* [rcu:dev.2019.09.23a 62/77] kernel/rcu/tree.c:2882 kfree_call_rcu() warn: inconsistent returns 'irqsave:flags'.
@ 2019-09-24 8:05 Dan Carpenter
2019-09-24 12:15 ` Joel Fernandes
0 siblings, 1 reply; 5+ messages in thread
From: Dan Carpenter @ 2019-09-24 8:05 UTC (permalink / raw)
To: kbuild, Joel Fernandes (Google)
Cc: kbuild-all, linux-kernel, Paul E. McKenney
tree: https://kernel.googlesource.com/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2019.09.23a
head: 97de53b94582c208ee239178b208b8e8b9472585
commit: 39676bb72323718a9e7bab1ba9c4a68319a96f62 [62/77] rcu: Add support for debug_objects debugging for kfree_rcu()
If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
smatch warnings:
kernel/rcu/tree.c:2882 kfree_call_rcu() warn: inconsistent returns 'irqsave:flags'.
Locked on: line 2867
Unlocked on: line 2882
git remote add rcu https://kernel.googlesource.com/pub/scm/linux/kernel/git/paulmck/linux-rcu.git
git remote update rcu
git checkout 39676bb72323718a9e7bab1ba9c4a68319a96f62
vim +2882 kernel/rcu/tree.c
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2850) void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2851) {
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2852) unsigned long flags;
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2853) struct kfree_rcu_cpu *krcp;
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2854)
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2855) head->func = func;
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2856)
87970ccf5a9125 Paul E. McKenney 2019-09-19 2857 local_irq_save(flags); // For safely calling this_cpu_ptr().
^^^^^^^^^^^^^^^^^^^^^
IRQs disabled.
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2858) krcp = this_cpu_ptr(&krc);
ff8db005e371cb Paul E. McKenney 2019-09-19 2859 if (krcp->initialized)
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2860) spin_lock(&krcp->lock);
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2861)
87970ccf5a9125 Paul E. McKenney 2019-09-19 2862 // Queue the object but don't yet schedule the batch.
39676bb7232371 Joel Fernandes (Google 2019-09-22 2863) if (debug_rcu_head_queue(head)) {
39676bb7232371 Joel Fernandes (Google 2019-09-22 2864) // Probable double kfree_rcu(), just leak.
39676bb7232371 Joel Fernandes (Google 2019-09-22 2865) WARN_ONCE(1, "%s(): Double-freed call. rcu_head %p\n",
39676bb7232371 Joel Fernandes (Google 2019-09-22 2866) __func__, head);
39676bb7232371 Joel Fernandes (Google 2019-09-22 2867) return;
Need to re-enable before returning.
39676bb7232371 Joel Fernandes (Google 2019-09-22 2868) }
87970ccf5a9125 Paul E. McKenney 2019-09-19 2869 head->func = func;
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2870) head->next = krcp->head;
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2871) krcp->head = head;
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2872)
87970ccf5a9125 Paul E. McKenney 2019-09-19 2873 // Set timer to drain after KFREE_DRAIN_JIFFIES.
ff8db005e371cb Paul E. McKenney 2019-09-19 2874 if (rcu_scheduler_active == RCU_SCHEDULER_RUNNING &&
be39848334e088 Paul E. McKenney 2019-09-22 2875 !krcp->monitor_todo) {
be39848334e088 Paul E. McKenney 2019-09-22 2876 krcp->monitor_todo = true;
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2877) schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES);
be39848334e088 Paul E. McKenney 2019-09-22 2878 }
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2879)
ff8db005e371cb Paul E. McKenney 2019-09-19 2880 if (krcp->initialized)
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2881) spin_unlock(&krcp->lock);
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 @2882) local_irq_restore(flags);
5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2883) }
495aa969dbaef2 Andreea-Cristina Bernat 2014-03-18 2884 EXPORT_SYMBOL_GPL(kfree_call_rcu);
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [rcu:dev.2019.09.23a 62/77] kernel/rcu/tree.c:2882 kfree_call_rcu() warn: inconsistent returns 'irqsave:flags'. 2019-09-24 8:05 [rcu:dev.2019.09.23a 62/77] kernel/rcu/tree.c:2882 kfree_call_rcu() warn: inconsistent returns 'irqsave:flags' Dan Carpenter @ 2019-09-24 12:15 ` Joel Fernandes 2019-09-24 16:03 ` Paul E. McKenney 0 siblings, 1 reply; 5+ messages in thread From: Joel Fernandes @ 2019-09-24 12:15 UTC (permalink / raw) To: Dan Carpenter Cc: kbuild, kbuild-all, LKML, Paul E. McKenney, Joel Fernandes (Google) On Tue, Sep 24, 2019 at 4:05 AM Dan Carpenter <dan.carpenter@oracle.com> wrote: > > tree: https://kernel.googlesource.com/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2019.09.23a > head: 97de53b94582c208ee239178b208b8e8b9472585 > commit: 39676bb72323718a9e7bab1ba9c4a68319a96f62 [62/77] rcu: Add support for debug_objects debugging for kfree_rcu() > > If you fix the issue, kindly add following tag > Reported-by: kbuild test robot <lkp@intel.com> > Reported-by: Dan Carpenter <dan.carpenter@oracle.com> > > smatch warnings: > kernel/rcu/tree.c:2882 kfree_call_rcu() warn: inconsistent returns 'irqsave:flags'. > Locked on: line 2867 > Unlocked on: line 2882 > > git remote add rcu https://kernel.googlesource.com/pub/scm/linux/kernel/git/paulmck/linux-rcu.git > git remote update rcu > git checkout 39676bb72323718a9e7bab1ba9c4a68319a96f62 > vim +2882 kernel/rcu/tree.c > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2850) void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2851) { > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2852) unsigned long flags; > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2853) struct kfree_rcu_cpu *krcp; > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2854) > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2855) head->func = func; > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2856) > 87970ccf5a9125 Paul E. McKenney 2019-09-19 2857 local_irq_save(flags); // For safely calling this_cpu_ptr(). > ^^^^^^^^^^^^^^^^^^^^^ > IRQs disabled. > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2858) krcp = this_cpu_ptr(&krc); > ff8db005e371cb Paul E. McKenney 2019-09-19 2859 if (krcp->initialized) > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2860) spin_lock(&krcp->lock); > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2861) > 87970ccf5a9125 Paul E. McKenney 2019-09-19 2862 // Queue the object but don't yet schedule the batch. > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2863) if (debug_rcu_head_queue(head)) { > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2864) // Probable double kfree_rcu(), just leak. > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2865) WARN_ONCE(1, "%s(): Double-freed call. rcu_head %p\n", > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2866) __func__, head); > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2867) return; > > Need to re-enable before returning. Right. At this point the system has a bug anyway since it is a double-free. But yes, no reason to introduce more bugs. Will fix. Thank you, Dan! ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [rcu:dev.2019.09.23a 62/77] kernel/rcu/tree.c:2882 kfree_call_rcu() warn: inconsistent returns 'irqsave:flags'. 2019-09-24 12:15 ` Joel Fernandes @ 2019-09-24 16:03 ` Paul E. McKenney 2019-09-26 18:19 ` Joel Fernandes 0 siblings, 1 reply; 5+ messages in thread From: Paul E. McKenney @ 2019-09-24 16:03 UTC (permalink / raw) To: Joel Fernandes; +Cc: Dan Carpenter, kbuild, kbuild-all, LKML On Tue, Sep 24, 2019 at 08:15:12AM -0400, Joel Fernandes wrote: > On Tue, Sep 24, 2019 at 4:05 AM Dan Carpenter <dan.carpenter@oracle.com> wrote: > > > > tree: https://kernel.googlesource.com/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2019.09.23a > > head: 97de53b94582c208ee239178b208b8e8b9472585 > > commit: 39676bb72323718a9e7bab1ba9c4a68319a96f62 [62/77] rcu: Add support for debug_objects debugging for kfree_rcu() > > > > If you fix the issue, kindly add following tag > > Reported-by: kbuild test robot <lkp@intel.com> > > Reported-by: Dan Carpenter <dan.carpenter@oracle.com> > > > > smatch warnings: > > kernel/rcu/tree.c:2882 kfree_call_rcu() warn: inconsistent returns 'irqsave:flags'. > > Locked on: line 2867 > > Unlocked on: line 2882 > > > > git remote add rcu https://kernel.googlesource.com/pub/scm/linux/kernel/git/paulmck/linux-rcu.git > > git remote update rcu > > git checkout 39676bb72323718a9e7bab1ba9c4a68319a96f62 > > vim +2882 kernel/rcu/tree.c > > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2850) void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2851) { > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2852) unsigned long flags; > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2853) struct kfree_rcu_cpu *krcp; > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2854) > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2855) head->func = func; > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2856) > > 87970ccf5a9125 Paul E. McKenney 2019-09-19 2857 local_irq_save(flags); // For safely calling this_cpu_ptr(). > > ^^^^^^^^^^^^^^^^^^^^^ > > IRQs disabled. > > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2858) krcp = this_cpu_ptr(&krc); > > ff8db005e371cb Paul E. McKenney 2019-09-19 2859 if (krcp->initialized) > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2860) spin_lock(&krcp->lock); > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2861) > > 87970ccf5a9125 Paul E. McKenney 2019-09-19 2862 // Queue the object but don't yet schedule the batch. > > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2863) if (debug_rcu_head_queue(head)) { > > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2864) // Probable double kfree_rcu(), just leak. > > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2865) WARN_ONCE(1, "%s(): Double-freed call. rcu_head %p\n", > > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2866) __func__, head); > > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2867) return; > > > > Need to re-enable before returning. > > Right. At this point the system has a bug anyway since it is a > double-free. But yes, no reason to introduce more bugs. Will fix. > Thank you, Dan! What Joel said! As long as I am doing several other reports anyway... How does the to-be-squashed patch below look? Thanx, Paul ------------------------------------------------------------------------ commit 39af4c08038a8a6a7b1c9804fdd2c1921d583222 Author: Paul E. McKenney <paulmck@kernel.org> Date: Tue Sep 24 09:02:00 2019 -0700 squash! rcu: Add support for debug_objects debugging for kfree_rcu() [ paulmck: Fix IRQ per kbuild test robot <lkp@intel.com> feedback. ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 921daa7..edb7539 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -2870,7 +2870,7 @@ void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) // Probable double kfree_rcu(), just leak. WARN_ONCE(1, "%s(): Double-freed call. rcu_head %p\n", __func__, head); - return; + goto unlock_return; } head->func = func; head->next = krcp->head; @@ -2883,6 +2883,7 @@ void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES); } +unlock_return: if (krcp->initialized) spin_unlock(&krcp->lock); local_irq_restore(flags); ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [rcu:dev.2019.09.23a 62/77] kernel/rcu/tree.c:2882 kfree_call_rcu() warn: inconsistent returns 'irqsave:flags'. 2019-09-24 16:03 ` Paul E. McKenney @ 2019-09-26 18:19 ` Joel Fernandes 2019-09-26 19:24 ` Paul E. McKenney 0 siblings, 1 reply; 5+ messages in thread From: Joel Fernandes @ 2019-09-26 18:19 UTC (permalink / raw) To: Paul E. McKenney; +Cc: Dan Carpenter, kbuild, kbuild-all, LKML On Tue, Sep 24, 2019 at 09:03:48AM -0700, Paul E. McKenney wrote: > On Tue, Sep 24, 2019 at 08:15:12AM -0400, Joel Fernandes wrote: > > On Tue, Sep 24, 2019 at 4:05 AM Dan Carpenter <dan.carpenter@oracle.com> wrote: > > > > > > tree: https://kernel.googlesource.com/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2019.09.23a > > > head: 97de53b94582c208ee239178b208b8e8b9472585 > > > commit: 39676bb72323718a9e7bab1ba9c4a68319a96f62 [62/77] rcu: Add support for debug_objects debugging for kfree_rcu() > > > > > > If you fix the issue, kindly add following tag > > > Reported-by: kbuild test robot <lkp@intel.com> > > > Reported-by: Dan Carpenter <dan.carpenter@oracle.com> > > > > > > smatch warnings: > > > kernel/rcu/tree.c:2882 kfree_call_rcu() warn: inconsistent returns 'irqsave:flags'. > > > Locked on: line 2867 > > > Unlocked on: line 2882 > > > > > > git remote add rcu https://kernel.googlesource.com/pub/scm/linux/kernel/git/paulmck/linux-rcu.git > > > git remote update rcu > > > git checkout 39676bb72323718a9e7bab1ba9c4a68319a96f62 > > > vim +2882 kernel/rcu/tree.c > > > > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2850) void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2851) { > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2852) unsigned long flags; > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2853) struct kfree_rcu_cpu *krcp; > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2854) > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2855) head->func = func; > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2856) > > > 87970ccf5a9125 Paul E. McKenney 2019-09-19 2857 local_irq_save(flags); // For safely calling this_cpu_ptr(). > > > ^^^^^^^^^^^^^^^^^^^^^ > > > IRQs disabled. > > > > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2858) krcp = this_cpu_ptr(&krc); > > > ff8db005e371cb Paul E. McKenney 2019-09-19 2859 if (krcp->initialized) > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2860) spin_lock(&krcp->lock); > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2861) > > > 87970ccf5a9125 Paul E. McKenney 2019-09-19 2862 // Queue the object but don't yet schedule the batch. > > > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2863) if (debug_rcu_head_queue(head)) { > > > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2864) // Probable double kfree_rcu(), just leak. > > > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2865) WARN_ONCE(1, "%s(): Double-freed call. rcu_head %p\n", > > > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2866) __func__, head); > > > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2867) return; > > > > > > Need to re-enable before returning. > > > > Right. At this point the system has a bug anyway since it is a > > double-free. But yes, no reason to introduce more bugs. Will fix. > > Thank you, Dan! > > What Joel said! > > As long as I am doing several other reports anyway... > > How does the to-be-squashed patch below look? Hi Paul, Sorry for the late reply due to the conference.. This patch looks Ok, the code in your tree though is slightly different mine I think because you reworked the kfree_rcu() code for working during early boot. After my talk tomorrow, I will go through your rcu/dev tree in detail to review the reworks you did in detail. Let me know if you have the kfree_rcu() changes in a separate topic branch, as well. So it will make reviewing easier. thanks, - Joel > > Thanx, Paul > > ------------------------------------------------------------------------ > > commit 39af4c08038a8a6a7b1c9804fdd2c1921d583222 > Author: Paul E. McKenney <paulmck@kernel.org> > Date: Tue Sep 24 09:02:00 2019 -0700 > > squash! rcu: Add support for debug_objects debugging for kfree_rcu() > > [ paulmck: Fix IRQ per kbuild test robot <lkp@intel.com> feedback. ] > Signed-off-by: Paul E. McKenney <paulmck@kernel.org> > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index 921daa7..edb7539 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -2870,7 +2870,7 @@ void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) > // Probable double kfree_rcu(), just leak. > WARN_ONCE(1, "%s(): Double-freed call. rcu_head %p\n", > __func__, head); > - return; > + goto unlock_return; > } > head->func = func; > head->next = krcp->head; > @@ -2883,6 +2883,7 @@ void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) > schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES); > } > > +unlock_return: > if (krcp->initialized) > spin_unlock(&krcp->lock); > local_irq_restore(flags); ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [rcu:dev.2019.09.23a 62/77] kernel/rcu/tree.c:2882 kfree_call_rcu() warn: inconsistent returns 'irqsave:flags'. 2019-09-26 18:19 ` Joel Fernandes @ 2019-09-26 19:24 ` Paul E. McKenney 0 siblings, 0 replies; 5+ messages in thread From: Paul E. McKenney @ 2019-09-26 19:24 UTC (permalink / raw) To: Joel Fernandes; +Cc: Dan Carpenter, kbuild, kbuild-all, LKML On Thu, Sep 26, 2019 at 02:19:54PM -0400, Joel Fernandes wrote: > On Tue, Sep 24, 2019 at 09:03:48AM -0700, Paul E. McKenney wrote: > > On Tue, Sep 24, 2019 at 08:15:12AM -0400, Joel Fernandes wrote: > > > On Tue, Sep 24, 2019 at 4:05 AM Dan Carpenter <dan.carpenter@oracle.com> wrote: > > > > > > > > tree: https://kernel.googlesource.com/pub/scm/linux/kernel/git/paulmck/linux-rcu.git dev.2019.09.23a > > > > head: 97de53b94582c208ee239178b208b8e8b9472585 > > > > commit: 39676bb72323718a9e7bab1ba9c4a68319a96f62 [62/77] rcu: Add support for debug_objects debugging for kfree_rcu() > > > > > > > > If you fix the issue, kindly add following tag > > > > Reported-by: kbuild test robot <lkp@intel.com> > > > > Reported-by: Dan Carpenter <dan.carpenter@oracle.com> > > > > > > > > smatch warnings: > > > > kernel/rcu/tree.c:2882 kfree_call_rcu() warn: inconsistent returns 'irqsave:flags'. > > > > Locked on: line 2867 > > > > Unlocked on: line 2882 > > > > > > > > git remote add rcu https://kernel.googlesource.com/pub/scm/linux/kernel/git/paulmck/linux-rcu.git > > > > git remote update rcu > > > > git checkout 39676bb72323718a9e7bab1ba9c4a68319a96f62 > > > > vim +2882 kernel/rcu/tree.c > > > > > > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2850) void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) > > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2851) { > > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2852) unsigned long flags; > > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2853) struct kfree_rcu_cpu *krcp; > > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2854) > > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2855) head->func = func; > > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2856) > > > > 87970ccf5a9125 Paul E. McKenney 2019-09-19 2857 local_irq_save(flags); // For safely calling this_cpu_ptr(). > > > > ^^^^^^^^^^^^^^^^^^^^^ > > > > IRQs disabled. > > > > > > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2858) krcp = this_cpu_ptr(&krc); > > > > ff8db005e371cb Paul E. McKenney 2019-09-19 2859 if (krcp->initialized) > > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2860) spin_lock(&krcp->lock); > > > > 5f5046cc15d514 Joel Fernandes (Google 2019-08-05 2861) > > > > 87970ccf5a9125 Paul E. McKenney 2019-09-19 2862 // Queue the object but don't yet schedule the batch. > > > > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2863) if (debug_rcu_head_queue(head)) { > > > > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2864) // Probable double kfree_rcu(), just leak. > > > > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2865) WARN_ONCE(1, "%s(): Double-freed call. rcu_head %p\n", > > > > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2866) __func__, head); > > > > 39676bb7232371 Joel Fernandes (Google 2019-09-22 2867) return; > > > > > > > > Need to re-enable before returning. > > > > > > Right. At this point the system has a bug anyway since it is a > > > double-free. But yes, no reason to introduce more bugs. Will fix. > > > Thank you, Dan! > > > > What Joel said! > > > > As long as I am doing several other reports anyway... > > > > How does the to-be-squashed patch below look? > > Hi Paul, > > Sorry for the late reply due to the conference.. > > This patch looks Ok, the code in your tree though is slightly different mine > I think because you reworked the kfree_rcu() code for working during early > boot. Yes, I did pull some of the changes earlier. > After my talk tomorrow, I will go through your rcu/dev tree in detail to > review the reworks you did in detail. Sounds good, and best of everything with the talk! > Let me know if you have the kfree_rcu() changes in a separate topic branch, > as well. So it will make reviewing easier. They will be, shortly after -rc1 comes out. Thanx, Paul > thanks, > > - Joel > > > > > > Thanx, Paul > > > > ------------------------------------------------------------------------ > > > > commit 39af4c08038a8a6a7b1c9804fdd2c1921d583222 > > Author: Paul E. McKenney <paulmck@kernel.org> > > Date: Tue Sep 24 09:02:00 2019 -0700 > > > > squash! rcu: Add support for debug_objects debugging for kfree_rcu() > > > > [ paulmck: Fix IRQ per kbuild test robot <lkp@intel.com> feedback. ] > > Signed-off-by: Paul E. McKenney <paulmck@kernel.org> > > > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > > index 921daa7..edb7539 100644 > > --- a/kernel/rcu/tree.c > > +++ b/kernel/rcu/tree.c > > @@ -2870,7 +2870,7 @@ void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) > > // Probable double kfree_rcu(), just leak. > > WARN_ONCE(1, "%s(): Double-freed call. rcu_head %p\n", > > __func__, head); > > - return; > > + goto unlock_return; > > } > > head->func = func; > > head->next = krcp->head; > > @@ -2883,6 +2883,7 @@ void kfree_call_rcu(struct rcu_head *head, rcu_callback_t func) > > schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES); > > } > > > > +unlock_return: > > if (krcp->initialized) > > spin_unlock(&krcp->lock); > > local_irq_restore(flags); ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2019-09-26 19:24 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2019-09-24 8:05 [rcu:dev.2019.09.23a 62/77] kernel/rcu/tree.c:2882 kfree_call_rcu() warn: inconsistent returns 'irqsave:flags' Dan Carpenter 2019-09-24 12:15 ` Joel Fernandes 2019-09-24 16:03 ` Paul E. McKenney 2019-09-26 18:19 ` Joel Fernandes 2019-09-26 19:24 ` Paul E. McKenney
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