Function linker_file_unload

freebsd/kern/kern_linker.c:634–755

}

int
linker_file_unload(linker_file_t file, int flags)
{
	module_t mod, next;
	modlist_t ml, nextml;
	struct common_symbol *cp;
	int error, i;

	/* Refuse to unload modules if securelevel raised. */
	if (prison0.pr_securelevel > 0)
		return (EPERM);

	sx_assert(&kld_sx, SA_XLOCKED);
	KLD_DPF(FILE, ("linker_file_unload: lf->refs=%d\n", file->refs));

	/* Easy case of just dropping a reference. */
	if (file->refs > 1) {
		file->refs--;
		return (0);
	}

	/* Give eventhandlers a chance to prevent the unload. */
	error = 0;
	EVENTHANDLER_INVOKE(kld_unload_try, file, &error);
	if (error != 0)
		return (EBUSY);

	KLD_DPF(FILE, ("linker_file_unload: file is unloading,"
	    " informing modules\n"));

	/*
	 * Quiesce all the modules to give them a chance to veto the unload.
	 */
	MOD_SLOCK;
	for (mod = TAILQ_FIRST(&file->modules); mod;
	     mod = module_getfnext(mod)) {
		error = module_quiesce(mod);
		if (error != 0 && flags != LINKER_UNLOAD_FORCE) {
			KLD_DPF(FILE, ("linker_file_unload: module %s"
			    " vetoed unload\n", module_getname(mod)));
			/*
			 * XXX: Do we need to tell all the quiesced modules
			 * that they can resume work now via a new module
			 * event?
			 */
			MOD_SUNLOCK;
			return (error);
		}
	}
	MOD_SUNLOCK;

	/*
	 * Inform any modules associated with this file that they are
	 * being unloaded.
	 */
	MOD_XLOCK;
	for (mod = TAILQ_FIRST(&file->modules); mod; mod = next) {
		next = module_getfnext(mod);