[PATCH] ARC: Fix array-out-of-bounds issue in tlb overlap handler

From: Mischa Jonker
Date: Thu Sep 26 2013 - 09:46:33 EST


Even after fixing the issue, GCC 4.8 still complains with a warning,
but with the fix, I think it's a false positive. Therefore I have
also added a #pragma to ignore the warning.

Signed-off-by: Mischa Jonker <mjonker@xxxxxxxxxxxx>
---
arch/arc/mm/tlb.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c
index 129af50..5af7c98 100644
--- a/arch/arc/mm/tlb.c
+++ b/arch/arc/mm/tlb.c
@@ -635,13 +635,20 @@ void do_tlb_overlap_fault(unsigned long cause, unsigned long address,
continue;

/* Scan the set for duplicate ways: needs a nested loop */
- for (way = 0; way < mmu->ways; way++) {
+ for (way = 0; way < (mmu->ways - 1); way++) {
if (!pd0[way])
continue;

for (n = way + 1; n < mmu->ways; n++) {
+/*
+ * GCC 4.8 does not understand that way < (mmu->ways - 1), and as such
+ * n < mmu->ways. So, ignore the warning
+ */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Warray-bounds"
if ((pd0[way] & PAGE_MASK) ==
(pd0[n] & PAGE_MASK)) {
+#pragma GCC diagnostic pop

if (dup_pd_verbose) {
pr_info("Duplicate PD's @"
--
1.7.9.5

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