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

suryasaimadhu · Ingo Molnar · commit 4a1a8e1b8f9f · 2016-07-27T14:59:59.000+02:00
... in order to avoid #ifdeffery in code computing the ASLR randomization offset. Remove that #ifdeffery in the microcode loader. Suggested-by: Kees Cook <keescook@chromium.org> Signed-off-by: Borislav 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: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/include/asm/page_32_types.h b/arch/x86/include/asm/page_32_types.h
@@ -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
 
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
@@ -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);
