All of lore.kernel.org
 help / color / mirror / Atom feed
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Linus Torvalds <torvalds@linux-foundation.org>,
	Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
	efault@gmx.de, Peter Zijlstra <a.p.zijlstra@chello.nl>
Subject: [PATCH 2/4] lockdep: Fix trace_{soft,hard}irqs_{on,off}() recursion
Date: Tue, 21 Jun 2011 17:17:27 +0200	[thread overview]
Message-ID: <20110621153806.185242734@chello.nl> (raw)
In-Reply-To: <20110621151725.705140475@chello.nl>

[-- Attachment #1: lockdep-trace_irq-recursion.patch --]
[-- Type: text/plain, Size: 2645 bytes --]

Commit 1efc5da3 explains the reason for having raw_local_irq_*() and
lockdep_off() in printk(). Instead of working around the broken
recursion detection of interrupt state tracking, fix it.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
 kernel/lockdep.c |   30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

Index: linux-2.6/kernel/lockdep.c
===================================================================
--- linux-2.6.orig/kernel/lockdep.c
+++ linux-2.6/kernel/lockdep.c
@@ -2478,15 +2478,10 @@ mark_held_locks(struct task_struct *curr
 /*
  * Hardirqs will be enabled:
  */
-void trace_hardirqs_on_caller(unsigned long ip)
+static void __trace_hardirqs_on_caller(unsigned long ip)
 {
 	struct task_struct *curr = current;
 
-	time_hardirqs_on(CALLER_ADDR0, ip);
-
-	if (unlikely(!debug_locks || current->lockdep_recursion))
-		return;
-
 	if (DEBUG_LOCKS_WARN_ON(unlikely(early_boot_irqs_disabled)))
 		return;
 
@@ -2502,8 +2497,6 @@ void trace_hardirqs_on_caller(unsigned l
 	/* we'll do an OFF -> ON transition: */
 	curr->hardirqs_enabled = 1;
 
-	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
-		return;
 	if (DEBUG_LOCKS_WARN_ON(current->hardirq_context))
 		return;
 	/*
@@ -2525,6 +2518,21 @@ void trace_hardirqs_on_caller(unsigned l
 	curr->hardirq_enable_event = ++curr->irq_events;
 	debug_atomic_inc(hardirqs_on_events);
 }
+
+void trace_hardirqs_on_caller(unsigned long ip)
+{
+	time_hardirqs_on(CALLER_ADDR0, ip);
+
+	if (unlikely(!debug_locks || current->lockdep_recursion))
+		return;
+
+	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
+		return;
+
+	current->lockdep_recursion = 1;
+	__trace_hardirqs_on_caller(ip);
+	current->lockdep_recursion = 0;
+}
 EXPORT_SYMBOL(trace_hardirqs_on_caller);
 
 void trace_hardirqs_on(void)
@@ -2574,7 +2582,7 @@ void trace_softirqs_on(unsigned long ip)
 {
 	struct task_struct *curr = current;
 
-	if (unlikely(!debug_locks))
+	if (unlikely(!debug_locks || current->lockdep_recursion))
 		return;
 
 	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
@@ -2585,6 +2593,7 @@ void trace_softirqs_on(unsigned long ip)
 		return;
 	}
 
+	current->lockdep_recursion = 1;
 	/*
 	 * We'll do an OFF -> ON transition:
 	 */
@@ -2599,6 +2608,7 @@ void trace_softirqs_on(unsigned long ip)
 	 */
 	if (curr->hardirqs_enabled)
 		mark_held_locks(curr, SOFTIRQ);
+	current->lockdep_recursion = 0;
 }
 
 /*
@@ -2608,7 +2618,7 @@ void trace_softirqs_off(unsigned long ip
 {
 	struct task_struct *curr = current;
 
-	if (unlikely(!debug_locks))
+	if (unlikely(!debug_locks || current->lockdep_recursion))
 		return;
 
 	if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))



  parent reply	other threads:[~2011-06-21 15:41 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-06-21 15:17 [PATCH 0/4] printk: Remove lockdep_off() and wakeups -v3 Peter Zijlstra
2011-06-21 15:17 ` [PATCH 1/4] printk: Release console_sem after logbuf_lock Peter Zijlstra
2011-06-21 15:17 ` Peter Zijlstra [this message]
2011-06-22 15:13   ` [tip:core/printk] lockdep: Fix trace_[soft,hard]irqs_[on,off]() recursion tip-bot for Peter Zijlstra
2011-06-21 15:17 ` [PATCH 3/4] printk, lockdep: Remove lockdep_off() usage Peter Zijlstra
2011-06-21 15:17 ` [PATCH 4/4] printk: Avoid all wakeups from printk Peter Zijlstra
2011-06-22  9:20 ` [PATCH 0/4] printk: Remove lockdep_off() and wakeups -v3 Peter Zijlstra
2011-06-22 11:50   ` Ingo Molnar
2011-06-22 13:44     ` Peter Zijlstra
2011-06-22 14:22   ` [tip:core/printk] printk: Fix console_sem vs logbuf_lock unlock race tip-bot for Peter Zijlstra

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=20110621153806.185242734@chello.nl \
    --to=a.p.zijlstra@chello.nl \
    --cc=akpm@linux-foundation.org \
    --cc=efault@gmx.de \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@elte.hu \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    --subject='Re: [PATCH 2/4] lockdep: Fix trace_{soft,hard}irqs_{on,off}() recursion' \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.