On 3/27/2012 7:27 PM, Ray Overby wrote:
Like any SVC when invoked it will get control in an authorized state (PSW Key 0). Further this SVC issues a STM instruction very early in the SVC code storing into where ever R13 points to. This type of defect is easily exploited writing a simple program (could have been posted on the web) that would issue the SVC and:
Defect is the correct description; your SVC sounds as though written by an incompetent programmer. User's registers are preserved in the RB (PRB, SVRB), where they are protected, rather than the save area. Off-hand I can't recall any SVC that needs R13 to point to a save area, rather there are cases where R13 is destroyed.
Gerhard Postpischil Bradford, VT ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
