Linux® on the Mainframe

22.1. What information you need

Let's briefly review the information you need for successful debugging on the mainframe.

22.1.1. User address spaces

You may remember from 20.3, “Exploiting mainframe processor architecture,” that there are several kinds of address spaces. In particular, the Linux kernel runs in primary space mode, and all user programs run in home space mode.

Let's have a short look at the virtual address space or user space process. In Figure 22-1 we see the organization of the virtual memory. The stack grows from high addresses to low. The dynamic segments are used, e.g., for shared libraries, and are located above the anonymous mapping base. The code and heap of a user program are located between the program base and the anonymous ...