1 // SPDX-License-Identifier: GPL-2.0
5  * These functions handle creation of KMSAN metadata for memory allocations.
7  * Copyright (C) 2018-2022 Google LLC
13 #include <linux/dma-direction.h>
55 	 * There's a ctor or this is an RCU cache - do nothing. The memory  in kmsan_slab_alloc()
58 	if (s->ctor || (s->flags & SLAB_TYPESAFE_BY_RCU))  in kmsan_slab_alloc()
63 		kmsan_internal_unpoison_memory(object, s->object_size,  in kmsan_slab_alloc()
66 		kmsan_internal_poison_memory(object, s->object_size, flags,  in kmsan_slab_alloc()
77 	if (unlikely(s->flags & SLAB_TYPESAFE_BY_RCU))  in kmsan_slab_free()
80 	 * If there's a constructor, freed memory must remain in the same state  in kmsan_slab_free()
82 	 * use-after-free bugs, instead we just keep it unpoisoned.  in kmsan_slab_free()
84 	if (s->ctor)  in kmsan_slab_free()
87 	kmsan_internal_poison_memory(object, s->object_size, GFP_KERNEL,  in kmsan_slab_free()
145  * This function creates new shadow/origin pages for the physical pages mapped
146  * into the virtual memory. If those physical pages already had shadow/origin,
156 	int nr, err = 0, clean = 0, mapped;  in kmsan_ioremap_page_range()  local
161 	nr = (end - start) / PAGE_SIZE;  in kmsan_ioremap_page_range()
167 			err = -ENOMEM;  in kmsan_ioremap_page_range()
170 		mapped = __vmap_pages_range_noflush(  in kmsan_ioremap_page_range()
174 		if (mapped) {  in kmsan_ioremap_page_range()
175 			err = mapped;  in kmsan_ioremap_page_range()
179 		mapped = __vmap_pages_range_noflush(  in kmsan_ioremap_page_range()
183 		if (mapped) {  in kmsan_ioremap_page_range()
187 			err = mapped;  in kmsan_ioremap_page_range()
228 	nr = (end - start) / PAGE_SIZE;  in kmsan_iounmap_page_range()
256 	 * At this point we've copied the memory already. It's hard to check it  in kmsan_copy_to_user()
270 		/* This is a user memory access, check it. */  in kmsan_copy_to_user()
271 		kmsan_internal_check_memory((void *)from, to_copy - left, to,  in kmsan_copy_to_user()
274 		/* Otherwise this is a kernel memory access. This happens when a  in kmsan_copy_to_user()
281 						to_copy - left);  in kmsan_copy_to_user()
304 		kmsan_internal_check_memory(urb->transfer_buffer,  in kmsan_handle_urb()
305 					    urb->transfer_buffer_length,  in kmsan_handle_urb()
309 		kmsan_internal_unpoison_memory(urb->transfer_buffer,  in kmsan_handle_urb()
310 					       urb->transfer_buffer_length,  in kmsan_handle_urb()
354 		to_go = min(PAGE_SIZE - page_offset, (u64)size);  in kmsan_handle_dma()
357 		size -= to_go;  in kmsan_handle_dma()
369 		kmsan_handle_dma(sg_page(item), item->offset, item->length,  in kmsan_handle_dma_sg()
373 /* Functions from kmsan-checks.h follow. */
385 	/* The users may want to poison/unpoison random memory. */  in kmsan_poison_memory()
404 	/* The users may want to poison/unpoison random memory. */  in kmsan_unpoison_memory()
430 	KMSAN_WARN_ON(current->kmsan_ctx.depth == 0);  in kmsan_enable_current()
431 	current->kmsan_ctx.depth--;  in kmsan_enable_current()
437 	current->kmsan_ctx.depth++;  in kmsan_disable_current()
438 	KMSAN_WARN_ON(current->kmsan_ctx.depth == 0);  in kmsan_disable_current()