Messages in this thread | | | Date | Thu, 24 Jul 1997 16:13:51 -0400 (EDT) | From | Jon Lewis <> | Subject | Re: Reserved PID's |
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On Thu, 24 Jul 1997, B. James Phillippe wrote:
> I've considered writing a simple PID reservation patch that would > reserve a number of PID's (controlled on the fly by echo'ing an int to > /proc/sys/kernel/reserved-pids) for root use only. It sounds easy enough > to implement. If all non-reserved PID's are in use and a process attempts > to be created under a UID >0, kernel would return EGAIN. This would allow > only root-owned processes to fill the process table. In other cases, the > superuser would be able to log in and fix the problem.
Isn't that already basically done via:
[kernel/fork.c] static inline int find_empty_process(void) { int i;
if (nr_tasks >= NR_TASKS - MIN_TASKS_LEFT_FOR_ROOT) { if (current->uid) return -EAGAIN; }
in include/linux/tasks.h MIN_TASKS_LEFT_FOR_ROOT defaults to 4, but I generally raise it to 64. Ideally, this should stop anyone but root (or root owned processes) from filling the process table...if you have enough processes reserved for root.
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