From patchwork Mon Feb 3 21:58:16 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jakub Kicinski X-Patchwork-Id: 13958309 X-Patchwork-Delegate: kuba@kernel.org Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 4AFBA20F07C for ; Mon, 3 Feb 2025 21:58:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738619901; cv=none; b=m/sSBqpJReHH7u7rOxVL6AScYWdCHevblDS4Mv8qY+R7ef7zZE9Xc+wulTp9zmp4Qna8Xg3CWZ6ayaCpA8nAz0fUc0Tm3QPQbRRLexXPpyT49qT54k0kkZ8CWrUKA2g1VGPo4dw6aBHdRorS6/8cx7m9lneVj+KgBxhxBnSE5t8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738619901; c=relaxed/simple; bh=Qi9FRgHkkrnnXzQ6qTP6FBQ/+DAq2OsOWTdWS9sXlF8=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=hTEGqh86N7ONii2qUOA+cg9+3E1ln5NjJiicuWgQhTu9I2o8Kq3vyZjPk9pUJ1n7GH+3Tt1wYVL/K+VSXv7EicniQLWDlVt1tZ7HlWv5n728IAyC6U++7fqYT4SwNNA8ZwRC0Q+erdSDT3g0FxfrzOXKgWz2lmQyn8dTD+DdXIA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=PuLNUJlH; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="PuLNUJlH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6FE24C4CED2; Mon, 3 Feb 2025 21:58:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1738619900; bh=Qi9FRgHkkrnnXzQ6qTP6FBQ/+DAq2OsOWTdWS9sXlF8=; h=From:To:Cc:Subject:Date:From; b=PuLNUJlHhZYr2TZT5dZXp0VTsFfatMQCBNAgtlFp4VpW+2KyKLWRYBzjCxZEUU2O7 q1Mx9lO+SYUjJenP4WFpuP2ztIi1/9/zQNCvjmF2maQIGZ3wD7pPQnWQOjMGZXgNm6 gtCMF0ttW7P4yquNZTF3vgPetxoIgHZHzRrzcEuRgOXFFICaOPEdjnD2WVTnV0pRDs aarU1eB1XibmIovtwZld7bS+cWbZxWS97QpPad0wK29dNrX5/BZqJF7ophKB47GGho RvZCPUyJq2V/wLsxPB2n1r5gmsU9D5TThi2TLYsMPfEu1Qb4a4z59iLvkmY0CCLrBt iaCsnkYsgipww== From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch, horms@kernel.org, Jakub Kicinski Subject: [PATCH net-next] net: warn if NAPI instance wasn't shut down Date: Mon, 3 Feb 2025 13:58:16 -0800 Message-ID: <20250203215816.1294081-1-kuba@kernel.org> X-Mailer: git-send-email 2.48.1 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org Drivers should always disable a NAPI instance before removing it. If they don't the instance may be queued for polling. Since commit 86e25f40aa1e ("net: napi: Add napi_config") we also remove the NAPI from the busy polling hash table in napi_disable(), so not disabling would leave a stale entry there. Use of busy polling is relatively uncommon so bugs may be lurking in the drivers. Add an explicit warning. Signed-off-by: Jakub Kicinski Reviewed-by: Joe Damato Reviewed-by: Eric Dumazet --- net/core/dev.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/core/dev.c b/net/core/dev.c index c0021cbd28fc..2b141f20b13b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -7071,6 +7071,9 @@ void __netif_napi_del_locked(struct napi_struct *napi) if (!test_and_clear_bit(NAPI_STATE_LISTED, &napi->state)) return; + /* Make sure NAPI is disabled (or was never enabled). */ + WARN_ON(!test_bit(NAPI_STATE_SCHED, &napi->state)); + if (napi->config) { napi->index = -1; napi->config = NULL;