diff options
| -rw-r--r-- | kernel/pid.c | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/kernel/pid.c b/kernel/pid.c index fbbd5f6b6f2f..d55c6fb8d087 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -169,7 +169,12 @@ static int alloc_pidmap(struct pid_namespace *pid_ns) 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; + /* + * If last_pid points into the middle of the map->page we + * want to scan this bitmap block twice, the second time + * we start with offset == 0 (or RESERVED_PIDS). + */ + max_scan = DIV_ROUND_UP(pid_max, BITS_PER_PAGE) - !offset; for (i = 0; i <= max_scan; ++i) { if (unlikely(!map->page)) { void *page = kzalloc(PAGE_SIZE, GFP_KERNEL); @@ -196,15 +201,7 @@ static int alloc_pidmap(struct pid_namespace *pid_ns) } offset = find_next_offset(map, offset); pid = mk_pid(pid_ns, map, offset); - /* - * find_next_offset() found a bit, the pid from it - * is in-bounds, and if we fell back to the last - * bitmap block and the final block was the same - * as the starting point, pid is before last_pid. - */ - } while (offset < BITS_PER_PAGE && pid < pid_max && - (i != max_scan || pid < last || - !((last+1) & BITS_PER_PAGE_MASK))); + } while (offset < BITS_PER_PAGE && pid < pid_max); } if (map < &pid_ns->pidmap[(pid_max-1)/BITS_PER_PAGE]) { ++map; |