Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756281AbYJHT0c (ORCPT ); Wed, 8 Oct 2008 15:26:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754639AbYJHT0W (ORCPT ); Wed, 8 Oct 2008 15:26:22 -0400 Received: from e28smtp05.in.ibm.com ([59.145.155.5]:50491 "EHLO e28esmtp05.in.ibm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756165AbYJHT0V (ORCPT ); Wed, 8 Oct 2008 15:26:21 -0400 Date: Thu, 9 Oct 2008 00:56:11 +0530 From: "K.Prasad" To: Linux Kernel Mailing List Cc: Alan Stern , Roland McGrath , akpm@linux-foundation.org, mingo@elte.hu, jason.wessel@windriver.com, avi@qumranet.com, richardj_moore@uk.ibm.com Subject: [RFC Patch 7/9] Modify signal handling code to refrain from re-enabling HW Breakpoints Message-ID: <20081008192611.GG4989@in.ibm.com> Reply-To: prasad@linux.vnet.ibm.com References: <20081008192044.GA4510@in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081008192044.GA4510@in.ibm.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2179 Lines: 54 This patch disables re-enabling of Hardware Breakpoint registers through the signal handling code. This is now during hw_breakpoint_handler(). Signed-off-by: K.Prasad Signed-off-by: Alan Stern --- arch/x86/kernel/signal_32.c | 9 --------- arch/x86/kernel/signal_64.c | 8 -------- 2 files changed, 17 deletions(-) Index: linux-bkpt-lkml-27-rc9/arch/x86/kernel/signal_32.c =================================================================== --- linux-bkpt-lkml-27-rc9.orig/arch/x86/kernel/signal_32.c +++ linux-bkpt-lkml-27-rc9/arch/x86/kernel/signal_32.c @@ -600,15 +600,6 @@ static void do_signal(struct pt_regs *re signr = get_signal_to_deliver(&info, &ka, regs, NULL); if (signr > 0) { - /* - * Re-enable any watchpoints before delivering the - * signal to user space. The processor register will - * have been cleared if the watchpoint triggered - * inside the kernel. - */ - if (current->thread.debugreg7) - set_debugreg(current->thread.debugreg7, 7); - /* Whee! Actually deliver the signal. */ if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { /* Index: linux-bkpt-lkml-27-rc9/arch/x86/kernel/signal_64.c =================================================================== --- linux-bkpt-lkml-27-rc9.orig/arch/x86/kernel/signal_64.c +++ linux-bkpt-lkml-27-rc9/arch/x86/kernel/signal_64.c @@ -496,14 +496,6 @@ static void do_signal(struct pt_regs *re signr = get_signal_to_deliver(&info, &ka, regs, NULL); if (signr > 0) { - /* Re-enable any watchpoints before delivering the - * signal to user space. The processor register will - * have been cleared if the watchpoint triggered - * inside the kernel. - */ - if (current->thread.debugreg7) - set_debugreg(current->thread.debugreg7, 7); - /* Whee! Actually deliver the signal. */ if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { /* -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/