From 3c47d19ff4dccf1500c33bcbe3b5bc804907a0da Mon Sep 17 00:00:00 2001 From: Arend van Spriel Date: Thu, 11 Jan 2018 09:36:38 +0100 Subject: drivers: base: add coredump driver ops This adds the coredump driver operation. When the driver defines it a coredump file is added in the sysfs folder of the device upon driver binding. The file is removed when the driver is unbound. User-space can trigger a coredump for this device by echo'ing to the coredump file. Signed-off-by: Arend van Spriel Signed-off-by: Greg Kroah-Hartman --- drivers/base/dd.c | 40 +++++++++++++++++++++++++++++++++------- 1 file changed, 33 insertions(+), 7 deletions(-) (limited to 'drivers/base') diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 533c82f55cea..de6fd092bf2f 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -288,6 +288,18 @@ static void driver_bound(struct device *dev) kobject_uevent(&dev->kobj, KOBJ_BIND); } +static ssize_t coredump_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + device_lock(dev); + if (dev->driver->coredump) + dev->driver->coredump(dev); + device_unlock(dev); + + return count; +} +static DEVICE_ATTR_WO(coredump); + static int driver_sysfs_add(struct device *dev) { int ret; @@ -297,14 +309,26 @@ static int driver_sysfs_add(struct device *dev) BUS_NOTIFY_BIND_DRIVER, dev); ret = sysfs_create_link(&dev->driver->p->kobj, &dev->kobj, + kobject_name(&dev->kobj)); + if (ret) + goto fail; + + ret = sysfs_create_link(&dev->kobj, &dev->driver->p->kobj, + "driver"); + if (ret) + goto rm_dev; + + if (!IS_ENABLED(CONFIG_DEV_COREDUMP) || !dev->driver->coredump || + !device_create_file(dev, &dev_attr_coredump)) + return 0; + + sysfs_remove_link(&dev->kobj, "driver"); + +rm_dev: + sysfs_remove_link(&dev->driver->p->kobj, kobject_name(&dev->kobj)); - if (ret == 0) { - ret = sysfs_create_link(&dev->kobj, &dev->driver->p->kobj, - "driver"); - if (ret) - sysfs_remove_link(&dev->driver->p->kobj, - kobject_name(&dev->kobj)); - } + +fail: return ret; } @@ -313,6 +337,8 @@ static void driver_sysfs_remove(struct device *dev) struct device_driver *drv = dev->driver; if (drv) { + if (drv->coredump) + device_remove_file(dev, &dev_attr_coredump); sysfs_remove_link(&drv->p->kobj, kobject_name(&dev->kobj)); sysfs_remove_link(&dev->kobj, "driver"); } -- cgit v1.2.3