drivers/base - fix sparse warnings

There are a number of sparse warnings from the latest sparse snapshot being generated from the drivers/base build. The main culprits are due to the initialisation functions not being declared in a header file.

Also, the firmware.c file should include <linux/device.h> to get the prototype of firmware_register() and firmware_unregister().

This patch moves the init function declerations from the init.c file to the base.h, and ensures it is included in all the relevant c sources. It also adds <linux/device.h> to the included headers for firmware.c.

The patch does not solve all the sparse errors generated, but reduces the count significantly.

drivers/base/core.c:161:1: warning: symbol 'devices_subsys' was not declared. Should it be static? drivers/base/core.c:417:12: warning: symbol 'devices_init' was not declared. Should it be static? drivers/base/sys.c:253:6: warning: symbol 'sysdev_shutdown' was not declared. Should it be static? drivers/base/sys.c:326:5: warning: symbol 'sysdev_suspend' was not declared. Should it be static? drivers/base/sys.c:428:5: warning: symbol 'sysdev_resume' was not declared. Should it be static? drivers/base/sys.c:450:12: warning: symbol 'system_bus_init' was not declared. Should it be static? drivers/base/bus.c:133:1: warning: symbol 'bus_subsys' was not declared. Should it be static? drivers/base/bus.c:667:12: warning: symbol 'buses_init' was not declared. Should it be static? drivers/base/class.c:759:12: warning: symbol 'classes_init' was not declared. Should it be static? drivers/base/platform.c:313:12: warning: symbol 'platform_bus_init' was not declared. Should it be static? drivers/base/cpu.c:110:12: warning: symbol 'cpu_dev_init' was not declared. Should it be static? drivers/base/firmware.c:17:5: warning: symbol 'firmware_register' was not declared. Should it be static? drivers/base/firmware.c:23:6: warning: symbol 'firmware_unregister' was not declared. Should it be static? drivers/base/firmware.c:28:12: warning: symbol 'firmware_init' was not declared. Should it be static? drivers/base/init.c:28:13: warning: symbol 'driver_init' was not declared. Should it be static? drivers/base/dmapool.c:174:10: warning: implicit cast from nocast type drivers/base/attribute_container.c:439:1: warning: symbol 'attribute_container_init' was not declared. Should it be static? drivers/base/power/runtime.c:76:6: warning: symbol 'dpm_set_power_state' was not declared. Should it be static?

diff -urpN -X ../dontdiff linux-2.6.14-rc4-bjd1/drivers/base/attribute_container.c linux-2.6.14-rc4-bjd2/drivers/base/attribute_container.c
@@ -19,6 +19,8 @@
 #include <linux/list.h>
 #include <linux/module.h>
 
+#include "base.h"
+
 /* This is a private structure used to tie the classdev and the
  * container .. it should never be visible outside this file */
 struct internal_container {

diff -urpN -X ../dontdiff linux-2.6.14-rc4-bjd1/drivers/base/base.h linux-2.6.14-rc4-bjd2/drivers/base/base.h
@@ -1,3 +1,15 @@
+
+/* initialisation functions */
+
+extern int devices_init(void);
+extern int buses_init(void);
+extern int classes_init(void);
+extern int firmware_init(void);
+extern int platform_bus_init(void);
+extern int system_bus_init(void);
+extern int cpu_dev_init(void);
+extern int attribute_container_init(void);
+
 extern int bus_add_device(struct device * dev);
 extern void bus_remove_device(struct device * dev);
 

diff -urpN -X ../dontdiff linux-2.6.14-rc4-bjd1/drivers/base/cpu.c linux-2.6.14-rc4-bjd2/drivers/base/cpu.c
@@ -9,6 +9,7 @@
 #include <linux/topology.h>
 #include <linux/device.h>
 
+#include "base.h"
 
 struct sysdev_class cpu_sysdev_class = {
 	set_kset_name("cpu"),

diff -urpN -X ../dontdiff linux-2.6.14-rc4-bjd1/drivers/base/firmware.c linux-2.6.14-rc4-bjd2/drivers/base/firmware.c
@@ -11,6 +11,9 @@
 #include <linux/kobject.h>
 #include <linux/module.h>
 #include <linux/init.h>
+#include <linux/device.h>
+
+#include "base.h"
 
 static decl_subsys(firmware, NULL, NULL);
 

diff -urpN -X ../dontdiff linux-2.6.14-rc4-bjd1/drivers/base/init.c linux-2.6.14-rc4-bjd2/drivers/base/init.c
@@ -10,14 +10,8 @@
 #include <linux/device.h>
 #include <linux/init.h>
 
-extern int devices_init(void);
-extern int buses_init(void);
-extern int classes_init(void);
-extern int firmware_init(void);
-extern int platform_bus_init(void);
-extern int system_bus_init(void);
-extern int cpu_dev_init(void);
-extern int attribute_container_init(void);
+#include "base.h"
+
 /**
  *	driver_init - initialize driver model.
  *

diff -urpN -X ../dontdiff linux-2.6.14-rc4-bjd1/drivers/base/platform.c linux-2.6.14-rc4-bjd2/drivers/base/platform.c
@@ -17,6 +17,8 @@
 #include <linux/bootmem.h>
 #include <linux/err.h>
 
+#include "base.h"
+
 struct device platform_bus = {
 	.bus_id		= "platform",
 };

Well, you should also then remove the _bad_ declarations.

For example, attribute_container_init() right now is defined in attribute_container.c, but then it's _declared_ (with no checking) where it's used in init.c.

The sparse warnign is appropriate: it was not declared where that declaration is actually visible to the definition, so the code basically isn't type-safe at all (since there's nothing that enforces the declaration actually matching the definition).

You made the declaration properly visible, but you should also remove the bogus declaration. A declaration that isn't visible to the definition is always bad - since in the absense of a compiler with global visibility it may or may not actually match what it supposedly declares.

I wonder if I should make sparse warn about multiple declarations..

These days, sparse actually has some limited support for checking _global_ visibility, and we could do cross-checking across thousands of files. However, the build environment isn't really very amenable to that, so doing a global sparse check is pretty hard in practice.

We could possibly do a per-directory global check, which might be better than nothing (ie if you were to have incorrect declaration in a C file that is in the same directory as another C file, then we could cross-check).

But the kernel kbuild environment is pretty hairy, and I wouldn't even know where to begin trying to do that. It's also fundamentally hard to do if there are per-file pre-defines (since to do a cross-check, sparse wants to see all C files together on the command line).

Linus

Erm, lets take your example - attribute_container_init(). It's defined in attribute_container.c, where the base.h include was added:

diff -urpN -X ../dontdiff linux-2.6.14-rc4-bjd1/drivers/base/attribute_container.c linux-2.6.14-rc4-bjd2/drivers/base/attribute_container.c
@@ -19,6 +19,8 @@
 #include <linux/list.h>
 #include <linux/module.h>
 
+#include "base.h"
+
 /* This is a private structure used to tie the classdev and the
  * container .. it should never be visible outside this file */
 struct internal_container {

The base.h include contains the definition:

diff -urpN -X ../dontdiff linux-2.6.14-rc4-bjd1/drivers/base/base.h linux-2.6.14-rc4-bjd2/drivers/base/base.h
@@ -1,3 +1,15 @@
+
+/* initialisation functions */
+
+extern int devices_init(void);
+extern int buses_init(void);
+extern int classes_init(void);
+extern int firmware_init(void);
+extern int platform_bus_init(void);
+extern int system_bus_init(void);
+extern int cpu_dev_init(void);
+extern int attribute_container_init(void);
+
 extern int bus_add_device(struct device * dev);
 extern void bus_remove_device(struct device * dev);
 

And base.h was included in init.c and the bogus declaration removed:

diff -urpN -X ../dontdiff linux-2.6.14-rc4-bjd1/drivers/base/init.c linux-2.6.14-rc4-bjd2/drivers/base/init.c
@@ -10,14 +10,8 @@
 #include <linux/device.h>
 #include <linux/init.h>
 
-extern int devices_init(void);
-extern int buses_init(void);
-extern int classes_init(void);
-extern int firmware_init(void);
-extern int platform_bus_init(void);
-extern int system_bus_init(void);
-extern int cpu_dev_init(void);
-extern int attribute_container_init(void);
+#include "base.h"
+
 /**
  *	driver_init - initialize driver model.
  *

I can't see anything that was missed.

Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 Serial core

Duh. My mistake, I looked at the patch twice, but I still missed the place where it removed the declaration. Twice.

Gaah. Where are my brain-pills again?

Linus

Sorry, I do not follow you, can you clarify this for me. My patch did not generate any more errors, just removed the ones that where easy to see a solution too.

I pulled the old declerations out of drivers/base/init.c ? I'm sure the patch shows that?

Ben ([email protected], http://www.fluff.org/)

  'a smiley only costs 4 bytes'