linux-kernel - [PATCH 07/12] hw-breakpoints: modify signal handling code to refrain from re-enabling HW Breakpoints

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Date:	Wed,  3 Jun 2009 00:43:31 +0200
From:	Frederic Weisbecker <fweisbec@...il.com>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	"K.Prasad" <prasad@...ux.vnet.ibm.com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Alan Stern <stern@...land.harvard.edu>,
	Frederic Weisbecker <fweisbec@...il.com>
Subject: [PATCH 07/12] hw-breakpoints: modify signal handling code to refrain from re-enabling HW Breakpoints

From: K.Prasad <prasad@...ux.vnet.ibm.com>

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

Original-patch-by: Alan Stern <stern@...land.harvard.edu>
Signed-off-by: K.Prasad <prasad@...ux.vnet.ibm.com>
Reviewed-by: Alan Stern <stern@...land.harvard.edu>
Signed-off-by: Frederic Weisbecker <fweisbec@...il.com>
---
 arch/x86/kernel/signal.c |    9 ---------
 1 files changed, 0 insertions(+), 9 deletions(-)

diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c
index 1442516..f33d2e0 100644
--- a/arch/x86/kernel/signal.c
+++ b/arch/x86/kernel/signal.c
@@ -800,15 +800,6 @@ static void do_signal(struct pt_regs *regs)
 
 	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) {
 			/*
-- 
1.6.2.3

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