Patch Name: PHKL_30288

Patch Description: s700_800 11.11 Thread Abort syscall

Creation Date: 04/02/03

Post Date: 04/04/01

Hardware Platforms - OS Releases:
	s700: 11.11
	s800: 11.11

Products: N/A

Filesets:
	OS-Core.CORE2-KRN,fr=B.11.11,fa=HP-UX_B.11.11_32,v=HP
	OS-Core.CORE2-KRN,fr=B.11.11,fa=HP-UX_B.11.11_64,v=HP

Automatic Reboot?: Yes

Status: General Release

Critical:
	Yes
	PHKL_30288: HANG

Category Tags:
	defect_repair enhancement general_release critical
	halts_system manual_dependencies

Path Name: /hp-ux_patches/s700_800/11.X/PHKL_30288

Symptoms:
	PHKL_30288:
	( SR:8606337549 CR:JAGae98556 )
	A multi-threaded user application using Light Weight
	Process (LWP) threads might experience an unkillable hang
	after a thread is asynchronously canceled.  This is more
	likely to occur on a uniprocessor system but can also
	happen on a multiprocessor system.

	PHKL_25842:
	( SR:8606229034 CR:JAGad98088 )
	Enhancement to provide support for the interruption of a
	specic thread blocked interruptibly in a system call.

Defect Description:
	PHKL_30288:
	( SR:8606337549 CR:JAGae98556 )
	When a LWP thread is aborted by a pthread_cancel, a side
	effect of is that the aborting thread may execute briefly
	before being aborted completely.  The thread may return to
	user space and execute user program code during this brief
	interval.  Depending on what the user program does during
	that period, unexpected, detrimental effects to the system
	could result.  For instance, the program could immediately
	perform another system call where a semaphore or other
	global resources could be acquired and cause the thread to
	become unkillable, lead to a system deadlock/hang, etc.

	Resolution:
	The fix is to insert a call at the end of syscall to handle
	the terminating process instead of letting it exit out of
	syscall.  That is, check the condition in the syscall path
	where a thread returns to user space from the kernel to
	ensure that an aborted thread does not return to user space.

	PHKL_25842:
	( SR:8606229034 CR:JAGad98088 )
	The Operating System currently has no way to abort a
	specific thread blocked interruptibly in a system call.

	Resolution:
	A new kernel internal interface (function) is introduced to
	provide kernel subsystems the ability to abort a thread that
	is currently blocked interruptibly in a system call.This
	portion of the functionality clears flags associated with
	the new routine.

Enhancement:
	No (superseded patches contained enhancements)
	PHKL_30288:
		Enhancements were delivered in a patch this one has
		superseded.  Please review the Defect Description
		text for more information.

SR:
	8606229034 8606337549

Patch Files:
	
	OS-Core.CORE2-KRN,fr=B.11.11,fa=HP-UX_B.11.11_32,v=HP:
	/usr/conf/lib/libscall.a(syscall.o)

	OS-Core.CORE2-KRN,fr=B.11.11,fa=HP-UX_B.11.11_64,v=HP:
	/usr/conf/lib/libscall.a(syscall.o)

what(1) Output:
	
	OS-Core.CORE2-KRN,fr=B.11.11,fa=HP-UX_B.11.11_32,v=HP:
	/usr/conf/lib/libscall.a(syscall.o):
		syscall.c $Date: 2004/01/29 17:10:28 $Revision: r11.
			11/2 PATCH_11.11 (PHKL_30288)

	OS-Core.CORE2-KRN,fr=B.11.11,fa=HP-UX_B.11.11_64,v=HP:
	/usr/conf/lib/libscall.a(syscall.o):
		syscall.c $Date: 2004/01/29 17:10:28 $Revision: r11.
			11/2 PATCH_11.11 (PHKL_30288)

cksum(1) Output:
	
	OS-Core.CORE2-KRN,fr=B.11.11,fa=HP-UX_B.11.11_32,v=HP:
	3128076875 15792 /usr/conf/lib/libscall.a(syscall.o)

	OS-Core.CORE2-KRN,fr=B.11.11,fa=HP-UX_B.11.11_64,v=HP:
	3527953249 40152 /usr/conf/lib/libscall.a(syscall.o)

Patch Conflicts: None

Patch Dependencies: None

Hardware Dependencies: None

Other Dependencies:
	PHKL_25842:For enablement of this feature, PHKL_25840 also
	needs to be installed in the system.  Installation of either
	patch by itself has no effect on the system.

Supersedes:
	PHKL_25842 

Equivalent Patches:
	PHKL_30287:
	s700: 11.00
	s800: 11.00

Patch Package Size: 50 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_30288

	5. Run swinstall to install the patch:

		swinstall -x autoreboot=true -x patch_match_target=true \
			  -s /tmp/PHKL_30288.depot

	By default swinstall will archive the original software in 
	/var/adm/sw/save/PHKL_30288.  If you do not wish to retain a
	copy of the original software, include the patch_save_files
	option in the swinstall command above:

		-x patch_save_files=false

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

	For future reference, the contents of the PHKL_30288.text file is 
	available in the product readme:

		swlist -l product -a readme -d @ /tmp/PHKL_30288.depot

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

		dd if=/tmp/PHKL_30288.depot of=/dev/rmt/0m bs=2k

Special Installation Instructions: None