From 78cac48c0434c82e860fade3cd0420a7a4adbb08 Mon Sep 17 00:00:00 2001
From: Borislav Petkov <bp@suse.de>
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 <jkosina@suse.cz>
Suggested-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 arch/x86/include/uapi/asm/bootparam.h | 1 +
 1 file changed, 1 insertion(+)

(limited to 'arch/x86/include/uapi')

diff --git a/arch/x86/include/uapi/asm/bootparam.h b/arch/x86/include/uapi/asm/bootparam.h
index 225b0988043a..ab456dc233b5 100644
--- a/arch/x86/include/uapi/asm/bootparam.h
+++ b/arch/x86/include/uapi/asm/bootparam.h
@@ -15,6 +15,7 @@
 
 /* loadflags */
 #define LOADED_HIGH	(1<<0)
+#define KASLR_FLAG	(1<<1)
 #define QUIET_FLAG	(1<<5)
 #define KEEP_SEGMENTS	(1<<6)
 #define CAN_USE_HEAP	(1<<7)
-- 
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