From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754875AbbHFIEq (ORCPT ); Thu, 6 Aug 2015 04:04:46 -0400 Received: from mx2.suse.de ([195.135.220.15]:58369 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753311AbbHFIEn (ORCPT ); Thu, 6 Aug 2015 04:04:43 -0400 From: Juergen Gross To: luto@kernel.org, bp@suse.de, x86@kernel.org, hpa@zytor.com, mingo@redhat.com, tglx@linutronix.de, linux-kernel@vger.kernel.org Cc: Juergen Gross , Subject: [PATCH] x86/ldt: correct ldt access in single stepping logic Date: Thu, 6 Aug 2015 10:04:38 +0200 Message-Id: <1438848278-12906-1-git-send-email-jgross@suse.com> X-Mailer: git-send-email 2.1.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 37868fe113ff ("x86/ldt: Make modify_ldt synchronous") introduced a new struct ldt_struct anchored at mm->context.ldt. convert_ip_to_linear() was changed to reflect this, but indexing into the ldt has to be changed as the pointer is no longer void *. Cc: # 37868fe113ff: x86/ldt: Make modify_ldt synchronous Signed-off-by: Juergen Gross --- arch/x86/kernel/step.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/step.c b/arch/x86/kernel/step.c index 6273324..0ccb53a 100644 --- a/arch/x86/kernel/step.c +++ b/arch/x86/kernel/step.c @@ -28,11 +28,11 @@ unsigned long convert_ip_to_linear(struct task_struct *child, struct pt_regs *re struct desc_struct *desc; unsigned long base; - seg &= ~7UL; + seg >>= 3; mutex_lock(&child->mm->context.lock); if (unlikely(!child->mm->context.ldt || - (seg >> 3) >= child->mm->context.ldt->size)) + seg >= child->mm->context.ldt->size)) addr = -1L; /* bogus selector, access would fault */ else { desc = &child->mm->context.ldt->entries[seg]; -- 2.1.4