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 D7691397AF2 for ; Tue, 12 May 2026 13:39:12 +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=1778593152; cv=none; b=qrMheKQuNkNeR+MjKTfhC+BmB6emz7NJkFL1lJpFG8MKonTz3kGNuRB8MfMpjWL8bmzZKvNweetHHlsRNVNvDbf0PWrYX/cLNfHomkfw1IxKrh5SmOdCjMC3XHPly7O79VHQ1SWP2k3Rjqbp41maMRknuPIGjknaTq4QdUwWZUk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778593152; c=relaxed/simple; bh=gXRDxwgqqamYXVsrcV+hAXtoGw0q858FCjMXV59T/Mg=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=jX1HnQBEsEOOz1JgLPRQ1x0jYsuay6PIc39dS4f+cMwrjZRbl8wuuviSh8uJ7aTM6n2s8YsH7pONDlQwfbXRqRiTSkPum6s411c0lXkwSQba8CxiijUrZdz9WRodx8IRU3h7XCvMoOIDBjXcFI211MEaMaDBovOJNWuEpNGHUYM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Rrz/4YtZ; 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="Rrz/4YtZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D4F11C2BCB0; Tue, 12 May 2026 13:39:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778593152; bh=gXRDxwgqqamYXVsrcV+hAXtoGw0q858FCjMXV59T/Mg=; h=Subject:To:Cc:From:Date:From; b=Rrz/4YtZyqG5pBOhuU74rnc3eJsgvZIa3Krijwfi8YZwy+Pxz8088W2B+7R1lziWE GMNvWpiLH0C/NA6eOyRv+23UqAziIaPKgj+bOogHIFnUA2Ie0TgTZrAUUh7xEGiVn3 nxeKBoGDPhxG0+KRvunGy1JkdWIGceTvsJvW04Sw= Subject: FAILED: patch "[PATCH] pseries/papr-hvpipe: Fix race with interrupt handler" failed to apply to 6.18-stable tree To: ritesh.list@gmail.com,maddy@linux.ibm.com Cc: From: Date: Tue, 12 May 2026 15:39:17 +0200 Message-ID: <2026051217-briskness-posing-6f46@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y git checkout FETCH_HEAD git cherry-pick -x 7a4f0846ee6cc8cf44ae0046ed42e3259d1dd45b # git commit -s git send-email --to '' --in-reply-to '2026051217-briskness-posing-6f46@gregkh' --subject-prefix 'PATCH 6.18.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 7a4f0846ee6cc8cf44ae0046ed42e3259d1dd45b Mon Sep 17 00:00:00 2001 From: "Ritesh Harjani (IBM)" Date: Fri, 1 May 2026 09:41:40 +0530 Subject: [PATCH] pseries/papr-hvpipe: Fix race with interrupt handler 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 diff --git a/arch/powerpc/platforms/pseries/papr-hvpipe.c b/arch/powerpc/platforms/pseries/papr-hvpipe.c index 14ae480d060a..c41d45e1986d 100644 --- 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(struct inode *inode, 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(struct inode *inode, */ 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_hvpipe_handle_ops = { 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(u32 srcID) 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); }