape marks have been written. To correct for this condition, the backup process must be reinitiated, which can lengthen the time to complete backups within allocated production time frames. The following is a typical changer KMF stack trace example: crash> tf > 0 stop_secondary_cpu src/kernel/arch/alpha/cpu.c : 1398 1 panic src/kernel/bsd/subr_prf.c : 1325 2 event_timeout src/kernel/arch/alpha/cpu.c : 2348 3 printf src/kernel/bsd/subr_prf.c : 1008 4 panic src/kernel/bsd/subr_prf.c : 1382 5 trap src/kernel/arch/alpha/trap.c : 2285 6 _XentMM src/kernel/arch/alpha/locore.s : 2237 7 ccmn_record_eei_status3 src/kernel/io/cam/pdrv3_common.c : 4763 8 changer_complete src/kernel/io/cam/cam_changer.c : 7681 9 xpt_callback_thread src/kernel/io/cam/xpt.c : 3357 The Patch Kit Installation Instructions and the Patch Summary and Release Notes documents provide patch kit installation and removal instructions and a summary of each patch. Please read these documents prior to installing patches on your system. INSTALLATION NOTES: 1) Install this kit with the dupatch utility that is included in the patch kit. You may need to baseline your system if you have manually changed system files on your system. The dupatch utility provides the baselining capability. 2) This ERP kit will NOT install over any Customer Specific Patches (CSPs) which have file intersections with this ERP kit. Contact your normal Service Provider for assistance if the installation of this ERP kit is blocked by any of your installed CSPs. INSTALLATION PREREQUISITES: You must have installed HP Tru64 UNIX V5.1A PK6 (BL24) prior to installing this Early Release Patch Kit. SUPERSEDE INFORMATION: T64KIT0025059-V51AB24-E-20050302 replaces kit T64KIT0024085-V51AB24-E-20041028 KNOWN PROBLEMS WITH THE PATCH KIT: None. RELEASE NOTES FOR T64KIT0025059-V51AB24-E-20050302: Release Notes This document summarizes the contents and special instructions for the Tru64 UNIX V5.1A patches contained in this kit. For information about installing or removing patches, baselining, and general patch management, see the Patch Kit Installation Instructions document. 1 Release Notes This Early Release Patch Kit Distribution contains: - fixes that resolve the problem(s) reported in: o 242 QXCM1000219890 * for Tru64 UNIX V5.1A T64V51AB24AS0006-20031031.tar (BL24) This kit includes a patch which requires system reboot. The patches in this kit are being released early for general customer use. Refer to the Release Notes for a summary of each patch and installation prerequisites. Patches in this kit are installed by running dupatch from the directory in which the kit was untarred. For example, as root on the target system: > mkdir -p /tmp/CSPkit1 > cd /tmp/CSPkit1 > > tar -xpvf DUV40D13-C0044900-1285-20000328.tar > cd patch_kit > ./dupatch 2 Special Instructions There are no special instructions for Tru64 UNIX V5.1A Patch C1649.00 3 Summary of CSPatches contained in this kit Tru64 UNIX V5.1A PatchId Summary Of Fix ---------------------------------------- C1649.00 ERP, KMF and Dead Lock issue in cam_changer code. 4 Additional information from Engineering None 5 Affected system files This patch delivers the following files: Tru64 UNIX V5.1A Patch C1649.00 ./sys/BINARY/cam.mod CHECKSUM: 12309 619 SUBSET: OSFHWBIN520 ./sys/BINARY/cam_changer.mod CHECKSUM: 42233 324 SUBSET: OSFHWBIN520 ./usr/sys/include/io/cam/cam_changer.h CHECKSUM: 04555 32 SUBSET: OSFHWBINCOM520 [R] UNIX is a registered trademark in the United States and other countries licensed exclusively through X/Open Company Limited. Copyright Hewlett-Packard Company 2005. All Rights reserved. This software is proprietary to and embodies the confidential technology of Hewlett-Packard Company. Possession, use, or copying of this software and media is authorized only pursuant to a valid written license from Hewlett-Packard or an authorized sublicensor. This ECO has not been through an exhaustive field test process. Due to the experimental stage of this ECO/workaround, Hewlett-Packard makes no representations regarding its use or performance. The customer shall have the sole responsibility for adequate protection and back-up data used in conjunction with this ECO/workaround.