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From:   andrey.konovalov@linux.dev
To:     Marco Elver <elver@google.com>,
        Alexander Potapenko <glider@google.com>
Cc:     Andrey Konovalov <andreyknvl@gmail.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        kasan-dev@googlegroups.com, Peter Collingbourne <pcc@google.com>,
        Evgenii Stepanov <eugenis@google.com>,
        Florian Mayer <fmayer@google.com>,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org,
        Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH 07/32] kasan: introduce kasan_get_alloc_track
Date:   Mon, 13 Jun 2022 22:13:58 +0200
Message-Id: <184ac9df81406e73611e1f639c5d4d09f8d7693a.1655150842.git.andreyknvl@google.com>
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From: Andrey Konovalov <andreyknvl@google.com>

Add a kasan_get_alloc_track() helper that fetches alloc_track for a slab
object and use this helper in the common reporting code.

For now, the implementations of this helper are the same for the Generic
and tag-based modes, but they will diverge later in the series.

This change hides references to alloc_meta from the common reporting code.
This is desired as only the Generic mode will be using per-object metadata
after this series.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 mm/kasan/generic.c | 14 +++++++++++++-
 mm/kasan/kasan.h   |  4 +++-
 mm/kasan/report.c  |  8 ++++----
 mm/kasan/tags.c    | 14 +++++++++++++-
 4 files changed, 33 insertions(+), 7 deletions(-)

diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c
index 98c451a3b01f..f212b9ae57b5 100644
--- a/mm/kasan/generic.c
+++ b/mm/kasan/generic.c
@@ -381,8 +381,20 @@ void kasan_save_free_info(struct kmem_cache *cache,
 	*(u8 *)kasan_mem_to_shadow(object) = KASAN_SLAB_FREETRACK;
 }
 
+struct kasan_track *kasan_get_alloc_track(struct kmem_cache *cache,
+						void *object)
+{
+	struct kasan_alloc_meta *alloc_meta;
+
+	alloc_meta = kasan_get_alloc_meta(cache, object);
+	if (!alloc_meta)
+		return NULL;
+
+	return &alloc_meta->alloc_track;
+}
+
 struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
-				void *object, u8 tag)
+						void *object, u8 tag)
 {
 	if (*(u8 *)kasan_mem_to_shadow(object) != KASAN_SLAB_FREETRACK)
 		return NULL;
diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
index bcea5ed15631..4005da62a1e1 100644
--- a/mm/kasan/kasan.h
+++ b/mm/kasan/kasan.h
@@ -282,8 +282,10 @@ depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc);
 void kasan_set_track(struct kasan_track *track, gfp_t flags);
 void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags);
 void kasan_save_free_info(struct kmem_cache *cache, void *object, u8 tag);
+struct kasan_track *kasan_get_alloc_track(struct kmem_cache *cache,
+						void *object);
 struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
-				void *object, u8 tag);
+						void *object, u8 tag);
 
 #if defined(CONFIG_KASAN_GENERIC) && \
 	(defined(CONFIG_SLAB) || defined(CONFIG_SLUB))
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index 35dd8aeb115c..f951fd39db74 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -251,12 +251,12 @@ static void describe_object_addr(struct kmem_cache *cache, void *object,
 static void describe_object_stacks(struct kmem_cache *cache, void *object,
 					const void *addr, u8 tag)
 {
-	struct kasan_alloc_meta *alloc_meta;
+	struct kasan_track *alloc_track;
 	struct kasan_track *free_track;
 
-	alloc_meta = kasan_get_alloc_meta(cache, object);
-	if (alloc_meta) {
-		print_track(&alloc_meta->alloc_track, "Allocated");
+	alloc_track = kasan_get_alloc_track(cache, object);
+	if (alloc_track) {
+		print_track(alloc_track, "Allocated");
 		pr_err("\n");
 	}
 
diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c
index e0e5de8ce834..7b1fc8e7c99c 100644
--- a/mm/kasan/tags.c
+++ b/mm/kasan/tags.c
@@ -38,8 +38,20 @@ void kasan_save_free_info(struct kmem_cache *cache,
 	kasan_set_track(&alloc_meta->free_track, GFP_NOWAIT);
 }
 
+struct kasan_track *kasan_get_alloc_track(struct kmem_cache *cache,
+						void *object)
+{
+	struct kasan_alloc_meta *alloc_meta;
+
+	alloc_meta = kasan_get_alloc_meta(cache, object);
+	if (!alloc_meta)
+		return NULL;
+
+	return &alloc_meta->alloc_track;
+}
+
 struct kasan_track *kasan_get_free_track(struct kmem_cache *cache,
-				void *object, u8 tag)
+						void *object, u8 tag)
 {
 	struct kasan_alloc_meta *alloc_meta;
 
-- 
2.25.1