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 <aspriel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Arend van Spriel 2018-01-11 09:36:38 +01:00 committed by Greg Kroah-Hartman
parent 36d1d09af1
commit 3c47d19ff4
2 changed files with 34 additions and 8 deletions

View file

@ -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");
}

View file

@ -287,6 +287,7 @@ struct device_driver {
const struct attribute_group **groups;
const struct dev_pm_ops *pm;
int (*coredump) (struct device *dev);
struct driver_private *p;
};
@ -300,7 +301,6 @@ extern struct device_driver *driver_find(const char *name,
extern int driver_probe_done(void);
extern void wait_for_device_probe(void);
/* sysfs interface for exporting driver attributes */
struct driver_attribute {