[PATCH 3/4] arm64: Move the zero page to rodata
From: Ard Biesheuvel <hidden>
Date: 2026-01-19 16:56:23
Also in:
linux-hardening, lkml
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
From: Ard Biesheuvel <ardb@kernel.org> The zero page should contain only zero bytes, and so mapping it read-write is unnecessary. Move it to __ro_after_init instead. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> --- arch/arm64/mm/mmu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 2a18637ecc15..d978b07ab7b8 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c@@ -68,7 +68,8 @@ long __section(".mmuoff.data.write") __early_cpu_boot_status; * Empty_zero_page is a special page that is used for zero-initialized data * and COW. */ -unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] __page_aligned_bss; +unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)] + __ro_after_init __aligned(PAGE_SIZE); EXPORT_SYMBOL(empty_zero_page); static DEFINE_SPINLOCK(swapper_pgdir_lock);
--
2.52.0.457.g6b5491de43-goog