linux-kernel - [PATCH AUTOSEL 4.9 02/13] MIPS: tlbex: Explicitly cast _PAGE_NO

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Date:   Sun, 29 Sep 2019 13:36:12 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Nathan Chancellor <natechancellor@...il.com>,
        Paul Burton <paul.burton@...s.com>,
        Ralf Baechle <ralf@...ux-mips.org>,
        James Hogan <jhogan@...nel.org>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        linux-mips@...r.kernel.org, clang-built-linux@...glegroups.com,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH AUTOSEL 4.9 02/13] MIPS: tlbex: Explicitly cast _PAGE_NO_EXEC to a boolean

From: Nathan Chancellor <natechancellor@...il.com>

[ Upstream commit c59ae0a1055127dd3828a88e111a0db59b254104 ]

clang warns:

arch/mips/mm/tlbex.c:634:19: error: use of logical '&&' with constant
operand [-Werror,-Wconstant-logical-operand]
        if (cpu_has_rixi && _PAGE_NO_EXEC) {
                         ^  ~~~~~~~~~~~~~
arch/mips/mm/tlbex.c:634:19: note: use '&' for a bitwise operation
        if (cpu_has_rixi && _PAGE_NO_EXEC) {
                         ^~
                         &
arch/mips/mm/tlbex.c:634:19: note: remove constant to silence this
warning
        if (cpu_has_rixi && _PAGE_NO_EXEC) {
                        ~^~~~~~~~~~~~~~~~
1 error generated.

Explicitly cast this value to a boolean so that clang understands we
intend for this to be a non-zero value.

Fixes: 00bf1c691d08 ("MIPS: tlbex: Avoid placing software PTE bits in Entry* PFN fields")
Link: https://github.com/ClangBuiltLinux/linux/issues/609
Signed-off-by: Nathan Chancellor <natechancellor@...il.com>
Signed-off-by: Paul Burton <paul.burton@...s.com>
Cc: Ralf Baechle <ralf@...ux-mips.org>
Cc: James Hogan <jhogan@...nel.org>
Cc: Nick Desaulniers <ndesaulniers@...gle.com>
Cc: linux-mips@...r.kernel.org
Cc: linux-kernel@...r.kernel.org
Cc: clang-built-linux@...glegroups.com
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 arch/mips/mm/tlbex.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index 3cc5b2e4263c0..47d50197789be 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -637,7 +637,7 @@ static __maybe_unused void build_convert_pte_to_entrylo(u32 **p,
 		return;
 	}
 
-	if (cpu_has_rixi && _PAGE_NO_EXEC) {
+	if (cpu_has_rixi && !!_PAGE_NO_EXEC) {
 		if (fill_includes_sw_bits) {
 			UASM_i_ROTR(p, reg, reg, ilog2(_PAGE_GLOBAL));
 		} else {
-- 
2.20.1