get_kernel_syms(2) — Linux manual page


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

NAME         top

       get_kernel_syms - retrieve exported kernel and module symbols

SYNOPSIS         top

       #include <linux/module.h>

       int get_kernel_syms(struct kernel_sym *table);

       Note: No declaration of this system call is provided in glibc
       headers; see NOTES.

DESCRIPTION         top

       Note: This system call is present only in kernels before Linux

       If table is NULL, get_kernel_syms() returns the number of symbols
       available for query.  Otherwise, it fills in a table of

           struct kernel_sym {
               unsigned long value;
               char          name[60];

       The symbols are interspersed with magic symbols of the form
       #module-name with the kernel having an empty name.  The value
       associated with a symbol of this form is the address at which the
       module is loaded.

       The symbols exported from each module follow their magic module
       tag and the modules are returned in the reverse of the order in
       which they were loaded.

RETURN VALUE         top

       On success, returns the number of symbols copied to table.  On
       error, -1 is returned and errno is set to indicate the error.

ERRORS         top

       There is only one possible error return:

       ENOSYS get_kernel_syms() is not supported in this version of the

VERSIONS         top

       This system call is present on Linux only up until kernel 2.4; it
       was removed in Linux 2.6.

CONFORMING TO         top

       get_kernel_syms() is Linux-specific.

NOTES         top

       This obsolete system call is not supported by glibc.  No
       declaration is provided in glibc headers, but, through a quirk of
       history, glibc versions before 2.23 did export an ABI for this
       system call.  Therefore, in order to employ this system call, it
       was sufficient to manually declare the interface in your code;
       alternatively, you could invoke the system call using syscall(2).

BUGS         top

       There is no way to indicate the size of the buffer allocated for
       table.  If symbols have been added to the kernel since the
       program queried for the symbol table size, memory will be

       The length of exported symbol names is limited to 59 characters.

       Because of these limitations, this system call is deprecated in
       favor of query_module(2) (which is itself nowadays deprecated in
       favor of other interfaces described on its manual page).

SEE ALSO         top

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

COLOPHON         top

       This page is part of release 5.13 of the Linux man-pages project.
       A description of the project, information about reporting bugs,
       and the latest version of this page, can be found at

Linux                          2021-03-22             GET_KERNEL_SYMS(2)

Pages that refer to this page: query_module(2)syscalls(2)