QUERY_MODULE(2) 					     Linux Programmer's Manual						   QUERY_MODULE(2)

NAME

       query_module - query the kernel for various bits pertaining to modules

SYNOPSIS

       #include <linux/module.h>

       int query_module(const char *name, int which, void *buf,
			size_t bufsize, size_t *ret);

DESCRIPTION

       query_module() requests information from the kernel about loadable modules.  The returned information is placed in the buffer pointed to by
       buf.  The caller must specify the size of buf in bufsize.  The precise nature and format of the returned information depend on  the  opera-
       tion  specified	by  which.  Some operations require name to identify a currently loaded module, some allow name to be NULL, indicating the
       kernel proper.

       The following values can be specified for which:

       0      Returns success, if the kernel supports query_module().  Used to probe for availability of the system call.

       QM_MODULES
	      Returns the names of all loaded modules.	The returned buffer consists of a sequence of null-terminated strings; ret is set  to  the
	      number of modules.

       QM_DEPS
	      Returns  the  names  of  all  modules  used  by the indicated module.  The returned buffer consists of a sequence of null-terminated
	      strings; ret is set to the number of modules.

       QM_REFS
	      Returns the names of all modules using the indicated module.  This is the inverse of QM_DEPS.  The returned  buffer  consists  of  a
	      sequence of null-terminated strings; ret is set to the number of modules.

       QM_SYMBOLS
	      Returns the symbols and values exported by the kernel or the indicated module.  The returned buffer is an array of structures of the
	      following form

		  struct module_symbol {
		      unsigned long value;
		      unsigned long name;
		  };

	      followed by null-terminated strings.  The value of name is the character offset of the string relative to the start of buf;  ret	is
	      set to the number of symbols.

       QM_INFO
	      Returns miscellaneous information about the indicated module.  The output buffer format is:

		  struct module_info {
		      unsigned long address;
		      unsigned long size;
		      unsigned long flags;
		  };

	      where  address  is  the  kernel address at which the module resides, size is the size of the module in bytes, and flags is a mask of
	      MOD_RUNNING, MOD_AUTOCLEAN, etc. that indicates the current status of the module (see  the  kernel  source  file	include/linux/mod-
	      ule.h).  ret is set to the size of the module_info structure.

RETURN VALUE

       On success, zero is returned.  On error, -1 is returned and errno is set appropriately.

ERRORS

       EFAULT At least one of name, buf, or ret was outside the program's accessible address space.

       EINVAL Invalid which; or name is NULL (indicating "the kernel"), but this is not permitted with the specified value of which.

       ENOENT No module by that name exists.

       ENOSPC The buffer size provided was too small.  ret is set to the minimum size needed.

       ENOSYS query_module() is not supported in this version of the kernel.

CONFORMING TO

       query_module() is Linux-specific.

NOTES

       This system call is only present on Linux up until kernel 2.4; it was removed in Linux 2.6.  Some of the information that was available via
       query_module() can be obtained from /proc/modules, /proc/kallsyms, and /sys/modules.

SEE ALSO

       create_module(2), delete_module(2), get_kernel_syms(2), init_module(2)

COLOPHON

       This page is part of release 3.25 of the Linux man-pages project.  A description of the project, and information about reporting bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

Linux								    2007-06-03							   QUERY_MODULE(2)