On Fri, Jan 20, 2023 at 12:26:50PM +0800, Kevin Hao wrote:
commit a85ee6401a47ae3fc64ba506cacb3e7873823c65 upstream.
The struct dbs_data embeds a struct gov_attr_set and the struct gov_attr_set embeds a kobject. Since every kobject must have a release() method and we can't use kfree() to free it directly, so introduce cpufreq_dbs_data_release() to release the dbs_data via the kobject::release() method. This fixes the calltrace like below:
ODEBUG: free active (active state 0) object type: timer_list hint: delayed_work_timer_fn+0x0/0x34 WARNING: CPU: 12 PID: 810 at lib/debugobjects.c:505 debug_print_object+0xb8/0x100 Modules linked in: CPU: 12 PID: 810 Comm: sh Not tainted 5.16.0-next-20220120-yocto-standard+ #536 Hardware name: Marvell OcteonTX CN96XX board (DT) pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : debug_print_object+0xb8/0x100 lr : debug_print_object+0xb8/0x100 sp : ffff80001dfcf9a0 x29: ffff80001dfcf9a0 x28: 0000000000000001 x27: ffff0001464f0000 x26: 0000000000000000 x25: ffff8000090e3f00 x24: ffff80000af60210 x23: ffff8000094dfb78 x22: ffff8000090e3f00 x21: ffff0001080b7118 x20: ffff80000aeb2430 x19: ffff800009e8f5e0 x18: 0000000000000000 x17: 0000000000000002 x16: 00004d62e58be040 x15: 013590470523aff8 x14: ffff8000090e1828 x13: 0000000001359047 x12: 00000000f5257d14 x11: 0000000000040591 x10: 0000000066c1ffea x9 : ffff8000080d15e0 x8 : ffff80000a1765a8 x7 : 0000000000000000 x6 : 0000000000000001 x5 : ffff800009e8c000 x4 : ffff800009e8c760 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 0000000000000000 x0 : ffff0001474ed040 Call trace: debug_print_object+0xb8/0x100 __debug_check_no_obj_freed+0x1d0/0x25c debug_check_no_obj_freed+0x24/0xa0 kfree+0x11c/0x440 cpufreq_dbs_governor_exit+0xa8/0xac cpufreq_exit_governor+0x44/0x90 cpufreq_set_policy+0x29c/0x570 store_scaling_governor+0x110/0x154 store+0xb0/0xe0 sysfs_kf_write+0x58/0x84 kernfs_fop_write_iter+0x12c/0x1c0 new_sync_write+0xf0/0x18c vfs_write+0x1cc/0x220 ksys_write+0x74/0x100 __arm64_sys_write+0x28/0x3c invoke_syscall.constprop.0+0x58/0xf0 do_el0_svc+0x70/0x170 el0_svc+0x54/0x190 el0t_64_sync_handler+0xa4/0x130 el0t_64_sync+0x1a0/0x1a4 irq event stamp: 189006 hardirqs last enabled at (189005): [<ffff8000080849d0>] finish_task_switch.isra.0+0xe0/0x2c0 hardirqs last disabled at (189006): [<ffff8000090667a4>] el1_dbg+0x24/0xa0 softirqs last enabled at (188966): [<ffff8000080106d0>] __do_softirq+0x4b0/0x6a0 softirqs last disabled at (188957): [<ffff80000804a618>] __irq_exit_rcu+0x108/0x1a4
[ rjw: Because can be freed by the gov_attr_set_put() in cpufreq_dbs_governor_exit() now, it is also necessary to put the invocation of the governor ->exit() callback into the new cpufreq_dbs_data_release() function. ]
Fixes: c4435630361d ("cpufreq: governor: New sysfs show/store callbacks for governor tunables") Signed-off-by: Kevin Hao haokexin@gmail.com Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com
Hi,
The original upstream patch has the Fixes tag, but I have no idea why it wasn't picked up by the 5.15 stable kernel. So resend it to the linux stable. The original upstream patch can apply to the 5.15.y kernel cleanly.
applies but has build error:
/home/tsaeger/workspace/linux/linux-5.15.y/drivers/cpufreq/cpufreq_governor.c: In function ���cpufreq_dbs_data_release���: /home/tsaeger/workspace/linux/linux-5.15.y/drivers/cpufreq/cpufreq_governor.c:393:49: error: implicit declaration of function ���to_gov_attr_set��� [-Werror=implicit-function-declaration] 393 | struct dbs_data *dbs_data = to_dbs_data(to_gov_attr_set(kobj)); | ^~~~~~~~~~~~~~~ /home/tsaeger/workspace/linux/linux-5.15.y/drivers/cpufreq/cpufreq_governor.c:393:49: warning: passing argument 1 of ���to_dbs_data��� makes pointer from integer without a cast [-Wint-conversion] 393 | struct dbs_data *dbs_data = to_dbs_data(to_gov_attr_set(kobj)); | ^~~~~~~~~~~~~~~~~~~~~ | | | int In file included from /home/tsaeger/workspace/linux/linux-5.15.y/drivers/cpufreq/cpufreq_governor.c:20: /home/tsaeger/workspace/linux/linux-5.15.y/drivers/cpufreq/cpufreq_governor.h:49:65: note: expected ���struct gov_attr_set *��� but argument is of type ���int��� 49 | static inline struct dbs_data *to_dbs_data(struct gov_attr_set *attr_set) | ~~~~~~~~~~~~~~~~~~~~~^~~~~~~~ cc1: some warnings being treated as errors
5.15.y first with: ae2650865127 ("cpufreq: Move to_gov_attr_set() to cpufreq.h")
then a85ee6401a47 ("cpufreq: governor: Use kobject release() method to free dbs_data")
compiled clean
Regards, --Tom