From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 1795137880E for ; Thu, 26 Feb 2026 08:11:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772093481; cv=none; b=nzg0s7ibILvCFwJOzuCkz3JCYBPdmcCu7SdMN4BuY4oy2cgoDfZ3vqU/DEs0Ti/OZ4jFN486jSMP7sUlAuNlq8Yw5gg5Tl7T91hkhsLRfTIhjCmXEN4VHtK/Bjq+QqIQONMUZeESda+K+V1vepOt6Zs+dq5tQNmspGnaNjhel+s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772093481; c=relaxed/simple; bh=EEyCUYAIX5Uwr9+fHgE9Jif0O5SXtYu+RME7yHDx3tk=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=ZSFBEpLghM/AtkLVQ3H5utwFUQHJpdk7LHd69TGj/H3llPU4J1AXi3iErH6uJq7lDogWIKSzz3/fLxnlb+HIBcPRIJvbVbnM0KbyUPU98/a3uaFoXpgs5kfqTO44QqlwbbqekvGWq6BGCNOuJVMHE+Dou3FJL+zcW2+nI9GD0M0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=ReGgoH+y; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=t4ArF0xq; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="ReGgoH+y"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="t4ArF0xq" From: Kurt Kanzenbach DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1772093478; 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: in-reply-to:in-reply-to:references:references; bh=Y9iIOV5FqFnR5rXzWQNPd5xi9vS2oDBpKRTfshCc/ng=; b=ReGgoH+yEM0Td8voIBrsDgdswzcQO3FyqZh9k1ps2Sab0wY/Wltrq8Sy4lDUFY9Qr4gls3 usY3r9eZA/BZDZqfJyRr1/Y9UsRlWlCWCUrBwp+4MVB1y0i2cxttSdAkKKUSOTTStrEiOC FK/ezrokY6Yu5AIMdiucVrH46t4KlK4HIClD9aRqgrZHRYWXvReAobeZDXtdGT+RQPs3KH m+e8Sm+X4RrrlQobdkNqCcHetoLJdsTbgmTO1TEpuomtocWMTKahIfH4rWTbZ0ywSfNfd4 P9chTmZAiM3YTw3m2pyi7/nLL15kmpR0mUZvvINx42VLSpfuWvPJh4Db+sRIsQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1772093478; 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: in-reply-to:in-reply-to:references:references; bh=Y9iIOV5FqFnR5rXzWQNPd5xi9vS2oDBpKRTfshCc/ng=; b=t4ArF0xqa0hgs0ePn9L2RUsdULHRws9w8O2LUVZkv/d01Sj61letT523rCAzDy3WKuXCIi GmRC9EmFOOg0BnAA== To: patchwork-bot+netdevbpf@kernel.org, Sebastian Andrzej Siewior Cc: netdev@vger.kernel.org, willemdebruijn.kernel@gmail.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, willemb@google.com Subject: Re: [PATCH net v2] net: Drop the lock in skb_may_tx_timestamp() In-Reply-To: <177193020629.3444651.13248671448207071630.git-patchwork-notify@kernel.org> References: <20260220183858.N4ERjFW6@linutronix.de> <177193020629.3444651.13248671448207071630.git-patchwork-notify@kernel.org> Date: Thu, 26 Feb 2026 09:11:16 +0100 Message-ID: <87jyvzvs9n.fsf@jax.kurt.home> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" --=-=-= Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Tue Feb 24 2026, patchwork-bot+netdevbpf@kernel.org wrote: > Hello: > > This patch was applied to netdev/net.git (main) > by Paolo Abeni : > > On Fri, 20 Feb 2026 19:38:58 +0100 you wrote: >> skb_may_tx_timestamp() may acquire sock::sk_callback_lock. The lock must >> not be taken in IRQ context, only softirq is okay. A few drivers receive >> the timestamp via a dedicated interrupt and complete the TX timestamp >> from that handler. This will lead to a deadlock if the lock is already >> write-locked on the same CPU. >>=20 >> Taking the lock can be avoided. The socket (pointed by the skb) will >> remain valid until the skb is released. The ->sk_socket and ->file >> member will be set to NULL once the user closes the socket which may >> happen before the timestamp arrives. >> If we happen to observe the pointer while the socket is closing but >> before the pointer is set to NULL then we may use it because both >> pointer (and the file's cred member) are RCU freed. >>=20 >> [...] > > Here is the summary with links: > - [net,v2] net: Drop the lock in skb_may_tx_timestamp() > https://git.kernel.org/netdev/net/c/983512f3a87f > > You are awesome, thank you! Hi maintainers, thanks for applying the patch. What's your preferred solution for igb? Can we do the time stamping from IRQ context now [1] or should we switch to BH workqueue [2]? Thanks, Kurt [1] - https://lore.kernel.org/intel-wired-lan/20260205-igb_irq_ts-v3-1-2efc= 7bc4b885@linutronix.de/ [2] - https://lore.kernel.org/intel-wired-lan/20260211134436.1e623034@kerne= l.org/ --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQJHBAEBCgAxFiEEvLm/ssjDfdPf21mSwZPR8qpGc4IFAmmgACQTHGt1cnRAbGlu dXRyb25peC5kZQAKCRDBk9HyqkZzgp8yEACpKGuvtHWD9jBdkIbi371SJZAGASYv Ndc7BTPHhLabi4whGR5S5cRiVKUPex7qNhs7h4dnzsBI2TcSMMll0z83xxmHl7uL PUcXCCfUUW4xgRhNH6ddUr5Ss/IiiDDPJgtJbnoYjmFJX3keXA8qK4Gzs0ZJHjNX WWNvptxS32TipFuBHcojXvgtBuJ40owuga8qw3jrS/CIW6QkQM7FtvLex180rfjJ liJ3MVYgxZg3Jg9QUIfvI0Sk97Zjm+f7Xo9pXdqNYn6hV48xY1BbNXFUPe5qDT4b RB1u8BtWLx2i8eFenykBUlmv3VPlLMuPwYPa5TRHxD9mKhwaTRUgvSJgM/yrFQqN 5QBX+fIbBYzRaPSwSabOLQrKqOe2KNRmo0Byprt5AaJe/by8YHRKQxwYxNs4za0S IaFrFeF84CyeP9OdZbvOohsaQ90G2yFSN3EP7MP44BMaW0T88i5t0muoMWTGxHig gdrOAfbs16+mk0YluvPszndMfaTlitfLwFTo3iPaELW3k+3pImNViXS05G+mnDpH /AQCFiSoWYDSf3prN4Wh5dSsxsE4sgvOKNlQJ3YzYSD1s/dCPtKKJP6T2lCCa5i0 tNOI5xIuEW4f1uojWjGjuUG8mefZa9rUFFGqIChGeHkC2hHLiAJ28cua+jjG4QLS EWGhXSFbfUg6aA== =n5sV -----END PGP SIGNATURE----- --=-=-=--