From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:46043 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753943AbcGYU5E (ORCPT ); Mon, 25 Jul 2016 16:57:04 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Borislav Petkov , Linus Torvalds , Peter Zijlstra , Thomas Gleixner , Ingo Molnar Subject: [PATCH 4.4 025/146] x86/amd_nb: Fix boot crash on non-AMD systems Date: Mon, 25 Jul 2016 13:54:40 -0700 Message-Id: <20160725203522.407163588@linuxfoundation.org> In-Reply-To: <20160725203521.340401316@linuxfoundation.org> References: <20160725203521.340401316@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Borislav Petkov commit 1ead852dd88779eda12cb09cc894a03d9abfe1ec upstream. Fix boot crash that triggers if this driver is built into a kernel and run on non-AMD systems. AMD northbridges users call amd_cache_northbridges() and it returns a negative value to signal that we weren't able to cache/detect any northbridges on the system. At least, it should do so as all its callers expect it to do so. But it does return a negative value only when kmalloc() fails. Fix it to return -ENODEV if there are no NBs cached as otherwise, amd_nb users like amd64_edac, for example, which relies on it to know whether it should load or not, gets loaded on systems like Intel Xeons where it shouldn't. Reported-and-tested-by: Tony Battersby Signed-off-by: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1466097230-5333-2-git-send-email-bp@alien8.de Link: https://lkml.kernel.org/r/5761BEB0.9000807@cybernetics.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/amd_nb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/x86/kernel/amd_nb.c +++ b/arch/x86/kernel/amd_nb.c @@ -71,8 +71,8 @@ int amd_cache_northbridges(void) while ((misc = next_northbridge(misc, amd_nb_misc_ids)) != NULL) i++; - if (i == 0) - return 0; + if (!i) + return -ENODEV; nb = kzalloc(i * sizeof(struct amd_northbridge), GFP_KERNEL); if (!nb)