From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 5 Dec 2018 10:05:44 +0000 From: Lee Jones To: Enric Balletbo i Serra Cc: gwendal@chromium.org, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, groeck@chromium.org, kernel@collabora.com, bleung@chromium.org, dtor@google.com, stable@vger.kernel.org Subject: Re: [PATCH] Revert "mfd: cros_ec: Use devm_kzalloc for private data" Message-ID: <20181205100544.GB26661@dell> References: <20181204155843.11411-1-enric.balletbo@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20181204155843.11411-1-enric.balletbo@collabora.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: On Tue, 04 Dec 2018, Enric Balletbo i Serra wrote: > 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 > --- > > drivers/mfd/cros_ec_dev.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) Applied, thanks. -- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog