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drivers/base: fix corrupt device tree 

dev_add_child is a very unsafe function. If called multiple times
it allows setting the same device to different parents thus corrupting
the siblings list. This happens regularly since:

| commit c2e568d19c
| Author: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
| Date:   Sat Nov 3 16:11:05 2012 +0100
|
|    bus: add bus device
|
|    automatically add it as parent of any bus device if none already specified
|
|    we have now a nice output per bus

If for example a FATfs is mounted this nice output per bus often ends with:

>     `---- fat0
>     `---- 0
>          `---- 0x86f0000087020031-0x86f000410df27124: /dev/<NULL>
>          `---- sram00
>               `---- 0x00000000-0xffffffffffffffff: /dev/<NULL>
>               `---- 0x00000000-0xffffffffffffffff: /dev/<NULL>
>               unable to handle NULL pointer dereference at address 0x0000000c
> pc : [<87f08a20>]    lr : [<87f08a04>]
> sp : 86eff8c0  ip : 87f3fbde  fp : ffffffff
> r10: ffffffff  r9 : 00000000  r8 : 00000003
> r7 : 86f075b8  r6 : 00000002  r5 : ffffffec  r4 : 86f07544
> r3 : 00000000  r2 : 43f900b4  r1 : 00000020  r0 : 00000005
> Flags: Nzcv  IRQs off  FIQs off  Mode SVC_32
> [<87f08a20>] (do_devinfo_subtree+0x90/0x130) from [<87f08a90>] (do_devinfo_subtree+0x100/0x130)
>
> [<87f3e070>] (unwind_backtrace+0x0/0x90) from [<87f28514>] (panic+0x28/0x3c)
> [<87f28514>] (panic+0x28/0x3c) from [<87f3e4b8>] (do_exception+0x10/0x14)
> [<87f3e4b8>] (do_exception+0x10/0x14) from [<87f3e544>] (do_data_abort+0x2c/0x38)
> [<87f3e544>] (do_data_abort+0x2c/0x38) from [<87f3e268>] (data_abort+0x48/0x60)

This patch fixes this by adding a device to its parents children list in
register_device so that dev_add_child is no longer needed. This function
is removed from the tree. Now callers of register_device have to clearly
set the parent *before* registering a device.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reported-by: Jan Lübbe <jlu@pengutronix.de>
This commit is contained in:
Sascha Hauer 2012-12-12 14:55:40 +01:00
parent c7c9c88cc2
commit 1a9e93cc81
12 changed files with 19 additions and 47 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
common/console.c
View File

@ -151,7 +151,7 @@ int console_register(struct console_device *newcdev)
dev->id = DEVICE_ID_DYNAMIC;
strcpy(dev->name, "cs");
if (newcdev->dev)
dev_add_child(newcdev->dev, dev);
dev->parent = newcdev->dev;
platform_device_register(dev);
if (newcdev->setbrg) {

32
drivers/base/driver.c
View File

@ -133,20 +133,20 @@ int register_device(struct device_d *new_device)
INIT_LIST_HEAD(&new_device->parameters);
INIT_LIST_HEAD(&new_device->active);
if (!new_device->bus)
return 0;
if (new_device->bus) {
if (!new_device->parent)
new_device->parent = &new_device->bus->dev;
if (!new_device->parent) {
new_device->parent = &new_device->bus->dev;
dev_add_child(new_device->parent, new_device);
list_add_tail(&new_device->bus_list, &new_device->bus->device_list);
bus_for_each_driver(new_device->bus, drv) {
if (!match(drv, new_device))
break;
}
}
list_add_tail(&new_device->bus_list, &new_device->bus->device_list);
bus_for_each_driver(new_device->bus, drv) {
if (!match(drv, new_device))
break;
}
if (new_device->parent)
list_add_tail(&new_device->sibling, &new_device->parent->children);
return 0;
}
@ -186,16 +186,6 @@ int unregister_device(struct device_d *old_dev)
}
EXPORT_SYMBOL(unregister_device);
int dev_add_child(struct device_d *dev, struct device_d *child)
{
child->parent = dev;
list_add_tail(&child->sibling, &dev->children);
return 0;
}
EXPORT_SYMBOL(dev_add_child);
struct driver_d *get_driver_by_name(const char *name)
{
struct driver_d *drv;

4
drivers/i2c/i2c.c
View File

@ -258,7 +258,6 @@ struct i2c_client *i2c_new_device(struct i2c_adapter *adapter,
client->addr = chip->addr;
client->dev.parent = &adapter->dev;
dev_add_child(client->dev.parent, &client->dev);
status = register_device(&client->dev);
@ -403,9 +402,6 @@ int i2c_add_numbered_adapter(struct i2c_adapter *adapter)
adapter->dev.id = adapter->nr;
strcpy(adapter->dev.name, "i2c");
if (adapter->dev.parent)
dev_add_child(adapter->dev.parent, &adapter->dev);
ret = register_device(&adapter->dev);
if (ret)
return ret;

2
drivers/mci/mci-core.c
View File

@ -1557,7 +1557,7 @@ int mci_register(struct mci_host *host)
mci_dev->id = DEVICE_ID_DYNAMIC;
strcpy(mci_dev->name, mci_driver.name);
mci_dev->platform_data = host;
dev_add_child(host->hw_dev, mci_dev);
mci_dev->parent = host->hw_dev;
return platform_device_register(mci_dev);
}

4
drivers/mtd/core.c
View File

@ -184,10 +184,8 @@ int add_mtd_device(struct mtd_info *mtd, char *devname)
devname = "mtd";
strcpy(mtd->class_dev.name, devname);
mtd->class_dev.id = DEVICE_ID_DYNAMIC;
if (mtd->parent) {
if (mtd->parent)
mtd->class_dev.parent = mtd->parent;
dev_add_child(mtd->class_dev.parent, &mtd->class_dev);
}
register_device(&mtd->class_dev);
mtd->cdev.ops = &mtd_ops;

4
drivers/net/phy/mdio_bus.c
View File

@ -47,8 +47,6 @@ int mdiobus_register(struct mii_bus *bus)
bus->dev.id = DEVICE_ID_DYNAMIC;
strcpy(bus->dev.name, "miibus");
bus->dev.parent = bus->parent;
if (bus->parent)
dev_add_child(bus->parent, &bus->dev);
err = register_device(&bus->dev);
if (err) {
@ -157,8 +155,6 @@ static int mdio_bus_probe(struct device_d *_dev)
char str[16];
dev->attached_dev->phydev = dev;
dev->dev.parent = &dev->attached_dev->dev;
dev_add_child(dev->dev.parent, _dev);
if (drv->probe) {
ret = drv->probe(dev);

3
drivers/net/phy/phy.c
View File

@ -157,7 +157,6 @@ static struct phy_device *phy_device_create(struct mii_bus *bus, int addr, int p
dev->phy_id = phy_id;
dev->bus = bus;
dev->dev.parent = bus->parent;
dev->dev.bus = &mdio_bus_type;
strcpy(dev->dev.name, "phy");
@ -229,6 +228,8 @@ static int phy_register_device(struct phy_device* dev)
{
int ret;
dev->dev.parent = &dev->attached_dev->dev;
ret = register_device(&dev->dev);
if (ret)
return ret;

2
drivers/spi/spi.c
View File

@ -81,7 +81,7 @@ struct spi_device *spi_new_device(struct spi_master *master,
proxy->dev.id = DEVICE_ID_DYNAMIC;
proxy->dev.type_data = proxy;
proxy->dev.device_node = chip->device_node;
dev_add_child(master->dev, &proxy->dev);
proxy->dev.parent = master->dev;
/* drivers may modify this initial i/o setup */
status = master->setup(proxy);

4
drivers/w1/w1.c
View File

@ -413,7 +413,6 @@ static int w1_device_register(struct w1_bus *bus, struct w1_device *dev)
dev->bus = bus;
dev->dev.parent = &bus->dev;
dev_add_child(dev->dev.parent, &dev->dev);
ret = register_device(&dev->dev);
if (ret)
@ -600,10 +599,7 @@ int w1_bus_register(struct w1_bus *bus)
strcpy(bus->dev.name, "w1_bus");
bus->dev.id = DEVICE_ID_DYNAMIC;
bus->dev.parent = bus->parent;
if (bus->parent)
dev_add_child(bus->parent, &bus->dev);
ret = register_device(&bus->dev);
if (ret)

2
fs/fs.c
View File

@ -1227,7 +1227,7 @@ int mount(const char *device, const char *fsname, const char *_path)
fsdev->cdev = cdev_by_name(device + 5);
if (fsdev->cdev) {
dev_add_child(fsdev->cdev->dev, &fsdev->dev);
fsdev->dev.parent = fsdev->cdev->dev;
fsdev->parent_device = fsdev->cdev->dev;
}

5
include/driver.h
View File

@ -158,11 +158,6 @@ int device_probe(struct device_d *dev);
*/
int unregister_device(struct device_d *);
/* Organize devices in a tree. These functions do _not_ register or
* unregister a device. Only registered devices are allowed here.
*/
int dev_add_child(struct device_d *dev, struct device_d *child);
/* Iterate over a devices children
*/
#define device_for_each_child(dev, child) \

2
net/eth.c
View File

@ -260,7 +260,7 @@ int eth_register(struct eth_device *edev)
edev->dev.id = DEVICE_ID_DYNAMIC;
if (edev->parent)
dev_add_child(edev->parent, &edev->dev);
edev->dev.parent = edev->parent;
register_device(&edev->dev);