From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f53.google.com (mail-wr1-f53.google.com [209.85.221.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 31A552E8B75 for ; Thu, 25 Sep 2025 06:12:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758780725; cv=none; b=XPWSQOYM6ot5WCbId1tmvYqv6Cw39J3NIsqhFXlJyw+1Qy1Si+SScJ5qn++Kp1Rfx6/QhfTabzkKOyI5b+ro6Cx8spwNcyvA/p2+0uiZ8Zmn9f4tDKq9rdrZJ2MQeRUWbayQUshMJFEdQteN0Powi6Qy/lh1H/3Wko2TlBi3MlM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758780725; c=relaxed/simple; bh=uSFb8MHXwLqA9OKwUwZ9qPfEDx9KKhVW9XfP9kuC53s=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=NgQ8MBlbx4Vg1ku1EkpO3qu27/EatnqSP6vm/VUZB/TjfgAC/jmTpRG5LVchdfMtVDgB8EQl/8FFkwZkfXAzMM18ZY0G4nekVh16jiE2shuSUBrjO9oX8zVyjaPDud2NUsdKErG+cxgo1Ad1K6HJrF1cJ7RrH3ZGv+eWa8cu8Dg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org; spf=pass smtp.mailfrom=linaro.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b=qqkzfmjy; arc=none smtp.client-ip=209.85.221.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="qqkzfmjy" Received: by mail-wr1-f53.google.com with SMTP id ffacd0b85a97d-3f3a47b639aso362491f8f.2 for ; Wed, 24 Sep 2025 23:12:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1758780722; x=1759385522; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=yEYWGfF11/g3FTMFlorTwEZrbGBIs3tO9z9pPNiHJAo=; b=qqkzfmjyigSpLUoNqAMuAQPl/zPXizRaJfpLiXhw2cfQSwVL8u7D95BnPvpPfPoA04 c7DPuIq+tHha0AqLofEqBwuLohznbyQTmFnioXKf18DW04Tma9rsEaqu67ZxtHuW1YTh SEK+jdgVOgwOdcUUudwlrEk0K6tqdtiSgdFO3IR8N+KoEe/C8V9Nque9V3Jv/Xb3yNeB Gro94cqz5bWoY5+kR2qM1bVW6F41cM5/NlgqWbNlrN4E0uQ9Hy4BWBktjrMiCXWr82iB iIg3aGdJ586DTiy+EhmAXH+NVFYsSsAhMFOZPsE1NTTdlMOOZvEVlsgRFd82pyXpAxlP qQJw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1758780722; x=1759385522; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=yEYWGfF11/g3FTMFlorTwEZrbGBIs3tO9z9pPNiHJAo=; b=A4ypCpzTrFhNYpE+I5SnQc775xBf8S/M6Z5S2V/rhRRpW57Sn4WtHfZl1daHByi3rl /ntAKwyOwyIqUGnLGq/r/PKkLGZY6nTk2rzyv3PHJjossVlTLfKSh2bizD44Xz0knHCi lO3pqnQPr3sJ22z9X8c4aY2QO/d1MCihgcBz4XO/vFIEFYGRCWiiMzkT7P8NRH+aGwFB 2PvXyJzfhhghiaKcGQYmUx+TaDOxs4LIcfrGaXDFnNmrfEDTKB5zfWapg8eImRN3CRrq MNRMiUtnHV/VNxxHzYkYvCUUY3BK7b5qqFCkXq+vJHiRszp/rUSWXiWRSqxH2VlZyU5h pBaw== X-Forwarded-Encrypted: i=1; AJvYcCUom2ghywRPu8GPZsxC1hbDdCTRGrgeRZ5oAwl8iZMUoeVGox9rl8ZdTLGwVDwnchPq5PZzwJ4=@vger.kernel.org X-Gm-Message-State: AOJu0YzndrJ9nArlJYmU7vYMw2edly7Dfn7voOElcXFGFmqB+Nae695m bQTNiz+Iug/tMVO5J7Zf6ZgO3P41PG6gxn5gLk5yQrKll/3i9rmKPd5fTnUlXXYiIdI= X-Gm-Gg: ASbGnctdqt3uKWcHpdL6KtK6zLKLhAJCGQfkdZFM6NzlQXMwaKqsoHLQaVBP11CzhPI tMfmR0fw5wlWnJwxYjcFJBbV5DvIUroQoHcmf6uYbiTd8PY6bfBu1WYeaixmuoymxu8UNXM7s/7 VuPgy8eWwwOsHgSqkeKdeSS7JF3e22pO4JqA1OUqVqxsuDQoPBi8aGMxuip+8YzVB8rM+gtAcFz oyYksJg/iAwX+9cVF3LSTR9094JlHi2q1xpMuz59K/0Zcu6qS3Lan91DW3LhaLV/aYHJ4nwb1Ie fQLBt7IVqQKARvBAUAXDxwNp//Mrh9LiGuzSau7/gwqQMuLUXwHWLUlzg/yB8wNbIyHKzWHZEqv 7nb7ghB/7w+WeW+fX+r9gsSEoW5Q= X-Google-Smtp-Source: AGHT+IFRkpqclsNYUNbGMkAuZhXHS3Qv2yCkSEuPjzYXQeiL3SAyG+ATQky02YBh1lI/bsu4q3uPPA== X-Received: by 2002:a05:6000:2381:b0:3e5:47a9:1c7a with SMTP id ffacd0b85a97d-40e4a52475bmr1878562f8f.62.1758780722328; Wed, 24 Sep 2025 23:12:02 -0700 (PDT) Received: from localhost ([41.210.143.179]) by smtp.gmail.com with UTF8SMTPSA id ffacd0b85a97d-40fc5602f15sm1453105f8f.39.2025.09.24.23.12.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 Sep 2025 23:12:02 -0700 (PDT) Date: Thu, 25 Sep 2025 09:11:57 +0300 From: Dan Carpenter To: Qingfang Deng Cc: Andreas Koensgen , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , linux-hams@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+5fd749c74105b0e1b302@syzkaller.appspotmail.com Subject: Re: [PATCH net-next v2] 6pack: drop redundant locking and refcounting Message-ID: References: <20250925051059.26876-1-dqfext@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250925051059.26876-1-dqfext@gmail.com> On Thu, Sep 25, 2025 at 01:10:59PM +0800, Qingfang Deng wrote: > The TTY layer already serializes line discipline operations with > tty->ldisc_sem, so the extra disc_data_lock and refcnt in 6pack > are unnecessary. > > Removing them simplifies the code and also resolves a lockdep warning > reported by syzbot. The warning did not indicate a real deadlock, since > the write-side lock was only taken in process context with hardirqs > disabled. > > Reported-by: syzbot+5fd749c74105b0e1b302@syzkaller.appspotmail.com > Closes: https://lore.kernel.org/all/68c858b0.050a0220.3c6139.0d1c.GAE@google.com/ > Signed-off-by: Qingfang Deng > --- > v2: add Closes tag > - https://lore.kernel.org/netdev/20250923060706.10232-1-dqfext@gmail.com/ > Thanks! Reviewed-by: Dan Carpenter regards, dan carpenter