Unverified Commit 40a826bd authored by Petr Pavlu's avatar Petr Pavlu Committed by Daniel Gomez
Browse files

module: Rename MAX_PARAM_PREFIX_LEN to __MODULE_NAME_LEN 



The maximum module name length (MODULE_NAME_LEN) is somewhat confusingly
defined in terms of the maximum parameter prefix length
(MAX_PARAM_PREFIX_LEN), when in fact the dependency is in the opposite
direction.

This split originates from commit 730b69d2 ("module: check kernel param
length at compile time, not runtime"). The code needed to use
MODULE_NAME_LEN in moduleparam.h, but because module.h requires
moduleparam.h, this created a circular dependency. It was resolved by
introducing MAX_PARAM_PREFIX_LEN in moduleparam.h and defining
MODULE_NAME_LEN in module.h in terms of MAX_PARAM_PREFIX_LEN.

Rename MAX_PARAM_PREFIX_LEN to __MODULE_NAME_LEN for clarity. This matches
the similar approach of defining MODULE_INFO in module.h and __MODULE_INFO
in moduleparam.h.

Signed-off-by: default avatarPetr Pavlu <petr.pavlu@suse.com>
Reviewed-by: default avatarDaniel Gomez <da.gomez@samsung.com>
Link: https://lore.kernel.org/r/20250630143535.267745-6-petr.pavlu@suse.com


Signed-off-by: default avatarDaniel Gomez <da.gomez@samsung.com>
parent a7c54b2b

include/linux/module.h

+1 −1
Original line number Diff line number Diff line
@@ -33,7 +33,7 @@ 
#include <linux/percpu.h>

#include <asm/module.h>



#define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN

#define MODULE_NAME_LEN __MODULE_NAME_LEN



struct modversion_info {

	unsigned long crc;

include/linux/moduleparam.h

+8 −4
Original line number Diff line number Diff line
@@ -6,6 +6,13 @@ 
#include <linux/stringify.h>

#include <linux/kernel.h>



/*

 * The maximum module name length, including the NUL byte.

 * Chosen so that structs with an unsigned long line up, specifically

 * modversion_info.

 */

#define __MODULE_NAME_LEN (64 - sizeof(unsigned long))



/* You can override this manually, but generally this should match the

   module name. */

#ifdef MODULE
@@ -17,9 +24,6 @@ 
#define __MODULE_INFO_PREFIX KBUILD_MODNAME "."

#endif



/* 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)[]				  \

		__used __section(".modinfo") __aligned(1)		  \
@@ -284,7 +288,7 @@ struct kparam_array 


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

#define __module_param_call(prefix, name, ops, arg, perm, level, flags)	\

	static_assert(sizeof(""prefix) - 1 <= MAX_PARAM_PREFIX_LEN);	\

	static_assert(sizeof(""prefix) - 1 <= __MODULE_NAME_LEN);	\

	static const char __param_str_##name[] = prefix #name;		\

	static struct kernel_param __moduleparam_const __param_##name	\

	__used __section("__param")					\