riscv: mm: implement pgprot_nx

xhackerustc · palmer-dabbelt · commit 0ffe1ae7026d · 2024-03-27T07:09:06.000-07:00
commit cca98e9 ("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> Reviewed-by: Samuel Holland <samuel.holland@sifive.com> Tested-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com> Link: https://lore.kernel.org/r/20231121160637.3856-1-jszhang@kernel.org Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
@@ -593,6 +593,12 @@ 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)
 {

Original file line number	Diff line number	Diff line change
`@@ -593,6 +593,12 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,`
`593`	`593`	`return ptep_test_and_clear_young(vma, address, ptep);`
`594`	`594`	`}`
`595`	`595`
	`596`	`+#define pgprot_nx pgprot_nx`
	`597`	`+static inline pgprot_t pgprot_nx(pgprot_t _prot)`
	`598`	`+{`
	`599`	`+ return __pgprot(pgprot_val(_prot) & ~_PAGE_EXEC);`
	`600`	`+}`
	`601`	`+`
`596`	`602`	`#define pgprot_noncached pgprot_noncached`
`597`	`603`	`static inline pgprot_t pgprot_noncached(pgprot_t _prot)`
`598`	`604`	`{`