query_module(2) - Linux manual page (original) (raw)

querymodule(2) System Calls Manual querymodule(2)

NAME top

   query_module - query the kernel for various bits pertaining to
   modules

SYNOPSIS top

   **#include <linux/module.h>**

   **[[deprecated]] int query_module(const char ***_name_**, int** _which_**,**
                                   **void** _buf_**[.**_bufsize_**], size_t** _bufsize_**,**
                                   **size_t ***_ret_**);**

DESCRIPTION top

   _Note_: This system call is present only before Linux 2.6.

   **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 operation 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**, and so on, that
          indicates the current status of the module (see the Linux
          kernel source file _include/linux/module.h_).  _ret_ is set to
          the size of the _moduleinfo_ structure.

RETURN VALUE top

   On success, zero is returned.  On error, -1 is returned and _[errno](../man3/errno.3.html)_
   is set to indicate the error.

ERRORS top

   **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 (e.g., Linux 2.6 or later).

STANDARDS top

   Linux.

VERSIONS top

   Removed in Linux 2.6.

   Some of the information that was formerly available via
   **query_module**() can be obtained from _/proc/modules_, _/proc/kallsyms_,
   and the files under the directory _/sys/module_.

   The **query_module**() system call is not supported by glibc.  No
   declaration is provided in glibc headers, but, through a quirk of
   history, glibc does export an ABI for this system call.
   Therefore, in order to employ this system call, it is sufficient
   to manually declare the interface in your code; alternatively, you
   can invoke the system call using [syscall(2)](../man2/syscall.2.html).

SEE ALSO top

   [create_module(2)](../man2/create%5Fmodule.2.html), [delete_module(2)](../man2/delete%5Fmodule.2.html), [get_kernel_syms(2)](../man2/get%5Fkernel%5Fsyms.2.html),
   [init_module(2)](../man2/init%5Fmodule.2.html), [lsmod(8)](../man8/lsmod.8.html), [modinfo(8)](../man8/modinfo.8.html)

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Linux man-pages 6.10 2024-05-02 querymodule(2)

Pages that refer to this page:create_module(2), delete_module(2), get_kernel_syms(2), init_module(2), syscalls(2)