Patch Name: PHKL_22328

Patch Description: s700 10.20 Data page fault in remove_callout() fix

Creation Date: 00/10/27

Post Date:  00/11/07

Hardware Platforms - OS Releases:
	s700: 10.20

Products: N/A

Filesets:
	OS-Core.CORE-KRN

Automatic Reboot?: Yes

Status: General Release

Critical: No

Path Name: /hp-ux_patches/s700/10.X/PHKL_22328

Symptoms:
	PHKL_22328:
	(SR: 8606147352   CR: JAGad16695)
	Callout list corruption causing spinlock deadlock
	panic due to CPU0 holding callout_lock for too long.

Defect Description:
	PHKL_22328:
	(SR: 8606147352   CR: JAGad16695)
	Possible race condition that may allow a callout to
	appear on 2 callout lists.

	When cleanout_bucket() transiently removes a callout
	from one callout list and re-insert it to another, there
	is a small window in which the callout's c_flag doesn't
	have PENDING_CALLOUT set as remove_callout() always
	clears PENDING_CALLOUT bit in c_flag.

	Resolution:
	The fix is to introduce a new flag C_DONTFREEIT_TRANSITION
	while calling remove_callout() before insert_callout().
	This will ensure that the callout does not end up in more
	than one callout lists.

SR:
	8606147352

Patch Files:
	/usr/conf/lib/libhp-ux.a(pm_callout.o)

what(1) Output:
	/usr/conf/lib/libhp-ux.a(pm_callout.o):
		pm_callout.c $Date: 2000/09/05 10:42:22 $ $Revision:
			 1.5.98.2 $ PATCH_10.20 (PHKL_22328)

cksum(1) Output:
	3864830929 11512 /usr/conf/lib/libhp-ux.a(pm_callout.o)

Patch Conflicts: None

Patch Dependencies: None

Hardware Dependencies: None

Other Dependencies: None

Supersedes: None

Equivalent Patches:
	PHKL_22329:
	s800: 10.20

Patch Package Size: 70 KBytes

Installation Instructions:
	Please review all instructions and the Hewlett-Packard
	SupportLine User Guide or your Hewlett-Packard support terms
	and conditions for precautions, scope of license,
	restrictions, and, limitation of liability and warranties,
	before installing this patch.
	------------------------------------------------------------
	1. Back up your system before installing a patch.

	2. Login as root.

	3. Copy the patch to the /tmp directory.

	4. Move to the /tmp directory and unshar the patch:

		cd /tmp
		sh PHKL_22328

	5a. For a standalone system, run swinstall to install the
	    patch:

		swinstall -x autoreboot=true -x match_target=true \
			-s /tmp/PHKL_22328.depot

	By default swinstall will archive the original software in
	/var/adm/sw/patch/PHKL_22328.  If you do not wish to retain a
	copy of the original software, you can create an empty file
	named /var/adm/sw/patch/PATCH_NOSAVE.

	WARNING: If this file exists when a patch is installed, the
	         patch cannot be deinstalled.  Please be careful
		 when using this feature.

	It is recommended that you move the PHKL_22328.text file to
	/var/adm/sw/patch for future reference.

	To put this patch on a magnetic tape and install from the
	tape drive, use the command:

		dd if=/tmp/PHKL_22328.depot of=/dev/rmt/0m bs=2k

Special Installation Instructions: None