[3/4] of: Convert to using %pOFn instead of device_node.name
diff mbox series

Message ID 20180828155254.10709-4-robh@kernel.org
State Accepted
Headers show
Series
  • of: Convert to using %pOFn for node name printf
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Commit Message

Rob Herring Aug. 28, 2018, 3:52 p.m. UTC
In preparation to remove the node name pointer from struct device_node,
convert printf users to use the %pOFn format specifier.

Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: devicetree@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
---
 drivers/of/device.c   |  4 ++--
 drivers/of/of_mdio.c  | 12 ++++++------
 drivers/of/of_numa.c  |  4 ++--
 drivers/of/overlay.c  |  4 ++--
 drivers/of/platform.c |  8 ++++----
 drivers/of/unittest.c | 12 ++++++------
 6 files changed, 22 insertions(+), 22 deletions(-)

Comments

Thierry Reding Sept. 7, 2018, 12:29 p.m. UTC | #1
On Tue, Aug 28, 2018 at 10:52:53AM -0500, Rob Herring wrote:
> In preparation to remove the node name pointer from struct device_node,
> convert printf users to use the %pOFn format specifier.
> 
> Cc: Frank Rowand <frowand.list@gmail.com>
> Cc: Andrew Lunn <andrew@lunn.ch>
> Cc: Florian Fainelli <f.fainelli@gmail.com>
> Cc: devicetree@vger.kernel.org
> Cc: netdev@vger.kernel.org
> Signed-off-by: Rob Herring <robh@kernel.org>
> ---
>  drivers/of/device.c   |  4 ++--
>  drivers/of/of_mdio.c  | 12 ++++++------
>  drivers/of/of_numa.c  |  4 ++--
>  drivers/of/overlay.c  |  4 ++--
>  drivers/of/platform.c |  8 ++++----
>  drivers/of/unittest.c | 12 ++++++------
>  6 files changed, 22 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/of/device.c b/drivers/of/device.c
> index 5957cd4fa262..daa075d87317 100644
> --- a/drivers/of/device.c
> +++ b/drivers/of/device.c
> @@ -219,7 +219,7 @@ static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len
>  		return -ENODEV;
>  
>  	/* Name & Type */
> -	csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
> +	csize = snprintf(str, len, "of:N%pOFnT%s", dev->of_node,
>  			 dev->of_node->type);
>  	tsize = csize;
>  	len -= csize;

This seems to cause the modalias to be improperly constructed. As a
consequence, automatic module loading at boot time is now broken. I
think the reason why this fails is because vsnprintf() will skip all
alpha-numeric characters after a call to pointer(). Presumably this
is meant to be a generic way of skipping whatever specifiers we throw
at it.

Unfortunately for the case of OF modaliases, this means that the 'T'
character gets eaten, so we end up with something like this:

	# udevadm info /sys/bus/platform/devices/54200000.dc
	[...]
	E: MODALIAS=of:Ndc<NULL>Cnvidia,tegra124-dc
	[...]

instead of this:

	# udevadm info /sys/bus/platform/devices/54200000.dc
	[...]
	E: MODALIAS=of:NdcT<NULL>Cnvidia,tegra124-dc
	[...]

Everything is back to normal if I revert this patch. However, since
that's obviously not what we want, I think perhaps what we need is a
way for pointer() (and its implementations) to report back how many
characters in the format string it consumed so that we can support
these kinds of back-to-back strings.

If nobody else has the time I can look into coding up a fix, but in the
meantime it might be best to back this one out until we can handle the
OF modalias format string.

Thierry
Rob Herring Sept. 7, 2018, 2:58 p.m. UTC | #2
On Fri, Sep 7, 2018 at 7:29 AM Thierry Reding <thierry.reding@gmail.com> wrote:
>
> On Tue, Aug 28, 2018 at 10:52:53AM -0500, Rob Herring wrote:
> > In preparation to remove the node name pointer from struct device_node,
> > convert printf users to use the %pOFn format specifier.
> >
> > Cc: Frank Rowand <frowand.list@gmail.com>
> > Cc: Andrew Lunn <andrew@lunn.ch>
> > Cc: Florian Fainelli <f.fainelli@gmail.com>
> > Cc: devicetree@vger.kernel.org
> > Cc: netdev@vger.kernel.org
> > Signed-off-by: Rob Herring <robh@kernel.org>
> > ---
> >  drivers/of/device.c   |  4 ++--
> >  drivers/of/of_mdio.c  | 12 ++++++------
> >  drivers/of/of_numa.c  |  4 ++--
> >  drivers/of/overlay.c  |  4 ++--
> >  drivers/of/platform.c |  8 ++++----
> >  drivers/of/unittest.c | 12 ++++++------
> >  6 files changed, 22 insertions(+), 22 deletions(-)
> >
> > diff --git a/drivers/of/device.c b/drivers/of/device.c
> > index 5957cd4fa262..daa075d87317 100644
> > --- a/drivers/of/device.c
> > +++ b/drivers/of/device.c
> > @@ -219,7 +219,7 @@ static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len
> >               return -ENODEV;
> >
> >       /* Name & Type */
> > -     csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
> > +     csize = snprintf(str, len, "of:N%pOFnT%s", dev->of_node,
> >                        dev->of_node->type);
> >       tsize = csize;
> >       len -= csize;
>
> This seems to cause the modalias to be improperly constructed. As a
> consequence, automatic module loading at boot time is now broken. I
> think the reason why this fails is because vsnprintf() will skip all
> alpha-numeric characters after a call to pointer(). Presumably this
> is meant to be a generic way of skipping whatever specifiers we throw
> at it.
>
> Unfortunately for the case of OF modaliases, this means that the 'T'
> character gets eaten, so we end up with something like this:
>
>         # udevadm info /sys/bus/platform/devices/54200000.dc
>         [...]
>         E: MODALIAS=of:Ndc<NULL>Cnvidia,tegra124-dc
>         [...]
>
> instead of this:
>
>         # udevadm info /sys/bus/platform/devices/54200000.dc
>         [...]
>         E: MODALIAS=of:NdcT<NULL>Cnvidia,tegra124-dc
>         [...]

Oops. Thanks for finding this.

> Everything is back to normal if I revert this patch. However, since
> that's obviously not what we want, I think perhaps what we need is a
> way for pointer() (and its implementations) to report back how many
> characters in the format string it consumed so that we can support
> these kinds of back-to-back strings.

I don't think we can change it because if I have something like
%pOFMoreWords and then later on want to add 'M' as a new modifier we'd
break any existing cases with 'M'. Of course, I could search the tree
for that case and find unused characters, but that seems fragile
(though silently throwing away the characters does too).

> If nobody else has the time I can look into coding up a fix, but in the
> meantime it might be best to back this one out until we can handle the
> OF modalias format string.

There's an easy fix though. Just replace the 'T' with a '%c'.

I found one other case in the clock code and one in soundbus (which I
haven't posted yet).

Rob
Joe Perches Sept. 8, 2018, 12:30 a.m. UTC | #3
On Fri, 2018-09-07 at 14:29 +0200, Thierry Reding wrote:
> On Tue, Aug 28, 2018 at 10:52:53AM -0500, Rob Herring wrote:
> > In preparation to remove the node name pointer from struct device_node,
> > convert printf users to use the %pOFn format specifier.
> > 
> > Cc: Frank Rowand <frowand.list@gmail.com>
> > Cc: Andrew Lunn <andrew@lunn.ch>
> > Cc: Florian Fainelli <f.fainelli@gmail.com>
> > Cc: devicetree@vger.kernel.org
> > Cc: netdev@vger.kernel.org
> > Signed-off-by: Rob Herring <robh@kernel.org>
> > ---
> >  drivers/of/device.c   |  4 ++--
> >  drivers/of/of_mdio.c  | 12 ++++++------
> >  drivers/of/of_numa.c  |  4 ++--
> >  drivers/of/overlay.c  |  4 ++--
> >  drivers/of/platform.c |  8 ++++----
> >  drivers/of/unittest.c | 12 ++++++------
> >  6 files changed, 22 insertions(+), 22 deletions(-)
> > 
> > diff --git a/drivers/of/device.c b/drivers/of/device.c
> > index 5957cd4fa262..daa075d87317 100644
> > --- a/drivers/of/device.c
> > +++ b/drivers/of/device.c
> > @@ -219,7 +219,7 @@ static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len
> >  		return -ENODEV;
> >  
> >  	/* Name & Type */
> > -	csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
> > +	csize = snprintf(str, len, "of:N%pOFnT%s", dev->of_node,
> >  			 dev->of_node->type);
> >  	tsize = csize;
> >  	len -= csize;
> 
> This seems to cause the modalias to be improperly constructed. As a
> consequence, automatic module loading at boot time is now broken. I
> think the reason why this fails is because vsnprintf() will skip all
> alpha-numeric characters after a call to pointer(). Presumably this
> is meant to be a generic way of skipping whatever specifiers we throw
> at it.
> 
> Unfortunately for the case of OF modaliases, this means that the 'T'
> character gets eaten, so we end up with something like this:
> 
> 	# udevadm info /sys/bus/platform/devices/54200000.dc
> 	[...]
> 	E: MODALIAS=of:Ndc<NULL>Cnvidia,tegra124-dc
> 	[...]
> 
> instead of this:
> 
> 	# udevadm info /sys/bus/platform/devices/54200000.dc
> 	[...]
> 	E: MODALIAS=of:NdcT<NULL>Cnvidia,tegra124-dc
> 	[...]
> 
> Everything is back to normal if I revert this patch. However, since
> that's obviously not what we want, I think perhaps what we need is a
> way for pointer() (and its implementations) to report back how many
> characters in the format string it consumed so that we can support
> these kinds of back-to-back strings.
> 
> If nobody else has the time I can look into coding up a fix, but in the
> meantime it might be best to back this one out until we can handle the
> OF modalias format string.

Or just use 2 consecutive snprintf calls

	csize = snprintf(str, len, "of:N%pOFn", dev->of_node);
	csize += snprintf(str + csize, len - csize, "T%s",
			  dev->of_node->type);
Thierry Reding Sept. 10, 2018, 9:06 a.m. UTC | #4
On Fri, Sep 07, 2018 at 05:30:23PM -0700, Joe Perches wrote:
> On Fri, 2018-09-07 at 14:29 +0200, Thierry Reding wrote:
> > On Tue, Aug 28, 2018 at 10:52:53AM -0500, Rob Herring wrote:
> > > In preparation to remove the node name pointer from struct device_node,
> > > convert printf users to use the %pOFn format specifier.
> > > 
> > > Cc: Frank Rowand <frowand.list@gmail.com>
> > > Cc: Andrew Lunn <andrew@lunn.ch>
> > > Cc: Florian Fainelli <f.fainelli@gmail.com>
> > > Cc: devicetree@vger.kernel.org
> > > Cc: netdev@vger.kernel.org
> > > Signed-off-by: Rob Herring <robh@kernel.org>
> > > ---
> > >  drivers/of/device.c   |  4 ++--
> > >  drivers/of/of_mdio.c  | 12 ++++++------
> > >  drivers/of/of_numa.c  |  4 ++--
> > >  drivers/of/overlay.c  |  4 ++--
> > >  drivers/of/platform.c |  8 ++++----
> > >  drivers/of/unittest.c | 12 ++++++------
> > >  6 files changed, 22 insertions(+), 22 deletions(-)
> > > 
> > > diff --git a/drivers/of/device.c b/drivers/of/device.c
> > > index 5957cd4fa262..daa075d87317 100644
> > > --- a/drivers/of/device.c
> > > +++ b/drivers/of/device.c
> > > @@ -219,7 +219,7 @@ static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len
> > >  		return -ENODEV;
> > >  
> > >  	/* Name & Type */
> > > -	csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
> > > +	csize = snprintf(str, len, "of:N%pOFnT%s", dev->of_node,
> > >  			 dev->of_node->type);
> > >  	tsize = csize;
> > >  	len -= csize;
> > 
> > This seems to cause the modalias to be improperly constructed. As a
> > consequence, automatic module loading at boot time is now broken. I
> > think the reason why this fails is because vsnprintf() will skip all
> > alpha-numeric characters after a call to pointer(). Presumably this
> > is meant to be a generic way of skipping whatever specifiers we throw
> > at it.
> > 
> > Unfortunately for the case of OF modaliases, this means that the 'T'
> > character gets eaten, so we end up with something like this:
> > 
> > 	# udevadm info /sys/bus/platform/devices/54200000.dc
> > 	[...]
> > 	E: MODALIAS=of:Ndc<NULL>Cnvidia,tegra124-dc
> > 	[...]
> > 
> > instead of this:
> > 
> > 	# udevadm info /sys/bus/platform/devices/54200000.dc
> > 	[...]
> > 	E: MODALIAS=of:NdcT<NULL>Cnvidia,tegra124-dc
> > 	[...]
> > 
> > Everything is back to normal if I revert this patch. However, since
> > that's obviously not what we want, I think perhaps what we need is a
> > way for pointer() (and its implementations) to report back how many
> > characters in the format string it consumed so that we can support
> > these kinds of back-to-back strings.
> > 
> > If nobody else has the time I can look into coding up a fix, but in the
> > meantime it might be best to back this one out until we can handle the
> > OF modalias format string.
> 
> Or just use 2 consecutive snprintf calls
> 
> 	csize = snprintf(str, len, "of:N%pOFn", dev->of_node);
> 	csize += snprintf(str + csize, len - csize, "T%s",
> 			  dev->of_node->type);

Yeah, that's what I ended up doing. Rob came up with another alternative
which is to output the 'T' via %c, which also works around the issue.

Thierry

Patch
diff mbox series

diff --git a/drivers/of/device.c b/drivers/of/device.c
index 5957cd4fa262..daa075d87317 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -219,7 +219,7 @@  static ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len
 		return -ENODEV;
 
 	/* Name & Type */
-	csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
+	csize = snprintf(str, len, "of:N%pOFnT%s", dev->of_node,
 			 dev->of_node->type);
 	tsize = csize;
 	len -= csize;
@@ -298,7 +298,7 @@  void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
 	if ((!dev) || (!dev->of_node))
 		return;
 
-	add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
+	add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node);
 	add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);
 	if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
 		add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index e92391d6d1bd..5ad1342f5682 100644
--- a/drivers/of/of_mdio.c
+++ b/drivers/of/of_mdio.c
@@ -97,8 +97,8 @@  static int of_mdiobus_register_phy(struct mii_bus *mdio,
 		return rc;
 	}
 
-	dev_dbg(&mdio->dev, "registered phy %s at address %i\n",
-		child->name, addr);
+	dev_dbg(&mdio->dev, "registered phy %pOFn at address %i\n",
+		child, addr);
 	return 0;
 }
 
@@ -127,8 +127,8 @@  static int of_mdiobus_register_device(struct mii_bus *mdio,
 		return rc;
 	}
 
-	dev_dbg(&mdio->dev, "registered mdio device %s at address %i\n",
-		child->name, addr);
+	dev_dbg(&mdio->dev, "registered mdio device %pOFn at address %i\n",
+		child, addr);
 	return 0;
 }
 
@@ -263,8 +263,8 @@  int of_mdiobus_register(struct mii_bus *mdio, struct device_node *np)
 				continue;
 
 			/* be noisy to encourage people to set reg property */
-			dev_info(&mdio->dev, "scan phy %s at address %i\n",
-				 child->name, addr);
+			dev_info(&mdio->dev, "scan phy %pOFn at address %i\n",
+				 child, addr);
 
 			if (of_mdiobus_child_is_phy(child)) {
 				rc = of_mdiobus_register_phy(mdio, child, addr);
diff --git a/drivers/of/of_numa.c b/drivers/of/of_numa.c
index 27d9b4bba535..67d3386195bf 100644
--- a/drivers/of/of_numa.c
+++ b/drivers/of/of_numa.c
@@ -163,8 +163,8 @@  int of_node_to_nid(struct device_node *device)
 		np = of_get_next_parent(np);
 	}
 	if (np && r)
-		pr_warn("Invalid \"numa-node-id\" property in node %s\n",
-			np->name);
+		pr_warn("Invalid \"numa-node-id\" property in node %pOFn\n",
+			np);
 	of_node_put(np);
 
 	/*
diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index eda57ef12fd0..42b1f73ac5f6 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -425,8 +425,8 @@  static int build_changeset_next_level(struct overlay_changeset *ovcs,
 	for_each_child_of_node(overlay_node, child) {
 		ret = add_changeset_node(ovcs, target_node, child);
 		if (ret) {
-			pr_debug("Failed to apply node @%pOF/%s, err=%d\n",
-				 target_node, child->name, ret);
+			pr_debug("Failed to apply node @%pOF/%pOFn, err=%d\n",
+				 target_node, child, ret);
 			of_node_put(child);
 			return ret;
 		}
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 7ba90c290a42..868905f2d638 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -91,8 +91,8 @@  static void of_device_make_bus_id(struct device *dev)
 		 */
 		reg = of_get_property(node, "reg", NULL);
 		if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
-			dev_set_name(dev, dev_name(dev) ? "%llx.%s:%s" : "%llx.%s",
-				     (unsigned long long)addr, node->name,
+			dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn",
+				     (unsigned long long)addr, node,
 				     dev_name(dev));
 			return;
 		}
@@ -142,8 +142,8 @@  struct platform_device *of_device_alloc(struct device_node *np,
 			WARN_ON(rc);
 		}
 		if (of_irq_to_resource_table(np, res, num_irq) != num_irq)
-			pr_debug("not all legacy IRQ resources mapped for %s\n",
-				 np->name);
+			pr_debug("not all legacy IRQ resources mapped for %pOFn\n",
+				 np);
 	}
 
 	dev->dev.of_node = of_node_get(np);
diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c
index 9def7be9c111..d9d012198ca5 100644
--- a/drivers/of/unittest.c
+++ b/drivers/of/unittest.c
@@ -212,8 +212,8 @@  static int __init of_unittest_check_node_linkage(struct device_node *np)
 
 	for_each_child_of_node(np, child) {
 		if (child->parent != np) {
-			pr_err("Child node %s links to wrong parent %s\n",
-				 child->name, np->name);
+			pr_err("Child node %pOFn links to wrong parent %pOFn\n",
+				 child, np);
 			rc = -EINVAL;
 			goto put_child;
 		}
@@ -1040,16 +1040,16 @@  static void __init of_unittest_platform_populate(void)
 	for_each_child_of_node(np, child) {
 		for_each_child_of_node(child, grandchild)
 			unittest(of_find_device_by_node(grandchild),
-				 "Could not create device for node '%s'\n",
-				 grandchild->name);
+				 "Could not create device for node '%pOFn'\n",
+				 grandchild);
 	}
 
 	of_platform_depopulate(&test_bus->dev);
 	for_each_child_of_node(np, child) {
 		for_each_child_of_node(child, grandchild)
 			unittest(!of_find_device_by_node(grandchild),
-				 "device didn't get destroyed '%s'\n",
-				 grandchild->name);
+				 "device didn't get destroyed '%pOFn'\n",
+				 grandchild);
 	}
 
 	platform_device_unregister(test_bus);