public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: "K.Prasad" <prasad@linux.vnet.ibm.com>
To: Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>,
	Roland McGrath <roland@redhat.com>,
	akpm@linux-foundation.org, mingo@elte.hu,
	richardj_moore@uk.ibm.com
Subject: [RFC Patch 7/10] Modify signal handling code to refrain from re-enabling HW Breakpoints
Date: Thu, 22 Jan 2009 19:38:50 +0530	[thread overview]
Message-ID: <20090122140850.GF19592@in.ibm.com> (raw)
In-Reply-To: <20090122135640.GA11161@in.ibm.com>

This patch disables re-enabling of Hardware Breakpoint registers through
the  signal handling code. This is now done during hw_breakpoint_handler().
 
Signed-off-by: K.Prasad <prasad@linux.vnet.ibm.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
---
 arch/x86/kernel/signal.c |    9 ---------
 1 file changed, 9 deletions(-)

Index: linux-hbkpt-lkml-29-rc2/arch/x86/kernel/signal.c
===================================================================
--- linux-hbkpt-lkml-29-rc2.orig/arch/x86/kernel/signal.c
+++ linux-hbkpt-lkml-29-rc2/arch/x86/kernel/signal.c
@@ -814,15 +814,6 @@ 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:[~2009-01-22 14:09 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-01-22 13:56 [RFC Patch 0/9] Hardware Breakpoint interfaces - v4 K.Prasad
2009-01-22 14:00 ` [RFC Patch 1/10] Introducing generic hardware breakpoint handler interfaces K.Prasad
2009-01-29  3:55   ` Paul E. McKenney
2009-01-30 11:19     ` K.Prasad
2009-01-30 15:55       ` Alan Stern
2009-02-01 13:54         ` Paul E. McKenney
2009-02-01 18:05           ` Alan Stern
2009-02-03 17:23             ` K.Prasad
2009-02-03 20:07               ` Alan Stern
2009-01-22 14:04 ` [RFC Patch 2/10] x86 architecture implementation of Hardware Breakpoint interfaces K.Prasad
2009-01-22 14:05 ` [RFC Patch 3/10] Modifying generic debug exception to use virtual debug registers K.Prasad
2009-01-22 14:05 ` [RFC Patch 4/10] Modify kprobe exception handler to recognise single-stepping by HW Breakpoint handler K.Prasad
2009-01-22 14:06 ` [RFC Patch 5/10] Use wrapper routines around debug registers in processor related functions K.Prasad
2009-01-22 14:07 ` [RFC Patch 6/10] Use virtual debug registers in process/thread handling code K.Prasad
2009-01-22 14:08 ` K.Prasad [this message]
2009-01-22 14:09 ` [RFC Patch 8/10] Modify Ptrace routines to access breakpoint registers K.Prasad
2009-01-22 14:10 ` [RFC Patch 9/10] Cleanup HW Breakpoint registers before kexec K.Prasad
2009-01-22 14:12 ` [RFC Patch 10/10] Sample HW breakpoint over kernel data address K.Prasad
2009-01-22 15:42 ` [RFC Patch 0/9] Hardware Breakpoint interfaces - v4 Alan Stern
2009-01-23 11:07   ` K.Prasad
2009-01-29  7:05     ` K.Prasad
2009-01-28  0:15 ` Andrew Morton
2009-01-28 18:08   ` K.Prasad

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20090122140850.GF19592@in.ibm.com \
    --to=prasad@linux.vnet.ibm.com \
    --cc=akpm@linux-foundation.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=richardj_moore@uk.ibm.com \
    --cc=roland@redhat.com \
    --cc=stern@rowland.harvard.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox