cpusets: fix bug when adding nonexistent cpu or mem

Adding a nonexistent cpu to a cpuset will be omitted quietly.  It should
return -EINVAL.

Example: (real_nr_cpus <= 4 < NR_CPUS or cpu#4 was just offline)

# cat cpus
0-1
# /bin/echo 4 > cpus
# /bin/echo $?
0
# cat cpus

#

The same occurs when add a nonexistent mem.
This patch will fix this bug.
And when *buf == "", the check is unneeded.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Paul Jackson <pj@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 3 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 86ea9e34e326..039baa4cd90c 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -797,8 +797,10 @@ static int update_cpumask(struct cpuset *cs, char *buf)
                 retval = cpulist_parse(buf, trialcs.cpus_allowed);
                 if (retval < 0)
                         return retval;
+
+                if (!cpus_subset(trialcs.cpus_allowed, cpu_online_map))
+                        return -EINVAL;
         }
-        cpus_and(trialcs.cpus_allowed, trialcs.cpus_allowed, cpu_online_map);
         retval = validate_change(cs, &trialcs);
         if (retval < 0)
                 return retval;
@@ -932,9 +934,11 @@ static int update_nodemask(struct cpuset *cs, char *buf)
                 retval = nodelist_parse(buf, trialcs.mems_allowed);
                 if (retval < 0)
                         goto done;
+
+                if (!nodes_subset(trialcs.mems_allowed,
+                                node_states[N_HIGH_MEMORY]))
+                        return -EINVAL;
         }
-        nodes_and(trialcs.mems_allowed, trialcs.mems_allowed,
-                                                node_states[N_HIGH_MEMORY]);
         oldmem = cs->mems_allowed;
         if (nodes_equal(oldmem, trialcs.mems_allowed)) {
                 retval = 0;             /* Too easy - nothing to do */