For CONFIG_STRICT_KERNEL_RWX align __init_begin to 16M. We use 16M since its the larger of 2M on radix and 16M on hash for our linear mapping. The plan is to have .text, .rodata and everything upto __init_begin marked as RX. Note we still have executable read only data. We could further align read only data to another 16M boundary. I've used keeping text plus rodata as read-only-executable as a trade-off to doing read-only-executable for text and read-only for rodata.
We don't use multi PT_LOAD in PHDRS because we are not sure if all bootloaders support them Signed-off-by: Balbir Singh <bsinghar...@gmail.com> --- arch/powerpc/kernel/vmlinux.lds.S | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S index ace6b65..b1a2505 100644 --- a/arch/powerpc/kernel/vmlinux.lds.S +++ b/arch/powerpc/kernel/vmlinux.lds.S @@ -8,6 +8,12 @@ #include <asm/cache.h> #include <asm/thread_info.h> +#ifdef CONFIG_STRICT_KERNEL_RWX +#define STRICT_ALIGN_SIZE (1 << 24) +#else +#define STRICT_ALIGN_SIZE PAGE_SIZE +#endif + ENTRY(_stext) PHDRS { @@ -123,7 +129,7 @@ SECTIONS PROVIDE32 (etext = .); /* Read-only data */ - RODATA + RO_DATA(PAGE_SIZE) EXCEPTION_TABLE(0) @@ -140,7 +146,7 @@ SECTIONS /* * Init sections discarded at runtime */ - . = ALIGN(PAGE_SIZE); + . = ALIGN(STRICT_ALIGN_SIZE); __init_begin = .; INIT_TEXT_SECTION(PAGE_SIZE) :kernel -- 2.9.4