[CRIU] [PATCH] restore: Allow to ignore resource limits from image

[Cyrill Gorcunov]

On Tue, Jul 02, 2013 at 03:16:41PM +0400, Pavel Emelyanov wrote:
> > +		if (nr_rlim < RLIM_NLIMITS) {
> 
> This is always true for images got from rhel6 kernel. Why do we bother at all?

There is NO guarantee that image was not corrupted and there are a way
more entries present on binary level. Thus when we read it in cycle

	while (1) {
		RlimitEntry *re;

		ret = pb_read_one_eof(fd, &re, PB_RLIMIT);
		if (ret <= 0)
			break;

		if (nr_rlim < RLIM_NLIMITS) {
			struct rlimit *r = &ta->rlims[nr_rlim];

			r->rlim_cur = decode_rlim(re->cur);
			r->rlim_max = decode_rlim(re->max);
			if (r->rlim_cur > r->rlim_max) {
				pr_err("Can't restore cur > max for %d.%d\n",
				       pid, nr_rlim);
				r->rlim_cur = r->rlim_max;
			}
		} else {
			pr_warn("Resource limit %d ignored for %d\n",
				nr_rlim, pid);
		}

		rlimit_entry__free_unpacked(re, NULL);
		nr_rlim++;
	}

	ta->nr_rlim = min(nr_rlim, RLIM_NLIMITS);

we don't wont to access out of array bound. Thus it's always true
when criu has been compiled on new system, but on rhel6 it it's
not true at all. OpenVZ image has own definition for RLIM_NLIMITS
hardcoded to 16, and if criu compiled on rhel6 the system RLIM_NLIMITS
is 15 -- thus we allocate only 15 entries in array.