hugetlb: fix handling of parse errors in sysfs
authorEric B Munson <emunson@mgebm.net>
Thu, 13 Jan 2011 23:47:28 +0000 (15:47 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 14 Jan 2011 01:32:49 +0000 (17:32 -0800)
When parsing changes to the huge page pool sizes made from userspace via
the sysfs interface, bogus input values are being covered up by
nr_hugepages_store_common and nr_overcommit_hugepages_store returning 0
when strict_strtoul returns an error.  This can cause an infinite loop in
the nr_hugepages_store code.  This patch changes the return value for
these functions to -EINVAL when strict_strtoul returns an error.

Signed-off-by: Eric B Munson <emunson@mgebm.net>
Reported-by: CAI Qian <caiqian@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/hugetlb.c

index ce8e5bb6f031d20be5c4102bb50e7f50c95664d0..bb0b7c128015f5cbb9f23d78b88c4b5e6eec2e7b 100644 (file)
@@ -1375,10 +1375,8 @@ static ssize_t nr_hugepages_store_common(bool obey_mempolicy,
        NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY);
 
        err = strict_strtoul(buf, 10, &count);
-       if (err) {
-               err = 0;                /* This seems wrong */
+       if (err)
                goto out;
-       }
 
        h = kobj_to_hstate(kobj, &nid);
        if (h->order >= MAX_ORDER) {
@@ -1469,7 +1467,7 @@ static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj,
 
        err = strict_strtoul(buf, 10, &input);
        if (err)
-               return 0;
+               return err;
 
        spin_lock(&hugetlb_lock);
        h->nr_overcommit_huge_pages = input;