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NetBSD/sys/kern/kern_module.c

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/* $NetBSD: kern_module.c,v 1.130 2017/12/14 22:28:59 pgoyette Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software developed for The NetBSD Foundation
* by Andrew Doran.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Kernel module support.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: kern_module.c,v 1.130 2017/12/14 22:28:59 pgoyette Exp $");
#define _MODULE_INTERNAL
#ifdef _KERNEL_OPT
#include "opt_ddb.h"
#include "opt_modular.h"
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/kauth.h>
#include <sys/kobj.h>
#include <sys/kmem.h>
#include <sys/module.h>
#include <sys/kthread.h>
#include <sys/sysctl.h>
#include <sys/lock.h>
#include <uvm/uvm_extern.h>
struct vm_map *module_map;
const char *module_machine;
char module_base[MODULE_BASE_SIZE];
struct modlist module_list = TAILQ_HEAD_INITIALIZER(module_list);
struct modlist module_builtins = TAILQ_HEAD_INITIALIZER(module_builtins);
static struct modlist module_bootlist = TAILQ_HEAD_INITIALIZER(module_bootlist);
static module_t *module_active;
bool module_verbose_on;
#ifdef MODULAR_DEFAULT_AUTOLOAD
bool module_autoload_on = true;
#else
bool module_autoload_on = false;
#endif
u_int module_count;
u_int module_builtinlist;
u_int module_autotime = 10;
u_int module_gen = 1;
static kcondvar_t module_thread_cv;
static kmutex_t module_thread_lock;
static int module_thread_ticks;
int (*module_load_vfs_vec)(const char *, int, bool, module_t *,
prop_dictionary_t *) = (void *)eopnotsupp;
static kauth_listener_t module_listener;
/* Ensure that the kernel's link set isn't empty. */
static modinfo_t module_dummy;
__link_set_add_rodata(modules, module_dummy);
static module_t *module_newmodule(modsrc_t);
static void module_require_force(module_t *);
static int module_do_load(const char *, bool, int, prop_dictionary_t,
module_t **, modclass_t modclass, bool);
static int module_do_unload(const char *, bool);
static int module_do_builtin(const module_t *, const char *, module_t **,
prop_dictionary_t);
static int module_fetch_info(module_t *);
static void module_thread(void *);
static module_t *module_lookup(const char *);
static void module_enqueue(module_t *);
static bool module_merge_dicts(prop_dictionary_t, const prop_dictionary_t);
static void sysctl_module_setup(void);
static int sysctl_module_autotime(SYSCTLFN_PROTO);
#define MODULE_CLASS_MATCH(mi, modclass) \
((modclass) == MODULE_CLASS_ANY || (modclass) == (mi)->mi_class)
static void
module_incompat(const modinfo_t *mi, int modclass)
{
module_error("incompatible module class for `%s' (%d != %d)",
mi->mi_name, modclass, mi->mi_class);
}
/*
* module_error:
*
* Utility function: log an error.
*/
void
module_error(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
printf("WARNING: module error: ");
vprintf(fmt, ap);
printf("\n");
va_end(ap);
}
/*
* module_print:
*
* Utility function: log verbose output.
*/
void
module_print(const char *fmt, ...)
{
va_list ap;
if (module_verbose_on) {
va_start(ap, fmt);
printf("DEBUG: module: ");
vprintf(fmt, ap);
printf("\n");
va_end(ap);
}
}
static int
module_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
void *arg0, void *arg1, void *arg2, void *arg3)
{
int result;
result = KAUTH_RESULT_DEFER;
if (action != KAUTH_SYSTEM_MODULE)
return result;
if ((uintptr_t)arg2 != 0) /* autoload */
result = KAUTH_RESULT_ALLOW;
return result;
}
/*
* Allocate a new module_t
*/
static module_t *
module_newmodule(modsrc_t source)
{
module_t *mod;
mod = kmem_zalloc(sizeof(*mod), KM_SLEEP);
mod->mod_source = source;
mod->mod_info = NULL;
mod->mod_flags = 0;
return mod;
}
/*
* Require the -f (force) flag to load a module
*/
static void
module_require_force(struct module *mod)
{
mod->mod_flags |= MODFLG_MUST_FORCE;
}
/*
* Add modules to the builtin list. This can done at boottime or
* at runtime if the module is linked into the kernel with an
* external linker. All or none of the input will be handled.
* Optionally, the modules can be initialized. If they are not
* initialized, module_init_class() or module_load() can be used
* later, but these are not guaranteed to give atomic results.
*/
int
module_builtin_add(modinfo_t *const *mip, size_t nmodinfo, bool init)
{
struct module **modp = NULL, *mod_iter;
int rv = 0, i, mipskip;
if (init) {
rv = kauth_authorize_system(kauth_cred_get(),
KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_LOAD,
(void *)(uintptr_t)1, NULL);
if (rv) {
return rv;
}
}
for (i = 0, mipskip = 0; i < nmodinfo; i++) {
if (mip[i] == &module_dummy) {
KASSERT(nmodinfo > 0);
nmodinfo--;
}
}
if (nmodinfo == 0)
return 0;
modp = kmem_zalloc(sizeof(*modp) * nmodinfo, KM_SLEEP);
for (i = 0, mipskip = 0; i < nmodinfo; i++) {
if (mip[i+mipskip] == &module_dummy) {
mipskip++;
continue;
}
modp[i] = module_newmodule(MODULE_SOURCE_KERNEL);
modp[i]->mod_info = mip[i+mipskip];
}
kernconfig_lock();
/* do this in three stages for error recovery and atomicity */
/* first check for presence */
for (i = 0; i < nmodinfo; i++) {
TAILQ_FOREACH(mod_iter, &module_builtins, mod_chain) {
if (strcmp(mod_iter->mod_info->mi_name,
modp[i]->mod_info->mi_name) == 0)
break;
}
if (mod_iter) {
rv = EEXIST;
goto out;
}
if (module_lookup(modp[i]->mod_info->mi_name) != NULL) {
rv = EEXIST;
goto out;
}
}
/* then add to list */
for (i = 0; i < nmodinfo; i++) {
TAILQ_INSERT_TAIL(&module_builtins, modp[i], mod_chain);
module_builtinlist++;
}
/* finally, init (if required) */
if (init) {
for (i = 0; i < nmodinfo; i++) {
rv = module_do_builtin(modp[i],
modp[i]->mod_info->mi_name, NULL, NULL);
/* throw in the towel, recovery hard & not worth it */
if (rv)
panic("%s: builtin module \"%s\" init failed:"
" %d", __func__,
modp[i]->mod_info->mi_name, rv);
}
}
out:
kernconfig_unlock();
if (rv != 0) {
for (i = 0; i < nmodinfo; i++) {
if (modp[i])
kmem_free(modp[i], sizeof(*modp[i]));
}
}
kmem_free(modp, sizeof(*modp) * nmodinfo);
return rv;
}
/*
* Optionally fini and remove builtin module from the kernel.
* Note: the module will now be unreachable except via mi && builtin_add.
*/
int
module_builtin_remove(modinfo_t *mi, bool fini)
{
struct module *mod;
int rv = 0;
if (fini) {
rv = kauth_authorize_system(kauth_cred_get(),
KAUTH_SYSTEM_MODULE, 0, (void *)(uintptr_t)MODCTL_UNLOAD,
NULL, NULL);
if (rv)
return rv;
kernconfig_lock();
rv = module_do_unload(mi->mi_name, true);
if (rv) {
goto out;
}
} else {
kernconfig_lock();
}
TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
if (strcmp(mod->mod_info->mi_name, mi->mi_name) == 0)
break;
}
if (mod) {
TAILQ_REMOVE(&module_builtins, mod, mod_chain);
module_builtinlist--;
} else {
KASSERT(fini == false);
rv = ENOENT;
}
out:
kernconfig_unlock();
return rv;
}
/*
* module_init:
*
* Initialize the module subsystem.
*/
void
module_init(void)
{
__link_set_decl(modules, modinfo_t);
extern struct vm_map *module_map;
modinfo_t *const *mip;
int rv;
if (module_map == NULL) {
module_map = kernel_map;
}
cv_init(&module_thread_cv, "mod_unld");
mutex_init(&module_thread_lock, MUTEX_DEFAULT, IPL_NONE);
#ifdef MODULAR /* XXX */
module_init_md();
#endif
if (!module_machine)
module_machine = machine;
#if __NetBSD_Version__ / 1000000 % 100 == 99 /* -current */
snprintf(module_base, sizeof(module_base), "/stand/%s/%s/modules",
module_machine, osrelease);
#else /* release */
snprintf(module_base, sizeof(module_base), "/stand/%s/%d.%d/modules",
module_machine, __NetBSD_Version__ / 100000000,
__NetBSD_Version__ / 1000000 % 100);
#endif
module_listener = kauth_listen_scope(KAUTH_SCOPE_SYSTEM,
module_listener_cb, NULL);
__link_set_foreach(mip, modules) {
if ((rv = module_builtin_add(mip, 1, false)) != 0)
module_error("builtin %s failed: %d\n",
(*mip)->mi_name, rv);
}
sysctl_module_setup();
}
/*
* module_start_unload_thread:
*
* Start the auto unload kthread.
*/
void
module_start_unload_thread(void)
{
int error;
error = kthread_create(PRI_VM, KTHREAD_MPSAFE, NULL, module_thread,
NULL, NULL, "modunload");
if (error != 0)
panic("%s: %d", __func__, error);
}
/*
* module_builtin_require_force
*
* Require MODCTL_MUST_FORCE to load any built-in modules that have
* not yet been initialized
*/
void
module_builtin_require_force(void)
{
module_t *mod;
kernconfig_lock();
TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
module_require_force(mod);
}
kernconfig_unlock();
}
static struct sysctllog *module_sysctllog;
static int
sysctl_module_autotime(SYSCTLFN_ARGS)
{
struct sysctlnode node;
int t, error;
t = *(int *)rnode->sysctl_data;
node = *rnode;
node.sysctl_data = &t;
error = sysctl_lookup(SYSCTLFN_CALL(&node));
if (error || newp == NULL)
return (error);
if (t < 0)
return (EINVAL);
*(int *)rnode->sysctl_data = t;
return (0);
}
static void
sysctl_module_setup(void)
{
const struct sysctlnode *node = NULL;
sysctl_createv(&module_sysctllog, 0, NULL, &node,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "module",
SYSCTL_DESCR("Module options"),
NULL, 0, NULL, 0,
CTL_KERN, CTL_CREATE, CTL_EOL);
if (node == NULL)
return;
sysctl_createv(&module_sysctllog, 0, &node, NULL,
CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
CTLTYPE_BOOL, "autoload",
SYSCTL_DESCR("Enable automatic load of modules"),
NULL, 0, &module_autoload_on, 0,
CTL_CREATE, CTL_EOL);
sysctl_createv(&module_sysctllog, 0, &node, NULL,
CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
CTLTYPE_BOOL, "verbose",
SYSCTL_DESCR("Enable verbose output"),
NULL, 0, &module_verbose_on, 0,
CTL_CREATE, CTL_EOL);
sysctl_createv(&module_sysctllog, 0, &node, NULL,
CTLFLAG_PERMANENT | CTLFLAG_READONLY,
CTLTYPE_STRING, "path",
SYSCTL_DESCR("Default module load path"),
NULL, 0, module_base, 0,
CTL_CREATE, CTL_EOL);
sysctl_createv(&module_sysctllog, 0, &node, NULL,
CTLFLAG_PERMANENT | CTLFLAG_READWRITE,
CTLTYPE_INT, "autotime",
SYSCTL_DESCR("Auto-unload delay"),
sysctl_module_autotime, 0, &module_autotime, 0,
CTL_CREATE, CTL_EOL);
}
/*
* module_init_class:
*
* Initialize all built-in and pre-loaded modules of the
* specified class.
*/
void
module_init_class(modclass_t modclass)
{
TAILQ_HEAD(, module) bi_fail = TAILQ_HEAD_INITIALIZER(bi_fail);
module_t *mod;
modinfo_t *mi;
kernconfig_lock();
/*
* Builtins first. These will not depend on pre-loaded modules
* (because the kernel would not link).
*/
do {
TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
mi = mod->mod_info;
if (!MODULE_CLASS_MATCH(mi, modclass))
continue;
/*
* If initializing a builtin module fails, don't try
* to load it again. But keep it around and queue it
* on the builtins list after we're done with module
* init. Don't set it to MODFLG_MUST_FORCE in case a
* future attempt to initialize can be successful.
* (If the module has previously been set to
* MODFLG_MUST_FORCE, don't try to override that!)
*/
if ((mod->mod_flags & MODFLG_MUST_FORCE) ||
module_do_builtin(mod, mi->mi_name, NULL,
NULL) != 0) {
TAILQ_REMOVE(&module_builtins, mod, mod_chain);
TAILQ_INSERT_TAIL(&bi_fail, mod, mod_chain);
}
break;
}
} while (mod != NULL);
/*
* Now preloaded modules. These will be pulled off the
* list as we call module_do_load();
*/
do {
TAILQ_FOREACH(mod, &module_bootlist, mod_chain) {
mi = mod->mod_info;
if (!MODULE_CLASS_MATCH(mi, modclass))
continue;
module_do_load(mi->mi_name, false, 0, NULL, NULL,
modclass, false);
break;
}
} while (mod != NULL);
/* return failed builtin modules to builtin list */
while ((mod = TAILQ_FIRST(&bi_fail)) != NULL) {
TAILQ_REMOVE(&bi_fail, mod, mod_chain);
TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain);
}
kernconfig_unlock();
}
/*
* module_compatible:
*
* Return true if the two supplied kernel versions are said to
* have the same binary interface for kernel code. The entire
* version is signficant for the development tree (-current),
* major and minor versions are significant for official
* releases of the system.
*/
bool
module_compatible(int v1, int v2)
{
#if __NetBSD_Version__ / 1000000 % 100 == 99 /* -current */
return v1 == v2;
#else /* release */
return abs(v1 - v2) < 10000;
#endif
}
/*
* module_load:
*
* Load a single module from the file system.
*/
int
module_load(const char *filename, int flags, prop_dictionary_t props,
modclass_t modclass)
{
module_t *mod;
int error;
/* Test if we already have the module loaded before
* authorizing so we have the opportunity to return EEXIST. */
kernconfig_lock();
mod = module_lookup(filename);
if (mod != NULL) {
module_print("%s module `%s' already loaded",
"requested", filename);
error = EEXIST;
goto out;
}
/* Authorize. */
error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE,
0, (void *)(uintptr_t)MODCTL_LOAD, NULL, NULL);
if (error != 0)
goto out;
error = module_do_load(filename, false, flags, props, NULL, modclass,
false);
out:
kernconfig_unlock();
return error;
}
/*
* module_autoload:
*
* Load a single module from the file system, system initiated.
*/
int
module_autoload(const char *filename, modclass_t modclass)
{
int error;
kernconfig_lock();
/* Nothing if the user has disabled it. */
if (!module_autoload_on) {
kernconfig_unlock();
return EPERM;
}
/* Disallow path separators and magic symlinks. */
if (strchr(filename, '/') != NULL || strchr(filename, '@') != NULL ||
strchr(filename, '.') != NULL) {
kernconfig_unlock();
return EPERM;
}
/* Authorize. */
error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE,
0, (void *)(uintptr_t)MODCTL_LOAD, (void *)(uintptr_t)1, NULL);
if (error == 0)
error = module_do_load(filename, false, 0, NULL, NULL, modclass,
true);
kernconfig_unlock();
return error;
}
/*
* module_unload:
*
* Find and unload a module by name.
*/
int
module_unload(const char *name)
{
int error;
/* Authorize. */
error = kauth_authorize_system(kauth_cred_get(), KAUTH_SYSTEM_MODULE,
0, (void *)(uintptr_t)MODCTL_UNLOAD, NULL, NULL);
if (error != 0) {
return error;
}
kernconfig_lock();
error = module_do_unload(name, true);
kernconfig_unlock();
return error;
}
/*
* module_lookup:
*
* Look up a module by name.
*/
module_t *
module_lookup(const char *name)
{
module_t *mod;
KASSERT(kernconfig_is_held());
TAILQ_FOREACH(mod, &module_list, mod_chain) {
if (strcmp(mod->mod_info->mi_name, name) == 0) {
break;
}
}
return mod;
}
/*
* module_hold:
*
* Add a single reference to a module. It's the caller's
* responsibility to ensure that the reference is dropped
* later.
*/
int
module_hold(const char *name)
{
module_t *mod;
kernconfig_lock();
mod = module_lookup(name);
if (mod == NULL) {
kernconfig_unlock();
return ENOENT;
}
mod->mod_refcnt++;
kernconfig_unlock();
return 0;
}
/*
* module_rele:
*
* Release a reference acquired with module_hold().
*/
void
module_rele(const char *name)
{
module_t *mod;
kernconfig_lock();
mod = module_lookup(name);
if (mod == NULL) {
kernconfig_unlock();
panic("%s: gone", __func__);
}
mod->mod_refcnt--;
kernconfig_unlock();
}
/*
* module_enqueue:
*
* Put a module onto the global list and update counters.
*/
void
module_enqueue(module_t *mod)
{
int i;
KASSERT(kernconfig_is_held());
/*
* Put new entry at the head of the queue so autounload can unload
* requisite modules with only one pass through the queue.
*/
TAILQ_INSERT_HEAD(&module_list, mod, mod_chain);
if (mod->mod_nrequired) {
/* Add references to the requisite modules. */
for (i = 0; i < mod->mod_nrequired; i++) {
KASSERT(mod->mod_required[i] != NULL);
mod->mod_required[i]->mod_refcnt++;
}
}
module_count++;
module_gen++;
}
/*
* module_do_builtin:
*
* Initialize a module from the list of modules that are
* already linked into the kernel.
*/
static int
module_do_builtin(const module_t *pmod, const char *name, module_t **modp,
prop_dictionary_t props)
{
const char *p, *s;
char buf[MAXMODNAME];
modinfo_t *mi = NULL;
module_t *mod, *mod2, *mod_loaded, *prev_active;
size_t len;
int error;
KASSERT(kernconfig_is_held());
/*
* Search the list to see if we have a module by this name.
*/
TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
if (strcmp(mod->mod_info->mi_name, name) == 0) {
mi = mod->mod_info;
break;
}
}
/*
* Check to see if already loaded. This might happen if we
* were already loaded as a dependency.
*/
if ((mod_loaded = module_lookup(name)) != NULL) {
KASSERT(mod == NULL);
if (modp)
*modp = mod_loaded;
return 0;
}
/* Note! This is from TAILQ, not immediate above */
if (mi == NULL) {
/*
* XXX: We'd like to panic here, but currently in some
* cases (such as nfsserver + nfs), the dependee can be
* succesfully linked without the dependencies.
*/
module_error("%s: can't find builtin dependency `%s'",
pmod->mod_info->mi_name, name);
return ENOENT;
}
/*
* Initialize pre-requisites.
*/
if (mi->mi_required != NULL) {
for (s = mi->mi_required; *s != '\0'; s = p) {
if (*s == ',')
s++;
p = s;
while (*p != '\0' && *p != ',')
p++;
len = min(p - s + 1, sizeof(buf));
strlcpy(buf, s, len);
if (buf[0] == '\0')
break;
if (mod->mod_nrequired == MAXMODDEPS - 1) {
module_error("%s: too many required modules "
"%d >= %d", pmod->mod_info->mi_name,
mod->mod_nrequired, MAXMODDEPS - 1);
return EINVAL;
}
error = module_do_builtin(mod, buf, &mod2, NULL);
if (error != 0) {
return error;
}
mod->mod_required[mod->mod_nrequired++] = mod2;
}
}
/*
* Try to initialize the module.
*/
prev_active = module_active;
module_active = mod;
error = (*mi->mi_modcmd)(MODULE_CMD_INIT, props);
module_active = prev_active;
if (error != 0) {
module_error("builtin module `%s' "
"failed to init, error %d", mi->mi_name, error);
return error;
}
/* load always succeeds after this point */
TAILQ_REMOVE(&module_builtins, mod, mod_chain);
module_builtinlist--;
if (modp != NULL) {
*modp = mod;
}
module_enqueue(mod);
return 0;
}
/*
* module_do_load:
*
* Helper routine: load a module from the file system, or one
* pushed by the boot loader.
*/
static int
module_do_load(const char *name, bool isdep, int flags,
prop_dictionary_t props, module_t **modp, modclass_t modclass,
bool autoload)
{
#define MODULE_MAX_DEPTH 6
TAILQ_HEAD(pending_t, module);
static int depth = 0;
static struct pending_t *pending_lists[MODULE_MAX_DEPTH];
struct pending_t *pending;
struct pending_t new_pending = TAILQ_HEAD_INITIALIZER(new_pending);
modinfo_t *mi;
module_t *mod, *mod2, *prev_active;
prop_dictionary_t filedict;
char buf[MAXMODNAME];
const char *s, *p;
int error;
size_t len;
KASSERT(kernconfig_is_held());
filedict = NULL;
error = 0;
/*
* Avoid recursing too far.
*/
if (++depth > MODULE_MAX_DEPTH) {
module_error("recursion too deep for `%s' %d > %d", name,
depth, MODULE_MAX_DEPTH);
depth--;
return EMLINK;
}
/*
* Set up the pending list for this depth. If this is a
* recursive entry, then use same list as for outer call,
* else use the locally allocated list. In either case,
* remember which one we're using.
*/
if (isdep) {
KASSERT(depth > 1);
pending = pending_lists[depth - 2];
} else
pending = &new_pending;
pending_lists[depth - 1] = pending;
/*
* Search the list of disabled builtins first.
*/
TAILQ_FOREACH(mod, &module_builtins, mod_chain) {
if (strcmp(mod->mod_info->mi_name, name) == 0) {
break;
}
}
if (mod) {
if ((mod->mod_flags & MODFLG_MUST_FORCE) &&
(flags & MODCTL_LOAD_FORCE) == 0) {
if (!autoload) {
module_error("use -f to reinstate "
"builtin module `%s'", name);
}
depth--;
return EPERM;
} else {
error = module_do_builtin(mod, name, modp, props);
depth--;
return error;
}
}
/*
* Load the module and link. Before going to the file system,
* scan the list of modules loaded by the boot loader.
*/
TAILQ_FOREACH(mod, &module_bootlist, mod_chain) {
if (strcmp(mod->mod_info->mi_name, name) == 0) {
TAILQ_REMOVE(&module_bootlist, mod, mod_chain);
break;
}
}
if (mod != NULL) {
TAILQ_INSERT_TAIL(pending, mod, mod_chain);
} else {
/*
* Check to see if module is already present.
*/
mod = module_lookup(name);
if (mod != NULL) {
if (modp != NULL) {
*modp = mod;
}
module_print("%s module `%s' already loaded",
isdep ? "dependent" : "requested", name);
depth--;
return EEXIST;
}
mod = module_newmodule(MODULE_SOURCE_FILESYS);
if (mod == NULL) {
module_error("out of memory for `%s'", name);
depth--;
return ENOMEM;
}
error = module_load_vfs_vec(name, flags, autoload, mod,
&filedict);
if (error != 0) {
#ifdef DEBUG
/*
* The exec class of modules contains a list of
* modules that is the union of all the modules
* available for each architecture, so we don't
* print an error if they are missing.
*/
if ((modclass != MODULE_CLASS_EXEC || error != ENOENT)
&& root_device != NULL)
module_error("vfs load failed for `%s', "
"error %d", name, error);
#endif
kmem_free(mod, sizeof(*mod));
depth--;
return error;
}
TAILQ_INSERT_TAIL(pending, mod, mod_chain);
error = module_fetch_info(mod);
if (error != 0) {
module_error("cannot fetch info for `%s', error %d",
name, error);
goto fail;
}
}
/*
* Check compatibility.
*/
mi = mod->mod_info;
if (strlen(mi->mi_name) >= MAXMODNAME) {
error = EINVAL;
module_error("module name `%s' longer than %d", mi->mi_name,
MAXMODNAME);
goto fail;
}
if (!module_compatible(mi->mi_version, __NetBSD_Version__)) {
module_error("module `%s' built for `%d', system `%d'",
mi->mi_name, mi->mi_version, __NetBSD_Version__);
if ((flags & MODCTL_LOAD_FORCE) != 0) {
module_error("forced load, system may be unstable");
} else {
error = EPROGMISMATCH;
goto fail;
}
}
/*
* If a specific kind of module was requested, ensure that we have
* a match.
*/
if (!MODULE_CLASS_MATCH(mi, modclass)) {
module_incompat(mi, modclass);
error = ENOENT;
goto fail;
}
/*
* If loading a dependency, `name' is a plain module name.
* The name must match.
*/
if (isdep && strcmp(mi->mi_name, name) != 0) {
module_error("dependency name mismatch (`%s' != `%s')",
name, mi->mi_name);
error = ENOENT;
goto fail;
}
/*
* If we loaded a module from the filesystem, check the actual
* module name (from the modinfo_t) to ensure another module
* with the same name doesn't already exist. (There's no
* guarantee the filename will match the module name, and the
* dup-symbols check may not be sufficient.)
*/
if (mod->mod_source == MODULE_SOURCE_FILESYS) {
mod2 = module_lookup(mod->mod_info->mi_name);
if ( mod2 && mod2 != mod) {
module_error("module with name `%s' already loaded",
mod2->mod_info->mi_name);
error = EEXIST;
goto fail;
}
}
/*
* Block circular dependencies.
*/
TAILQ_FOREACH(mod2, pending, mod_chain) {
if (mod == mod2) {
continue;
}
if (strcmp(mod2->mod_info->mi_name, mi->mi_name) == 0) {
error = EDEADLK;
module_error("circular dependency detected for `%s'",
mi->mi_name);
goto fail;
}
}
/*
* Now try to load any requisite modules.
*/
if (mi->mi_required != NULL) {
for (s = mi->mi_required; *s != '\0'; s = p) {
if (*s == ',')
s++;
p = s;
while (*p != '\0' && *p != ',')
p++;
len = p - s + 1;
if (len >= MAXMODNAME) {
error = EINVAL;
module_error("required module name `%s' "
"longer than %d", mi->mi_required,
MAXMODNAME);
goto fail;
}
strlcpy(buf, s, len);
if (buf[0] == '\0')
break;
if (mod->mod_nrequired == MAXMODDEPS - 1) {
error = EINVAL;
module_error("too many required modules "
"%d >= %d", mod->mod_nrequired,
MAXMODDEPS - 1);
goto fail;
}
if (strcmp(buf, mi->mi_name) == 0) {
error = EDEADLK;
module_error("self-dependency detected for "
"`%s'", mi->mi_name);
goto fail;
}
error = module_do_load(buf, true, flags, NULL,
&mod2, MODULE_CLASS_ANY, true);
if (error != 0 && error != EEXIST) {
module_error("recursive load failed for `%s' "
"(`%s' required), error %d", mi->mi_name,
buf, error);
goto fail;
}
mod->mod_required[mod->mod_nrequired++] = mod2;
}
}
/*
* We loaded all needed modules successfully: perform global
* relocations and initialize.
*/
error = kobj_affix(mod->mod_kobj, mi->mi_name);
if (error != 0) {
/* Cannot touch 'mi' as the module is now gone. */
module_error("unable to affix module `%s', error %d", name,
error);
goto fail2;
}
if (filedict) {
if (!module_merge_dicts(filedict, props)) {
module_error("module properties failed for %s", name);
error = EINVAL;
goto fail;
}
}
prev_active = module_active;
module_active = mod;
error = (*mi->mi_modcmd)(MODULE_CMD_INIT, filedict ? filedict : props);
module_active = prev_active;
if (filedict) {
prop_object_release(filedict);
filedict = NULL;
}
if (error != 0) {
module_error("modcmd function failed for `%s', error %d",
mi->mi_name, error);
goto fail;
}
/*
* If a recursive load already added a module with the same
* name, abort.
*/
mod2 = module_lookup(mi->mi_name);
if (mod2 && mod2 != mod) {
module_error("recursive load causes duplicate module `%s'",
mi->mi_name);
error = EEXIST;
goto fail1;
}
/*
* Good, the module loaded successfully. Put it onto the
* list and add references to its requisite modules.
*/
TAILQ_REMOVE(pending, mod, mod_chain);
module_enqueue(mod);
if (modp != NULL) {
*modp = mod;
}
if (autoload && module_autotime > 0) {
/*
* Arrange to try unloading the module after
* a short delay unless auto-unload is disabled.
*/
mod->mod_autotime = time_second + module_autotime;
mod->mod_flags |= MODFLG_AUTO_LOADED;
module_thread_kick();
}
depth--;
module_print("module `%s' loaded successfully", mi->mi_name);
return 0;
fail1:
(*mi->mi_modcmd)(MODULE_CMD_FINI, NULL);
fail:
kobj_unload(mod->mod_kobj);
fail2:
if (filedict != NULL) {
prop_object_release(filedict);
filedict = NULL;
}
TAILQ_REMOVE(pending, mod, mod_chain);
kmem_free(mod, sizeof(*mod));
depth--;
return error;
}
/*
* module_do_unload:
*
* Helper routine: do the dirty work of unloading a module.
*/
static int
module_do_unload(const char *name, bool load_requires_force)
{
module_t *mod, *prev_active;
int error;
u_int i;
KASSERT(kernconfig_is_held());
KASSERT(name != NULL);
module_print("unload requested for '%s' (%s)", name,
load_requires_force ? "TRUE" : "FALSE");
mod = module_lookup(name);
if (mod == NULL) {
module_error("module `%s' not found", name);
return ENOENT;
}
if (mod->mod_refcnt != 0) {
module_print("module `%s' busy (%d refs)", name,
mod->mod_refcnt);
return EBUSY;
}
/*
* Builtin secmodels are there to stay.
*/
if (mod->mod_source == MODULE_SOURCE_KERNEL &&
mod->mod_info->mi_class == MODULE_CLASS_SECMODEL) {
module_print("cannot unload built-in secmodel module `%s'",
name);
return EPERM;
}
prev_active = module_active;
module_active = mod;
error = (*mod->mod_info->mi_modcmd)(MODULE_CMD_FINI, NULL);
module_active = prev_active;
if (error != 0) {
module_print("cannot unload module `%s' error=%d", name,
error);
return error;
}
module_count--;
TAILQ_REMOVE(&module_list, mod, mod_chain);
for (i = 0; i < mod->mod_nrequired; i++) {
mod->mod_required[i]->mod_refcnt--;
}
module_print("unloaded module `%s'", name);
if (mod->mod_kobj != NULL) {
kobj_unload(mod->mod_kobj);
}
if (mod->mod_source == MODULE_SOURCE_KERNEL) {
mod->mod_nrequired = 0; /* will be re-parsed */
if (load_requires_force)
module_require_force(mod);
TAILQ_INSERT_TAIL(&module_builtins, mod, mod_chain);
module_builtinlist++;
} else {
kmem_free(mod, sizeof(*mod));
}
module_gen++;
return 0;
}
/*
* module_prime:
*
* Push a module loaded by the bootloader onto our internal
* list.
*/
int
module_prime(const char *name, void *base, size_t size)
{
__link_set_decl(modules, modinfo_t);
modinfo_t *const *mip;
module_t *mod;
int error;
/* Check for module name same as a built-in module */
__link_set_foreach(mip, modules) {
if (*mip == &module_dummy)
continue;
if (strcmp((*mip)->mi_name, name) == 0) {
module_error("module `%s' pushed by boot loader "
"already exists", name);
return EEXIST;
}
}
/* Also eliminate duplicate boolist entries */
TAILQ_FOREACH(mod, &module_bootlist, mod_chain) {
if (strcmp(mod->mod_info->mi_name, name) == 0) {
module_error("duplicate bootlist entry for module "
"`%s'", name);
return EEXIST;
}
}
mod = module_newmodule(MODULE_SOURCE_BOOT);
if (mod == NULL) {
return ENOMEM;
}
error = kobj_load_mem(&mod->mod_kobj, name, base, size);
if (error != 0) {
kmem_free(mod, sizeof(*mod));
module_error("unable to load `%s' pushed by boot loader, "
"error %d", name, error);
return error;
}
error = module_fetch_info(mod);
if (error != 0) {
kobj_unload(mod->mod_kobj);
kmem_free(mod, sizeof(*mod));
module_error("unable to fetch_info for `%s' pushed by boot "
"loader, error %d", name, error);
return error;
}
TAILQ_INSERT_TAIL(&module_bootlist, mod, mod_chain);
return 0;
}
/*
* module_fetch_into:
*
* Fetch modinfo record from a loaded module.
*/
static int
module_fetch_info(module_t *mod)
{
int error;
void *addr;
size_t size;
/*
* Find module info record and check compatibility.
*/
error = kobj_find_section(mod->mod_kobj, "link_set_modules",
&addr, &size);
if (error != 0) {
module_error("`link_set_modules' section not present, "
"error %d", error);
return error;
}
if (size != sizeof(modinfo_t **)) {
module_error("`link_set_modules' section wrong size %zu != %zu",
size, sizeof(modinfo_t **));
return ENOEXEC;
}
mod->mod_info = *(modinfo_t **)addr;
return 0;
}
/*
* module_find_section:
*
* Allows a module that is being initialized to look up a section
* within its ELF object.
*/
int
module_find_section(const char *name, void **addr, size_t *size)
{
KASSERT(kernconfig_is_held());
KASSERT(module_active != NULL);
return kobj_find_section(module_active->mod_kobj, name, addr, size);
}
/*
* module_thread:
*
* Automatically unload modules. We try once to unload autoloaded
* modules after module_autotime seconds. If the system is under
* severe memory pressure, we'll try unloading all modules, else if
* module_autotime is zero, we don't try to unload, even if the
* module was previously scheduled for unload.
*/
static void
module_thread(void *cookie)
{
module_t *mod, *next;
modinfo_t *mi;
int error;
for (;;) {
kernconfig_lock();
for (mod = TAILQ_FIRST(&module_list); mod != NULL; mod = next) {
next = TAILQ_NEXT(mod, mod_chain);
/* skip built-in modules */
if (mod->mod_source == MODULE_SOURCE_KERNEL)
continue;
/* skip modules that weren't auto-loaded */
if ((mod->mod_flags & MODFLG_AUTO_LOADED) == 0)
continue;
if (uvmexp.free < uvmexp.freemin) {
module_thread_ticks = hz;
} else if (module_autotime == 0 ||
mod->mod_autotime == 0) {
continue;
} else if (time_second < mod->mod_autotime) {
module_thread_ticks = hz;
continue;
} else {
mod->mod_autotime = 0;
}
/*
* If this module wants to avoid autounload then
* skip it. Some modules can ping-pong in and out
* because their use is transient but often.
* Example: exec_script.
*/
mi = mod->mod_info;
error = (*mi->mi_modcmd)(MODULE_CMD_AUTOUNLOAD, NULL);
if (error == 0 || error == ENOTTY) {
(void)module_do_unload(mi->mi_name, false);
} else
module_print("module `%s' declined to be "
"auto-unloaded error=%d", mi->mi_name,
error);
}
kernconfig_unlock();
mutex_enter(&module_thread_lock);
(void)cv_timedwait(&module_thread_cv, &module_thread_lock,
module_thread_ticks);
module_thread_ticks = 0;
mutex_exit(&module_thread_lock);
}
}
/*
* module_thread:
*
* Kick the module thread into action, perhaps because the
* system is low on memory.
*/
void
module_thread_kick(void)
{
mutex_enter(&module_thread_lock);
module_thread_ticks = hz;
cv_broadcast(&module_thread_cv);
mutex_exit(&module_thread_lock);
}
#ifdef DDB
/*
* module_whatis:
*
* Helper routine for DDB.
*/
void
module_whatis(uintptr_t addr, void (*pr)(const char *, ...))
{
module_t *mod;
size_t msize;
vaddr_t maddr;
TAILQ_FOREACH(mod, &module_list, mod_chain) {
if (mod->mod_kobj == NULL) {
continue;
}
if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0)
continue;
if (addr < maddr || addr >= maddr + msize) {
continue;
}
(*pr)("%p is %p+%zu, in kernel module `%s'\n",
(void *)addr, (void *)maddr,
(size_t)(addr - maddr), mod->mod_info->mi_name);
}
}
/*
* module_print_list:
*
* Helper routine for DDB.
*/
void
module_print_list(void (*pr)(const char *, ...))
{
const char *src;
module_t *mod;
size_t msize;
vaddr_t maddr;
(*pr)("%16s %16s %8s %8s\n", "NAME", "TEXT/DATA", "SIZE", "SOURCE");
TAILQ_FOREACH(mod, &module_list, mod_chain) {
switch (mod->mod_source) {
case MODULE_SOURCE_KERNEL:
src = "builtin";
break;
case MODULE_SOURCE_FILESYS:
src = "filesys";
break;
case MODULE_SOURCE_BOOT:
src = "boot";
break;
default:
src = "unknown";
break;
}
if (mod->mod_kobj == NULL) {
maddr = 0;
msize = 0;
} else if (kobj_stat(mod->mod_kobj, &maddr, &msize) != 0)
continue;
(*pr)("%16s %16lx %8ld %8s\n", mod->mod_info->mi_name,
(long)maddr, (long)msize, src);
}
}
#endif /* DDB */
static bool
module_merge_dicts(prop_dictionary_t existing_dict,
const prop_dictionary_t new_dict)
{
prop_dictionary_keysym_t props_keysym;
prop_object_iterator_t props_iter;
prop_object_t props_obj;
const char *props_key;
bool error;
if (new_dict == NULL) { /* nothing to merge */
return true;
}
error = false;
props_iter = prop_dictionary_iterator(new_dict);
if (props_iter == NULL) {
return false;
}
while ((props_obj = prop_object_iterator_next(props_iter)) != NULL) {
props_keysym = (prop_dictionary_keysym_t)props_obj;
props_key = prop_dictionary_keysym_cstring_nocopy(props_keysym);
props_obj = prop_dictionary_get_keysym(new_dict, props_keysym);
if ((props_obj == NULL) || !prop_dictionary_set(existing_dict,
props_key, props_obj)) {
error = true;
goto out;
}
}
error = false;
out:
prop_object_iterator_release(props_iter);
return !error;
}
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