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From: "K.Prasad" <prasad@linux.vnet.ibm.com>
To: Ingo Molnar <mingo@elte.hu>, Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Alan Stern <stern@rowland.harvard.edu>,
	"K.Prasad" <prasad@linux.vnet.ibm.com>
Subject: [Patch 07/12] Modify signal handling code to refrain from re-enabling HW Breakpoints
Date: Thu, 21 May 2009 19:32:21 +0530	[thread overview]
Message-ID: <20090521140221.GH13849@in.ibm.com> (raw)
In-Reply-To: 20090521095613.834622717@prasadkr_t60p.in.ibm.com

[-- Attachment #1: modify_signal_07 --]
[-- Type: text/plain, Size: 1154 bytes --]

This patch disables re-enabling of Hardware Breakpoint registers through
the  signal handling code. This is now done during
hw_breakpoint_handler().

Original-patch-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
---
 arch/x86/kernel/signal.c |    9 ---------
 1 file changed, 9 deletions(-)

Index: linux-2.6-tip.hbkpt/arch/x86/kernel/signal.c
===================================================================
--- linux-2.6-tip.hbkpt.orig/arch/x86/kernel/signal.c
+++ linux-2.6-tip.hbkpt/arch/x86/kernel/signal.c
@@ -799,15 +799,6 @@ 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) {
 			/*


  parent reply	other threads:[~2009-05-21 14:02 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20090521095613.834622717@prasadkr_t60p.in.ibm.com>
2009-05-21 14:00 ` [Patch 01/12] Prepare the code for Hardware Breakpoint interfaces K.Prasad
2009-05-21 16:16   ` David Daney
2009-05-22  6:18     ` K.Prasad
2009-05-27  1:40       ` David Daney
2009-05-27  1:01   ` Frederic Weisbecker
2009-05-27  8:49     ` K.Prasad
2009-05-27 11:48       ` Frederic Weisbecker
2009-05-27 14:21         ` K.Prasad
2009-05-27 15:40           ` Frederic Weisbecker
2009-05-27 14:13   ` K.Prasad
2009-05-21 14:01 ` [Patch 02/12] Introducing generic hardware breakpoint handler interfaces K.Prasad
2009-05-21 14:01 ` [Patch 03/12] x86 architecture implementation of Hardware Breakpoint interfaces K.Prasad
2009-05-21 14:01 ` [Patch 04/12] Modifying generic debug exception to use thread-specific debug registers K.Prasad
2009-05-21 14:02 ` [Patch 05/12] Use wrapper routines around debug registers in processor related functions K.Prasad
2009-05-21 14:02 ` [Patch 06/12] Use the new wrapper routines to access debug registers in process/thread code K.Prasad
2009-05-21 14:02 ` K.Prasad [this message]
2009-05-21 14:02 ` [Patch 08/12] Modify Ptrace routines to access breakpoint registers K.Prasad
2009-05-27  0:07   ` Frederic Weisbecker
2009-05-27  8:45     ` K.Prasad
2009-05-27 14:15   ` K.Prasad
2009-05-21 14:02 ` [Patch 09/12] Cleanup HW Breakpoint registers before kexec K.Prasad
2009-05-21 14:02 ` [Patch 10/12] Sample HW breakpoint over kernel data address K.Prasad
2009-05-21 14:03 ` [Patch 11/12] ftrace plugin for kernel symbol tracing using HW Breakpoint interfaces - v6 K.Prasad
2009-05-21 14:03 ` [Patch 12/12] Reset bits in dr6 after the corresponding exception is handled K.Prasad
     [not found] <20090601180605.799735829@prasadkr_t60p.in.ibm.com>
2009-06-01 18:15 ` [Patch 07/12] Modify signal handling code to refrain from re-enabling HW Breakpoints K.Prasad
     [not found] <20090530103857.715014561@prasadkr_t60p.in.ibm.com>
2009-05-30 10:52 ` K.Prasad
     [not found] <20090515105133.629980476@prasadkr_t60p.in.ibm.com>
2009-05-15 10:58 ` K.Prasad
2009-05-16  0:29 ` K.Prasad
     [not found] <20090513160546.592373797@prasadkr_t60p.in.ibm.com>
2009-05-13 16:14 ` K.Prasad
     [not found] <20090511114422.133566343@prasadkr_t60p.in.ibm.com>
2009-05-11 11:53 ` K.Prasad
     [not found] <20090424055710.764502564@prasadkr_t60p.in.ibm.com>
2009-04-24  6:17 ` K.Prasad

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