From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752399AbaKUV0Y (ORCPT ); Fri, 21 Nov 2014 16:26:24 -0500 Received: from mail-pd0-f173.google.com ([209.85.192.173]:43849 "EHLO mail-pd0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752225AbaKUV0U (ORCPT ); Fri, 21 Nov 2014 16:26:20 -0500 From: Andy Lutomirski To: Borislav Petkov , x86@kernel.org, Linus Torvalds Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Oleg Nesterov , Tony Luck , Andi Kleen , Andy Lutomirski Subject: [PATCH v4 1/5] uprobes, x86: Fix _TIF_UPROBE vs _TIF_NOTIFY_RESUME Date: Fri, 21 Nov 2014 13:26:07 -0800 Message-Id: <4eb18b212f8f62d0ea3dc0679930ede82d7d37fc.1416604491.git.luto@amacapital.net> X-Mailer: git-send-email 1.9.3 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org x86 call do_notify_resume on paranoid returns if TIF_UPROBE is set but not on non-paranoid returns. I suspect that this is a mistake and that the code only works because int3 is paranoid. Setting _TIF_NOTIFY_RESUME in the uprobe code was probably a workaround for the x86 bug. With that bug fixed, we can remove _TIF_NOTIFY_RESUME from the uprobes code. Acked-by: Srikar Dronamraju Reported-by: Oleg Nesterov Signed-off-by: Andy Lutomirski --- arch/x86/include/asm/thread_info.h | 2 +- kernel/events/uprobes.c | 1 - 2 files changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index 854053889d4d..547e344a6dc6 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -141,7 +141,7 @@ struct thread_info { /* Only used for 64 bit */ #define _TIF_DO_NOTIFY_MASK \ (_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME | \ - _TIF_USER_RETURN_NOTIFY) + _TIF_USER_RETURN_NOTIFY | _TIF_UPROBE) /* flags to check in __switch_to() */ #define _TIF_WORK_CTXSW \ diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 1d0af8a2c646..ed8f2cde34c5 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1640,7 +1640,6 @@ bool uprobe_deny_signal(void) if (__fatal_signal_pending(t) || arch_uprobe_xol_was_trapped(t)) { utask->state = UTASK_SSTEP_TRAPPED; set_tsk_thread_flag(t, TIF_UPROBE); - set_tsk_thread_flag(t, TIF_NOTIFY_RESUME); } } -- 1.9.3