From 78cac48c0434c82e860fade3cd0420a7a4adbb08 Mon Sep 17 00:00:00 2001 From: Borislav Petkov Date: Wed, 1 Apr 2015 12:49:52 +0200 Subject: x86/mm/KASLR: Propagate KASLR status to kernel proper Commit: e2b32e678513 ("x86, kaslr: randomize module base load address") made module base address randomization unconditional and didn't regard disabled KKASLR due to CONFIG_HIBERNATION and command line option "nokaslr". For more info see (now reverted) commit: f47233c2d34f ("x86/mm/ASLR: Propagate base load address calculation") In order to propagate KASLR status to kernel proper, we need a single bit in boot_params.hdr.loadflags and we've chosen bit 1 thus leaving the top-down allocated bits for bits supposed to be used by the bootloader. Originally-From: Jiri Kosina Suggested-by: H. Peter Anvin Signed-off-by: Borislav Petkov Cc: Kees Cook Signed-off-by: Ingo Molnar --- arch/x86/include/asm/setup.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/x86/include/asm/setup.h') diff --git a/arch/x86/include/asm/setup.h b/arch/x86/include/asm/setup.h index ff4e7b236e21..f69e06b283fb 100644 --- a/arch/x86/include/asm/setup.h +++ b/arch/x86/include/asm/setup.h @@ -66,6 +66,11 @@ static inline void x86_ce4100_early_setup(void) { } */ extern struct boot_params boot_params; +static inline bool kaslr_enabled(void) +{ + return !!(boot_params.hdr.loadflags & KASLR_FLAG); +} + /* * Do NOT EVER look at the BIOS memory size location. * It does not work on many machines. -- cgit v1.2.1