AIX Patch Considerations

Some patch levels of AIX 4.3.2 contain a kernel bug where the ptrace(PT_REATT) system call fails with EPERM when debugging IBM parallel environment (PE) programs. A patch for this problem is available for AIX 4.3.2 as:

    APAR IY02037 -- HOT: ptrace(PT_REATT...) returns -1 and sets er

In addition, this patch is quite huge, 262 filesets occupying 420MB. If you apply this patch, you will effectively upgrade your system to AIX 4.3.3, and you should also apply the following patch:

    APAR IY03550 -- DBX CANNOT SET BREAK POINTS IN DATA SECTION IN

Consequently, we recommend that you obtain the AIX 4.3.3 distribution CD from IBM.

On 64-bit Power3-based RS/6000 systems, or any system that has split instruction and data caches, ptrace() fails to copy back the data cache for breakpoints planted in the target program's data space. The TotalView compiled expression evaluator and interpreted expression function call features plant breakpoints in the target program's data space, making these feature unusable on 64-bit Power3-based systems. The symptom is that TotalView sometimes hangs when creating a process at the start of execution. To fix this problem, you should apply:

    APAR IY03550 -- DBX CANNOT SET BREAK POINTS IN DATA SECTION IN