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* [PATCH] cpufreq: schedutil: Use kobject release() method to free sugov_tunables
@ 2021-07-15  9:53 Kevin Hao
  2021-08-04 16:54 ` Rafael J. Wysocki
  0 siblings, 1 reply; 3+ messages in thread
From: Kevin Hao @ 2021-07-15  9:53 UTC (permalink / raw)
  To: Rafael J. Wysocki, Viresh Kumar, Ingo Molnar, Peter Zijlstra,
	Juri Lelli, Vincent Guittot
  Cc: linux-pm, linux-kernel, stable

The struct sugov_tunables is protected by the kobject, so we can't free
it directly. Otherwise we would get a call trace like this:
  ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x30
  WARNING: CPU: 3 PID: 720 at lib/debugobjects.c:505 debug_print_object+0xb8/0x100
  Modules linked in:
  CPU: 3 PID: 720 Comm: a.sh Tainted: G        W         5.14.0-rc1-next-20210715-yocto-standard+ #507
  Hardware name: Marvell OcteonTX CN96XX board (DT)
  pstate: 40400009 (nZcv daif +PAN -UAO -TCO BTYPE=--)
  pc : debug_print_object+0xb8/0x100
  lr : debug_print_object+0xb8/0x100
  sp : ffff80001ecaf910
  x29: ffff80001ecaf910 x28: ffff00011b10b8d0 x27: ffff800011043d80
  x26: ffff00011a8f0000 x25: ffff800013cb3ff0 x24: 0000000000000000
  x23: ffff80001142aa68 x22: ffff800011043d80 x21: ffff00010de46f20
  x20: ffff800013c0c520 x19: ffff800011d8f5b0 x18: 0000000000000010
  x17: 6e6968207473696c x16: 5f72656d6974203a x15: 6570797420746365
  x14: 6a626f2029302065 x13: 303378302f307830 x12: 2b6e665f72656d69
  x11: ffff8000124b1560 x10: ffff800012331520 x9 : ffff8000100ca6b0
  x8 : 000000000017ffe8 x7 : c0000000fffeffff x6 : 0000000000000001
  x5 : ffff800011d8c000 x4 : ffff800011d8c740 x3 : 0000000000000000
  x2 : ffff0001108301c0 x1 : ab3c90eedf9c0f00 x0 : 0000000000000000
  Call trace:
   debug_print_object+0xb8/0x100
   __debug_check_no_obj_freed+0x1c0/0x230
   debug_check_no_obj_freed+0x20/0x88
   slab_free_freelist_hook+0x154/0x1c8
   kfree+0x114/0x5d0
   sugov_exit+0xbc/0xc0
   cpufreq_exit_governor+0x44/0x90
   cpufreq_set_policy+0x268/0x4a8
   store_scaling_governor+0xe0/0x128
   store+0xc0/0xf0
   sysfs_kf_write+0x54/0x80
   kernfs_fop_write_iter+0x128/0x1c0
   new_sync_write+0xf0/0x190
   vfs_write+0x2d4/0x478
   ksys_write+0x74/0x100
   __arm64_sys_write+0x24/0x30
   invoke_syscall.constprop.0+0x54/0xe0
   do_el0_svc+0x64/0x158
   el0_svc+0x2c/0xb0
   el0t_64_sync_handler+0xb0/0xb8
   el0t_64_sync+0x198/0x19c
  irq event stamp: 5518
  hardirqs last  enabled at (5517): [<ffff8000100cbd7c>] console_unlock+0x554/0x6c8
  hardirqs last disabled at (5518): [<ffff800010fc0638>] el1_dbg+0x28/0xa0
  softirqs last  enabled at (5504): [<ffff8000100106e0>] __do_softirq+0x4d0/0x6c0
  softirqs last disabled at (5483): [<ffff800010049548>] irq_exit+0x1b0/0x1b8

So add a release() method for sugov_tunables_ktype to release the
sugov_tunables safely.

Fixes: 9bdcb44e391d ("cpufreq: schedutil: New governor based on scheduler utilization data")
Cc: stable@vger.kernel.org
Signed-off-by: Kevin Hao <haokexin@gmail.com>
---
 kernel/sched/cpufreq_schedutil.c | 23 ++++++++++++-----------
 1 file changed, 12 insertions(+), 11 deletions(-)

diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
index 57124614363d..ac171496da4b 100644
--- a/kernel/sched/cpufreq_schedutil.c
+++ b/kernel/sched/cpufreq_schedutil.c
@@ -537,9 +537,17 @@ static struct attribute *sugov_attrs[] = {
 };
 ATTRIBUTE_GROUPS(sugov);
 
+static void sugov_tunables_free(struct kobject *kobj)
+{
+	struct gov_attr_set *attr_set = container_of(kobj, struct gov_attr_set, kobj);
+
+	kfree(to_sugov_tunables(attr_set));
+}
+
 static struct kobj_type sugov_tunables_ktype = {
 	.default_groups = sugov_groups,
 	.sysfs_ops = &governor_sysfs_ops,
+	.release = &sugov_tunables_free,
 };
 
 /********************** cpufreq governor interface *********************/
@@ -639,14 +647,6 @@ static struct sugov_tunables *sugov_tunables_alloc(struct sugov_policy *sg_polic
 	return tunables;
 }
 
-static void sugov_tunables_free(struct sugov_tunables *tunables)
-{
-	if (!have_governor_per_policy())
-		global_tunables = NULL;
-
-	kfree(tunables);
-}
-
 static int sugov_init(struct cpufreq_policy *policy)
 {
 	struct sugov_policy *sg_policy;
@@ -707,7 +707,8 @@ static int sugov_init(struct cpufreq_policy *policy)
 fail:
 	kobject_put(&tunables->attr_set.kobj);
 	policy->governor_data = NULL;
-	sugov_tunables_free(tunables);
+	if (!have_governor_per_policy())
+		global_tunables = NULL;
 
 stop_kthread:
 	sugov_kthread_stop(sg_policy);
@@ -733,8 +734,8 @@ static void sugov_exit(struct cpufreq_policy *policy)
 
 	count = gov_attr_set_put(&tunables->attr_set, &sg_policy->tunables_hook);
 	policy->governor_data = NULL;
-	if (!count)
-		sugov_tunables_free(tunables);
+	if (!count && !have_governor_per_policy())
+		global_tunables = NULL;
 
 	mutex_unlock(&global_tunables_lock);
 
-- 
2.31.1


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] cpufreq: schedutil: Use kobject release() method to free sugov_tunables
  2021-07-15  9:53 [PATCH] cpufreq: schedutil: Use kobject release() method to free sugov_tunables Kevin Hao
@ 2021-08-04 16:54 ` Rafael J. Wysocki
  2021-08-05  7:22   ` Kevin Hao
  0 siblings, 1 reply; 3+ messages in thread
From: Rafael J. Wysocki @ 2021-08-04 16:54 UTC (permalink / raw)
  To: Kevin Hao
  Cc: Rafael J. Wysocki, Viresh Kumar, Ingo Molnar, Peter Zijlstra,
	Juri Lelli, Vincent Guittot, Linux PM, Linux Kernel Mailing List,
	Stable

On Thu, Jul 15, 2021 at 11:56 AM Kevin Hao <haokexin@gmail.com> wrote:
>
> The struct sugov_tunables is protected by the kobject, so we can't free
> it directly. Otherwise we would get a call trace like this:
>   ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x30
>   WARNING: CPU: 3 PID: 720 at lib/debugobjects.c:505 debug_print_object+0xb8/0x100
>   Modules linked in:
>   CPU: 3 PID: 720 Comm: a.sh Tainted: G        W         5.14.0-rc1-next-20210715-yocto-standard+ #507
>   Hardware name: Marvell OcteonTX CN96XX board (DT)
>   pstate: 40400009 (nZcv daif +PAN -UAO -TCO BTYPE=--)
>   pc : debug_print_object+0xb8/0x100
>   lr : debug_print_object+0xb8/0x100
>   sp : ffff80001ecaf910
>   x29: ffff80001ecaf910 x28: ffff00011b10b8d0 x27: ffff800011043d80
>   x26: ffff00011a8f0000 x25: ffff800013cb3ff0 x24: 0000000000000000
>   x23: ffff80001142aa68 x22: ffff800011043d80 x21: ffff00010de46f20
>   x20: ffff800013c0c520 x19: ffff800011d8f5b0 x18: 0000000000000010
>   x17: 6e6968207473696c x16: 5f72656d6974203a x15: 6570797420746365
>   x14: 6a626f2029302065 x13: 303378302f307830 x12: 2b6e665f72656d69
>   x11: ffff8000124b1560 x10: ffff800012331520 x9 : ffff8000100ca6b0
>   x8 : 000000000017ffe8 x7 : c0000000fffeffff x6 : 0000000000000001
>   x5 : ffff800011d8c000 x4 : ffff800011d8c740 x3 : 0000000000000000
>   x2 : ffff0001108301c0 x1 : ab3c90eedf9c0f00 x0 : 0000000000000000
>   Call trace:
>    debug_print_object+0xb8/0x100
>    __debug_check_no_obj_freed+0x1c0/0x230
>    debug_check_no_obj_freed+0x20/0x88
>    slab_free_freelist_hook+0x154/0x1c8
>    kfree+0x114/0x5d0
>    sugov_exit+0xbc/0xc0
>    cpufreq_exit_governor+0x44/0x90
>    cpufreq_set_policy+0x268/0x4a8
>    store_scaling_governor+0xe0/0x128
>    store+0xc0/0xf0
>    sysfs_kf_write+0x54/0x80
>    kernfs_fop_write_iter+0x128/0x1c0
>    new_sync_write+0xf0/0x190
>    vfs_write+0x2d4/0x478
>    ksys_write+0x74/0x100
>    __arm64_sys_write+0x24/0x30
>    invoke_syscall.constprop.0+0x54/0xe0
>    do_el0_svc+0x64/0x158
>    el0_svc+0x2c/0xb0
>    el0t_64_sync_handler+0xb0/0xb8
>    el0t_64_sync+0x198/0x19c
>   irq event stamp: 5518
>   hardirqs last  enabled at (5517): [<ffff8000100cbd7c>] console_unlock+0x554/0x6c8
>   hardirqs last disabled at (5518): [<ffff800010fc0638>] el1_dbg+0x28/0xa0
>   softirqs last  enabled at (5504): [<ffff8000100106e0>] __do_softirq+0x4d0/0x6c0
>   softirqs last disabled at (5483): [<ffff800010049548>] irq_exit+0x1b0/0x1b8
>
> So add a release() method for sugov_tunables_ktype to release the
> sugov_tunables safely.
>
> Fixes: 9bdcb44e391d ("cpufreq: schedutil: New governor based on scheduler utilization data")
> Cc: stable@vger.kernel.org
> Signed-off-by: Kevin Hao <haokexin@gmail.com>
> ---
>  kernel/sched/cpufreq_schedutil.c | 23 ++++++++++++-----------
>  1 file changed, 12 insertions(+), 11 deletions(-)
>
> diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
> index 57124614363d..ac171496da4b 100644
> --- a/kernel/sched/cpufreq_schedutil.c
> +++ b/kernel/sched/cpufreq_schedutil.c
> @@ -537,9 +537,17 @@ static struct attribute *sugov_attrs[] = {
>  };
>  ATTRIBUTE_GROUPS(sugov);
>
> +static void sugov_tunables_free(struct kobject *kobj)
> +{
> +       struct gov_attr_set *attr_set = container_of(kobj, struct gov_attr_set, kobj);
> +
> +       kfree(to_sugov_tunables(attr_set));
> +}
> +
>  static struct kobj_type sugov_tunables_ktype = {
>         .default_groups = sugov_groups,
>         .sysfs_ops = &governor_sysfs_ops,
> +       .release = &sugov_tunables_free,
>  };
>
>  /********************** cpufreq governor interface *********************/
> @@ -639,14 +647,6 @@ static struct sugov_tunables *sugov_tunables_alloc(struct sugov_policy *sg_polic
>         return tunables;
>  }
>
> -static void sugov_tunables_free(struct sugov_tunables *tunables)

Rename this to sugov_clear_global_tunables() and make it take no arguments.

> -{
> -       if (!have_governor_per_policy())
> -               global_tunables = NULL;
> -
> -       kfree(tunables);

Drop just this one line from it.

> -}
> -
>  static int sugov_init(struct cpufreq_policy *policy)
>  {
>         struct sugov_policy *sg_policy;
> @@ -707,7 +707,8 @@ static int sugov_init(struct cpufreq_policy *policy)
>  fail:
>         kobject_put(&tunables->attr_set.kobj);
>         policy->governor_data = NULL;
> -       sugov_tunables_free(tunables);

And call sugov_clear_global_tunables() instead of the above from here
and analogously below.

> +       if (!have_governor_per_policy())
> +               global_tunables = NULL;
>
>  stop_kthread:
>         sugov_kthread_stop(sg_policy);
> @@ -733,8 +734,8 @@ static void sugov_exit(struct cpufreq_policy *policy)
>
>         count = gov_attr_set_put(&tunables->attr_set, &sg_policy->tunables_hook);
>         policy->governor_data = NULL;
> -       if (!count)
> -               sugov_tunables_free(tunables);
> +       if (!count && !have_governor_per_policy())
> +               global_tunables = NULL;
>
>         mutex_unlock(&global_tunables_lock);
>
> --

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH] cpufreq: schedutil: Use kobject release() method to free sugov_tunables
  2021-08-04 16:54 ` Rafael J. Wysocki
@ 2021-08-05  7:22   ` Kevin Hao
  0 siblings, 0 replies; 3+ messages in thread
From: Kevin Hao @ 2021-08-05  7:22 UTC (permalink / raw)
  To: Rafael J. Wysocki
  Cc: Rafael J. Wysocki, Viresh Kumar, Ingo Molnar, Peter Zijlstra,
	Juri Lelli, Vincent Guittot, Linux PM, Linux Kernel Mailing List,
	Stable

[-- Attachment #1: Type: text/plain, Size: 5613 bytes --]

On Wed, Aug 04, 2021 at 06:54:10PM +0200, Rafael J. Wysocki wrote:
> On Thu, Jul 15, 2021 at 11:56 AM Kevin Hao <haokexin@gmail.com> wrote:
> >
> > The struct sugov_tunables is protected by the kobject, so we can't free
> > it directly. Otherwise we would get a call trace like this:
> >   ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x30
> >   WARNING: CPU: 3 PID: 720 at lib/debugobjects.c:505 debug_print_object+0xb8/0x100
> >   Modules linked in:
> >   CPU: 3 PID: 720 Comm: a.sh Tainted: G        W         5.14.0-rc1-next-20210715-yocto-standard+ #507
> >   Hardware name: Marvell OcteonTX CN96XX board (DT)
> >   pstate: 40400009 (nZcv daif +PAN -UAO -TCO BTYPE=--)
> >   pc : debug_print_object+0xb8/0x100
> >   lr : debug_print_object+0xb8/0x100
> >   sp : ffff80001ecaf910
> >   x29: ffff80001ecaf910 x28: ffff00011b10b8d0 x27: ffff800011043d80
> >   x26: ffff00011a8f0000 x25: ffff800013cb3ff0 x24: 0000000000000000
> >   x23: ffff80001142aa68 x22: ffff800011043d80 x21: ffff00010de46f20
> >   x20: ffff800013c0c520 x19: ffff800011d8f5b0 x18: 0000000000000010
> >   x17: 6e6968207473696c x16: 5f72656d6974203a x15: 6570797420746365
> >   x14: 6a626f2029302065 x13: 303378302f307830 x12: 2b6e665f72656d69
> >   x11: ffff8000124b1560 x10: ffff800012331520 x9 : ffff8000100ca6b0
> >   x8 : 000000000017ffe8 x7 : c0000000fffeffff x6 : 0000000000000001
> >   x5 : ffff800011d8c000 x4 : ffff800011d8c740 x3 : 0000000000000000
> >   x2 : ffff0001108301c0 x1 : ab3c90eedf9c0f00 x0 : 0000000000000000
> >   Call trace:
> >    debug_print_object+0xb8/0x100
> >    __debug_check_no_obj_freed+0x1c0/0x230
> >    debug_check_no_obj_freed+0x20/0x88
> >    slab_free_freelist_hook+0x154/0x1c8
> >    kfree+0x114/0x5d0
> >    sugov_exit+0xbc/0xc0
> >    cpufreq_exit_governor+0x44/0x90
> >    cpufreq_set_policy+0x268/0x4a8
> >    store_scaling_governor+0xe0/0x128
> >    store+0xc0/0xf0
> >    sysfs_kf_write+0x54/0x80
> >    kernfs_fop_write_iter+0x128/0x1c0
> >    new_sync_write+0xf0/0x190
> >    vfs_write+0x2d4/0x478
> >    ksys_write+0x74/0x100
> >    __arm64_sys_write+0x24/0x30
> >    invoke_syscall.constprop.0+0x54/0xe0
> >    do_el0_svc+0x64/0x158
> >    el0_svc+0x2c/0xb0
> >    el0t_64_sync_handler+0xb0/0xb8
> >    el0t_64_sync+0x198/0x19c
> >   irq event stamp: 5518
> >   hardirqs last  enabled at (5517): [<ffff8000100cbd7c>] console_unlock+0x554/0x6c8
> >   hardirqs last disabled at (5518): [<ffff800010fc0638>] el1_dbg+0x28/0xa0
> >   softirqs last  enabled at (5504): [<ffff8000100106e0>] __do_softirq+0x4d0/0x6c0
> >   softirqs last disabled at (5483): [<ffff800010049548>] irq_exit+0x1b0/0x1b8
> >
> > So add a release() method for sugov_tunables_ktype to release the
> > sugov_tunables safely.
> >
> > Fixes: 9bdcb44e391d ("cpufreq: schedutil: New governor based on scheduler utilization data")
> > Cc: stable@vger.kernel.org
> > Signed-off-by: Kevin Hao <haokexin@gmail.com>
> > ---
> >  kernel/sched/cpufreq_schedutil.c | 23 ++++++++++++-----------
> >  1 file changed, 12 insertions(+), 11 deletions(-)
> >
> > diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
> > index 57124614363d..ac171496da4b 100644
> > --- a/kernel/sched/cpufreq_schedutil.c
> > +++ b/kernel/sched/cpufreq_schedutil.c
> > @@ -537,9 +537,17 @@ static struct attribute *sugov_attrs[] = {
> >  };
> >  ATTRIBUTE_GROUPS(sugov);
> >
> > +static void sugov_tunables_free(struct kobject *kobj)
> > +{
> > +       struct gov_attr_set *attr_set = container_of(kobj, struct gov_attr_set, kobj);
> > +
> > +       kfree(to_sugov_tunables(attr_set));
> > +}
> > +
> >  static struct kobj_type sugov_tunables_ktype = {
> >         .default_groups = sugov_groups,
> >         .sysfs_ops = &governor_sysfs_ops,
> > +       .release = &sugov_tunables_free,
> >  };
> >
> >  /********************** cpufreq governor interface *********************/
> > @@ -639,14 +647,6 @@ static struct sugov_tunables *sugov_tunables_alloc(struct sugov_policy *sg_polic
> >         return tunables;
> >  }
> >
> > -static void sugov_tunables_free(struct sugov_tunables *tunables)
> 
> Rename this to sugov_clear_global_tunables() and make it take no arguments.

OK.

> 
> > -{
> > -       if (!have_governor_per_policy())
> > -               global_tunables = NULL;
> > -
> > -       kfree(tunables);
> 
> Drop just this one line from it.

OK.

> 
> > -}
> > -
> >  static int sugov_init(struct cpufreq_policy *policy)
> >  {
> >         struct sugov_policy *sg_policy;
> > @@ -707,7 +707,8 @@ static int sugov_init(struct cpufreq_policy *policy)
> >  fail:
> >         kobject_put(&tunables->attr_set.kobj);
> >         policy->governor_data = NULL;
> > -       sugov_tunables_free(tunables);
> 
> And call sugov_clear_global_tunables() instead of the above from here
> and analogously below.

Will do.

Thanks,
Kevin

> 
> > +       if (!have_governor_per_policy())
> > +               global_tunables = NULL;
> >
> >  stop_kthread:
> >         sugov_kthread_stop(sg_policy);
> > @@ -733,8 +734,8 @@ static void sugov_exit(struct cpufreq_policy *policy)
> >
> >         count = gov_attr_set_put(&tunables->attr_set, &sg_policy->tunables_hook);
> >         policy->governor_data = NULL;
> > -       if (!count)
> > -               sugov_tunables_free(tunables);
> > +       if (!count && !have_governor_per_policy())
> > +               global_tunables = NULL;
> >
> >         mutex_unlock(&global_tunables_lock);
> >
> > --

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^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2021-08-05  7:22 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2021-07-15  9:53 [PATCH] cpufreq: schedutil: Use kobject release() method to free sugov_tunables Kevin Hao
2021-08-04 16:54 ` Rafael J. Wysocki
2021-08-05  7:22   ` Kevin Hao

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