[PATCH v4 2/3] kasan: integrate the common part of two KASAN tag-based modes
Kuan-Ying Lee
Kuan-Ying.Lee at mediatek.com
Sat Jun 26 03:09:30 PDT 2021
1. Move kasan_get_free_track() and kasan_set_free_info()
into tags.c and combine these two functions for
SW_TAGS and HW_TAGS kasan mode.
2. Move kasan_get_bug_type() to report_tags.c and
make this function compatible for SW_TAGS and
HW_TAGS kasan mode.
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee at mediatek.com>
Suggested-by: Marco Elver <elver at google.com>
Suggested-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
Cc: Andrey Ryabinin <ryabinin.a.a at gmail.com>
Cc: Alexander Potapenko <glider at google.com>
Cc: Andrey Konovalov <andreyknvl at gmail.com>
Cc: Dmitry Vyukov <dvyukov at google.com>
Cc: Andrew Morton <akpm at linux-foundation.org>
---
mm/kasan/Makefile | 4 +--
mm/kasan/hw_tags.c | 22 ---------------
mm/kasan/report_hw_tags.c | 5 ----
mm/kasan/report_sw_tags.c | 43 ----------------------------
mm/kasan/report_tags.c | 51 +++++++++++++++++++++++++++++++++
mm/kasan/sw_tags.c | 41 ---------------------------
mm/kasan/tags.c | 59 +++++++++++++++++++++++++++++++++++++++
7 files changed, 112 insertions(+), 113 deletions(-)
create mode 100644 mm/kasan/report_tags.c
create mode 100644 mm/kasan/tags.c
diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile
index 9fe39a66388a..adcd9acaef61 100644
--- a/mm/kasan/Makefile
+++ b/mm/kasan/Makefile
@@ -37,5 +37,5 @@ CFLAGS_sw_tags.o := $(CC_FLAGS_KASAN_RUNTIME)
obj-$(CONFIG_KASAN) := common.o report.o
obj-$(CONFIG_KASAN_GENERIC) += init.o generic.o report_generic.o shadow.o quarantine.o
-obj-$(CONFIG_KASAN_HW_TAGS) += hw_tags.o report_hw_tags.o
-obj-$(CONFIG_KASAN_SW_TAGS) += init.o report_sw_tags.o shadow.o sw_tags.o
+obj-$(CONFIG_KASAN_HW_TAGS) += hw_tags.o report_hw_tags.o tags.o report_tags.o
+obj-$(CONFIG_KASAN_SW_TAGS) += init.o report_sw_tags.o shadow.o sw_tags.o tags.o report_tags.o
diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
index ed5e5b833d61..4ea8c368b5b8 100644
--- a/mm/kasan/hw_tags.c
+++ b/mm/kasan/hw_tags.c
@@ -216,28 +216,6 @@ void __init kasan_init_hw_tags(void)
pr_info("KernelAddressSanitizer initialized\n");
}
-void kasan_set_free_info(struct kmem_cache *cache,
- void *object, u8 tag)
-{
- struct kasan_alloc_meta *alloc_meta;
-
- alloc_meta = kasan_get_alloc_meta(cache, object);
- if (alloc_meta)
- kasan_set_track(&alloc_meta->free_track[0], GFP_NOWAIT);
-}
-
-struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
- void *object, u8 tag)
-{
- struct kasan_alloc_meta *alloc_meta;
-
- alloc_meta = kasan_get_alloc_meta(cache, object);
- if (!alloc_meta)
- return NULL;
-
- return &alloc_meta->free_track[0];
-}
-
void kasan_alloc_pages(struct page *page, unsigned int order, gfp_t flags)
{
/*
diff --git a/mm/kasan/report_hw_tags.c b/mm/kasan/report_hw_tags.c
index 42b2168755d6..5dbbbb930e7a 100644
--- a/mm/kasan/report_hw_tags.c
+++ b/mm/kasan/report_hw_tags.c
@@ -15,11 +15,6 @@
#include "kasan.h"
-const char *kasan_get_bug_type(struct kasan_access_info *info)
-{
- return "invalid-access";
-}
-
void *kasan_find_first_bad_addr(void *addr, size_t size)
{
return kasan_reset_tag(addr);
diff --git a/mm/kasan/report_sw_tags.c b/mm/kasan/report_sw_tags.c
index 821a14a19a92..d2298c357834 100644
--- a/mm/kasan/report_sw_tags.c
+++ b/mm/kasan/report_sw_tags.c
@@ -29,49 +29,6 @@
#include "kasan.h"
#include "../slab.h"
-const char *kasan_get_bug_type(struct kasan_access_info *info)
-{
-#ifdef CONFIG_KASAN_TAGS_IDENTIFY
- struct kasan_alloc_meta *alloc_meta;
- struct kmem_cache *cache;
- struct page *page;
- const void *addr;
- void *object;
- u8 tag;
- int i;
-
- tag = get_tag(info->access_addr);
- addr = kasan_reset_tag(info->access_addr);
- page = kasan_addr_to_page(addr);
- if (page && PageSlab(page)) {
- cache = page->slab_cache;
- object = nearest_obj(cache, page, (void *)addr);
- alloc_meta = kasan_get_alloc_meta(cache, object);
-
- if (alloc_meta) {
- for (i = 0; i < KASAN_NR_FREE_STACKS; i++) {
- if (alloc_meta->free_pointer_tag[i] == tag)
- return "use-after-free";
- }
- }
- return "out-of-bounds";
- }
-
-#endif
- /*
- * If access_size is a negative number, then it has reason to be
- * defined as out-of-bounds bug type.
- *
- * Casting negative numbers to size_t would indeed turn up as
- * a large size_t and its value will be larger than ULONG_MAX/2,
- * so that this can qualify as out-of-bounds.
- */
- if (info->access_addr + info->access_size < info->access_addr)
- return "out-of-bounds";
-
- return "invalid-access";
-}
-
void *kasan_find_first_bad_addr(void *addr, size_t size)
{
u8 tag = get_tag(addr);
diff --git a/mm/kasan/report_tags.c b/mm/kasan/report_tags.c
new file mode 100644
index 000000000000..8a319fc16dab
--- /dev/null
+++ b/mm/kasan/report_tags.c
@@ -0,0 +1,51 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd.
+ * Copyright (c) 2020 Google, Inc.
+ */
+
+#include "kasan.h"
+#include "../slab.h"
+
+const char *kasan_get_bug_type(struct kasan_access_info *info)
+{
+#ifdef CONFIG_KASAN_TAGS_IDENTIFY
+ struct kasan_alloc_meta *alloc_meta;
+ struct kmem_cache *cache;
+ struct page *page;
+ const void *addr;
+ void *object;
+ u8 tag;
+ int i;
+
+ tag = get_tag(info->access_addr);
+ addr = kasan_reset_tag(info->access_addr);
+ page = kasan_addr_to_page(addr);
+ if (page && PageSlab(page)) {
+ cache = page->slab_cache;
+ object = nearest_obj(cache, page, (void *)addr);
+ alloc_meta = kasan_get_alloc_meta(cache, object);
+
+ if (alloc_meta) {
+ for (i = 0; i < KASAN_NR_FREE_STACKS; i++) {
+ if (alloc_meta->free_pointer_tag[i] == tag)
+ return "use-after-free";
+ }
+ }
+ return "out-of-bounds";
+ }
+#endif
+
+ /*
+ * If access_size is a negative number, then it has reason to be
+ * defined as out-of-bounds bug type.
+ *
+ * Casting negative numbers to size_t would indeed turn up as
+ * a large size_t and its value will be larger than ULONG_MAX/2,
+ * so that this can qualify as out-of-bounds.
+ */
+ if (info->access_addr + info->access_size < info->access_addr)
+ return "out-of-bounds";
+
+ return "invalid-access";
+}
diff --git a/mm/kasan/sw_tags.c b/mm/kasan/sw_tags.c
index dd05e6c801fa..bd3f540feb47 100644
--- a/mm/kasan/sw_tags.c
+++ b/mm/kasan/sw_tags.c
@@ -167,47 +167,6 @@ void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size)
}
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 = kasan_get_alloc_meta(cache, object);
- if (!alloc_meta)
- return;
-
-#ifdef CONFIG_KASAN_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 = kasan_get_alloc_meta(cache, object);
- if (!alloc_meta)
- return NULL;
-
-#ifdef CONFIG_KASAN_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];
-}
-
void kasan_tag_mismatch(unsigned long addr, unsigned long access_info,
unsigned long ret_ip)
{
diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c
new file mode 100644
index 000000000000..8f48b9502a17
--- /dev/null
+++ b/mm/kasan/tags.c
@@ -0,0 +1,59 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * This file contains common tag-based KASAN code.
+ *
+ * Copyright (c) 2018 Google, Inc.
+ * Copyright (c) 2020 Google, Inc.
+ */
+
+#include <linux/init.h>
+#include <linux/kasan.h>
+#include <linux/kernel.h>
+#include <linux/memory.h>
+#include <linux/mm.h>
+#include <linux/static_key.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#include "kasan.h"
+
+void kasan_set_free_info(struct kmem_cache *cache,
+ void *object, u8 tag)
+{
+ struct kasan_alloc_meta *alloc_meta;
+ u8 idx = 0;
+
+ alloc_meta = kasan_get_alloc_meta(cache, object);
+ if (!alloc_meta)
+ return;
+
+#ifdef CONFIG_KASAN_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 = kasan_get_alloc_meta(cache, object);
+ if (!alloc_meta)
+ return NULL;
+
+#ifdef CONFIG_KASAN_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];
+}
--
2.18.0
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