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 8C5333FF8BA; Tue, 25 Aug 2026 13:33:33 +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=1787664814; cv=none; b=lGGzctvKGi8Hl0Y/RHGv/WjThXZ1RoBj3SgTgVUFfshEeZKMXnb5MERalygJOR4IAoqaY+W8ZY8TxpiBwcE+0mO7RYefQtVnCXcKmq66Re15bEKwCIDNHps8EfatUfU8or/KrZpnz83mjbIxxGi0JeCdPqjJe5/0SifryaU5dwY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787664814; c=relaxed/simple; bh=IKN5eiA41Q9/fc6ROZhTpu6Jc2LAlFLKHCcZGpasEyE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=peN/6EtF2s88a6xA+j00A8TwG4ssox45VtU1bxzrhEO0BN9fu4iHL1g3idWpdh93gerr5TbXW6Wmr/oJGfbzvzsVqavQpqiCK4co1EpCpomSCt17XJWHuLMm80YW044QOSdLtb+7FZayx8GlibGbQ4IvDTytjbV+Ekb7ArTcRY8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=T0LpBfRF; 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="T0LpBfRF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DDFDC1F000E9; Tue, 25 Aug 2026 13:33:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787664813; bh=xMPI8ti5HbbksGu1QlJVpPEgG5aJ5ydP6Oh2r2xiQgU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=T0LpBfRFWz62azazvLJ5JKthZxISxft1Rmc5D+R0q6oUjzxGQag/J3lXwkBowYC1n JHGUOq/64P5rn8Wb2FlC8+fMwVnU9kpXo/cd6OIRPZr4RgvvVAlZQWylHyp16IzMeT bVqj4yqHY/SMH7errGc2/pjy8IMhoF0o1qrGjIWg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jens Axboe Subject: [PATCH 7.1 014/101] io_uring/futex: only mark private futex waits as inflight Date: Tue, 25 Aug 2026 15:24:52 +0200 Message-ID: <20260825132542.559308164@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260825132541.986300899@linuxfoundation.org> References: <20260825132541.986300899@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 7.1-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;