What type of SVC? The SVRB only exists for 3, 3 and 4. -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 עַם יִשְׂרָאֵל חַי נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר
________________________________________ From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of Erik Janssen <0000062c999269e8-dmarc-requ...@listserv.ua.edu> Sent: Friday, April 26, 2024 3:20 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: finding callers key in svc Hello List, Is there way to determine the key that the caller of a SVC is executing in? For a PC routine doing an ESTA and some shifting seems to be the way to find the key, but I'm unsure how the same could be done from a user SVC. Is it somewhere in the SVRB? Also, I see this example in the authorized code scanner: https://www.ibm.com/docs/en/zos/2.4.0?topic=fixes-fetch-vulnerability-example vulnerable: LA R3,copyparms MVC 0(4,R3),0(R2) fixed: LHI R3,1 ESTA R0,R3 SRDL R0,48 LHI R0,3 LA R3,copyparms MVCSK 0(R3),0(R2) I noticed that the length loading in R0 for the MVCSK is 3, while in the vulnerable mvc example the length is 4. The POP for MVCSK says: L specifies the number of bytes to the right of the first byte of each operand. Therefore, the length in bytes of each operand is 1-256, corresponding to a length code in L of 0-255. Is there any logic behind why MVC uses the actual byte count and MVCSK uses the 'number of bytes to the right'? Kind regards, Erik Janssen. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
