kasan: integrate the common part of two KASAN tag-based modes

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.

Link: https://lkml.kernel.org/r/20210626100931.22794-3-Kuan-Ying.Lee@mediatek.com
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Suggested-by: Marco Elver <elver@google.com>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Nicholas Tang <nicholas.tang@mediatek.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile
index 9fe39a6..adcd9ac 100644 (file)
--- 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 4004388..d867b22 100644 (file)
--- 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];
-}
-
 #if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST)
 
 void kasan_set_tagging_report_once(bool state)

diff --git a/mm/kasan/report_hw_tags.c b/mm/kasan/report_hw_tags.c
index 42b2168..5dbbbb9 100644 (file)
--- 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 821a14a..d2298c3 100644 (file)
--- 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 (file)
index 0000000..8a319fc
--- /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 0d6e5e9..675e673 100644 (file)
--- a/mm/kasan/sw_tags.c
+++ b/mm/kasan/sw_tags.c
@@ -166,44 +166,3 @@ void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size)
        kasan_poison((void *)addr, size, tag, false);
 }
 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];
-}

diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c
new file mode 100644 (file)
index 0000000..8f48b95
--- /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];
+}