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 CF78934405B; Tue, 12 May 2026 18:09:17 +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=1778609357; cv=none; b=NJhXvUlSCFsKzVWdaLXwsJp9Sfca/waNBjGBRdcphIP0fBDJ9DcJ/7Yx/5UD+Z9pWaTsBtupw9aCvMmapsNka1cfr6Weuf3PuhiHhD2+zE8htH14hXNBLKcqtdtOaoMyJpFYqcsm64fWEVc8FObxRO6olraIQ7WOX/WLzXoIoUg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778609357; c=relaxed/simple; bh=pbyXHTPtCmx1QxiYBGsX3w0rUvvJzrAQadIJXk8mF5I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=r0TXNT6j3Gw+js+Wu5WzXdmwvOiIHlMsBvCo8odkS2zDbw75SXYX8I7yMpONhWvzVzVYKRBdYBxHkNfU/FcP6m6nbVb7t0HbSfO5vB3DcD1Fw4HLQwaujJfijFJFlxcZ0IZUKfh7o740P5ooy/GrRuTYtVrMB9g18OU+/KoCweQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Xrdm5UUO; 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="Xrdm5UUO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 683B0C2BCB0; Tue, 12 May 2026 18:09:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778609357; bh=pbyXHTPtCmx1QxiYBGsX3w0rUvvJzrAQadIJXk8mF5I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Xrdm5UUO1gkeYpC6s7w7Xd4WakAtcmezKMhrAQRL/ghuHBPGn2W0dwZHtKXtB1kKp vq40/M/WKpIcLKUgVdlno6pSfzeCjysCU6fLiISug0nEzlgn2MGuRaNvRBq6h9uVWf MYR47tlOd1tJqjYI41QhcvgpxuAIjSX9y1aOQE8k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Ritesh Harjani (IBM)" , Madhavan Srinivasan Subject: [PATCH 7.0 112/307] pseries/papr-hvpipe: Fix race with interrupt handler Date: Tue, 12 May 2026 19:38:27 +0200 Message-ID: <20260512173942.488429435@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260512173940.117428952@linuxfoundation.org> References: <20260512173940.117428952@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ritesh Harjani (IBM) commit 7a4f0846ee6cc8cf44ae0046ed42e3259d1dd45b upstream. While executing ->ioctl handler or ->release handler, if an interrupt fires on the same cpu, then we can enter into a deadlock. This patch fixes both these handlers to take spin_lock_irq{save|restore} versions of the lock to prevent this deadlock. Cc: stable@vger.kernel.org Fixes: 814ef095f12c9 ("powerpc/pseries: Add papr-hvpipe char driver for HVPIPE interfaces") Signed-off-by: Ritesh Harjani (IBM) Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/e4ed435c44fc191f2eb23c7907ba6f72f193e6aa.1777606826.git.ritesh.list@gmail.com Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/platforms/pseries/papr-hvpipe.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) --- a/arch/powerpc/platforms/pseries/papr-hvpipe.c +++ b/arch/powerpc/platforms/pseries/papr-hvpipe.c @@ -444,13 +444,14 @@ static int papr_hvpipe_handle_release(st struct file *file) { struct hvpipe_source_info *src_info; + unsigned long flags; /* * Hold the lock, remove source from src_list, reset the * hvpipe status and release the lock to prevent any race * with message event IRQ. */ - spin_lock(&hvpipe_src_list_lock); + spin_lock_irqsave(&hvpipe_src_list_lock, flags); src_info = file->private_data; list_del(&src_info->list); file->private_data = NULL; @@ -461,10 +462,10 @@ static int papr_hvpipe_handle_release(st */ if (src_info->hvpipe_status & HVPIPE_MSG_AVAILABLE) { src_info->hvpipe_status = 0; - spin_unlock(&hvpipe_src_list_lock); + spin_unlock_irqrestore(&hvpipe_src_list_lock, flags); hvpipe_rtas_recv_msg(NULL, 0); } else - spin_unlock(&hvpipe_src_list_lock); + spin_unlock_irqrestore(&hvpipe_src_list_lock, flags); kfree(src_info); return 0; @@ -480,20 +481,21 @@ static const struct file_operations papr static int papr_hvpipe_dev_create_handle(u32 srcID) { struct hvpipe_source_info *src_info __free(kfree) = NULL; + unsigned long flags; - spin_lock(&hvpipe_src_list_lock); + spin_lock_irqsave(&hvpipe_src_list_lock, flags); /* * Do not allow more than one process communicates with * each source. */ src_info = hvpipe_find_source(srcID); if (src_info) { - spin_unlock(&hvpipe_src_list_lock); + spin_unlock_irqrestore(&hvpipe_src_list_lock, flags); pr_err("pid(%d) is already using the source(%d)\n", src_info->tsk->pid, srcID); return -EALREADY; } - spin_unlock(&hvpipe_src_list_lock); + spin_unlock_irqrestore(&hvpipe_src_list_lock, flags); src_info = kzalloc_obj(*src_info, GFP_KERNEL_ACCOUNT); if (!src_info) @@ -510,18 +512,18 @@ static int papr_hvpipe_dev_create_handle return fdf.err; retain_and_null_ptr(src_info); - spin_lock(&hvpipe_src_list_lock); + spin_lock_irqsave(&hvpipe_src_list_lock, flags); /* * If two processes are executing ioctl() for the same * source ID concurrently, prevent the second process to * acquire FD. */ if (hvpipe_find_source(srcID)) { - spin_unlock(&hvpipe_src_list_lock); + spin_unlock_irqrestore(&hvpipe_src_list_lock, flags); return -EALREADY; } list_add(&src_info->list, &hvpipe_src_list); - spin_unlock(&hvpipe_src_list_lock); + spin_unlock_irqrestore(&hvpipe_src_list_lock, flags); return fd_publish(fdf); }