From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f198.google.com (mail-wr0-f198.google.com [209.85.128.198]) by kanga.kvack.org (Postfix) with ESMTP id 1F4A96B0359 for ; Fri, 24 Mar 2017 15:32:43 -0400 (EDT) Received: by mail-wr0-f198.google.com with SMTP id 20so7225144wrx.6 for ; Fri, 24 Mar 2017 12:32:43 -0700 (PDT) Received: from mail-wr0-x22c.google.com (mail-wr0-x22c.google.com. [2a00:1450:400c:c0c::22c]) by mx.google.com with ESMTPS id i63si4349919wmd.135.2017.03.24.12.32.41 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 24 Mar 2017 12:32:41 -0700 (PDT) Received: by mail-wr0-x22c.google.com with SMTP id y90so8023470wrb.0 for ; Fri, 24 Mar 2017 12:32:41 -0700 (PDT) From: Andrey Konovalov Subject: [PATCH v4 4/9] kasan: simplify address description logic Date: Fri, 24 Mar 2017 20:32:30 +0100 Message-Id: <91b198a9825326a3f3e9037df60d49704f5479ad.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 Simplify logic for describing a memory address. Add addr_to_page() helper function. Makes the code easier to follow. Signed-off-by: Andrey Konovalov --- mm/kasan/report.c | 36 ++++++++++++++++++++---------------- 1 file changed, 20 insertions(+), 16 deletions(-) diff --git a/mm/kasan/report.c b/mm/kasan/report.c index 382d4d2b9052..f77341979dae 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -188,11 +188,17 @@ static void print_track(struct kasan_track *track, const char *prefix) } } -static void kasan_object_err(struct kmem_cache *cache, void *object) +static struct page *addr_to_page(const void *addr) +{ + if ((addr >= (void *)PAGE_OFFSET) && (addr < high_memory)) + return virt_to_head_page(addr); + return NULL; +} + +static void describe_object(struct kmem_cache *cache, void *object) { struct kasan_alloc_meta *alloc_info = get_alloc_info(cache, object); - dump_stack(); pr_err("Object at %p, in cache %s size: %d\n", object, cache->name, cache->object_size); @@ -211,34 +217,32 @@ void kasan_report_double_free(struct kmem_cache *cache, void *object, kasan_start_report(&flags); pr_err("BUG: Double free or freeing an invalid pointer\n"); pr_err("Unexpected shadow byte: 0x%hhX\n", shadow); - kasan_object_err(cache, object); + dump_stack(); + describe_object(cache, object); kasan_end_report(&flags); } static void print_address_description(struct kasan_access_info *info) { const void *addr = info->access_addr; + struct page *page = addr_to_page(addr); - if ((addr >= (void *)PAGE_OFFSET) && - (addr < high_memory)) { - struct page *page = virt_to_head_page(addr); - - if (PageSlab(page)) { - void *object; - struct kmem_cache *cache = page->slab_cache; - object = nearest_obj(cache, page, - (void *)info->access_addr); - kasan_object_err(cache, object); - return; - } + if (page) dump_page(page, "kasan: bad access detected"); + + dump_stack(); + + if (page && PageSlab(page)) { + struct kmem_cache *cache = page->slab_cache; + void *object = nearest_obj(cache, page, (void *)addr); + + describe_object(cache, object); } if (kernel_or_module_addr(addr)) { if (!init_task_stack_addr(addr)) pr_err("Address belongs to variable %pS\n", addr); } - dump_stack(); } static bool row_is_guilty(const void *row, const void *guilty) -- 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