Show version information for built-in modules in sysfs

PATCH In review Dmitry Torokhov 3 participants 14 messages Dec 15, 2010 – Jan 11, 2011

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Dmitry Torokhov

author

2010-12-15 22:00 UTC #0 lore raw

PATCH 1/1 Show version information for built-in modules in sysfs

Currently only drivers that are built as modules have their versions shown in /sys/module/<module_name>/version, but this information might also be useful for built-in drivers as well. This especially important for drivers that do not define any parameters - such drivers, if built-in, are completely invisible from userspace.

This patch changes MODULE_VERSION() macro so that in case when we are compiling built-in module, version information is stored in a separate section. Kernel then uses this data to create 'version' sysfs attribute in the same fashion it creates attributes for module parameters.

Signed-off-by Dmitry Torokhov <[email protected]>

---

This change is driven by our desire to detect whether vmw_balloon driver is built-in into the kernel when we installing our tool package in the guest and avoid installing our own version of the driver.

Since vmw_balloon does not have any module parameter nor registers any driver core devices, without this patch it is completely invisible from userspace when built into the kernel.

Thanks,
Dmitry

 include/asm-generic/vmlinux.lds.h |    7 ++++
 include/linux/module.h            |   27 +++++++++++++++
 kernel/params.c                   |   65 ++++++++++++++++++++++++++++++------
 3 files changed, 88 insertions(+), 11 deletions(-)

include/asm-generic/vmlinux.lds.h +7 -0

index bd69d79..0d83dd1 100644
@@ -355,6 +355,13 @@
 		VMLINUX_SYMBOL(__start___param) = .;			\
 		*(__param)						\
 		VMLINUX_SYMBOL(__stop___param) = .;			\
+	}								\
+									\
+	/* Built-in module versions. */					\
+	__modver : AT(ADDR(__modver) - LOAD_OFFSET) {			\
+		VMLINUX_SYMBOL(__start___modver) = .;			\
+		*(__modver)						\
+		VMLINUX_SYMBOL(__stop___modver) = .;			\
 		. = ALIGN((align));					\
 		VMLINUX_SYMBOL(__end_rodata) = .;			\
 	}								\

include/linux/module.h +27 -0

index 7575bbb..f74ddda 100644
@@ -58,6 +58,12 @@ struct module_attribute {
 	void (*free)(struct module *);
 };
 
+struct module_version_attribute {
+	struct module_attribute mattr;
+	const char *module_name;
+	const char *version;
+};
+
 struct module_kobject
 {
 	struct kobject kobj;

@@ -161,7 +167,28 @@ extern struct module __this_module;
   Using this automatically adds a checksum of the .c files and the
   local headers in "srcversion".
 */
+
+#ifdef MODULE
 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
+#else
+#define MODULE_VERSION(_version)					\
+	extern ssize_t __modver_version_show(struct module_attribute *,	\
+					     struct module *, char *);	\
+	static struct module_version_attribute __modver_version_attr	\
+	__used								\
+    __attribute__ ((unused,__section__ ("__modver"),aligned(sizeof(void *)))) \
+	= {								\
+		.mattr	= {						\
+			.attr	= {					\
+				.name	= "version",			\
+				.mode	= S_IRUGO,			\
+			},						\
+			.show	= __modver_version_show,		\
+		},							\
+		.module_name	= KBUILD_MODNAME,			\
+		.version	= _version,				\
+	}
+#endif
 
 /* Optional firmware file (or files) needed by the module
  * format is simply firmware file name.  Multiple firmware

kernel/params.c +54 ~~-11~~

100 lines not on this page · raw message

Signature · 1 line

1.7.3.2

Alexey Dobriyan

2010-12-15 22:06 UTC #1 lore raw

Quoted 2 lines · Dmitry Torokhov

Currently only drivers that are built as modules have their versions shown in /sys/module/<module_name>/version, but this information might

Can you create just /sys/module/x?
Module version info is quite useless by itself.

Dmitry Torokhov

author

2010-12-15 22:14 UTC #2 lore raw

Quoted 6 lines · Alexey Dobriyan

Quoted 2 lines · Dmitry Torokhov
Currently only drivers that are built as modules have their versions shown in /sys/module/<module_name>/version, but this information might
Can you create just /sys/module/x?
Module version info is quite useless by itself.

It is as useful as in the case where driver is built as a module. I am just trying to unify the behavior a bit.

Code-wise it is almost as cheap to add /sys/module/x/version as adding just the directory.

Thanks,

Dmitry

Alexey Dobriyan

2010-12-15 23:33 UTC #3 lore raw

Quoted 5 lines · Dmitry Torokhov

Quoted 4 lines · Alexey Dobriyan
Quoted 2 lines · Dmitry Torokhov
Currently only drivers that are built as modules have their versions shown in /sys/module/<module_name>/version, but this information might

Quoted 8 lines

Quoted 2 lines
Can you create just /sys/module/x?
Module version info is quite useless by itself.
It is as useful as in the case where driver is built as a module. I am just trying to unify the behavior a bit.
Code-wise it is almost as cheap to add /sys/module/x/version as adding just the directory.

OK.

Still, people are using /sys/module/x presence as indicator of modular built (unsurprisingly).

http://codesearch.google.com/codesearch/p?hl=en#wZuuyuB8jKQ/src/third_party/autotest/files/client/profilers/powertop/src/bluetooth.c&q=/sys/modules&sa=N&cd=3&ct=rc&l=105

Dmitry Torokhov

author

2010-12-15 23:53 UTC #4 lore raw

Quoted 15 lines · Alexey Dobriyan

Quoted 5 lines · Dmitry Torokhov
Quoted 4 lines · Alexey Dobriyan
Quoted 2 lines · Dmitry Torokhov
Currently only drivers that are built as modules have their versions shown in /sys/module/<module_name>/version, but this information might
Quoted 8 lines
Quoted 2 lines
Can you create just /sys/module/x?
Module version info is quite useless by itself.
It is as useful as in the case where driver is built as a module. I am just trying to unify the behavior a bit.
Code-wise it is almost as cheap to add /sys/module/x/version as adding just the directory.

Quoted 6 lines

OK.
Still, people are using /sys/module/x presence as indicator of modular built (unsurprisingly).
http://codesearch.google.com/codesearch/p?hl=en#wZuuyuB8jKQ/src/third_party/autotest/files/client/profilers/powertop/src/bluetooth.c&q=/sys/modules&sa=N&cd=3&ct=rc&l=105

Yeah, I hate to disappoint them but it will break as soon as someone adds a module_param() to one of the objects... That's even without my changes.

Signature · 1 line

Dmitry

Dmitry Torokhov

author

2010-12-16 00:30 UTC #5 lore raw

Quoted 18 lines · Dmitry Torokhov

Quoted 17 lines · Alexey Dobriyan
Quoted 5 lines · Dmitry Torokhov
Quoted 4 lines · Alexey Dobriyan
Quoted 2 lines · Dmitry Torokhov
Currently only drivers that are built as modules have their versions shown in /sys/module/<module_name>/version, but this information might
Quoted 8 lines
Quoted 2 lines
Can you create just /sys/module/x?
Module version info is quite useless by itself.
It is as useful as in the case where driver is built as a module. I am just trying to unify the behavior a bit.
Code-wise it is almost as cheap to add /sys/module/x/version as adding just the directory.
OK.

Quoted 8 lines

Quoted 4 lines
Still, people are using /sys/module/x presence as indicator of modular built (unsurprisingly).
http://codesearch.google.com/codesearch/p?hl=en#wZuuyuB8jKQ/src/third_party/autotest/files/client/profilers/powertop/src/bluetooth.c&q=/sys/modules&sa=N&cd=3&ct=rc&l=105
Yeah, I hate to disappoint them but it will break as soon as someone adds a module_param() to one of the objects... That's even without my changes.

Looking at this some more they are concerned whether bluetooth is present in the kernel, not whether it is loaded: if you care about power consumption you need to shut off BT interface whether BT core is a module or built-in. In this regard I'd say my change will make that code behave better ;)

Signature · 1 line

Dmitry

Alexey Dobriyan

2010-12-16 12:58 UTC #6 lore raw

In reply to Dmitry Torokhov

Quoted 3 lines · Dmitry Torokhov

Yeah, I hate to disappoint them but it will break as soon as someone adds a module_param() to one of the objects... That's even without my changes.

Yeah, it should have been renamed to /sys/tristate :-\

Rusty Russell

2010-12-22 01:45 UTC #7 lore raw

Quoted 6 lines · Alexey Dobriyan

Quoted 3 lines · Dmitry Torokhov
Yeah, I hate to disappoint them but it will break as soon as someone adds a module_param() to one of the objects... That's even without my changes.
Yeah, it should have been renamed to /sys/tristate :-\

Anyway, I've appled the patch.

Thanks,
Rusty.

Rusty Russell

2010-12-22 01:02 UTC #8 lore raw

In reply to Dmitry Torokhov

Quoted 69 lines · Dmitry Torokhov

Currently only drivers that are built as modules have their versions shown in /sys/module/<module_name>/version, but this information might also be useful for built-in drivers as well. This especially important for drivers that do not define any parameters - such drivers, if built-in, are completely invisible from userspace.
This patch changes MODULE_VERSION() macro so that in case when we are compiling built-in module, version information is stored in a separate section. Kernel then uses this data to create 'version' sysfs attribute in the same fashion it creates attributes for module parameters.
Signed-off-by Dmitry Torokhov <[email protected]>
---
This change is driven by our desire to detect whether vmw_balloon driver is built-in into the kernel when we installing our tool package in the guest and avoid installing our own version of the driver.
Since vmw_balloon does not have any module parameter nor registers any driver core devices, without this patch it is completely invisible from userspace when built into the kernel.
Thanks,
Dmitry
 include/asm-generic/vmlinux.lds.h |    7 ++++
 include/linux/module.h            |   27 +++++++++++++++
 kernel/params.c                   |   65 ++++++++++++++++++++++++++++++------
 3 files changed, 88 insertions(+), 11 deletions(-)
include/asm-generic/vmlinux.lds.h +7 -0
index bd69d79..0d83dd1 100644
@@ -355,6 +355,13 @@
 		VMLINUX_SYMBOL(__start___param) = .;			\
 		*(__param)						\
 		VMLINUX_SYMBOL(__stop___param) = .;			\
+	}								\
+									\
+	/* Built-in module versions. */					\
+	__modver : AT(ADDR(__modver) - LOAD_OFFSET) {			\
+		VMLINUX_SYMBOL(__start___modver) = .;			\
+		*(__modver)						\
+		VMLINUX_SYMBOL(__stop___modver) = .;			\
 		. = ALIGN((align));					\
 		VMLINUX_SYMBOL(__end_rodata) = .;			\
 	}								\
include/linux/module.h +6 -0
index 7575bbb..f74ddda 100644
@@ -58,6 +58,12 @@ struct module_attribute {
 	void (*free)(struct module *);
 };
 
+struct module_version_attribute {
+	struct module_attribute mattr;
+	const char *module_name;
+	const char *version;
+};
+
 struct module_kobject
 {
 	struct kobject kobj;
@@ -161,7 +167,28 @@ extern struct module __this_module;
   Using this automatically adds a checksum of the .c files and the
   local headers in "srcversion".
 */

include/linux/module.h extern struct module __this_module; · line 179

Quoted 10 lines

include/linux/module.h +9 -0

+
+#ifdef MODULE
 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
+#else
+#define MODULE_VERSION(_version)					\
+	extern ssize_t __modver_version_show(struct module_attribute *,	\
+					     struct module *, char *);	\
+	static struct module_version_attribute __modver_version_attr	\
+	__used								\
+    __attribute__ ((unused,__section__ ("__modver"),aligned(sizeof(void *)))) \

__used and unused seems overkill, and confused.

Removed unused.

Cheers,
Rusty.

Dmitry Torokhov

author

2010-12-22 01:17 UTC #9 lore raw

Quoted 74 lines · Rusty Russell

Quoted 73 lines · Dmitry Torokhov
Currently only drivers that are built as modules have their versions shown in /sys/module/<module_name>/version, but this information might also be useful for built-in drivers as well. This especially important for drivers that do not define any parameters - such drivers, if built-in, are completely invisible from userspace.
This patch changes MODULE_VERSION() macro so that in case when we are compiling built-in module, version information is stored in a separate section. Kernel then uses this data to create 'version' sysfs attribute in the same fashion it creates attributes for module parameters.
Signed-off-by Dmitry Torokhov <[email protected]>
---
This change is driven by our desire to detect whether vmw_balloon driver is built-in into the kernel when we installing our tool package in the guest and avoid installing our own version of the driver.
Since vmw_balloon does not have any module parameter nor registers any driver core devices, without this patch it is completely invisible from userspace when built into the kernel.
Thanks,
Dmitry
 include/asm-generic/vmlinux.lds.h |    7 ++++
 include/linux/module.h            |   27 +++++++++++++++
 kernel/params.c                   |   65 ++++++++++++++++++++++++++++++------
 3 files changed, 88 insertions(+), 11 deletions(-)
include/asm-generic/vmlinux.lds.h +7 -0
index bd69d79..0d83dd1 100644
@@ -355,6 +355,13 @@
 		VMLINUX_SYMBOL(__start___param) = .;			\
 		*(__param)						\
 		VMLINUX_SYMBOL(__stop___param) = .;			\
+	}								\
+									\
+	/* Built-in module versions. */					\
+	__modver : AT(ADDR(__modver) - LOAD_OFFSET) {			\
+		VMLINUX_SYMBOL(__start___modver) = .;			\
+		*(__modver)						\
+		VMLINUX_SYMBOL(__stop___modver) = .;			\
 		. = ALIGN((align));					\
 		VMLINUX_SYMBOL(__end_rodata) = .;			\
 	}								\
include/linux/module.h +9 -0
index 7575bbb..f74ddda 100644
@@ -58,6 +58,12 @@ struct module_attribute {
 	void (*free)(struct module *);
 };
 
+struct module_version_attribute {
+	struct module_attribute mattr;
+	const char *module_name;
+	const char *version;
+};
+
 struct module_kobject
 {
 	struct kobject kobj;
@@ -161,7 +167,28 @@ extern struct module __this_module;
   Using this automatically adds a checksum of the .c files and the
   local headers in "srcversion".
 */
+
+#ifdef MODULE
 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
+#else

Quoted 9 lines

include/linux/module.h extern struct module __this_module; · line 179
Quoted 6 lines
include/linux/module.h +6 -0
+#define MODULE_VERSION(_version)					\
+	extern ssize_t __modver_version_show(struct module_attribute *,	\
+					     struct module *, char *);	\
+	static struct module_version_attribute __modver_version_attr	\
+	__used								\
+    __attribute__ ((unused,__section__ ("__modver"),aligned(sizeof(void *)))) \
__used and unused seems overkill, and confused.

Must admit that I copied used/unused verbatim from linux/moduleparam.h:

/* This is the fundamental function for registering boot/module
parameters. */

#define __module_param_call(prefix, name, ops, arg, isbool, perm)	\
	/* Default value instead of permissions? */			\
	static int __param_perm_check_##name __attribute__((unused)) =	\
	BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2))	\
	+ BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN);	\
	static const char __param_str_##name[] = prefix #name;		\
	static struct kernel_param __moduleparam_const __param_##name	\
	__used								\
    __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
	= { __param_str_##name, ops, perm, isbool ? KPARAM_ISBOOL : 0,	\
	    { arg } }

So should it be removed from here as well?

Thanks,

Dmitry

Rusty Russell

2010-12-22 01:48 UTC #10 lore raw

Quoted 102 lines · Dmitry Torokhov

Quoted 74 lines · Rusty Russell
Quoted 73 lines · Dmitry Torokhov
Currently only drivers that are built as modules have their versions shown in /sys/module/<module_name>/version, but this information might also be useful for built-in drivers as well. This especially important for drivers that do not define any parameters - such drivers, if built-in, are completely invisible from userspace.
This patch changes MODULE_VERSION() macro so that in case when we are compiling built-in module, version information is stored in a separate section. Kernel then uses this data to create 'version' sysfs attribute in the same fashion it creates attributes for module parameters.
Signed-off-by Dmitry Torokhov <[email protected]>
---
This change is driven by our desire to detect whether vmw_balloon driver is built-in into the kernel when we installing our tool package in the guest and avoid installing our own version of the driver.
Since vmw_balloon does not have any module parameter nor registers any driver core devices, without this patch it is completely invisible from userspace when built into the kernel.
Thanks,
Dmitry
 include/asm-generic/vmlinux.lds.h |    7 ++++
 include/linux/module.h            |   27 +++++++++++++++
 kernel/params.c                   |   65 ++++++++++++++++++++++++++++++------
 3 files changed, 88 insertions(+), 11 deletions(-)
include/asm-generic/vmlinux.lds.h +7 -0
index bd69d79..0d83dd1 100644
@@ -355,6 +355,13 @@
 		VMLINUX_SYMBOL(__start___param) = .;			\
 		*(__param)						\
 		VMLINUX_SYMBOL(__stop___param) = .;			\
+	}								\
+									\
+	/* Built-in module versions. */					\
+	__modver : AT(ADDR(__modver) - LOAD_OFFSET) {			\
+		VMLINUX_SYMBOL(__start___modver) = .;			\
+		*(__modver)						\
+		VMLINUX_SYMBOL(__stop___modver) = .;			\
 		. = ALIGN((align));					\
 		VMLINUX_SYMBOL(__end_rodata) = .;			\
 	}								\
include/linux/module.h +9 -0
index 7575bbb..f74ddda 100644
@@ -58,6 +58,12 @@ struct module_attribute {
 	void (*free)(struct module *);
 };
 
+struct module_version_attribute {
+	struct module_attribute mattr;
+	const char *module_name;
+	const char *version;
+};
+
 struct module_kobject
 {
 	struct kobject kobj;
@@ -161,7 +167,28 @@ extern struct module __this_module;
   Using this automatically adds a checksum of the .c files and the
   local headers in "srcversion".
 */
+
+#ifdef MODULE
 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
+#else
Quoted 9 lines
include/linux/module.h extern struct module __this_module; · line 179
Quoted 6 lines
include/linux/module.h +6 -0
+#define MODULE_VERSION(_version)					\
+	extern ssize_t __modver_version_show(struct module_attribute *,	\
+					     struct module *, char *);	\
+	static struct module_version_attribute __modver_version_attr	\
+	__used								\
+    __attribute__ ((unused,__section__ ("__modver"),aligned(sizeof(void *)))) \
__used and unused seems overkill, and confused.
Must admit that I copied used/unused verbatim from linux/moduleparam.h:
/* This is the fundamental function for registering boot/module
parameters. */
#define __module_param_call(prefix, name, ops, arg, isbool, perm)	\
	/* Default value instead of permissions? */			\
	static int __param_perm_check_##name __attribute__((unused)) =	\
	BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2))	\
	+ BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN);	\
	static const char __param_str_##name[] = prefix #name;		\
	static struct kernel_param __moduleparam_const __param_##name	\
	__used								\
    __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
	= { __param_str_##name, ops, perm, isbool ? KPARAM_ISBOOL : 0,	\
	    { arg } }

Quoted 1 line

So should it be removed from here as well?

I think so, but (as always!) check git blame.

Patch welcome!
Rusty.

Dmitry Torokhov

author

2010-12-23 00:38 UTC #11 lore raw

Quoted 34 lines · Rusty Russell

Quoted 33 lines · Dmitry Torokhov

Quoted 14 lines · Rusty Russell

Review

Quoted 10 lines · Dmitry Torokhov

(quoted diff) +9 -0

+
+#ifdef MODULE
 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
+#else
+#define MODULE_VERSION(_version)					\
+	extern ssize_t __modver_version_show(struct module_attribute *,	\
+					     struct module *, char *);	\
+	static struct module_version_attribute __modver_version_attr	\
+	__used								\
+    __attribute__ ((unused,__section__ ("__modver"),aligned(sizeof(void *)))) \

__used and unused seems overkill, and confused.

Must admit that I copied used/unused verbatim from linux/moduleparam.h:

/* This is the fundamental function for registering boot/module
parameters. */

#define __module_param_call(prefix, name, ops, arg, isbool, perm)	\
	/* Default value instead of permissions? */			\
	static int __param_perm_check_##name __attribute__((unused)) =	\
	BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2))	\
	+ BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN);	\
	static const char __param_str_##name[] = prefix #name;		\
	static struct kernel_param __moduleparam_const __param_##name	\
	__used								\
    __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
	= { __param_str_##name, ops, perm, isbool ? KPARAM_ISBOOL : 0,	\
	    { arg } }

Quoted 4 lines

Quoted 1 line
So should it be removed from here as well?
I think so, but (as always!) check git blame.

Whew, found it:

commit 4d62364652499ef106d1c0737968a879ef077bd4

Author: akpm <akpm>
Date:   Tue Jan 20 05:13:24 2004 +0000

[PATCH] make gcc 3.4 compilation work

From: David Mosberger <[email protected]>

With gcc-3.4 we need "attribute((used))" declarations to get "make modules_install" to work.

Otherwise these sections get dropped from the final image (I assume).

BKrev: 400cb8f4ByHxZCElstAaZ3mBZ2oflQ

...

include/linux/moduleparam.h +1 -0

index 0a5becb..cbca007 100644
@@ -52,6 +52,7 @@ struct kparam_array
 #define __module_param_call(prefix, name, set, get, arg, perm) \
        static char __param_str_##name[] __initdata = prefix #name; \
        static struct kernel_param const __param_##name \
+       __attribute_used__ \
     __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
        = { __param_str_##name, perm, set, get, arg }

Since we still claim to support GCC 3.4 I guess __used is still needed...

Thanks,

Dmitry

Rusty Russell

2010-12-23 02:28 UTC #12 lore raw

Quoted 72 lines · Dmitry Torokhov

Quoted 34 lines · Rusty Russell
Quoted 33 lines · Dmitry Torokhov
Quoted 14 lines · Rusty Russell
Review
Quoted 10 lines · Dmitry Torokhov
(quoted diff) +9 -0
+
+#ifdef MODULE
 #define MODULE_VERSION(_version) MODULE_INFO(version, _version)
+#else
+#define MODULE_VERSION(_version)					\
+	extern ssize_t __modver_version_show(struct module_attribute *,	\
+					     struct module *, char *);	\
+	static struct module_version_attribute __modver_version_attr	\
+	__used								\
+    __attribute__ ((unused,__section__ ("__modver"),aligned(sizeof(void *)))) \
__used and unused seems overkill, and confused.
Must admit that I copied used/unused verbatim from linux/moduleparam.h:
/* This is the fundamental function for registering boot/module
parameters. */
#define __module_param_call(prefix, name, ops, arg, isbool, perm)	\
	/* Default value instead of permissions? */			\
	static int __param_perm_check_##name __attribute__((unused)) =	\
	BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2))	\
	+ BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN);	\
	static const char __param_str_##name[] = prefix #name;		\
	static struct kernel_param __moduleparam_const __param_##name	\
	__used								\
    __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
	= { __param_str_##name, ops, perm, isbool ? KPARAM_ISBOOL : 0,	\
	    { arg } }
Quoted 4 lines
Quoted 1 line
So should it be removed from here as well?
I think so, but (as always!) check git blame.
Whew, found it:
commit 4d62364652499ef106d1c0737968a879ef077bd4
Author: akpm <akpm>
Date:   Tue Jan 20 05:13:24 2004 +0000
[PATCH] make gcc 3.4 compilation work
From: David Mosberger <[email protected]>
With gcc-3.4 we need "attribute((used))" declarations to get "make modules_install" to work.
Otherwise these sections get dropped from the final image (I assume).
BKrev: 400cb8f4ByHxZCElstAaZ3mBZ2oflQ
...
include/linux/moduleparam.h +1 -0
index 0a5becb..cbca007 100644
@@ -52,6 +52,7 @@ struct kparam_array
 #define __module_param_call(prefix, name, set, get, arg, perm) \
        static char __param_str_##name[] __initdata = prefix #name; \
        static struct kernel_param const __param_##name \
+       __attribute_used__ \
     __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
        = { __param_str_##name, perm, set, get, arg }
 

Quoted 2 lines

Since we still claim to support GCC 3.4 I guess __used is still needed...

Well, __used is correct. But this unused should have been removed at the same time.

Cheers,
Rusty.

Dmitry Torokhov

author

2011-01-11 19:03 UTC #13 lore raw

In reply to Rusty Russell

Quoted 12 lines · Rusty Russell

Quoted 11 lines · Dmitry Torokhov
Currently only drivers that are built as modules have their versions shown in /sys/module/<module_name>/version, but this information might also be useful for built-in drivers as well. This especially important for drivers that do not define any parameters - such drivers, if built-in, are completely invisible from userspace.
This patch changes MODULE_VERSION() macro so that in case when we are compiling built-in module, version information is stored in a separate section. Kernel then uses this data to create 'version' sysfs attribute in the same fashion it creates attributes for module parameters.

...

Quoted 5 lines

__used and unused seems overkill, and confused.
Removed unused.

Rusty,

What is the status of the patch? It woudl be nice if it coudl make it into .38.

Thanks!

Signature · 1 line

Dmitry