From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 90F543FB7DE; Tue, 25 Aug 2026 13:29:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787664569; cv=none; b=CB4yiVqWmVOQ38PNEz7bcmulm4kDoid9K9cj5t56KIY++/Rp847QNo28yDjahd7R0n+0p1rCUmDFQZSD0f54xKIG3VBVVcBjQGgHhagHNm8NtfQBlLLj7iPDTGhBw8IRANP+EJH9CGiK7oq7c57Hp9IizePvdrmrlMmshJ9BGMU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787664569; c=relaxed/simple; bh=9+EswWBJWyXazIXujtvGplA0WjGq9B5BZogV0LzXUmo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SdgxTlI4AIFijFL23mM+xCT3xNGtiLtX3skyW8ymvoGd+fqIjUiSH60TR+q87CTcHj+orpShrslWWS7TQkDPTWgq8Bzefh3odpdusn942vLSBenO5xcez49EYVFwQZpJ08UgZFwHLtOKygdUB71CWeCehEDad9md8ZrSqR+Nefs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ZVRrc9ED; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ZVRrc9ED" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E4D291F000E9; Tue, 25 Aug 2026 13:29:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787664568; bh=yA05GVJ4HUC6/yp3v5zIL39uIkEFqrBA/XunBuvG4VY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ZVRrc9EDgoAOnuZ26tUZX+KjOTSKu3fWvu6Md1lSFWguKL/NK8t8E/WW6hoseLKt0 Cth1ZtXDSClD+R+ZCfiWjOWMfkFvFsvrlJsbLrPmDQgAHwOmlS0gRQqusA8Y6MCUi4 URRpC7VDZmNrThznN31l6Rxl2VqgjaCJxRlTTsTc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jens Axboe Subject: [PATCH 7.2 15/82] io_uring/futex: only mark private futex waits as inflight Date: Tue, 25 Aug 2026 15:25:02 +0200 Message-ID: <20260825132542.122334415@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260825132541.560541185@linuxfoundation.org> References: <20260825132541.560541185@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 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jens Axboe commit 4d327bbd1cd2485783553b6b2b401aa475f90dd0 upstream. Inflight tracking of futex wait requests exists to ensure that do_exit() -> io_uring_files_cancel() cancels them before the mm goes away, as a private futex wait depends on the mm private futex hash staying alive for the duration of the request. Shared futexes have no such dependency. A FLAGS_SHARED request always resolves to either an inode based key or an mm-shared key, both of which fail futex_key_is_private() and hence always hash into the global futex hash, whose lifetime isn't tied to the mm. Only mark vectored futex waits as inflight if the futex is private. Cc: stable@vger.kernel.org Fixes: 079afb081c42 ("io_uring/futex: mark wait requests as inflight") Link: https://lore.kernel.org/io-uring/CANGjgdn=R_qyUdE=j9za+vkmqcxacbP-84OHXF4nZ4ho9qRyVg@mail.gmail.com/ Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- io_uring/futex.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) --- a/io_uring/futex.c +++ b/io_uring/futex.c @@ -154,14 +154,16 @@ int io_futex_prep(struct io_kiocb *req, int io_futex_wait_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe) { + struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex); int ret; ret = io_futex_prep(req, sqe); if (unlikely(ret)) return ret; - /* Mark as inflight, so file exit cancelation will find it */ - io_req_track_inflight(req); + /* inflight tracking only needed for mm private hash */ + if (!(iof->futex_flags & FLAGS_SHARED)) + io_req_track_inflight(req); return 0; } @@ -186,6 +188,7 @@ int io_futexv_prep(struct io_kiocb *req, { struct io_futex *iof = io_kiocb_to_cmd(req, struct io_futex); struct io_futexv_data *ifd; + unsigned int i; int ret; /* No flags or mask supported for waitv */ @@ -210,8 +213,14 @@ int io_futexv_prep(struct io_kiocb *req, return ret; } - /* Mark as inflight, so file exit cancelation will find it */ - io_req_track_inflight(req); + /* inflight tracking only needed for mm private hash */ + for (i = 0; i < iof->futex_nr; i++) { + if (!(ifd->futexv[i].w.flags & FLAGS_SHARED)) { + io_req_track_inflight(req); + break; + } + } + iof->futexv_unqueued = 0; req->flags |= REQ_F_ASYNC_DATA; req->async_data = ifd;