From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-189.mta0.migadu.com (out-189.mta0.migadu.com [91.218.175.189]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DEBB314F9DB for ; Fri, 31 May 2024 08:32:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717144326; cv=none; b=IQq4pI77DalOostTA+ZAMufK32+3IlZ0eU85NXBDTpjhV9M9o7/zypXc7rZoHQPHE4aYUUlkz1qaWnvOyLrlPgclyrByz09DdxAvNkufjl9n2zBxODxWW8OhH9qDZ3HsqeXurdjf/ohczHYLlTcgIls8UsK5rrHJcibTDxxbti4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717144326; c=relaxed/simple; bh=x58qvahiLWJ9l42qtXAob9nZ9sSWGTIY+wsTwkiQ6Pk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=hqtjSdzOUlzCcnQfHuFfal6lyQzkSd6Gxt01RitMAP9T0hBesQFAElVnWXlOM4AYfvVYslR8t+H9wA1cTbiyA2zvM9pbnuKf0gv9uaUUiGyKpMGoKD28ZrinE+7/ZnQuTYpZRE73MRZwLYeaA2ZY+9IWhCACE0wL1treGs3OvUU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=soJ2cCCU; arc=none smtp.client-ip=91.218.175.189 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="soJ2cCCU" X-Envelope-To: cl@gentwo.org DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1717144322; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=mHgLHUhxCEeWxCNJSXHptpDk0n+7D3OisdJ7k6oe/I0=; b=soJ2cCCUVPJxQoiCy/lPzeERw1gF34QVlNZzGq+cIC/9svcXTzgyuArdQ4wWeyQ8WPCD1B fH83u9/bQNfenATiqU1AT5HQ87YSBVl64atkNJ6aLKw84sNpYBERWwdvkfYNyKu7we4xfh 17w/oYT+wOiNx4PQwdHcyxUmt1owLls= X-Envelope-To: penberg@kernel.org X-Envelope-To: rientjes@google.com X-Envelope-To: iamjoonsoo.kim@lge.com X-Envelope-To: akpm@linux-foundation.org X-Envelope-To: vbabka@suse.cz X-Envelope-To: roman.gushchin@linux.dev X-Envelope-To: 42.hyeyoo@gmail.com X-Envelope-To: feng.tang@intel.com X-Envelope-To: linux-mm@kvack.org X-Envelope-To: linux-kernel@vger.kernel.org X-Envelope-To: zhouchengming@bytedance.com Message-ID: Date: Fri, 31 May 2024 16:31:31 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH 1/3] slab: check the return value of check_bytes_and_report() Content-Language: en-US To: "Christoph Lameter (Ampere)" Cc: Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Vlastimil Babka , Roman Gushchin , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Feng Tang , linux-mm@kvack.org, linux-kernel@vger.kernel.org, zhouchengming@bytedance.com References: <20240528-b4-slab-debug-v1-0-8694ef4802df@linux.dev> <20240528-b4-slab-debug-v1-1-8694ef4802df@linux.dev> <4e4d45b5-c684-2d93-49d2-b179a088c2d5@gentwo.org> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Chengming Zhou In-Reply-To: <4e4d45b5-c684-2d93-49d2-b179a088c2d5@gentwo.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On 2024/5/30 23:20, Christoph Lameter (Ampere) wrote: > On Tue, 28 May 2024, Chengming Zhou wrote: > >> diff --git a/mm/slub.c b/mm/slub.c >> index 0809760cf789..de57512734ac 100644 >> --- a/mm/slub.c >> +++ b/mm/slub.c >> @@ -1324,9 +1324,10 @@ static int check_object(struct kmem_cache *s, struct slab *slab, >>         } >>     } else { >>         if ((s->flags & SLAB_POISON) && s->object_size < s->inuse) { >> -            check_bytes_and_report(s, slab, p, "Alignment padding", >> +            if (!check_bytes_and_report(s, slab, p, "Alignment padding", >>                 endobject, POISON_INUSE, >> -                s->inuse - s->object_size); >> +                s->inuse - s->object_size)) >> +                return 0; >>         } >>     } > > This change means we will then skip the rest of the checks in check_object() such as the poison check. Yeah, only when this padding checking failed. Now, we always abort checking and return 0 when the first checking error happens, such as redzones checking above. Thanks.