Patch Name: PHKL_21004

Patch Description: s700 10.26 select(2) system call cumulative patch

Creation Date: 00/04/25

Post Date:  00/05/11

Hardware Platforms - OS Releases:
	s700: 10.26

Products: N/A

Filesets:
	OS-Core.CORE-KRN BLS.BLS-CORE

Automatic Reboot?: Yes

Status: General Release

Critical:
	Yes
	PHKL_21004: HANG

Path Name: /hp-ux_patches/s700/10.X/PHKL_21004

Symptoms:
	PHKL_21004:
	After resizing an X client multiple times, the resize border
	and coordinate box will not disappear and the X window
	system will become unresponsive.

	(PHKL_14282)
	Processes will sleep and never wakup (process
	appears hung).  Note that these are individual
	processes, and not the entire system.

Defect Description:
	PHKL_21004:
	Under some conditions on an MP system, the select(2) system
	call can hang. The problem is a race condition; the data to
	be selected arrives before select is ready.  Select then
	never sees this data and hangs waiting for it to arrive.

	(PHKL_14282)
	The defect was a race between real_sleep and sel_wakeup.  A
	thread that is going to sleep will update it's wchan, put
	itself on the sleepqueue, and drop the thread lock for
	signals.  It then re-acquires the thread lock and goes to
	sleep.  While the thread lock is "loose", another thread
	comes through selwakeup to wakeup the "sleepy thread".  It
	assumes that the kt_stat and wchan match, and then ignores
	the running thread, thinking it has already been woken.
	The original thread then continues to go to sleep, never
	to awaken again.


	Resolution:
	Port of PHKL_14282

SR:
	4701382440 5003343814

Patch Files:
	/usr/conf/lib/libhp-ux.a(sys_gen.o)
	/usr/conf/lib/libsec.a(sec_driver.o)
	/usr/conf/lib/libsec.a(sec_m6locks.o)

what(1) Output:
	/usr/conf/lib/libhp-ux.a(sys_gen.o):
		00/04/13 kern/sys/sys_gen.c, hpux, hpux_10.26, ic5eu
			 Revision 1.7 PATCH_10.26 (PHKL_21004)
	/usr/conf/lib/libsec.a(sec_driver.o):
		00/04/24 kern/sec/sec_driver.c, hpux, hpux_10.26, ic
			5eu Revision 1.5 PATCH_10.26 (PHKL_21004)
	/usr/conf/lib/libsec.a(sec_m6locks.o):
		00/04/24 kern/sec/sec_m6locks.c, hpux, hpux_10.26, i
			c5eu Revision 1.3 PATCH_10.26 (PHKL_21004)

cksum(1) Output:
	395785324 10540 /usr/conf/lib/libhp-ux.a(sys_gen.o)
	2781469068 14632 /usr/conf/lib/libsec.a(sec_driver.o)
	2699965150 2880 /usr/conf/lib/libsec.a(sec_m6locks.o)

Patch Conflicts: None

Patch Dependencies:
	s700: 10.26: PHKL_20471

Hardware Dependencies: None

Other Dependencies: None

Supersedes: None

Equivalent Patches:
	PHKL_21005:
	s800: 10.26

	PHKL_14282:
	s700: 10.20

	PHKL_14283:
	s800: 10.20

Patch Package Size: 90 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_21004

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

		swinstall -x autoreboot=true -x match_target=true \
			-s /tmp/PHKL_21004.depot

	By default swinstall will archive the original software in
	/var/adm/sw/patch/PHKL_21004.  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_21004.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_21004.depot of=/dev/rmt/0m bs=2k

Special Installation Instructions:
	This patch has a dependence on the kernel patch PHKL_20471.
	Please ensure that PHKL_20471 is installed before installing
	this patch.