[PATCH v2] target/mips: fix TLB huge page check to use 64-bit shift

[gerben]

From: Denis Rastyogin <ger...@altlinux.org>

Use extract64(entry, psn, 1) instead of (entry & (1 << psn)) to avoid
undefined behavior for shifts by 32???63 and to make bit extraction intent 
explicit.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Denis Rastyogin <ger...@altlinux.org>
---
 target/mips/tcg/system/tlb_helper.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/mips/tcg/system/tlb_helper.c 
b/target/mips/tcg/system/tlb_helper.c
index eccaf3624c..1e8901556d 100644
--- a/target/mips/tcg/system/tlb_helper.c
+++ b/target/mips/tcg/system/tlb_helper.c
@@ -652,7 +652,7 @@ static int walk_directory(CPUMIPSState *env, uint64_t 
*vaddr,
         return 0;
     }
 
-    if ((entry & (1 << psn)) && hugepg) {
+    if (extract64(entry, psn, 1) && hugepg) {
         *huge_page = true;
         *hgpg_directory_hit = true;
         entry = get_tlb_entry_layout(env, entry, leaf_mop, pf_ptew);
-- 
2.42.2