arm64: mm: Mark executable text as guarded pages

When the kernel is built for BTI and running on a system which supports
make all executable text guarded pages to ensure that loadable module
and JITed BPF code is protected by BTI.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20200506195138.22086-7-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index 250c490..bde0809 100644 (file)
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -126,13 +126,13 @@ int set_memory_nx(unsigned long addr, int numpages)
 {
        return change_memory_common(addr, numpages,
                                        __pgprot(PTE_PXN),
-                                       __pgprot(0));
+                                       __pgprot(PTE_MAYBE_GP));
 }
 
 int set_memory_x(unsigned long addr, int numpages)
 {
        return change_memory_common(addr, numpages,
-                                       __pgprot(0),
+                                       __pgprot(PTE_MAYBE_GP),
                                        __pgprot(PTE_PXN));
 }