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authorSaravana Kannan <saravanak@google.com>2021-01-10 20:54:07 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-01-21 22:12:40 +0300
commite020ff611ba9be54e959e6b548038f8a020da1c9 (patch)
treef6e0ab7384c3ab85a71ec5568fdace8135312a12 /drivers/base
parent3d1cf435e201d1fd63e4346b141881aed086effd (diff)
downloadlinux-e020ff611ba9be54e959e6b548038f8a020da1c9.tar.xz
driver core: Fix device link device name collision
The device link device's name was of the form: <supplier-dev-name>--<consumer-dev-name> This can cause name collision as reported here [1] as device names are not globally unique. Since device names have to be unique within the bus/class, add the bus/class name as a prefix to the device names used to construct the device link device name. So the devuce link device's name will be of the form: <supplier-bus-name>:<supplier-dev-name>--<consumer-bus-name>:<consumer-dev-name> [1] - https://lore.kernel.org/lkml/20201229033440.32142-1-michael@walle.cc/ Fixes: 287905e68dd2 ("driver core: Expose device link details in sysfs") Cc: stable@vger.kernel.org Reported-by: Michael Walle <michael@walle.cc> Tested-by: Michael Walle <michael@walle.cc> Signed-off-by: Saravana Kannan <saravanak@google.com> Link: https://lore.kernel.org/r/20210110175408.1465657-1-saravanak@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/core.c27
1 files changed, 15 insertions, 12 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 3819fd012e27..78f6db169d47 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -471,7 +471,9 @@ static int devlink_add_symlinks(struct device *dev,
struct device *con = link->consumer;
char *buf;
- len = max(strlen(dev_name(sup)), strlen(dev_name(con)));
+ len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)),
+ strlen(dev_bus_name(con)) + strlen(dev_name(con)));
+ len += strlen(":");
len += strlen("supplier:") + 1;
buf = kzalloc(len, GFP_KERNEL);
if (!buf)
@@ -485,12 +487,12 @@ static int devlink_add_symlinks(struct device *dev,
if (ret)
goto err_con;
- snprintf(buf, len, "consumer:%s", dev_name(con));
+ snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
ret = sysfs_create_link(&sup->kobj, &link->link_dev.kobj, buf);
if (ret)
goto err_con_dev;
- snprintf(buf, len, "supplier:%s", dev_name(sup));
+ snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup));
ret = sysfs_create_link(&con->kobj, &link->link_dev.kobj, buf);
if (ret)
goto err_sup_dev;
@@ -498,7 +500,7 @@ static int devlink_add_symlinks(struct device *dev,
goto out;
err_sup_dev:
- snprintf(buf, len, "consumer:%s", dev_name(con));
+ snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
sysfs_remove_link(&sup->kobj, buf);
err_con_dev:
sysfs_remove_link(&link->link_dev.kobj, "consumer");
@@ -521,7 +523,9 @@ static void devlink_remove_symlinks(struct device *dev,
sysfs_remove_link(&link->link_dev.kobj, "consumer");
sysfs_remove_link(&link->link_dev.kobj, "supplier");
- len = max(strlen(dev_name(sup)), strlen(dev_name(con)));
+ len = max(strlen(dev_bus_name(sup)) + strlen(dev_name(sup)),
+ strlen(dev_bus_name(con)) + strlen(dev_name(con)));
+ len += strlen(":");
len += strlen("supplier:") + 1;
buf = kzalloc(len, GFP_KERNEL);
if (!buf) {
@@ -529,9 +533,9 @@ static void devlink_remove_symlinks(struct device *dev,
return;
}
- snprintf(buf, len, "supplier:%s", dev_name(sup));
+ snprintf(buf, len, "supplier:%s:%s", dev_bus_name(sup), dev_name(sup));
sysfs_remove_link(&con->kobj, buf);
- snprintf(buf, len, "consumer:%s", dev_name(con));
+ snprintf(buf, len, "consumer:%s:%s", dev_bus_name(con), dev_name(con));
sysfs_remove_link(&sup->kobj, buf);
kfree(buf);
}
@@ -752,8 +756,9 @@ struct device_link *device_link_add(struct device *consumer,
link->link_dev.class = &devlink_class;
device_set_pm_not_required(&link->link_dev);
- dev_set_name(&link->link_dev, "%s--%s",
- dev_name(supplier), dev_name(consumer));
+ dev_set_name(&link->link_dev, "%s:%s--%s:%s",
+ dev_bus_name(supplier), dev_name(supplier),
+ dev_bus_name(consumer), dev_name(consumer));
if (device_register(&link->link_dev)) {
put_device(consumer);
put_device(supplier);
@@ -1823,9 +1828,7 @@ const char *dev_driver_string(const struct device *dev)
* never change once they are set, so they don't need special care.
*/
drv = READ_ONCE(dev->driver);
- return drv ? drv->name :
- (dev->bus ? dev->bus->name :
- (dev->class ? dev->class->name : ""));
+ return drv ? drv->name : dev_bus_name(dev);
}
EXPORT_SYMBOL(dev_driver_string);