kasan: introduce kasan_complete_mode_report_info

Add bug_type and alloc/free_track fields to kasan_report_info and add a
kasan_complete_mode_report_info() function that fills in these fields. 
This function is implemented differently for different KASAN mode.

Change the reporting code to use the filled in fields instead of invoking
kasan_get_bug_type() and kasan_get_alloc/free_track().

For the Generic mode, kasan_complete_mode_report_info() invokes these
functions instead.  For the tag-based modes, only the bug_type field is
filled in; alloc/free_track are handled in the next patch.

Using a single function that fills in these fields is required for the
tag-based modes, as the values for all three fields are determined in a
single procedure implemented in the following patch.

Link: https://lkml.kernel.org/r/8432b861054fa8d0cee79a8877dedeaf3b677ca8.1662411799.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Peter Collingbourne <pcc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 14 insertions, 16 deletions

diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index ec018f849992..39e8e5a80b82 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -185,8 +185,7 @@ static void print_error_description(struct kasan_report_info *info)
 		return;
 	}
 
-	pr_err("BUG: KASAN: %s in %pS\n",
-		kasan_get_bug_type(info), (void *)info->ip);
+	pr_err("BUG: KASAN: %s in %pS\n", info->bug_type, (void *)info->ip);
 	if (info->access_size)
 		pr_err("%s of size %zu at addr %px by task %s/%d\n",
 			info->is_write ? "Write" : "Read", info->access_size,
@@ -242,31 +241,25 @@ static void describe_object_addr(const void *addr, struct kmem_cache *cache,
 		(void *)(object_addr + cache->object_size));
 }
 
-static void describe_object_stacks(u8 tag, struct kasan_report_info *info)
+static void describe_object_stacks(struct kasan_report_info *info)
 {
-	struct kasan_track *alloc_track;
-	struct kasan_track *free_track;
-
-	alloc_track = kasan_get_alloc_track(info->cache, info->object);
-	if (alloc_track) {
-		print_track(alloc_track, "Allocated");
+	if (info->alloc_track.stack) {
+		print_track(&info->alloc_track, "Allocated");
 		pr_err("\n");
 	}
 
-	free_track = kasan_get_free_track(info->cache, info->object, tag);
-	if (free_track) {
-		print_track(free_track, "Freed");
+	if (info->free_track.stack) {
+		print_track(&info->free_track, "Freed");
 		pr_err("\n");
 	}
 
 	kasan_print_aux_stacks(info->cache, info->object);
 }
 
-static void describe_object(const void *addr, u8 tag,
-			    struct kasan_report_info *info)
+static void describe_object(const void *addr, struct kasan_report_info *info)
 {
 	if (kasan_stack_collection_enabled())
-		describe_object_stacks(tag, info);
+		describe_object_stacks(info);
 	describe_object_addr(addr, info->cache, info->object);
 }
 
@@ -295,7 +288,7 @@ static void print_address_description(void *addr, u8 tag,
 	pr_err("\n");
 
 	if (info->cache && info->object) {
-		describe_object(addr, tag, info);
+		describe_object(addr, info);
 		pr_err("\n");
 	}
 
@@ -426,6 +419,9 @@ static void complete_report_info(struct kasan_report_info *info)
 		info->object = nearest_obj(info->cache, slab, addr);
 	} else
 		info->cache = info->object = NULL;
+
+	/* Fill in mode-specific report info fields. */
+	kasan_complete_mode_report_info(info);
 }
 
 void kasan_report_invalid_free(void *ptr, unsigned long ip, enum kasan_report_type type)
@@ -443,6 +439,7 @@ void kasan_report_invalid_free(void *ptr, unsigned long ip, enum kasan_report_ty
 
 	start_report(&flags, true);
 
+	memset(&info, 0, sizeof(info));
 	info.type = type;
 	info.access_addr = ptr;
 	info.access_size = 0;
@@ -477,6 +474,7 @@ bool kasan_report(unsigned long addr, size_t size, bool is_write,
 
 	start_report(&irq_flags, true);
 
+	memset(&info, 0, sizeof(info));
 	info.type = KASAN_REPORT_ACCESS;
 	info.access_addr = ptr;
 	info.access_size = size;