From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f71.google.com (mail-wm0-f71.google.com [74.125.82.71]) by kanga.kvack.org (Postfix) with ESMTP id 5FC816B0371 for ; Fri, 24 Mar 2017 15:32:45 -0400 (EDT) Received: by mail-wm0-f71.google.com with SMTP id x124so7670573wmf.1 for ; Fri, 24 Mar 2017 12:32:45 -0700 (PDT) Received: from mail-wr0-x22d.google.com (mail-wr0-x22d.google.com. [2a00:1450:400c:c0c::22d]) by mx.google.com with ESMTPS id l28si4683676wrl.237.2017.03.24.12.32.43 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 24 Mar 2017 12:32:44 -0700 (PDT) Received: by mail-wr0-x22d.google.com with SMTP id u108so7958294wrb.3 for ; Fri, 24 Mar 2017 12:32:43 -0700 (PDT) From: Andrey Konovalov Subject: [PATCH v4 6/9] kasan: improve slab object description Date: Fri, 24 Mar 2017 20:32:32 +0100 Message-Id: <5ee51ce71c19e681d1e9bf10fb7632729bedd202.1490383597.git.andreyknvl@google.com> In-Reply-To: References: In-Reply-To: References: Sender: owner-linux-mm@kvack.org List-ID: To: Andrey Ryabinin , Alexander Potapenko , Dmitry Vyukov , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Andrey Konovalov Changes slab object description from: Object at ffff880068388540, in cache kmalloc-128 size: 128 to: Object at ffff88006a2d5a80 belongs to cache kmalloc-128 of size 128 accessed at offset 123 This adds information about relative offset of the accessed address to the start of the object. Signed-off-by: Andrey Konovalov --- mm/kasan/report.c | 38 +++++++++++++++++++++++++++----------- 1 file changed, 27 insertions(+), 11 deletions(-) diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 156f998199e2..06e27a342d1d 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -194,18 +194,34 @@ static struct page *addr_to_page(const void *addr) return NULL; } -static void describe_object(struct kmem_cache *cache, void *object) +static void describe_object_addr(struct kmem_cache *cache, void *object, + const void *addr) { - struct kasan_alloc_meta *alloc_info = get_alloc_info(cache, object); + unsigned long access_addr = (unsigned long)addr; + unsigned long object_addr = (unsigned long)object; + const char *rel_type; + int rel_bytes; - pr_err("Object at %p, in cache %s size: %d\n", object, cache->name, - cache->object_size); + pr_err("Object at %p belongs to cache %s of size %d\n", + object, cache->name, cache->object_size); - if (!(cache->flags & SLAB_KASAN)) + if (!addr) return; - print_track(&alloc_info->alloc_track, "Allocated"); - print_track(&alloc_info->free_track, "Freed"); + pr_err(" accessed at offset %d\n", access_addr - object_addr); +} + +static void describe_object(struct kmem_cache *cache, void *object, + const void *addr) +{ + struct kasan_alloc_meta *alloc_info = get_alloc_info(cache, object); + + if (cache->flags & SLAB_KASAN) { + print_track(&alloc_info->alloc_track, "Allocated"); + print_track(&alloc_info->free_track, "Freed"); + } + + describe_object_addr(cache, object, addr); } void kasan_report_double_free(struct kmem_cache *cache, void *object, @@ -217,13 +233,13 @@ void kasan_report_double_free(struct kmem_cache *cache, void *object, pr_err("BUG: Double free or freeing an invalid pointer\n"); pr_err("Unexpected shadow byte: 0x%hhX\n", shadow); dump_stack(); - describe_object(cache, object); + describe_object(cache, object, NULL); kasan_end_report(&flags); } static void print_address_description(struct kasan_access_info *info) { - const void *addr = info->access_addr; + void *addr = (void *)info->access_addr; struct page *page = addr_to_page(addr); if (page) @@ -233,9 +249,9 @@ static void print_address_description(struct kasan_access_info *info) if (page && PageSlab(page)) { struct kmem_cache *cache = page->slab_cache; - void *object = nearest_obj(cache, page, (void *)addr); + void *object = nearest_obj(cache, page, addr); - describe_object(cache, object); + describe_object(cache, object, addr); } if (kernel_or_module_addr(addr)) { -- 2.12.1.578.ge9c3154ca4-goog -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org