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 7A8D32609EE; Fri, 15 May 2026 16:25:27 +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=1778862327; cv=none; b=bfOaMZfkixsMOG2Aebm3zIwJpkSlTUWOyVGKyzWNJOSfHIlspJtOQsu8WWWyzUDRqda01PzYd3HKnsofVsUpkj9iNj3QOHS1/zcxEikIHi2yhN80MdB8RX4iVBDK2Q48vphSJHna+IDf7CFWuHSzqwwOMoPqA2Wv7rFW9o01R24= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778862327; c=relaxed/simple; bh=oFHliOU/GyWNr1u8iN5z4UHSYvJsao4Aq3z/VAfbEdg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=A8S8rfrSy7fiDfB/Ie4zLxBne2ILHu7LPnnIfjtpVkFycHJvQaf4Gi+9dYZl2/l/rLYGvnFJrgEzYUvK6eEs9Fd4d3SR6qSwj5Py1CL3YiKPuKgl/EmyLokgv7S+6TdIkk5umsD/qjjYoqkNmiECTlpuyZXqRrnJcXg4eY/hiME= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=k045NdM8; 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="k045NdM8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0C01BC2BCB0; Fri, 15 May 2026 16:25:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778862327; bh=oFHliOU/GyWNr1u8iN5z4UHSYvJsao4Aq3z/VAfbEdg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k045NdM8BxlriKMs+ZaBZc6l8jZoSkY4vr272i3DZltYGsC0QxEgpYgO2Xnm9yYqd IvnSm0vBgXmdjCuSycKlbSYztXcdS+6GKJ7zYe4Q5rNvLFVbNTsIjS00tqCjvCvSs3 CJCFblftCGcbWmjww4xCD1KOWE0Ok8NehU3rKeAk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Ritesh Harjani (IBM)" , Madhavan Srinivasan , Sasha Levin Subject: [PATCH 6.18 161/188] pseries/papr-hvpipe: Fix race with interrupt handler Date: Fri, 15 May 2026 17:49:38 +0200 Message-ID: <20260515154700.820980059@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260515154657.309489048@linuxfoundation.org> References: <20260515154657.309489048@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Ritesh Harjani (IBM)" [ Upstream commit 7a4f0846ee6cc8cf44ae0046ed42e3259d1dd45b ] 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: Sasha Levin 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 @@ -449,13 +449,14 @@ 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; @@ -466,10 +467,10 @@ 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; @@ -485,20 +486,21 @@ 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(sizeof(*src_info), GFP_KERNEL_ACCOUNT); if (!src_info) @@ -515,18 +517,18 @@ 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); }