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Commit 4a1a8e1b authored by Borislav Petkov's avatar Borislav Petkov Committed by Ingo Molnar
Browse files

x86/asm, x86/microcode: Add __PAGE_OFFSET_BASE define on 32-bit 



... in order to avoid #ifdeffery in code computing the ASLR randomization
offset. Remove that #ifdeffery in the microcode loader.

Suggested-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Nicolai Stange <nicstange@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Garnier <thgarnie@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160727120939.GA18911@nazgul.tnic


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent df15929f

arch/x86/include/asm/page_32_types.h

+2 −1
Original line number Diff line number Diff line
@@ -13,7 +13,8 @@ 
 * If you want more physical memory than this then see the CONFIG_HIGHMEM4G

 * and CONFIG_HIGHMEM64G options in the kernel configuration.

 */

#define __PAGE_OFFSET		_AC(CONFIG_PAGE_OFFSET, UL)

#define __PAGE_OFFSET_BASE	_AC(CONFIG_PAGE_OFFSET, UL)

#define __PAGE_OFFSET		__PAGE_OFFSET_BASE



#define __START_KERNEL_map	__PAGE_OFFSET

arch/x86/kernel/cpu/microcode/intel.c

+0 −2
Original line number Diff line number Diff line
@@ -818,13 +818,11 @@ void load_ucode_intel_ap(void) 
	if (blobs_p->valid) {

		start = blobs_p->start;



#ifdef CONFIG_RANDOMIZE_MEMORY

		/*

		 * Pay attention to CONFIG_RANDOMIZE_MEMORY=y as it shuffles

		 * physmem mapping too and there we have the initrd.

		 */

		start += PAGE_OFFSET - __PAGE_OFFSET_BASE;

#endif

	}



	collect_cpu_info_early(&uci);