cpusets: fix bug when adding nonexistent cpu or mem
Lai Jiangshan [Fri, 6 Jun 2008 05:46:32 +0000 (22:46 -0700)]
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>

kernel/cpuset.c

index 86ea9e3..039baa4 100644 (file)
@@ -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 */