From mboxrd@z Thu Jan 1 00:00:00 1970 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 B30B628CF61; Wed, 23 Apr 2025 15:05:40 +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=1745420741; cv=none; b=H9RJS6ztHS6zBqgLpy/SSB9nSSA8q78TUwvHAHICv1vNIrxsISIzvEN6jL/gvVS/wQnjeaFyl3b/4F87rIKGqYgO9H8J130Pb1VjGU3EU5cvmCV4HktO3Y7lIX7tAngK4mMMft5uXqMxbOacbQVleVJsCBNGkO4E90GjQxq4imE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745420741; c=relaxed/simple; bh=hMunZ6zfNFcGD0eeQ6W8Fyse0jo6T1bZNbVJ3E274KQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ufv6j0Ptbp6gLOljYnOjLgShDWuS6pe5oIF63mZhT9AWe3Q327c9K9qlD65W2BQrhMe9c8iAgO1jhZaDNtyjHpASulOqxqE9wiF0GjGDTz43do5MV4JWc6lFAn6AaiYuG73eAG+AscKfaKL5ykyDd8g2HrSsqu+RBa9VM7qyfFc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mm+JBH2t; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="mm+JBH2t" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4DB3C4CEE2; Wed, 23 Apr 2025 15:05:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1745420740; bh=hMunZ6zfNFcGD0eeQ6W8Fyse0jo6T1bZNbVJ3E274KQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mm+JBH2tGUe2TSNWeoL/smj7JAjgIe8HJVZLOVfAdf3ljNy/05g2JAxh+4+vjZuSU ga2ADpvY/PFn8YIotNhmEaxbxOphsOSMoyYoDu0splpxrwWYvEpPftUn/JqpFVZsVe ge7C4H2gFE2EvNYQia2jX/Ow9BqZBZpWfvvoVJCk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ryo Takakura , "Luis Claudio R. Goncalves" , Sebastian Andrzej Siewior , =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= , Bjorn Helgaas , Sasha Levin Subject: [PATCH 6.6 108/393] PCI: vmd: Make vmd_dev::cfg_lock a raw_spinlock_t type Date: Wed, 23 Apr 2025 16:40:04 +0200 Message-ID: <20250423142647.742978377@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250423142643.246005366@linuxfoundation.org> References: <20250423142643.246005366@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ryo Takakura [ Upstream commit 18056a48669a040bef491e63b25896561ee14d90 ] The access to the PCI config space via pci_ops::read and pci_ops::write is a low-level hardware access. The functions can be accessed with disabled interrupts even on PREEMPT_RT. The pci_lock is a raw_spinlock_t for this purpose. A spinlock_t becomes a sleeping lock on PREEMPT_RT, so it cannot be acquired with disabled interrupts. The vmd_dev::cfg_lock is accessed in the same context as the pci_lock. Make vmd_dev::cfg_lock a raw_spinlock_t type so it can be used with interrupts disabled. This was reported as: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:48 Call Trace: rt_spin_lock+0x4e/0x130 vmd_pci_read+0x8d/0x100 [vmd] pci_user_read_config_byte+0x6f/0xe0 pci_read_config+0xfe/0x290 sysfs_kf_bin_read+0x68/0x90 Signed-off-by: Ryo Takakura Tested-by: Luis Claudio R. Goncalves Acked-by: Luis Claudio R. Goncalves [bigeasy: reword commit message] Signed-off-by: Sebastian Andrzej Siewior Tested-off-by: Luis Claudio R. Goncalves Link: https://lore.kernel.org/r/20250218080830.ufw3IgyX@linutronix.de [kwilczynski: commit log] Signed-off-by: Krzysztof Wilczyński [bhelgaas: add back report info from https://lore.kernel.org/lkml/20241218115951.83062-1-ryotkkr98@gmail.com/] Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin --- drivers/pci/controller/vmd.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index 5ff2066aa5164..dfa222e02c4da 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -125,7 +125,7 @@ struct vmd_irq_list { struct vmd_dev { struct pci_dev *dev; - spinlock_t cfg_lock; + raw_spinlock_t cfg_lock; void __iomem *cfgbar; int msix_count; @@ -402,7 +402,7 @@ static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg, if (!addr) return -EFAULT; - spin_lock_irqsave(&vmd->cfg_lock, flags); + raw_spin_lock_irqsave(&vmd->cfg_lock, flags); switch (len) { case 1: *value = readb(addr); @@ -417,7 +417,7 @@ static int vmd_pci_read(struct pci_bus *bus, unsigned int devfn, int reg, ret = -EINVAL; break; } - spin_unlock_irqrestore(&vmd->cfg_lock, flags); + raw_spin_unlock_irqrestore(&vmd->cfg_lock, flags); return ret; } @@ -437,7 +437,7 @@ static int vmd_pci_write(struct pci_bus *bus, unsigned int devfn, int reg, if (!addr) return -EFAULT; - spin_lock_irqsave(&vmd->cfg_lock, flags); + raw_spin_lock_irqsave(&vmd->cfg_lock, flags); switch (len) { case 1: writeb(value, addr); @@ -455,7 +455,7 @@ static int vmd_pci_write(struct pci_bus *bus, unsigned int devfn, int reg, ret = -EINVAL; break; } - spin_unlock_irqrestore(&vmd->cfg_lock, flags); + raw_spin_unlock_irqrestore(&vmd->cfg_lock, flags); return ret; } @@ -1020,7 +1020,7 @@ static int vmd_probe(struct pci_dev *dev, const struct pci_device_id *id) if (features & VMD_FEAT_OFFSET_FIRST_VECTOR) vmd->first_vec = 1; - spin_lock_init(&vmd->cfg_lock); + raw_spin_lock_init(&vmd->cfg_lock); pci_set_drvdata(dev, vmd); err = vmd_enable_domain(vmd, features); if (err) -- 2.39.5