LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Heiko Carstens <heiko.carstens@de.ibm.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: Steven Rostedt <srostedt@redhat.com>, linux-kernel@vger.kernel.org
Subject: [PATCH] lockdep: fix irqs on/off ip tracing
Date: Tue, 28 Oct 2008 11:14:58 +0100	[thread overview]
Message-ID: <20081028101458.GA4964@osiris.boeblingen.de.ibm.com> (raw)

From: Heiko Carstens <heiko.carstens@de.ibm.com>

81d68a96 "ftrace: trace irq disabled critical timings" added wrappers around
trace_hardirqs_on/off_caller. However these functions use
__builtin_return_address(0) to figure out which function actually disabled
or enabled irqs. The result is that we save the ips of trace_hardirqs_on/off
instead of the real caller. Not very helpful.
However since the patch from Steven the ip already gets passed. So use that
and get rid of __builtin_return_address(0) in these two functions.

Cc: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
---
 kernel/lockdep.c |   12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

Index: linux-2.6/kernel/lockdep.c
===================================================================
--- linux-2.6.orig/kernel/lockdep.c
+++ linux-2.6/kernel/lockdep.c
@@ -2169,12 +2169,11 @@ void early_boot_irqs_on(void)
 /*
  * Hardirqs will be enabled:
  */
-void trace_hardirqs_on_caller(unsigned long a0)
+void trace_hardirqs_on_caller(unsigned long ip)
 {
 	struct task_struct *curr = current;
-	unsigned long ip;
 
-	time_hardirqs_on(CALLER_ADDR0, a0);
+	time_hardirqs_on(CALLER_ADDR0, ip);
 
 	if (unlikely(!debug_locks || current->lockdep_recursion))
 		return;
@@ -2188,7 +2187,6 @@ void trace_hardirqs_on_caller(unsigned l
 	}
 	/* we'll do an OFF -> ON transition: */
 	curr->hardirqs_enabled = 1;
-	ip = (unsigned long) __builtin_return_address(0);
 
 	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
 		return;
@@ -2224,11 +2222,11 @@ EXPORT_SYMBOL(trace_hardirqs_on);
 /*
  * Hardirqs were disabled:
  */
-void trace_hardirqs_off_caller(unsigned long a0)
+void trace_hardirqs_off_caller(unsigned long ip)
 {
 	struct task_struct *curr = current;
 
-	time_hardirqs_off(CALLER_ADDR0, a0);
+	time_hardirqs_off(CALLER_ADDR0, ip);
 
 	if (unlikely(!debug_locks || current->lockdep_recursion))
 		return;
@@ -2241,7 +2239,7 @@ void trace_hardirqs_off_caller(unsigned 
 		 * We have done an ON -> OFF transition:
 		 */
 		curr->hardirqs_enabled = 0;
-		curr->hardirq_disable_ip = _RET_IP_;
+		curr->hardirq_disable_ip = ip;
 		curr->hardirq_disable_event = ++curr->irq_events;
 		debug_atomic_inc(&hardirqs_off_events);
 	} else

             reply	other threads:[~2008-10-28 10:16 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-10-28 10:14 Heiko Carstens [this message]
2008-10-28 10:19 ` Ingo Molnar

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=20081028101458.GA4964@osiris.boeblingen.de.ibm.com \
    --to=heiko.carstens@de.ibm.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=srostedt@redhat.com \
    --subject='Re: [PATCH] lockdep: fix irqs on/off ip tracing' \
    /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

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).