MODCTL(2)                 NetBSD System Calls Manual                 MODCTL(2)

     modctl -- module control

     Standard C Library (libc, -lc)

     #include <sys/module.h>

     modctl(int operation, void *argp);

     modctl() provides control over loaded kernel modules.  The argument
     operation is one of MODCTL_LOAD, MODCTL_UNLOAD, MODCTL_STAT, or
     MODCTL_EXISTS.  The argument argp depends on the operation to be per-

     Operations are:

     MODCTL_LOAD    Load a module.  The argp argument should be a pointer to a
                    modctl_load_t structure, described below.

     MODCTL_UNLOAD  Unload a module.  In this case, argp should be a string
                    containing the name of the module to be unloaded.

     MODCTL_STAT    Return a list of loaded modules.  In this case, the argp
                    argument should be a struct iovec pointing to a suitable
                    block of memory.  The kernel will fill this block with an
                    array of modstat_t structures, one per loaded module.  If
                    the block is not large enough, the data returned will be
                    truncated to fit.  The kernel will then update the iov_len
                    member of the iovec to reflect the size of the complete
                    report, regardless of whether this is larger or smaller
                    than the size passed in.

     MODCTL_EXISTS  Test to see if the kernel was compiled with ``options
                    MODULAR'' and whether or not modules may be loaded at the
                    moment.  In this case, argp should be an integer.  It
                    should be ``0'' to test if a user can load a module via
                    MODCTL_LOAD, or it should be ``1'' to test if the system
                    can autoload modules.  Note that this test does not con-
                    sider the sysctl kern.module.autoload.

   Data Types
     The modctl_load_t structure used with MODCTL_LOAD contains the following
     elements, which should be filled in by the caller:

     const char *ml_filename
               The name/path of the module to load.

     int ml_flags
               Zero or more of the following flag values:
               MODCTL_NO_PROP     Don't load <module>.plist.
               MODCTL_LOAD_FORCE  Ignore kernel version mismatch.

     const char *ml_props
               Externalized proplib dictionary to pass to module.

     size_t ml_propslen
               Size of the dictionary blob.  ml_props may be NULL in which
               case ml_propslen must be 0.  An upper limit of 4096 bytes is
               imposed on the value of ml_propslen.  Attempting to load a pro-
               plib dictionary larger than this size will return ENOMEM.

     The modstat_t structure used with MODCTL_STAT contains the following ele-
     ments, which are filled in by the kernel:

     char ms_name[MAXMODNAME]
               The name of the module.

     char ms_required[MAXMODNAME * MAXMODDEPS]
               The list of modules required by this module as a comma-delim-
               ited list of module names.

     modsrc_t ms_source
               One of the following enumerated constants:
               MODULE_SOURCE_KERNEL   The module is compiled into the kernel.
               MODULE_SOURCE_BOOT     The module was provided by the bootstrap
               MODULE_SOURCE_FILESYS  The module was loaded from the file sys-

     modclass_t ms_class
               One of the following enumerated constants:
               MODULE_CLASS_SECMODEL  Security model.
               MODULE_CLASS_VFS       File system.
               MODULE_CLASS_DRIVER    Device driver.
               MODULE_CLASS_EXEC      Executable file format.
               MODULE_CLASS_MISC      Miscellaneous.
               MODULE_CLASS_ANY       Any module class.

     uint64_t ms_addr
               The load address within the kernel.

     u_int ms_size
               Loaded size of the module.

     u_int ms_refcnt
               Current number of live references to this module.

     u_int ms_flags
               The module's flags:
               MODFLAG_MUST_FORCE   The "force" flag must be specified to
                                    reload this module.
               MODFLAG_AUTO_LOADED  The module was auto-loaded by the operat-
                                    ing system.

     Upon successful completion, the value returned is 0.

     Otherwise, a value of -1 is returned and errno is set to indicate the

     modctl() will fail if:

     [EBUSY]            The argument operation is MODCTL_UNLOAD and the module
                        is in use or the module is compiled into the kernel.

     [EDEADLK]          The argument operation is MODCTL_LOAD and there is a
                        circular dependency in the module's dependency chain.

     [EEXIST]           The argument operation is MODCTL_LOAD and the module
                        is already loaded.

     [EFAULT]           A bad address was given for argp.

     [EFBIG]            The argument operation is MODCTL_LOAD, the specified
                        module resides in the file system, and the module's
                        default proplib file was too large.

     [EINVAL]           The argument operation is invalid.

                        The argument operation is MODCTL_LOAD and ml_props is
                        not NULL and ``ml_propslen'' is 0, or ml_props is NULL
                        and ``ml_propslen'' is not 0.  The kernel is unable to
                        internalize the plist.  Or, there is a problem with
                        the module or <module>.plist.

     [EMLINK]           The argument operation is MODCTL_LOAD and the module
                        has too many dependencies.

     [ENAMETOOLONG]     A module name/path is too long.

     [ENOENT]           The argument operation is MODCTL_LOAD and the module
                        or a dependency can't be found.  The argument
                        operation is MODCTL_UNLOAD and no module by the name
                        of argp is loaded.

     [ENOEXEC]          The argument operation is MODCTL_LOAD and the module
                        is not a valid object for the system.  Most likely,
                        one or more undefined symbols could not be resolved by
                        the in-kernel linker.

     [ENOMEM]           There was not enough memory to perform the operation.

     [EPERM]            Not allowed to perform the operation.

     [EPROGMISMATCH]    The argument operation is MODCTL_LOAD, the ml_flags
                        field in the modctl_load_t structure does not include
                        MODCTL_LOAD_FORCE, and the requested module does not
                        match the current kernel's version information.

     module(7), sysctl(7), module(9)

     The modctl() function call first appeared in NetBSD 5.0.

NetBSD 8.1                     November 4, 2015                     NetBSD 8.1

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