MODULE_INFO in Linux Device Driver

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'modinfo' section in the .ko (ELF) file stores the Module information. MODULE_INFO is the macro which can be used in the source code to add information to this section

#define MODULE_INFO(tag, info) __MODULE_INFO(tag, tag, info)
#define __MODULE_INFO(tag, name, info)                    \
static const char __UNIQUE_ID(name)[]                     \
  __used __attribute__((section(".modinfo"), unused, aligned(1)))     \
  = __stringify(tag) "=" info

MODULE_INFO is used in several places by other macros such as 
  • license, 
  • alias,
  • author,
  • vermagic.

Some of the fields can be retrieved through the THIS_MODULE (struct module)

Code:



Output:


 modinfo utility lists each attribute of the module in form fieldname:value, for easy reading  from the Linux Kernel modules given on the command line


In the above screenshot, we used readelf, to dump the contents of the modinfo section.

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