From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga05-in.huawei.com (szxga05-in.huawei.com [45.249.212.191]) (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 DF71224DCEA for ; Thu, 24 Jul 2025 09:35:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.191 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753349722; cv=none; b=iu54HJFkEhpzfNzg2l8oezfySyK8aeBRrcWOG9oZnao8dFMQKLUCkE+yaKbZFDSbJbh+dod01Nt+R3KKTg3D5TPBsoYdHmMj/UVdkGVNYR8mHVWVnOCOE05O9fKUN5AtEd72mI2HbxCy5lFLU8SJTLJCL3xBrdIzqa2GsGLu/bI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753349722; c=relaxed/simple; bh=MwYzkwplxjT8TFeYLLWOUaBok/od1wayyWGfll2r4bg=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=EiKE1qT/ogp1uX2ShJvXeLkUqVo7u9HC3PeRwZavwYKrnlcX2mVa2nDxMa8uolQokD8dGHJwWsUOQ++DJSQ7bJzDh8bY9dWnh60PObIneCG+Gzn+bXaHgy6OnmsfQYQ86kXGWb0KIbvMacNX7gt5h2czvYggw2fvZtXg1YAz45w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.191 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.162.112]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4bnm4h4SPtz1R8kk; Thu, 24 Jul 2025 17:32:36 +0800 (CST) Received: from kwepemj200003.china.huawei.com (unknown [7.202.194.15]) by mail.maildlp.com (Postfix) with ESMTPS id 8BD09140109; Thu, 24 Jul 2025 17:35:17 +0800 (CST) Received: from [10.67.120.170] (10.67.120.170) by kwepemj200003.china.huawei.com (7.202.194.15) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Thu, 24 Jul 2025 17:35:16 +0800 Message-ID: Date: Thu, 24 Jul 2025 17:35:16 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 2/2] dma-mapping: benchmark: Add padding to ensure uABI remained consistent To: Barry Song <21cnbao@gmail.com>, CC: , , , , , , References: <20250724085600.4101321-1-xiaqinxin@huawei.com> <20250724085600.4101321-3-xiaqinxin@huawei.com> From: Qinxin Xia In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: kwepems100002.china.huawei.com (7.221.188.206) To kwepemj200003.china.huawei.com (7.202.194.15) On 2025/7/24 17:07:08, Barry Song <21cnbao@gmail.com> wrote: > On Thu, Jul 24, 2025 at 4:56 PM Qinxin Xia wrote: >> >> The padding field in the structure was previously reserved to >> maintain a stable interface for potential new fields, ensuring >> compatibility with user-space shared data structures. >> However,it was accidentally removed by tiantao in a prior commit, >> which may lead to incompatibility between user space and the kernel. >> >> This patch reinstates the padding to restore the original structure >> layout and preserve compatibility. >> >> Fixes: 8ddde07a3d28 ("dma-mapping: benchmark: extract a common header file for map_benchmark definition") >> Cc: stable@vger.kernel.org >> Acked-by: Barry Song >> Signed-off-by: Qinxin Xia > > I don’t think these two patches should be part of the same series. This > one is a bug fix and should be handled separately—ideally picked up on > its own and backported to stable. > > Also, the subject should not say "Add"—it should be "Restore". I assume > Marek can handle it? > >> --- >> include/linux/map_benchmark.h | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/include/linux/map_benchmark.h b/include/linux/map_benchmark.h >> index 62674c83bde4..2ac2fe52f248 100644 >> --- a/include/linux/map_benchmark.h >> +++ b/include/linux/map_benchmark.h >> @@ -27,5 +27,6 @@ struct map_benchmark { >> __u32 dma_dir; /* DMA data direction */ >> __u32 dma_trans_ns; /* time for DMA transmission in ns */ >> __u32 granule; /* how many PAGE_SIZE will do map/unmap once a time */ >> + __u8 expansion[76]; /* For future use */ >> }; >> #endif /* _KERNEL_DMA_BENCHMARK_H */ >> -- >> 2.33.0 >> > > Thanks > Barry Ok, I will send a new version to fix it. Thanks