Quoting Sukadev Bhattiprolu ([email protected]): > > > Subject: [RFC][v5][PATCH 4/8]: Add target_pid parameter to alloc_pidmap() > > With support for setting a specific pid number for a process, > alloc_pidmap() will need a 'target_pid' parameter. > > Changelog[v3]: > - (Eric Biederman): Avoid set_pidmap() function. Added couple of > checks for target_pid in alloc_pidmap() itself. > Changelog[v2]: > - (Serge Hallyn) Check for 'pid < 0' in set_pidmap().(Code > actually checks for 'pid <= 0' for completeness). > > Signed-off-by: Sukadev Bhattiprolu <[email protected]>
Acked-by: Serge Hallyn <[email protected]> > > Index: linux-mmotm/kernel/pid.c > =================================================================== > --- linux-mmotm.orig/kernel/pid.c 2009-09-05 21:17:36.000000000 -0700 > +++ linux-mmotm/kernel/pid.c 2009-09-05 21:19:11.000000000 -0700 > @@ -146,16 +146,22 @@ > return 0; > } > > -static int alloc_pidmap(struct pid_namespace *pid_ns) > +static int alloc_pidmap(struct pid_namespace *pid_ns, int target_pid) > { > int i, offset, max_scan, pid, last = pid_ns->last_pid; > int rc = -EAGAIN; > int pid_max = pid_ns->pid_max; > struct pidmap *map; > > - pid = last + 1; > - if (pid >= pid_max) > - pid = RESERVED_PIDS; > + if (target_pid) { > + pid = target_pid; > + if (pid < 0 || pid >= pid_max) > + return -EINVAL; > + } else { > + pid = last + 1; > + if (pid >= pid_max) > + pid = RESERVED_PIDS; > + } > offset = pid & BITS_PER_PAGE_MASK; > map = &pid_ns->pidmap[pid/BITS_PER_PAGE]; > max_scan = (pid_max + BITS_PER_PAGE - 1)/BITS_PER_PAGE - !offset; > @@ -168,9 +174,14 @@ > do { > if (!test_and_set_bit(offset, map->page)) { > atomic_dec(&map->nr_free); > - pid_ns->last_pid = pid; > + if (!target_pid) > + pid_ns->last_pid = pid; > return pid; > + } else if (target_pid) { > + rc = -EBUSY; > + break; > } > + > offset = find_next_offset(map, offset); > pid = mk_pid(pid_ns, map, offset); > /* > @@ -196,6 +207,7 @@ > } > pid = mk_pid(pid_ns, map, offset); > } > + > return rc; > } > > @@ -272,7 +284,7 @@ > > tmp = ns; > for (i = ns->level; i >= 0; i--) { > - nr = alloc_pidmap(tmp); > + nr = alloc_pidmap(tmp, 0); > if (nr < 0) > goto out_free; _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers _______________________________________________ Devel mailing list [email protected] https://openvz.org/mailman/listinfo/devel
