x86/um/ldt.c

45  * In skas mode, we hold our own ldt data in UML.
48  * for arch/i386/kernel/ldt.c
60 	uml_ldt_t *ldt = &current->mm->context.arch.ldt;
62 	if (!ldt->entry_count)
68 	mutex_lock(&ldt->lock);
69 	if (ldt->entry_count <= LDT_DIRECT_ENTRIES) {
73 		if (copy_to_user(ptr, ldt->u.entries, size))
79 		for (i=0; i<ldt->entry_count/LDT_ENTRIES_PER_PAGE && bytecount;
84 			if (copy_to_user(ptr, ldt->u.pages[i], size)) {
92 	mutex_unlock(&ldt->lock);
114 	 * So, we don't really have a default ldt, but emulate
115 	 * an empty ldt of common host default ldt size.
125 	uml_ldt_t *ldt = &current->mm->context.arch.ldt;
149 	mutex_lock(&ldt->lock);
155 	if (ldt_info.entry_number >= ldt->entry_count &&
157 		for (i=ldt->entry_count/LDT_ENTRIES_PER_PAGE;
161 				memcpy(&entry0, ldt->u.entries,
163 			ldt->u.pages[i] = (struct ldt_entry *)
165 			if (!ldt->u.pages[i]) {
173 				memcpy(ldt->u.pages[0], &entry0,
175 				memcpy(ldt->u.pages[0]+1, ldt->u.entries+1,
178 			ldt->entry_count = (i + 1) * LDT_ENTRIES_PER_PAGE;
181 	if (ldt->entry_count <= ldt_info.entry_number)
182 		ldt->entry_count = ldt_info.entry_number + 1;
184 	if (ldt->entry_count <= LDT_DIRECT_ENTRIES)
185 		ldt_p = ldt->u.entries + ldt_info.entry_number;
187 		ldt_p = ldt->u.pages[ldt_info.entry_number/LDT_ENTRIES_PER_PAGE] +
204 	mutex_unlock(&ldt->lock);
236 	struct ldt_entry * ldt;
253 	ldt = (struct ldt_entry *)
255 	if (ldt == NULL) {
257 		       "for host ldt\n");
261 	ret = modify_ldt(0, ldt, (1<<order)*PAGE_SIZE);
263 		printk(KERN_ERR "ldt_get_host_info: couldn't read host ldt\n");
273 		if (ldt[i].a != 0 || ldt[i].b != 0)
284 			       "host ldt list\n");
291 		if (ldt[i].a != 0 || ldt[i].b != 0)
297 	free_pages((unsigned long)ldt, order);
309 	mutex_init(&new_mm->arch.ldt.lock);
314 		 * Now we try to retrieve info about the ldt, we
315 		 * inherited from the host. All ldt-entries found
326 		new_mm->arch.ldt.entry_count = 0;
337 	mutex_lock(&from_mm->arch.ldt.lock);
338 	if (from_mm->arch.ldt.entry_count <= LDT_DIRECT_ENTRIES)
339 		memcpy(new_mm->arch.ldt.u.entries, from_mm->arch.ldt.u.entries,
340 		       sizeof(new_mm->arch.ldt.u.entries));
342 		i = from_mm->arch.ldt.entry_count / LDT_ENTRIES_PER_PAGE;
349 			new_mm->arch.ldt.u.pages[i] =
351 			memcpy(new_mm->arch.ldt.u.pages[i],
352 			       from_mm->arch.ldt.u.pages[i], PAGE_SIZE);
355 	new_mm->arch.ldt.entry_count = from_mm->arch.ldt.entry_count;
356 	mutex_unlock(&from_mm->arch.ldt.lock);
367 	if (mm->arch.ldt.entry_count > LDT_DIRECT_ENTRIES) {
368 		i = mm->arch.ldt.entry_count / LDT_ENTRIES_PER_PAGE;
370 			free_page((long) mm->arch.ldt.u.pages[i]);
372 	mm->arch.ldt.entry_count = 0;