Attempts to attach the Postfix master process to the strace debugger fail and leave the master process in a non-working state. One must then individually kill all Postfix processes before restarting it.
Steps to Reproduce:
1. Start postfix.
2. Determine pid of the "master" process.
3. strace -p masterpid
'strace -p 14234' results in the following:
Process 14234 attached - interrupt to quit
trace: ptrace(PTRACE_SYSCALL, ...): Operation not permitted
detach: ptrace(PTRACE_DETACH, ...): Operation not permitted
Process 14234 detached
strace should connect to the process and begin to print debugging output to the
have you tried to run this as root? I don't have any problem running `strace -p $(pidof master)`. BTW, I don't have a stable system.
I was running it as root - but su root. To make sure su wasn't the problem, I just logged into the terminal directly as root and tried again. Same problem.
This is, for certain, being run as root.
What kernel are you running and are you using any security enhancement patches such as GRSecurity, SELinux, etc...?
root # cat /proc/version
Linux version 2.4.20-gentoo-r6 (email@example.com) (gcc version 3.2.3 20030422 (Gentoo Linux 1.4 3.2.3-r1, propolice)) #1 SMP Fri Sep 12 12:51:27 EDT 2003
Can you please try gentoo-sources-2.4.26?
I've confirmed that this problem stems from not having recent enough kernel sources. All people experiencing this problem should update their kernel sources to a more recent version.