On Tue, 11 May 2010 08:53:56 -0700 George Fogg <gf...@nwlink.com> wrote:
:>> Rob Scott wrote :>> I think the OP and Chris were referring to a situation where the target :>> address space is being "snooped" - rather than sharing its memory by a :>> controlled and approved x-memory linkage. There are example code snippets out :>> there in the public domain that attempt to access private storage in a foreign :>> non-swap ASID in AR-mode after adding an ALET using CHKEAX=NO on the ALESERV. :>> This technique is not to be encouraged and will eventually end in tears for :>> someone. :>Here's some of the code that the OP might be refering too from the Zephon :>article. :>** CROSS MEMORY CALL :>* :>@XMEM XR 2,2 ZERO REG 2 :> ESAR 2 OBTAIN OUR ADDR SP NUMBER :> ST 2,OURASN SAVE IT :>* :> MODESET KEY=ZERO,MODE=PROB KEY ZERO, PROB STATE :> BAL 14,@INXMEM :>* :> XR 1,1 REG 1 = 0 :> L 8,XMADDR ADDRESS TO READ FROM :> L 2,XMLENG LENGTH TO READ :> L 2,XMLENG LENGTH TO READ :> MVCP XMSTOR(2),0(8),1 :>* :> BAL 14,@OUTXMEM :> MODESET KEY=NZERO,MODE=PROB KEY USER, PROB STATE :>* :>the code following uses IKJCT441 to create variables to pass back to the REXX :>caller. One var contains the storage obtained from another ASID. :> . . . . . :>** SUBROUTINE - INTO CROSS MEMORY MODE ************************** :>* :>@INXMEM LA 2,1 REG 2 = 1 :> AXSET AX=(2) AUTH INDEX = 1 :> L 2,REQASN INTO XMEM MODE :> SSAR 2 :>@INXEND BR 14 :>* :>** SUBROUTINE - OUT OF CROSS MEMORY MODE ************************ :>* :>@OUTXMEM L 2,OURASN OUT OF XMEM MODE :> SSAR 2 :> XR 2,2 REG 2 = 0 :> AXSET AX=(2) AUTH INDEX = 0 :>@OUTXEND BR 14 :>This rexx assembler is defined in IKJTSO00 in AUTHPGM. :>BTW, I couldn't get it to work either. You can access fixed storage from a swapped in job (since that is guaranteed to be paged in) in this way. This code should work if REQASN and XMADDR are properly set. -- Binyamin Dissen <bdis...@dissensoftware.com> http://www.dissensoftware.com Director, Dissen Software, Bar & Grill - Israel Should you use the mailblocks package and expect a response from me, you should preauthorize the dissensoftware.com domain. I very rarely bother responding to challenge/response systems, especially those from irresponsible companies. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
