x86/kernel/ldt.c

26 #include <asm/ldt.h>
44 	struct ldt_struct *ldt;
47 	ldt = READ_ONCE(mm->context.ldt);
50 	 * Any change to mm->context.ldt is followed by an IPI to all
63 	if (unlikely(ldt)) {
65 			if (WARN_ON_ONCE((unsigned long)ldt->slot > 1)) {
76 			 * If page table isolation is enabled, ldt->entries
79 			 * at ldt_slot_va(ldt->slot).
81 			set_ldt(ldt_slot_va(ldt->slot), ldt->nr_entries);
83 			set_ldt(ldt->entries, ldt->nr_entries);
98 	 * prev->context.ldt actually matches LDTR, but, if LDTR is non-NULL,
99 	 * then prev->context.ldt will also be non-NULL.
109 	if (unlikely((unsigned long)prev->context.ldt |
110 		     (unsigned long)next->context.ldt))
193 	if (mm->context.ldt) {
243 	if (boot_cpu_has(X86_FEATURE_PTI) && !mm->context.ldt)
268 	if (boot_cpu_has(X86_FEATURE_PTI) && !mm->context.ldt)
288 map_ldt_struct(struct mm_struct *mm, struct ldt_struct *ldt, int slot)
302 	WARN_ON(ldt->slot != -1);
307 	is_vmalloc = is_vmalloc_addr(ldt->entries);
309 	nr_pages = DIV_ROUND_UP(ldt->nr_entries * LDT_ENTRY_SIZE, PAGE_SIZE);
313 		const void *src = (char *)ldt->entries + offset;
345 	ldt->slot = slot;
349 static void unmap_ldt_struct(struct mm_struct *mm, struct ldt_struct *ldt)
354 	if (!ldt)
361 	nr_pages = DIV_ROUND_UP(ldt->nr_entries * LDT_ENTRY_SIZE, PAGE_SIZE);
368 		va = (unsigned long)ldt_slot_va(ldt->slot) + offset;
376 	va = (unsigned long)ldt_slot_va(ldt->slot);
383 map_ldt_struct(struct mm_struct *mm, struct ldt_struct *ldt, int slot)
388 static void unmap_ldt_struct(struct mm_struct *mm, struct ldt_struct *ldt)
416 static void finalize_ldt_struct(struct ldt_struct *ldt)
418 	paravirt_alloc_ldt(ldt->entries, ldt->nr_entries);
421 static void install_ldt(struct mm_struct *mm, struct ldt_struct *ldt)
426 	smp_store_release(&mm->context.ldt, ldt);
434 static void free_ldt_struct(struct ldt_struct *ldt)
436 	if (likely(!ldt))
439 	paravirt_free_ldt(ldt->entries, ldt->nr_entries);
440 	if (ldt->nr_entries * LDT_ENTRY_SIZE > PAGE_SIZE)
441 		vfree_atomic(ldt->entries);
443 		free_page((unsigned long)ldt->entries);
444 	kfree(ldt);
460 	if (!old_mm->context.ldt)
463 	new_ldt = alloc_ldt_struct(old_mm->context.ldt->nr_entries);
469 	memcpy(new_ldt->entries, old_mm->context.ldt->entries,
479 	mm->context.ldt = new_ldt;
493 	free_ldt_struct(mm->context.ldt);
494 	mm->context.ldt = NULL;
510 	if (!mm->context.ldt) {
518 	entries_size = mm->context.ldt->nr_entries * LDT_ENTRY_SIZE;
522 	if (copy_to_user(ptr, mm->context.ldt->entries, entries_size)) {
584 	struct desc_struct ldt;
607 		memset(&ldt, 0, sizeof(ldt));
614 		fill_ldt(&ldt, &ldt_info);
616 			ldt.avl = 0;
622 	old_ldt       = mm->context.ldt;
634 	new_ldt->entries[ldt_info.entry_number] = ldt;