V50A_010 Tru64 UNIX V5.0A Taso-mode ECO Summary

TITLE: V50A_010 Tru64 UNIX V5.0A Taso-mode ECO Summary
 
Copyright (c) Compaq Computer Corporation 2000.  All rights reserved.


PRODUCT:    Tru64 UNIX V5.0 and V5.0A
SOURCE:     Compaq Computer Corporation


ECO INFORMATION:

     ECO Name:  V50A_010
     ECO Kit Approximate Size:   467 KB
     Kit Applies To:  Tru64 UNIX V5.0 and 5.0A


PROBLEM STATEMENT:

  Taso mode is a compatibility feature of Tru64 UNIX that allows applications
  which are not 64-bit clean to be ported to the platform by loading the
  application and shared libraries in the low 31 bits of the address space
  (0x0 to 0x7fffffff), and also locating the program's heap there.

  Prior to Tru64 UNIX V5.0, the threads library allocated thread stacks out of
  the program's heap.  In V5.0, this behavior was changed to allocate stacks
  by calling a new kernel interface, which located the stacks at high
  addresses, outside the taso-mode address space range.  This change causes
  threads and taso-mode to be mutually incompatible, starting with V5.0.

  There is no workaround to this problem.


SOLUTIONS:

  * For Tru64 UNIX V5.0/5.0A -

  - A patch is available to fix this problem. This patch, which consists of
    /shlib/libpthread.so and /usr/shlib/libpthreaddebug.so, restores the
    pre-V5.0 behavior of allocating stacks in the low 31 bits of the address
    space. 

  - This patch will be included in the BL16 patch kits currently under
    development for V5.0 (PK2) and V5.0A (PK3).


  * For Tru64 UNIX V5.1 -

    This problem has already been fixed in the version of Tru64 UNIX V5.1 to be
    released.


[R] UNIX is a registered trademark in the United States and other countries 
licensed exclusively through X/Open Company Limited.

Copyright Compaq Computer Corporation 2000.  All Rights reserved.

  This software is proprietary to and embodies the confidential technology
  of Compaq Computer Corporation.  Possession, use, or copying of this
  software and media is authorized only pursuant to a valid written license
  from Compaq or an authorized sublicensor.

       This ECO has not been through an exhaustive field test process.
       Due to the experimental stage of this ECO/workaround, Compaq
       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.

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v50a_010.README
v50a_010.CHKSUM
v50a_010.tar.gz