From Bugzilla Helper: User-Agent: Mozilla/4.76 [en] (X11; U; Linux 2.4.5 i686) Description of problem: Apparently at least some 7.1 x86 kernels incorporate patch-2.4.2-ac3, which breaks lseek on /proc/N/mem, giving a bogus EINVAL error for seeks to the top half of a process's memory. This breaks SUBTERFUGUE (http://subterfugue.org) and perhaps other programs. How reproducible: Didn't try Steps to Reproduce: 1. This is from a user error report 2.The systems are stock RedHat 7.1, running the 2.4.2-2 RedHat supplied kernel. Have tested with both smp and up versions. Linux slave6 2.4.2-2smp #1 SMP Sun Apr 8 20:21:34 EDT 2001 i686 unknown These are burnup systems, generic installation via kickstart. 3. If you obtain and build SUBTERFUGUE, the command 'sf --tri=Trace date' would trigger the bug. Actual Results: You'll see a python backtrace. Expected Results: successful execution Additional info: This bug appears to be fixed as of the 2.4.5-ac1 patch. It's also absent from all vanilla kernels, I believe. So, the fix is to upgrade or rebuild your kernel. (I'm filing this bug primarily for your errata page.)