From: James Yang <James.Yang@freescale.com>
Date: Fri, 14 Nov 2014 18:32:24 +0000 (-0600)
Subject: powerpc/mm/hugetlb: Sanity check gigantic hugepage count
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=c4f3eb5fc527b749d6fb0d47ffdcfe83706dbe2f;p=linux-beck.git

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 af56de82375d..747e0c616526 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -355,6 +355,13 @@ static int __init do_gpage_early_setup(char *param, char *val,
 		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;
 		}