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authorSascha Hauer <s.hauer@pengutronix.de>2012-12-12 14:55:40 +0100
committerSascha Hauer <s.hauer@pengutronix.de>2012-12-12 15:04:27 +0100
commit1a9e93cc81dbae55743c0dafae4bd6ac8241e8a3 (patch)
tree14b39c5b2124e25e4903e497a1bca7867e73d456 /drivers
parentc7c9c88cc2acbba29b8cbc9ddcf320857c93134c (diff)
downloadbarebox-1a9e93cc81dbae55743c0dafae4bd6ac8241e8a3.tar.gz
barebox-1a9e93cc81dbae55743c0dafae4bd6ac8241e8a3.tar.xz
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 c2e568d19c5c34a05a1002d25280bf113b72b752 | 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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/base/driver.c32
-rw-r--r--drivers/i2c/i2c.c4
-rw-r--r--drivers/mci/mci-core.c2
-rw-r--r--drivers/mtd/core.c4
-rw-r--r--drivers/net/phy/mdio_bus.c4
-rw-r--r--drivers/net/phy/phy.c3
-rw-r--r--drivers/spi/spi.c2
-rw-r--r--drivers/w1/w1.c4
8 files changed, 16 insertions, 39 deletions
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
index 5b3542b7d3..d4066fc178 100644
--- a/drivers/base/driver.c
+++ b/drivers/base/driver.c
@@ -133,21 +133,21 @@ 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->parent) {
- new_device->parent = &new_device->bus->dev;
- dev_add_child(new_device->parent, new_device);
- }
+ if (new_device->bus) {
+ if (!new_device->parent)
+ new_device->parent = &new_device->bus->dev;
- list_add_tail(&new_device->bus_list, &new_device->bus->device_list);
+ 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;
+ 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;
}
EXPORT_SYMBOL(register_device);
@@ -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;
diff --git a/drivers/i2c/i2c.c b/drivers/i2c/i2c.c
index 07eace94df..4862df3c00 100644
--- a/drivers/i2c/i2c.c
+++ b/drivers/i2c/i2c.c
@@ -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;
diff --git a/drivers/mci/mci-core.c b/drivers/mci/mci-core.c
index 88892b646f..e29bd2ed3e 100644
--- a/drivers/mci/mci-core.c
+++ b/drivers/mci/mci-core.c
@@ -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);
}
diff --git a/drivers/mtd/core.c b/drivers/mtd/core.c
index b5916dab02..92b6435f4d 100644
--- a/drivers/mtd/core.c
+++ b/drivers/mtd/core.c
@@ -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;
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 1d20bb0503..d1d802b57b 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -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);
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 58546f8546..9622455750 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -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;
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c
index 6a5bd6d2b8..d58b6646b5 100644
--- a/drivers/spi/spi.c
+++ b/drivers/spi/spi.c
@@ -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);
diff --git a/drivers/w1/w1.c b/drivers/w1/w1.c
index 11b8320d12..d2f94c938d 100644
--- a/drivers/w1/w1.c
+++ b/drivers/w1/w1.c
@@ -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)