[PATCH] riscv: mm: implement pgprot_nx

[Jisheng Zhang <jszhang@kernel.org>]

commit cca98e9f8b5e ("mm: enforce that vmap can't map pages
executable") enforces the W^X protection by not allowing remapping
existing pages as executable. Add riscv bits so that riscv can benefit
the same protection.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
---
 arch/riscv/include/asm/pgtable.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 294044429e8e..4fc6ee5226fb 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -608,6 +608,12 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
 	return ptep_test_and_clear_young(vma, address, ptep);
 }
 
+#define pgprot_nx pgprot_nx
+static inline pgprot_t pgprot_nx(pgprot_t _prot)
+{
+	return __pgprot(pgprot_val(_prot) & ~_PAGE_EXEC);
+}
+
 #define pgprot_noncached pgprot_noncached
 static inline pgprot_t pgprot_noncached(pgprot_t _prot)
 {
-- 
2.42.0