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Message-Id: <0c85871f259073ab3d9db74ef4f0f2cdb36907e3.1550775950.git.christophe.leroy@c-s.fr>
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From:   Christophe Leroy <christophe.leroy@c-s.fr>
Subject: [PATCH v5 09/16] powerpc/mmu: add is_strict_kernel_rwx() helper
To:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>, j.neuschaefer@gmx.net
Cc:     linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Date:   Thu, 21 Feb 2019 19:08:45 +0000 (UTC)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Add a helper to know whether STRICT_KERNEL_RWX is enabled.

This is based on rodata_enabled flag which is defined only
when CONFIG_STRICT_KERNEL_RWX is selected.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 arch/powerpc/include/asm/mmu.h | 11 +++++++++++
 arch/powerpc/mm/init_32.c      |  4 +---
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index 6d22a8e78fe2..d34ad1657d7b 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -289,6 +289,17 @@ static inline u16 get_mm_addr_key(struct mm_struct *mm, unsigned long address)
 }
 #endif /* CONFIG_PPC_MEM_KEYS */
 
+#ifdef CONFIG_STRICT_KERNEL_RWX
+static inline bool strict_kernel_rwx_enabled(void)
+{
+	return rodata_enabled;
+}
+#else
+static inline bool strict_kernel_rwx_enabled(void)
+{
+	return false;
+}
+#endif
 #endif /* !__ASSEMBLY__ */
 
 /* The kernel use the constants below to index in the page sizes array.
diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c
index 3e59e5d64b01..ee5a430b9a18 100644
--- a/arch/powerpc/mm/init_32.c
+++ b/arch/powerpc/mm/init_32.c
@@ -108,12 +108,10 @@ static void __init MMU_setup(void)
 		__map_without_bats = 1;
 		__map_without_ltlbs = 1;
 	}
-#ifdef CONFIG_STRICT_KERNEL_RWX
-	if (rodata_enabled) {
+	if (strict_kernel_rwx_enabled()) {
 		__map_without_bats = 1;
 		__map_without_ltlbs = 1;
 	}
-#endif
 }
 
 /*
-- 
2.13.3