From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752151AbdFNOGu (ORCPT ); Wed, 14 Jun 2017 10:06:50 -0400 Received: from mail.skyhub.de ([5.9.137.197]:52912 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752112AbdFNOGs (ORCPT ); Wed, 14 Jun 2017 10:06:48 -0400 From: Borislav Petkov To: X86 ML Cc: LKML Subject: [PATCH 1/2] x86/microcode: Look for the initrd at the correct address on 32-bit Date: Wed, 14 Jun 2017 16:06:25 +0200 Message-Id: <20170614140626.4462-1-bp@alien8.de> X-Mailer: git-send-email 2.13.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Borislav Petkov Early during boot, the BSP finds the ramdisk's position from boot_params but by the time the APs get to boot, the BSP has continued in the mean time and has potentially managed to relocate that ramdisk. And in that case, the APs need to find the ramdisk at its new position, in *physical* memory as they're running before paging has been enabled. Thus, get the updated physical location of the ramdisk which is in the relocated_ramdisk variable. Signed-off-by: Borislav Petkov --- arch/x86/kernel/cpu/microcode/core.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c index e53d3c909840..9cb98ee103db 100644 --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -290,6 +290,17 @@ struct cpio_data find_microcode_in_initrd(const char *path, bool use_pa) return (struct cpio_data){ NULL, 0, "" }; if (initrd_start) start = initrd_start; + } else { + /* + * The picture with physical addresses is a bit different: we + * need to get the *physical* address to which the ramdisk was + * relocated, i.e., relocated_ramdisk (not initrd_start) and + * since we're running from physical addresses, we need to access + * relocated_ramdisk through its *physical* address too. + */ + u64 *rr = (u64 *)__pa_nodebug(&relocated_ramdisk); + if (*rr) + start = *rr; } return find_cpio_data(path, (void *)start, size, NULL); -- 2.13.0