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  3. [PATCH 0/4] kbuild: generate module.builtin.modinfo from vmlinux.unstripped instead of vmlinux.o
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[PATCH 1/4] module: remove meaningless 'name' parameter from __MODULE_INFO()

Masahiro Yamada posted 4 patches 6 months, 2 weeks ago
[PATCH 1/4] module: remove meaningless 'name' parameter from __MODULE_INFO()
Posted by Masahiro Yamada 6 months, 2 weeks ago 
The symbol names in the .modinfo section are never used and already
randomized by the __UNIQUE_ID() macro.

Therefore, the second parameter of  __MODULE_INFO() is meaningless
and can be removed to simplify the code.

With this change, the symbol names in the .modinfo section will be
prefixed with __UNIQUE_ID_modinfo, making it clearer that they
originate from MODULE_INFO().

[Before]

  $ objcopy  -j .modinfo vmlinux.o modinfo.o
  $ nm -n modinfo.o | head -n10
  0000000000000000 r __UNIQUE_ID_license560
  0000000000000011 r __UNIQUE_ID_file559
  0000000000000030 r __UNIQUE_ID_description558
  0000000000000074 r __UNIQUE_ID_license580
  000000000000008e r __UNIQUE_ID_file579
  00000000000000bd r __UNIQUE_ID_description578
  00000000000000e6 r __UNIQUE_ID_license581
  00000000000000ff r __UNIQUE_ID_file580
  0000000000000134 r __UNIQUE_ID_description579
  0000000000000179 r __UNIQUE_ID_uncore_no_discover578

[After]

  $ objcopy  -j .modinfo vmlinux.o modinfo.o
  $ nm -n modinfo.o | head -n10
  0000000000000000 r __UNIQUE_ID_modinfo560
  0000000000000011 r __UNIQUE_ID_modinfo559
  0000000000000030 r __UNIQUE_ID_modinfo558
  0000000000000074 r __UNIQUE_ID_modinfo580
  000000000000008e r __UNIQUE_ID_modinfo579
  00000000000000bd r __UNIQUE_ID_modinfo578
  00000000000000e6 r __UNIQUE_ID_modinfo581
  00000000000000ff r __UNIQUE_ID_modinfo580
  0000000000000134 r __UNIQUE_ID_modinfo579
  0000000000000179 r __UNIQUE_ID_modinfo578

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---

 include/crypto/algapi.h     | 4 ++--
 include/linux/module.h      | 3 ---
 include/linux/moduleparam.h | 9 +++++----
 include/net/tcp.h           | 4 ++--
 4 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/include/crypto/algapi.h b/include/crypto/algapi.h
index 6e07bbc04089..f5e7454758bd 100644
--- a/include/crypto/algapi.h
+++ b/include/crypto/algapi.h
@@ -43,8 +43,8 @@
  * alias.
  */
 #define MODULE_ALIAS_CRYPTO(name)	\
-		__MODULE_INFO(alias, alias_userspace, name);	\
-		__MODULE_INFO(alias, alias_crypto, "crypto-" name)
+		MODULE_INFO(alias, name);	\
+		MODULE_INFO(alias, "crypto-" name)
 
 struct crypto_aead;
 struct crypto_instance;
diff --git a/include/linux/module.h b/include/linux/module.h
index 92e1420fccdf..81b41cc6a19e 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -164,9 +164,6 @@ extern void cleanup_module(void);
 
 struct module_kobject *lookup_or_create_module_kobject(const char *name);
 
-/* Generic info of form tag = "info" */
-#define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
-
 /* For userspace: you can also call me... */
 #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
 
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index bfb85fd13e1f..00166f747e27 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -20,18 +20,19 @@
 /* Chosen so that structs with an unsigned long line up. */
 #define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
 
-#define __MODULE_INFO(tag, name, info)					  \
-	static const char __UNIQUE_ID(name)[]				  \
+/* Generic info of form tag = "info" */
+#define MODULE_INFO(tag, info)					  \
+	static const char __UNIQUE_ID(modinfo)[]			  \
 		__used __section(".modinfo") __aligned(1)		  \
 		= __MODULE_INFO_PREFIX __stringify(tag) "=" info
 
 #define __MODULE_PARM_TYPE(name, _type)					  \
-	__MODULE_INFO(parmtype, name##type, #name ":" _type)
+	MODULE_INFO(parmtype, #name ":" _type)
 
 /* One for each parameter, describing how to use it.  Some files do
    multiple of these per line, so can't just use MODULE_INFO. */
 #define MODULE_PARM_DESC(_parm, desc) \
-	__MODULE_INFO(parm, _parm, #_parm ":" desc)
+	MODULE_INFO(parm, #_parm ":" desc)
 
 struct kernel_param;
 
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 4450c384ef17..ac6df59e4eea 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -2661,8 +2661,8 @@ void tcp_update_ulp(struct sock *sk, struct proto *p,
 		    void (*write_space)(struct sock *sk));
 
 #define MODULE_ALIAS_TCP_ULP(name)				\
-	__MODULE_INFO(alias, alias_userspace, name);		\
-	__MODULE_INFO(alias, alias_tcp_ulp, "tcp-ulp-" name)
+	MODULE_INFO(alias, name);		\
+	MODULE_INFO(alias, "tcp-ulp-" name)
 
 #ifdef CONFIG_NET_SOCK_MSG
 struct sk_msg;
-- 
2.43.0
Re: [PATCH 1/4] module: remove meaningless 'name' parameter from __MODULE_INFO()
Posted by Petr Pavlu 6 months, 1 week ago 
On 6/6/25 6:10 AM, Masahiro Yamada wrote:
> The symbol names in the .modinfo section are never used and already
> randomized by the __UNIQUE_ID() macro.
> 
> Therefore, the second parameter of  __MODULE_INFO() is meaningless
> and can be removed to simplify the code.
> 
> With this change, the symbol names in the .modinfo section will be
> prefixed with __UNIQUE_ID_modinfo, making it clearer that they
> originate from MODULE_INFO().
> 
> [Before]
> 
>   $ objcopy  -j .modinfo vmlinux.o modinfo.o
>   $ nm -n modinfo.o | head -n10
>   0000000000000000 r __UNIQUE_ID_license560
>   0000000000000011 r __UNIQUE_ID_file559
>   0000000000000030 r __UNIQUE_ID_description558
>   0000000000000074 r __UNIQUE_ID_license580
>   000000000000008e r __UNIQUE_ID_file579
>   00000000000000bd r __UNIQUE_ID_description578
>   00000000000000e6 r __UNIQUE_ID_license581
>   00000000000000ff r __UNIQUE_ID_file580
>   0000000000000134 r __UNIQUE_ID_description579
>   0000000000000179 r __UNIQUE_ID_uncore_no_discover578
> 
> [After]
> 
>   $ objcopy  -j .modinfo vmlinux.o modinfo.o
>   $ nm -n modinfo.o | head -n10
>   0000000000000000 r __UNIQUE_ID_modinfo560
>   0000000000000011 r __UNIQUE_ID_modinfo559
>   0000000000000030 r __UNIQUE_ID_modinfo558
>   0000000000000074 r __UNIQUE_ID_modinfo580
>   000000000000008e r __UNIQUE_ID_modinfo579
>   00000000000000bd r __UNIQUE_ID_modinfo578
>   00000000000000e6 r __UNIQUE_ID_modinfo581
>   00000000000000ff r __UNIQUE_ID_modinfo580
>   0000000000000134 r __UNIQUE_ID_modinfo579
>   0000000000000179 r __UNIQUE_ID_modinfo578
> 
> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
> ---
> [...]
> diff --git a/include/linux/module.h b/include/linux/module.h
> index 92e1420fccdf..81b41cc6a19e 100644
> --- a/include/linux/module.h
> +++ b/include/linux/module.h
> @@ -164,9 +164,6 @@ extern void cleanup_module(void);
>  
>  struct module_kobject *lookup_or_create_module_kobject(const char *name);
>  
> -/* Generic info of form tag = "info" */
> -#define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
> -
>  /* For userspace: you can also call me... */
>  #define MODULE_ALIAS(_alias) MODULE_INFO(alias, _alias)
>  
> diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
> index bfb85fd13e1f..00166f747e27 100644
> --- a/include/linux/moduleparam.h
> +++ b/include/linux/moduleparam.h
> @@ -20,18 +20,19 @@
>  /* Chosen so that structs with an unsigned long line up. */
>  #define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
>  
> -#define __MODULE_INFO(tag, name, info)					  \
> -	static const char __UNIQUE_ID(name)[]				  \
> +/* Generic info of form tag = "info" */
> +#define MODULE_INFO(tag, info)					  \
> +	static const char __UNIQUE_ID(modinfo)[]			  \
>  		__used __section(".modinfo") __aligned(1)		  \
>  		= __MODULE_INFO_PREFIX __stringify(tag) "=" info
>  

One nit is that MODULE_INFO() is now defined in moduleparam.h, even
though it is a general macro for adding module information and not
specifically tied to parameters. I realize it is needed in moduleparam.h
and that the dependency is from module.h to moduleparam.h, not the other
way around. We could potentially keep the MODULE_INFO() (in module.h) ->
__MODULE_INFO() (moduleparam.h) split solely for this, but it is
probably unnecessary.

The overall change looks ok to me.

Reviewed-by: Petr Pavlu <petr.pavlu@suse.com>

-- 
Thanks,
Petr

Patchew 2.1-devel-b67e4c2

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