From patchwork Tue Jul 30 06:31:04 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Herve Codina X-Patchwork-Id: 13746733 X-Patchwork-Delegate: kuba@kernel.org Received: from relay8-d.mail.gandi.net (relay8-d.mail.gandi.net [217.70.183.201]) (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 07FC3524C; Tue, 30 Jul 2024 06:31:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.183.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722321089; cv=none; b=KFTeCx5Cgsmjl1G+WHbC7GglL+qGRrGHueFKBjHH1bVD+cVossgF67gAYBJL4V3nAlddtF8GCGCIqFNLFp3SHjiTD557z4ITOhh2McXu87fYaPqPanRuYtp0MRRyU14iajjiytqhDNqtU9uhvE1U1OqHgbelKpCMGHEw7cI42zw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722321089; c=relaxed/simple; bh=mql6NdwGBe1Qe69m/PuXETcyOj1uy1ngSHMd8WhM/ho=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=MGtBKJL7ebkBHdn0tI1r5pVf6J05J7vaekhOZpBIgLncQx5Du4dwddLEBzRN9EW5dAaMneY8odNxaymRHZrEcuDu1PDJHP3alv/B3NWBA5da+XVsuS6AztTRsHR7rIc5RlSDsgPV+kvdF0zvRW51Vqs4+AS88ar58OJqXNbh3MQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com; spf=pass smtp.mailfrom=bootlin.com; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b=U6NbEj7Z; arc=none smtp.client-ip=217.70.183.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=bootlin.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=bootlin.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bootlin.com header.i=@bootlin.com header.b="U6NbEj7Z" Received: by mail.gandi.net (Postfix) with ESMTPA id 274B21BF205; Tue, 30 Jul 2024 06:31:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1722321078; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=CDtINm72N0vmrhW2aX5v9ObO9VZbS1J4o9kH7/qY2Eo=; b=U6NbEj7ZAY4gFtn0Z8a5KpEuI21GSLcS17ZTTbHPpn1lbpKMTFM2ytcG1+y5rxCyktd5fv kEqX9mDQ2pkpkPQxndTBhwOLAVr0gBESxa95WBx8mLH1WMWKkKvejW+ghveBKCgrpa8wYD H41CvKRQhIpDDOpGA002e2oYllIYDKNLC4fcElsPm1fp00qLYG7zpt0KTA7tM9dsgvRjJE lpeXr1vNK4/mquej3R2gK7z0JvehxzawhsKh1O/GkgRtC4jmP8NdNlodLI/DSr5f6HlgtX bS9Gh/9ojcNjsINhOTrS9fnr+SSFyCOEgBiJ3nX2x2e3KgW2AiV+4HWe9JINDg== From: Herve Codina To: Herve Codina , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Andy Shevchenko , Christophe Leroy Cc: netdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Thomas Petazzoni , stable@vger.kernel.org Subject: [PATCH net v1] net: wan: fsl_qmc_hdlc: Convert carrier_lock spinlock to a mutex Date: Tue, 30 Jul 2024 08:31:04 +0200 Message-ID: <20240730063104.179553-1-herve.codina@bootlin.com> X-Mailer: git-send-email 2.45.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-GND-Sasl: herve.codina@bootlin.com X-Patchwork-Delegate: kuba@kernel.org The carrier_lock spinlock protects the carrier detection. While it is hold, framer_get_status() is called witch in turn takes a mutex. This is not correct and can lead to a deadlock. A run with PROVE_LOCKING enabled detected the issue: [ BUG: Invalid wait context ] ... c204ddbc (&framer->mutex){+.+.}-{3:3}, at: framer_get_status+0x40/0x78 other info that might help us debug this: context-{4:4} 2 locks held by ifconfig/146: #0: c0926a38 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x12c/0x664 #1: c2006a40 (&qmc_hdlc->carrier_lock){....}-{2:2}, at: qmc_hdlc_framer_set_carrier+0x30/0x98 Avoid the spinlock usage and convert carrier_lock to a mutex. Fixes: 54762918ca85 ("net: wan: fsl_qmc_hdlc: Add framer support") Cc: stable@vger.kernel.org Signed-off-by: Herve Codina Reviewed-by: Simon Horman --- drivers/net/wan/fsl_qmc_hdlc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/net/wan/fsl_qmc_hdlc.c b/drivers/net/wan/fsl_qmc_hdlc.c index c5e7ca793c43..64b4bfa6fea7 100644 --- a/drivers/net/wan/fsl_qmc_hdlc.c +++ b/drivers/net/wan/fsl_qmc_hdlc.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include #include @@ -37,7 +38,7 @@ struct qmc_hdlc { struct qmc_chan *qmc_chan; struct net_device *netdev; struct framer *framer; - spinlock_t carrier_lock; /* Protect carrier detection */ + struct mutex carrier_lock; /* Protect carrier detection */ struct notifier_block nb; bool is_crc32; spinlock_t tx_lock; /* Protect tx descriptors */ @@ -60,7 +61,7 @@ static int qmc_hdlc_framer_set_carrier(struct qmc_hdlc *qmc_hdlc) if (!qmc_hdlc->framer) return 0; - guard(spinlock_irqsave)(&qmc_hdlc->carrier_lock); + guard(mutex)(&qmc_hdlc->carrier_lock); ret = framer_get_status(qmc_hdlc->framer, &framer_status); if (ret) { @@ -706,7 +707,7 @@ static int qmc_hdlc_probe(struct platform_device *pdev) qmc_hdlc->dev = dev; spin_lock_init(&qmc_hdlc->tx_lock); - spin_lock_init(&qmc_hdlc->carrier_lock); + mutex_init(&qmc_hdlc->carrier_lock); qmc_hdlc->qmc_chan = devm_qmc_chan_get_bychild(dev, dev->of_node); if (IS_ERR(qmc_hdlc->qmc_chan))