powerpc/mm/hugetlb: Sanity check gigantic hugepage count
Limit the number of gigantic hugepages specified by the
hugepages= parameter to MAX_NUMBER_GPAGES.
Signed-off-by: James Yang <James.Yang@freescale.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index af56de8..747e0c6 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -355,6 +355,13 @@
if (size != 0) {
if (sscanf(val, "%lu", &npages) <= 0)
npages = 0;
+ if (npages > MAX_NUMBER_GPAGES) {
+ pr_warn("MMU: %lu pages requested for page "
+ "size %llu KB, limiting to "
+ __stringify(MAX_NUMBER_GPAGES) "\n",
+ npages, size / 1024);
+ npages = MAX_NUMBER_GPAGES;
+ }
gpage_npages[shift_to_mmu_psize(__ffs(size))] = npages;
size = 0;
}