From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,HK_RANDOM_FROM,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 92555C433DF for ; Tue, 13 Oct 2020 12:50:18 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 28C9522512 for ; Tue, 13 Oct 2020 12:50:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 28C9522512 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 5B4236E8DA; Tue, 13 Oct 2020 12:50:17 +0000 (UTC) Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by gabe.freedesktop.org (Postfix) with ESMTPS id A78D26E8EB for ; Tue, 13 Oct 2020 12:50:16 +0000 (UTC) IronPort-SDR: WDAIuns6aq3ONqET8Y2M51LbkYvkns00Z/mrPD2BNkPRukNcg/hvrVYbMxpAO/ZookUmmDAlrJ 9wHAPE0mmoVw== X-IronPort-AV: E=McAfee;i="6000,8403,9772"; a="145219557" X-IronPort-AV: E=Sophos;i="5.77,370,1596524400"; d="scan'208";a="145219557" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Oct 2020 05:50:15 -0700 IronPort-SDR: xT3XIbK6oqN+RrpDPo366HVwU/0Xu1ZI+mwfzHFhy1iHFKVyXgHcaraz68LguLF66HOm8ujnS4 a2HVBiCLpWEA== X-IronPort-AV: E=Sophos;i="5.77,370,1596524400"; d="scan'208";a="530383037" Received: from leanneam-mobl.ger.corp.intel.com (HELO [10.249.36.69]) ([10.249.36.69]) by orsmga005-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Oct 2020 05:50:14 -0700 To: Chris Wilson , intel-gfx@lists.freedesktop.org References: <20201013110845.16127-1-chris@chris-wilson.co.uk> From: Tvrtko Ursulin Organization: Intel Corporation UK Plc Message-ID: <625d24eb-8b52-c4f8-d07f-7d5622aecbfc@linux.intel.com> Date: Tue, 13 Oct 2020 13:50:12 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201013110845.16127-1-chris@chris-wilson.co.uk> Content-Language: en-US Subject: Re: [Intel-gfx] [PATCH] drm/i915/gt: Cleanup kasan warning for on-stack (unsigned long) casting X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On 13/10/2020 12:08, Chris Wilson wrote: > Kasan is gving a warning for passing a u32 parameter into find_first_bit > (casting to a unsigned long *, with appropriate length restrictions): > > [ 44.678262] BUG: KASAN: stack-out-of-bounds in find_first_bit+0x2e/0x50 > [ 44.678295] Read of size 8 at addr ffff888233f4fc30 by task core_hotunplug/474 > [ 44.678326] > [ 44.678358] CPU: 0 PID: 474 Comm: core_hotunplug Not tainted 5.9.0+ #608 > [ 44.678465] Hardware name: BESSTAR (HK) LIMITED GN41/Default string, BIOS BLT-BI-MINIPC-F4G-EX3R110-GA65A-101-D 10/12/2018 > [ 44.678500] Call Trace: > [ 44.678534] dump_stack+0x84/0xba > [ 44.678569] print_address_description.constprop.0+0x21/0x220 > [ 44.678605] ? kmsg_dump_rewind_nolock+0x5f/0x5f > [ 44.678638] ? _raw_spin_lock_irqsave+0x6d/0xb0 > [ 44.678669] ? _raw_write_lock_irqsave+0xb0/0xb0 > [ 44.678702] ? set_task_cpu+0x1e0/0x1e0 > [ 44.678733] ? find_first_bit+0x2e/0x50 > [ 44.678763] kasan_report.cold+0x20/0x42 > [ 44.678794] ? find_first_bit+0x2e/0x50 > [ 44.678825] __asan_load8+0x69/0x90 > [ 44.678856] find_first_bit+0x2e/0x50 > [ 44.679027] __caps_show.isra.0+0x9e/0x1f0 [i915] > > Since we are only using the shorter type for our own convenience, > accomodate kasan and use unsigned long. > > Signed-off-by: Chris Wilson > Cc: Tvrtko Ursulin > --- > drivers/gpu/drm/i915/gt/sysfs_engines.c | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/sysfs_engines.c b/drivers/gpu/drm/i915/gt/sysfs_engines.c > index 535cc1169e54..967031056202 100644 > --- a/drivers/gpu/drm/i915/gt/sysfs_engines.c > +++ b/drivers/gpu/drm/i915/gt/sysfs_engines.c > @@ -79,14 +79,12 @@ static ssize_t repr_trim(char *buf, ssize_t len) > > static ssize_t > __caps_show(struct intel_engine_cs *engine, > - u32 caps, char *buf, bool show_unknown) > + unsigned long caps, char *buf, bool show_unknown) > { > const char * const *repr; > int count, n; > ssize_t len; > > - BUILD_BUG_ON(!typecheck(typeof(caps), engine->uabi_capabilities)); > - > switch (engine->class) { > case VIDEO_DECODE_CLASS: > repr = vcs_caps; > @@ -103,12 +101,10 @@ __caps_show(struct intel_engine_cs *engine, > count = 0; > break; > } > - GEM_BUG_ON(count > BITS_PER_TYPE(typeof(caps))); > + GEM_BUG_ON(count > BITS_PER_LONG); > > len = 0; > - for_each_set_bit(n, > - (unsigned long *)&caps, > - show_unknown ? BITS_PER_TYPE(typeof(caps)) : count) { > + for_each_set_bit(n, &caps, show_unknown ? BITS_PER_LONG : count) { > if (n >= count || !repr[n]) { > if (GEM_WARN_ON(show_unknown)) > len += snprintf(buf + len, PAGE_SIZE - len, > Reviewed-by: Tvrtko Ursulin Regards, Tvrtko _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx