hugetlb: fix overcommit locking
proc_doulongvec_minmax() calls copy_to_user()/copy_from_user(), so we can't
hold hugetlb_lock over the call. Use a dummy variable to store the sysctl
result, like in hugetlb_sysctl_handler(), then grab the lock to update
nr_overcommit_huge_pages.
Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Reported-by: Miles Lane <miles.lane@gmail.com>
Cc: Adam Litke <agl@us.ibm.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 924c674..8b7e954 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -978,8 +978,8 @@
{
.ctl_name = CTL_UNNUMBERED,
.procname = "nr_overcommit_hugepages",
- .data = &nr_overcommit_huge_pages,
- .maxlen = sizeof(nr_overcommit_huge_pages),
+ .data = &sysctl_overcommit_huge_pages,
+ .maxlen = sizeof(sysctl_overcommit_huge_pages),
.mode = 0644,
.proc_handler = &hugetlb_overcommit_handler,
},
