From patchwork Tue Mar 28 14:00:51 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Konovalov X-Patchwork-Id: 744301 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3vssyS0jfHz9s7K for ; Wed, 29 Mar 2017 01:01:52 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.b="kZoE+kFy"; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754120AbdC1OBl (ORCPT ); Tue, 28 Mar 2017 10:01:41 -0400 Received: from mail-wr0-f169.google.com ([209.85.128.169]:36069 "EHLO mail-wr0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753755AbdC1OBg (ORCPT ); Tue, 28 Mar 2017 10:01:36 -0400 Received: by mail-wr0-f169.google.com with SMTP id w11so88290351wrc.3 for ; Tue, 28 Mar 2017 07:01:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :in-reply-to:references; bh=jwpX9UZwBI7dAfxLiRLBN1KZUJGr8396jXKUxIJ7MOE=; b=kZoE+kFydxbCnLNVzqdtRDz7C8yLyV4TrCffgjK3zvqsoQSHNmoPjoTBR8iTZHwut4 7pjhRey7UajjsbWkjbpaJ/GcWUsF6LXqxadwO4LQwMasLVBFEdknTsdp6I0qiyQNr6m5 056iEGyeJjfys+qC4322khl6T5SplL1QdVaPASp3mNue75ll0oBD6/iE0S/OJlYxLBAa 5pT2ZfaF6m0enahYCNpkVEqVJOVAkW9f5IZp4VNrEdklwWUcYl/O2aAfFUCExsnYAiPl 46eb43ctZOEtCGY96F8B9S8lB2dl6VFFLeaUcihNToVeEAOFyCol/hUR01GO8Le9vB1V q75g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:in-reply-to:references; bh=jwpX9UZwBI7dAfxLiRLBN1KZUJGr8396jXKUxIJ7MOE=; b=sJyJ0Q1BiStivY8pIY2LVSj1Fhq4NqJtOGOZiMXf/ATQWepjlrErIAPE/cgzv/wWVC 5GkY6/NXXNlg1g05pc24CwlvzRBC35noLhN182i0dmQ9bryTk5GF3pFMX++Mz1jUm1mD oO3EcALYMVhBuoR3OIWal/BiFJBjub04nfT0ZnggZ4ZmYmNRPawLiddwPHEH1i5sWEN2 RpVnyy7t6F6k5y3gvL7ab7LuwpZepaLxcWfA0YwjvhFFDBhxvbMDFcUPbrCTgD6DKNo7 NNskDra5PLSAP3JFPGuX4qsPDZbIDCIP19OcXZyDvnPIcoDfzbd+pj19MjuBq0T2BuKj 2Xog== X-Gm-Message-State: AFeK/H1Qy1VaNhwmYGxAFN4B7wWOcSynajvgbQzH+XV0zCf/FRxBuFYzrfMx3GOoHWwZ5t5y X-Received: by 10.223.160.183 with SMTP id m52mr8735187wrm.201.1490709666324; Tue, 28 Mar 2017 07:01:06 -0700 (PDT) Received: from andreyknvl0.muc.corp.google.com ([100.105.12.17]) by smtp.gmail.com with ESMTPSA id p185sm3760381wme.20.2017.03.28.07.01.01 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 28 Mar 2017 07:01:04 -0700 (PDT) Received: by andreyknvl0.muc.corp.google.com (Postfix, from userid 206546) id 4B9BA182EE5; Tue, 28 Mar 2017 16:00:56 +0200 (CEST) From: Andrey Konovalov To: "David S . Miller" , Eric Dumazet , Willem de Bruijn , Craig Gallek Cc: netdev@vger.kernel.org, Dmitry Vyukov , Kostya Serebryany , Andrey Konovalov Subject: [PATCH v4 6/9] kasan: improve slab object description Date: Tue, 28 Mar 2017 16:00:51 +0200 Message-Id: <5ee51ce71c19e681d1e9bf10fb7632729bedd202.1490383597.git.andreyknvl@google.com> X-Mailer: git-send-email 2.12.2.564.g063fe858b8-goog In-Reply-To: References: In-Reply-To: References: Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 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)) {