All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH v4] driver core: Fix device link device name collision
@ 2021-01-09 22:45 Saravana Kannan
  2021-01-10  1:52 ` Michael Walle
  2021-01-10  8:32 ` Greg Kroah-Hartman
  0 siblings, 2 replies; 6+ messages in thread
From: Saravana Kannan @ 2021-01-09 22:45 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Rafael J. Wysocki, Saravana Kannan
  Cc: stable, Michael Walle, kernel-team, linux-kernel

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/

Cc: stable@vger.kernel.org
Fixes: 287905e68dd2 ("driver core: Expose device link details in sysfs")
Reported-by: Michael Walle <michael@walle.cc>
Signed-off-by: Saravana Kannan <saravanak@google.com>
---
 Documentation/ABI/testing/sysfs-class-devlink |  4 +--
 .../ABI/testing/sysfs-devices-consumer        |  5 ++--
 .../ABI/testing/sysfs-devices-supplier        |  5 ++--
 drivers/base/core.c                           | 27 ++++++++++---------
 include/linux/device.h                        | 12 +++++++++
 5 files changed, 35 insertions(+), 18 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-class-devlink b/Documentation/ABI/testing/sysfs-class-devlink
index b662f747c83e..8a21ce515f61 100644
--- a/Documentation/ABI/testing/sysfs-class-devlink
+++ b/Documentation/ABI/testing/sysfs-class-devlink
@@ -5,8 +5,8 @@ Description:
 		Provide a place in sysfs for the device link objects in the
 		kernel at any given time.  The name of a device link directory,
 		denoted as ... above, is of the form <supplier>--<consumer>
-		where <supplier> is the supplier device name and <consumer> is
-		the consumer device name.
+		where <supplier> is the supplier bus:device name and <consumer>
+		is the consumer bus:device name.
 
 What:		/sys/class/devlink/.../auto_remove_on
 Date:		May 2020
diff --git a/Documentation/ABI/testing/sysfs-devices-consumer b/Documentation/ABI/testing/sysfs-devices-consumer
index 1f06d74d1c3c..0809fda092e6 100644
--- a/Documentation/ABI/testing/sysfs-devices-consumer
+++ b/Documentation/ABI/testing/sysfs-devices-consumer
@@ -4,5 +4,6 @@ Contact:	Saravana Kannan <saravanak@google.com>
 Description:
 		The /sys/devices/.../consumer:<consumer> are symlinks to device
 		links where this device is the supplier. <consumer> denotes the
-		name of the consumer in that device link. There can be zero or
-		more of these symlinks for a given device.
+		name of the consumer in that device link and is of the form
+		bus:device name. There can be zero or more of these symlinks
+		for a given device.
diff --git a/Documentation/ABI/testing/sysfs-devices-supplier b/Documentation/ABI/testing/sysfs-devices-supplier
index a919e0db5e90..207f5972e98d 100644
--- a/Documentation/ABI/testing/sysfs-devices-supplier
+++ b/Documentation/ABI/testing/sysfs-devices-supplier
@@ -4,5 +4,6 @@ Contact:	Saravana Kannan <saravanak@google.com>
 Description:
 		The /sys/devices/.../supplier:<supplier> are symlinks to device
 		links where this device is the consumer. <supplier> denotes the
-		name of the supplier in that device link. There can be zero or
-		more of these symlinks for a given device.
+		name of the supplier in that device link and is of the form
+		bus:device name. There can be zero or more of these symlinks
+		for a given device.
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 25e08e5f40bd..47a6faf1605a 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -456,7 +456,9 @@ 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)
@@ -470,12 +472,12 @@ 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;
@@ -483,7 +485,7 @@ 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");
@@ -506,7 +508,9 @@ 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) {
@@ -514,9 +518,9 @@ 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);
 }
@@ -737,8 +741,9 @@ 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);
@@ -1808,9 +1813,7 @@ 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);
 
diff --git a/include/linux/device.h b/include/linux/device.h
index 89bb8b84173e..1779f90eeb4c 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -609,6 +609,18 @@ static inline const char *dev_name(const struct device *dev)
 	return kobject_name(&dev->kobj);
 }
 
+/**
+ * dev_bus_name - Return a device's bus/class name, if at all possible
+ * @dev: struct device to get the bus/class name of
+ *
+ * Will return the name of the bus/class the device is attached to.  If it is
+ * not attached to a bus/class, an empty string will be returned.
+ */
+static inline const char *dev_bus_name(const struct device *dev)
+{
+	return dev->bus ? dev->bus->name : (dev->class ? dev->class->name : "");
+}
+
 __printf(2, 3) int dev_set_name(struct device *dev, const char *name, ...);
 
 #ifdef CONFIG_NUMA
-- 
2.30.0.284.gd98b1dd5eaa7-goog


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH v4] driver core: Fix device link device name collision
  2021-01-09 22:45 [PATCH v4] driver core: Fix device link device name collision Saravana Kannan
@ 2021-01-10  1:52 ` Michael Walle
  2021-01-10  8:32 ` Greg Kroah-Hartman
  1 sibling, 0 replies; 6+ messages in thread
From: Michael Walle @ 2021-01-10  1:52 UTC (permalink / raw)
  To: Saravana Kannan
  Cc: Greg Kroah-Hartman, Rafael J. Wysocki, stable, kernel-team, linux-kernel

Am 2021-01-09 23:45, schrieb Saravana Kannan:
> 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/
> 
> Cc: stable@vger.kernel.org
> Fixes: 287905e68dd2 ("driver core: Expose device link details in 
> sysfs")
> Reported-by: Michael Walle <michael@walle.cc>
> Signed-off-by: Saravana Kannan <saravanak@google.com>

Tested-by: Michael Walle <michael@walle.cc>

Thanks!

-michael

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v4] driver core: Fix device link device name collision
  2021-01-09 22:45 [PATCH v4] driver core: Fix device link device name collision Saravana Kannan
  2021-01-10  1:52 ` Michael Walle
@ 2021-01-10  8:32 ` Greg Kroah-Hartman
  1 sibling, 0 replies; 6+ messages in thread
From: Greg Kroah-Hartman @ 2021-01-10  8:32 UTC (permalink / raw)
  To: Saravana Kannan
  Cc: Rafael J. Wysocki, stable, Michael Walle, kernel-team, linux-kernel

On Sat, Jan 09, 2021 at 02:45:06PM -0800, Saravana Kannan wrote:
> 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/
> 
> Cc: stable@vger.kernel.org
> Fixes: 287905e68dd2 ("driver core: Expose device link details in sysfs")
> Reported-by: Michael Walle <michael@walle.cc>
> Signed-off-by: Saravana Kannan <saravanak@google.com>
> ---
>  Documentation/ABI/testing/sysfs-class-devlink |  4 +--
>  .../ABI/testing/sysfs-devices-consumer        |  5 ++--
>  .../ABI/testing/sysfs-devices-supplier        |  5 ++--
>  drivers/base/core.c                           | 27 ++++++++++---------
>  include/linux/device.h                        | 12 +++++++++
>  5 files changed, 35 insertions(+), 18 deletions(-)
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
as indicated below:

- This looks like a new version of a previously submitted patch, but you
  did not list below the --- line any changes from the previous version.
  Please read the section entitled "The canonical patch format" in the
  kernel file, Documentation/SubmittingPatches for what needs to be done
  here to properly describe this.

If you wish to discuss this problem further, or you have questions about
how to resolve this issue, please feel free to respond to this email and
Greg will reply once he has dug out from the pending patches received
from other developers.

thanks,

greg k-h's patch email bot

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v4] driver core: Fix device link device name collision
  2021-01-21 19:01 ` Michael Walle
@ 2021-01-21 19:12   ` Greg Kroah-Hartman
  0 siblings, 0 replies; 6+ messages in thread
From: Greg Kroah-Hartman @ 2021-01-21 19:12 UTC (permalink / raw)
  To: Michael Walle
  Cc: Saravana Kannan, Rafael J. Wysocki, stable, kernel-team, linux-kernel

On Thu, Jan 21, 2021 at 08:01:24PM +0100, Michael Walle wrote:
> Hi,
> 
> Am 2021-01-10 18:54, schrieb Saravana Kannan:
> > 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/
> > 
> > Cc: stable@vger.kernel.org
> > Fixes: 287905e68dd2 ("driver core: Expose device link details in sysfs")
> > Reported-by: Michael Walle <michael@walle.cc>
> > Tested-by: Michael Walle <michael@walle.cc>
> > Signed-off-by: Saravana Kannan <saravanak@google.com>
> > ---
> 
> Greg, any news here?

Burried in other patches...

I'll go pick this up now, sorry for the delay.

greg k-h

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH v4] driver core: Fix device link device name collision
  2021-01-10 17:54 Saravana Kannan
@ 2021-01-21 19:01 ` Michael Walle
  2021-01-21 19:12   ` Greg Kroah-Hartman
  0 siblings, 1 reply; 6+ messages in thread
From: Michael Walle @ 2021-01-21 19:01 UTC (permalink / raw)
  To: Saravana Kannan, Greg Kroah-Hartman
  Cc: Rafael J. Wysocki, stable, kernel-team, linux-kernel

Hi,

Am 2021-01-10 18:54, schrieb Saravana Kannan:
> 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/
> 
> Cc: stable@vger.kernel.org
> Fixes: 287905e68dd2 ("driver core: Expose device link details in 
> sysfs")
> Reported-by: Michael Walle <michael@walle.cc>
> Tested-by: Michael Walle <michael@walle.cc>
> Signed-off-by: Saravana Kannan <saravanak@google.com>
> ---

Greg, any news here?

-michael

^ permalink raw reply	[flat|nested] 6+ messages in thread

* [PATCH v4] driver core: Fix device link device name collision
@ 2021-01-10 17:54 Saravana Kannan
  2021-01-21 19:01 ` Michael Walle
  0 siblings, 1 reply; 6+ messages in thread
From: Saravana Kannan @ 2021-01-10 17:54 UTC (permalink / raw)
  To: Greg Kroah-Hartman, Rafael J. Wysocki, Saravana Kannan
  Cc: stable, Michael Walle, kernel-team, linux-kernel

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/

Cc: stable@vger.kernel.org
Fixes: 287905e68dd2 ("driver core: Expose device link details in sysfs")
Reported-by: Michael Walle <michael@walle.cc>
Tested-by: Michael Walle <michael@walle.cc>
Signed-off-by: Saravana Kannan <saravanak@google.com>
---
v1:
- Fixed the collision in the device link device name.
v1 -> v2:
- Tried to fixed collision in the supplier: and consumer: symlinks
v2 -> v3:
- Fixed the truncation of the symlink names caused by v2.
v3 -> v4:
- Did all the above fixes for the symlink removal path.

 Documentation/ABI/testing/sysfs-class-devlink |  4 +--
 .../ABI/testing/sysfs-devices-consumer        |  5 ++--
 .../ABI/testing/sysfs-devices-supplier        |  5 ++--
 drivers/base/core.c                           | 27 ++++++++++---------
 include/linux/device.h                        | 12 +++++++++
 5 files changed, 35 insertions(+), 18 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-class-devlink b/Documentation/ABI/testing/sysfs-class-devlink
index b662f747c83e..8a21ce515f61 100644
--- a/Documentation/ABI/testing/sysfs-class-devlink
+++ b/Documentation/ABI/testing/sysfs-class-devlink
@@ -5,8 +5,8 @@ Description:
 		Provide a place in sysfs for the device link objects in the
 		kernel at any given time.  The name of a device link directory,
 		denoted as ... above, is of the form <supplier>--<consumer>
-		where <supplier> is the supplier device name and <consumer> is
-		the consumer device name.
+		where <supplier> is the supplier bus:device name and <consumer>
+		is the consumer bus:device name.
 
 What:		/sys/class/devlink/.../auto_remove_on
 Date:		May 2020
diff --git a/Documentation/ABI/testing/sysfs-devices-consumer b/Documentation/ABI/testing/sysfs-devices-consumer
index 1f06d74d1c3c..0809fda092e6 100644
--- a/Documentation/ABI/testing/sysfs-devices-consumer
+++ b/Documentation/ABI/testing/sysfs-devices-consumer
@@ -4,5 +4,6 @@ Contact:	Saravana Kannan <saravanak@google.com>
 Description:
 		The /sys/devices/.../consumer:<consumer> are symlinks to device
 		links where this device is the supplier. <consumer> denotes the
-		name of the consumer in that device link. There can be zero or
-		more of these symlinks for a given device.
+		name of the consumer in that device link and is of the form
+		bus:device name. There can be zero or more of these symlinks
+		for a given device.
diff --git a/Documentation/ABI/testing/sysfs-devices-supplier b/Documentation/ABI/testing/sysfs-devices-supplier
index a919e0db5e90..207f5972e98d 100644
--- a/Documentation/ABI/testing/sysfs-devices-supplier
+++ b/Documentation/ABI/testing/sysfs-devices-supplier
@@ -4,5 +4,6 @@ Contact:	Saravana Kannan <saravanak@google.com>
 Description:
 		The /sys/devices/.../supplier:<supplier> are symlinks to device
 		links where this device is the consumer. <supplier> denotes the
-		name of the supplier in that device link. There can be zero or
-		more of these symlinks for a given device.
+		name of the supplier in that device link and is of the form
+		bus:device name. There can be zero or more of these symlinks
+		for a given device.
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 25e08e5f40bd..47a6faf1605a 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -456,7 +456,9 @@ 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)
@@ -470,12 +472,12 @@ 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;
@@ -483,7 +485,7 @@ 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");
@@ -506,7 +508,9 @@ 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) {
@@ -514,9 +518,9 @@ 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);
 }
@@ -737,8 +741,9 @@ 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);
@@ -1808,9 +1813,7 @@ 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);
 
diff --git a/include/linux/device.h b/include/linux/device.h
index 89bb8b84173e..1779f90eeb4c 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -609,6 +609,18 @@ static inline const char *dev_name(const struct device *dev)
 	return kobject_name(&dev->kobj);
 }
 
+/**
+ * dev_bus_name - Return a device's bus/class name, if at all possible
+ * @dev: struct device to get the bus/class name of
+ *
+ * Will return the name of the bus/class the device is attached to.  If it is
+ * not attached to a bus/class, an empty string will be returned.
+ */
+static inline const char *dev_bus_name(const struct device *dev)
+{
+	return dev->bus ? dev->bus->name : (dev->class ? dev->class->name : "");
+}
+
 __printf(2, 3) int dev_set_name(struct device *dev, const char *name, ...);
 
 #ifdef CONFIG_NUMA
-- 
2.30.0.284.gd98b1dd5eaa7-goog


^ permalink raw reply related	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2021-01-21 19:14 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-01-09 22:45 [PATCH v4] driver core: Fix device link device name collision Saravana Kannan
2021-01-10  1:52 ` Michael Walle
2021-01-10  8:32 ` Greg Kroah-Hartman
2021-01-10 17:54 Saravana Kannan
2021-01-21 19:01 ` Michael Walle
2021-01-21 19:12   ` Greg Kroah-Hartman

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.