kasan: rename report and tags files

Rename generic_report.c to report_generic.c and tags_report.c to
report_sw_tags.c, as their content is more relevant to report.c file.
Also rename tags.c to sw_tags.c to better reflect that this file contains
code for software tag-based mode.

No functional changes.

Link: https://lkml.kernel.org/r/a6105d416da97d389580015afed66c4c3cfd4c08.1606161801.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Marco Elver <elver@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Branislav Rankov <Branislav.Rankov@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 0 insertions, 195 deletions

diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c
deleted file mode 100644
index c0b3f327812b..000000000000
--- a/mm/kasan/tags.c
+++ /dev/null
@@ -1,195 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * This file contains core tag-based KASAN code.
- *
- * Copyright (c) 2018 Google, Inc.
- * Author: Andrey Konovalov <andreyknvl@google.com>
- */
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/export.h>
-#include <linux/interrupt.h>
-#include <linux/init.h>
-#include <linux/kasan.h>
-#include <linux/kernel.h>
-#include <linux/kmemleak.h>
-#include <linux/linkage.h>
-#include <linux/memblock.h>
-#include <linux/memory.h>
-#include <linux/mm.h>
-#include <linux/module.h>
-#include <linux/printk.h>
-#include <linux/random.h>
-#include <linux/sched.h>
-#include <linux/sched/task_stack.h>
-#include <linux/slab.h>
-#include <linux/stacktrace.h>
-#include <linux/string.h>
-#include <linux/types.h>
-#include <linux/vmalloc.h>
-#include <linux/bug.h>
-
-#include "kasan.h"
-#include "../slab.h"
-
-static DEFINE_PER_CPU(u32, prng_state);
-
-void kasan_init_tags(void)
-{
-	int cpu;
-
-	for_each_possible_cpu(cpu)
-		per_cpu(prng_state, cpu) = (u32)get_cycles();
-}
-
-/*
- * If a preemption happens between this_cpu_read and this_cpu_write, the only
- * side effect is that we'll give a few allocated in different contexts objects
- * the same tag. Since tag-based KASAN is meant to be used a probabilistic
- * bug-detection debug feature, this doesn't have significant negative impact.
- *
- * Ideally the tags use strong randomness to prevent any attempts to predict
- * them during explicit exploit attempts. But strong randomness is expensive,
- * and we did an intentional trade-off to use a PRNG. This non-atomic RMW
- * sequence has in fact positive effect, since interrupts that randomly skew
- * PRNG at unpredictable points do only good.
- */
-u8 random_tag(void)
-{
-	u32 state = this_cpu_read(prng_state);
-
-	state = 1664525 * state + 1013904223;
-	this_cpu_write(prng_state, state);
-
-	return (u8)(state % (KASAN_TAG_MAX + 1));
-}
-
-void *kasan_reset_tag(const void *addr)
-{
-	return reset_tag(addr);
-}
-
-bool check_memory_region(unsigned long addr, size_t size, bool write,
-				unsigned long ret_ip)
-{
-	u8 tag;
-	u8 *shadow_first, *shadow_last, *shadow;
-	void *untagged_addr;
-
-	if (unlikely(size == 0))
-		return true;
-
-	if (unlikely(addr + size < addr))
-		return !kasan_report(addr, size, write, ret_ip);
-
-	tag = get_tag((const void *)addr);
-
-	/*
-	 * Ignore accesses for pointers tagged with 0xff (native kernel
-	 * pointer tag) to suppress false positives caused by kmap.
-	 *
-	 * Some kernel code was written to account for archs that don't keep
-	 * high memory mapped all the time, but rather map and unmap particular
-	 * pages when needed. Instead of storing a pointer to the kernel memory,
-	 * this code saves the address of the page structure and offset within
-	 * that page for later use. Those pages are then mapped and unmapped
-	 * with kmap/kunmap when necessary and virt_to_page is used to get the
-	 * virtual address of the page. For arm64 (that keeps the high memory
-	 * mapped all the time), kmap is turned into a page_address call.
-
-	 * The issue is that with use of the page_address + virt_to_page
-	 * sequence the top byte value of the original pointer gets lost (gets
-	 * set to KASAN_TAG_KERNEL (0xFF)).
-	 */
-	if (tag == KASAN_TAG_KERNEL)
-		return true;
-
-	untagged_addr = reset_tag((const void *)addr);
-	if (unlikely(untagged_addr <
-			kasan_shadow_to_mem((void *)KASAN_SHADOW_START))) {
-		return !kasan_report(addr, size, write, ret_ip);
-	}
-	shadow_first = kasan_mem_to_shadow(untagged_addr);
-	shadow_last = kasan_mem_to_shadow(untagged_addr + size - 1);
-	for (shadow = shadow_first; shadow <= shadow_last; shadow++) {
-		if (*shadow != tag) {
-			return !kasan_report(addr, size, write, ret_ip);
-		}
-	}
-
-	return true;
-}
-
-#define DEFINE_HWASAN_LOAD_STORE(size)					\
-	void __hwasan_load##size##_noabort(unsigned long addr)		\
-	{								\
-		check_memory_region(addr, size, false, _RET_IP_);	\
-	}								\
-	EXPORT_SYMBOL(__hwasan_load##size##_noabort);			\
-	void __hwasan_store##size##_noabort(unsigned long addr)		\
-	{								\
-		check_memory_region(addr, size, true, _RET_IP_);	\
-	}								\
-	EXPORT_SYMBOL(__hwasan_store##size##_noabort)
-
-DEFINE_HWASAN_LOAD_STORE(1);
-DEFINE_HWASAN_LOAD_STORE(2);
-DEFINE_HWASAN_LOAD_STORE(4);
-DEFINE_HWASAN_LOAD_STORE(8);
-DEFINE_HWASAN_LOAD_STORE(16);
-
-void __hwasan_loadN_noabort(unsigned long addr, unsigned long size)
-{
-	check_memory_region(addr, size, false, _RET_IP_);
-}
-EXPORT_SYMBOL(__hwasan_loadN_noabort);
-
-void __hwasan_storeN_noabort(unsigned long addr, unsigned long size)
-{
-	check_memory_region(addr, size, true, _RET_IP_);
-}
-EXPORT_SYMBOL(__hwasan_storeN_noabort);
-
-void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size)
-{
-	poison_range((void *)addr, size, tag);
-}
-EXPORT_SYMBOL(__hwasan_tag_memory);
-
-void kasan_set_free_info(struct kmem_cache *cache,
-				void *object, u8 tag)
-{
-	struct kasan_alloc_meta *alloc_meta;
-	u8 idx = 0;
-
-	alloc_meta = get_alloc_info(cache, object);
-
-#ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
-	idx = alloc_meta->free_track_idx;
-	alloc_meta->free_pointer_tag[idx] = tag;
-	alloc_meta->free_track_idx = (idx + 1) % KASAN_NR_FREE_STACKS;
-#endif
-
-	kasan_set_track(&alloc_meta->free_track[idx], GFP_NOWAIT);
-}
-
-struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
-				void *object, u8 tag)
-{
-	struct kasan_alloc_meta *alloc_meta;
-	int i = 0;
-
-	alloc_meta = get_alloc_info(cache, object);
-
-#ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY
-	for (i = 0; i < KASAN_NR_FREE_STACKS; i++) {
-		if (alloc_meta->free_pointer_tag[i] == tag)
-			break;
-	}
-	if (i == KASAN_NR_FREE_STACKS)
-		i = alloc_meta->free_track_idx;
-#endif
-
-	return &alloc_meta->free_track[i];
-}