Commits
Enric Balletbo i Serra committed c91ec2c4eb6
Revert "mfd: cros_ec: Use devm_kzalloc for private data" commit 48a2ca0ee3994df53da230c7079a18a70ec914f9 upstream. This reverts commit 3aa2177e47878f7e7616da8a2050c44f22301b6e. That commit triggered a new WARN when unloading the module (see at the end of the commit message). When a class_dev is embedded in a structure then that class_dev is the thing that controls the lifetime of that structure, for that reason device managed allocations can't be used here. See Documentation/kobject.txt. Revert the above patch, so the struct is allocated using kzalloc and we have a release function for it that frees the allocated memory, otherwise it is broken. ------------[ cut here ]------------ Device 'cros_ec' does not have a release() function, it is broken and must be fixed. WARNING: CPU: 3 PID: 3675 at drivers/base/core.c:895 device_release+0x80/0x90 Modules linked in: btusb btrtl btintel btbcm bluetooth ... CPU: 3 PID: 3675 Comm: rmmod Not tainted 4.20.0-rc4 #76 Hardware name: Google Kevin (DT) pstate: 40000005 (nZcv daif -PAN -UAO) pc : device_release+0x80/0x90 lr : device_release+0x80/0x90 sp : ffff00000c47bc70 x29: ffff00000c47bc70 x28: ffff8000e86b0d40 x27: 0000000000000000 x26: 0000000000000000 x25: 0000000056000000 x24: 0000000000000015 x23: ffff8000f0bbf860 x22: ffff000000d320a0 x21: ffff8000ee93e100 x20: ffff8000ed931428 x19: ffff8000ed931418 x18: 0000000000000020 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000400 x14: 0000000000000143 x13: 0000000000000000 x12: 0000000000000400 x11: 0000000000000157 x10: 0000000000000960 x9 : ffff00000c47b9b0 x8 : ffff8000e86b1700 x7 : 0000000000000000 x6 : ffff8000f7d520b8 x5 : ffff8000f7d520b8 x4 : 0000000000000000 x3 : ffff8000f7d58e68 x2 : ffff8000e86b0d40 x1 : 37d859939c964800 x0 : 0000000000000000 Call trace: device_release+0x80/0x90 kobject_put+0x74/0xe8 device_unregister+0x20/0x30 ec_device_remove+0x34/0x48 [cros_ec_dev] platform_drv_remove+0x28/0x48 device_release_driver_internal+0x1a8/0x240 driver_detach+0x40/0x80 bus_remove_driver+0x54/0xa8 driver_unregister+0x2c/0x58 platform_driver_unregister+0x10/0x18 cros_ec_dev_exit+0x1c/0x2d8 [cros_ec_dev] __arm64_sys_delete_module+0x16c/0x1f8 el0_svc_common+0x84/0xd8 el0_svc_handler+0x2c/0x80 el0_svc+0x8/0xc ---[ end trace a57c4625f3c60ae8 ]--- Cc: stable@vger.kernel.org Fixes: 3aa2177e4787 ("mfd: cros_ec: Use devm_kzalloc for private data") Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Reviewed-by: Guenter Roeck <groeck@chromium.org> Reviewed-by: Dmitry Torokhov <dtor@chromium.org> Signed-off-by: Lee Jones <lee.jones@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>