| Message ID | 20210715095337.19453-1-haokexin@gmail.com |
|---|---|
| State | Accepted |
| Commit | e5c6b312ce3cc97e90ea159446e6bfa06645364d |
| Headers | show |
| Series | cpufreq: schedutil: Use kobject release() method to free sugov_tunables | expand |
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); > > > > --
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);
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(-)