Module Name: src
Committed By: martin
Date: Sun Apr 1 08:45:43 UTC 2018
Modified Files:
src/sys/kern [netbsd-8]: kern_proc.c
Log Message:
Pull up following revision(s) (requested by kamil in ticket #679):
sys/kern/kern_proc.c: revision 1.211
Make sysctl_doeproc() more predictable
Swap the order of looking into zombie and all process lists, start now
with the zombie one. This prevents a race observed previously that the
same process could be detected on both lists during a single polling call.
While there:
- Short-circuit break for KERN_PROC_PID, once a pid has been detected.
- Removal of redundant "if (kbuf)" and "if (marker)" checks.
- Update of comments regarding potential optimization, explaining why we
don't want to it as of now. Performance gain from lookup call vs
iteration over a list is neglible on a regular system.
- Return ESRCH when no results have been found. This allows more easily
to implement a retry or abandon algorithm.
This corrects races observed in the existing ATF ptrace(2) tests, related
to await_zombie(). This function was expecting to check whether a process
has been transformed into a zombie, however it was causing occasional
crashes as it was overflowing the return buffer, returning the same pid
twice: once from allproc list and the second time from zombieproc one.
Fix suggested by <christos>
Short-circuit break suggested by <kre>
Discussed on tech-kern.
Sponsored by <The NetBSD Foundation>
To generate a diff of this commit:
cvs rdiff -u -r1.206.6.1 -r1.206.6.2 src/sys/kern/kern_proc.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
