4.19-stable review patch. If anyone has any objections, please let me know.
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From: Enric Balletbo i Serra enric.balletbo@collabora.com
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
--- drivers/mfd/cros_ec_dev.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-)
--- a/drivers/mfd/cros_ec_dev.c +++ b/drivers/mfd/cros_ec_dev.c @@ -263,6 +263,11 @@ static const struct file_operations fops #endif };
+static void cros_ec_class_release(struct device *dev) +{ + kfree(to_cros_ec_dev(dev)); +} + static void cros_ec_sensors_register(struct cros_ec_dev *ec) { /* @@ -395,7 +400,7 @@ static int ec_device_probe(struct platfo int retval = -ENOMEM; struct device *dev = &pdev->dev; struct cros_ec_platform *ec_platform = dev_get_platdata(dev); - struct cros_ec_dev *ec = devm_kzalloc(dev, sizeof(*ec), GFP_KERNEL); + struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
if (!ec) return retval; @@ -417,6 +422,7 @@ static int ec_device_probe(struct platfo ec->class_dev.devt = MKDEV(ec_major, pdev->id); ec->class_dev.class = &cros_class; ec->class_dev.parent = dev; + ec->class_dev.release = cros_ec_class_release;
retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name); if (retval) {