[PATCH v5 09/16] powerpc/mmu: add is_strict_kernel_rwx() helper

Christophe Leroy
2019-02-21T19:09:36Z

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