From patchwork Sun Dec 24 05:01:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Ahelenia_Ziemia=C5=84ska?= X-Patchwork-Id: 758199 Received: from tarta.nabijaczleweli.xyz (tarta.nabijaczleweli.xyz [139.28.40.42]) (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 5F4D2EC0; Sun, 24 Dec 2023 05:01:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=nabijaczleweli.xyz Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=nabijaczleweli.xyz Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=nabijaczleweli.xyz header.i=@nabijaczleweli.xyz header.b="jHk9hGJB" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=nabijaczleweli.xyz; s=202305; t=1703394109; bh=8JqjLYgVpBXyZxmwMpSVDZbE1TJ3MF+mAG3wx6Uw9pQ=; h=Date:From:Cc:Subject:References:In-Reply-To:From; b=jHk9hGJB5O3WI8fjG4cLk3aQJtGC+pfA0r0KZO3OH1sUKU5kWEp0+fh4OVGlfMtMi K+dlbxT25iY5MS+SPpD5IRmF3TuTU5vo46Y7bjzBts7Gaa2eju425b80QL8d95XKMV oEuAasy7V3VjGivCeoLyhnKCyfHJg5L4ELNjAlhFJ23qlJyETRTimLl7C3AFplIvhQ ZThiJDSm9GP4nb092DACHKBbNcYOH2qplLF8TQK1WM0k1TkYiNgSfG8Hqj7z7edvM3 WmaxrW+zaE82xLkdKCiTbbDiYZiIPXeePzmmh2nMnt1e7a0vNaYkPsV1eIHw3+98OC YyXAX7hZgbESA== Received: from tarta.nabijaczleweli.xyz (unknown [192.168.1.250]) by tarta.nabijaczleweli.xyz (Postfix) with ESMTPSA id 5AE9E1421C; Sun, 24 Dec 2023 06:01:49 +0100 (CET) Date: Sun, 24 Dec 2023 06:01:49 +0100 From: Ahelenia =?utf-8?q?Ziemia=C5=84ska?= Cc: Jens Axboe , Christian Brauner , Alexander Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Greg Kroah-Hartman , Jiri Slaby , linux-serial@vger.kernel.org Subject: [PATCH v2 13/11] tty: splice_write: disable Message-ID: References: Precedence: bulk X-Mailing-List: linux-serial@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: NeoMutt/20231103 Given: cat > ttyW.c <<^D #define _GNU_SOURCE #include #include int main() { int pt = posix_openpt(O_RDWR); grantpt(pt); unlockpt(pt); int cl = open(ptsname(pt), O_WRONLY); for (;;) splice(0, 0, cl, 0, 128 * 1024 * 1024, 0); } ^D cc ttyW.c -o ttyW mkfifo fifo truncate 32M 32M ./ttyW < fifo & cp 32M fifo & sleep 0.1 read -r _ < fifo ttyW used to sleep in splice and the shell used to enter an uninterruptible sleep in open("fifo"); now the splice returns -EINVAL and the whole program completes. This is also symmetric with the splice_read removal. Signed-off-by: Ahelenia Ziemiańska --- It hit me that I should actually probably exhaustively re-evaluate splice_write as well since re-evaluating splice_read went so well. fs/fuse/dev.c: .splice_write = fuse_dev_splice_write, drivers/char/virtio_console.c: .splice_write = port_fops_splice_write, locks, takes some pages, unlocks, writes, so OK drivers/char/mem.c: .splice_write = splice_write_null, drivers/char/mem.c: .splice_write = splice_write_zero, no-op drivers/char/random.c: .splice_write = iter_file_splice_write, drivers/char/random.c: .splice_write = iter_file_splice_write, AFAICT write_pool_user is okay to invoke like this? net/socket.c: .splice_write = splice_to_socket, already dealt with in 11/11 drivers/tty/tty_io.c: .splice_write = iter_file_splice_write, drivers/tty/tty_io.c: .splice_write = iter_file_splice_write, they do lock the pipe and try the write with the lock held; we already killed splice_read so just kill splice_write for symmetry (13/11) fs/fuse/file.c: .splice_write = iter_file_splice_write, same logic as splice_read applies (14/11) drivers/tty/tty_io.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 50c2957a9c7f..d931c34ddcbf 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -465,7 +465,6 @@ static const struct file_operations tty_fops = { .llseek = no_llseek, .read_iter = tty_read, .write_iter = tty_write, - .splice_write = iter_file_splice_write, .poll = tty_poll, .unlocked_ioctl = tty_ioctl, .compat_ioctl = tty_compat_ioctl, @@ -479,7 +478,6 @@ static const struct file_operations console_fops = { .llseek = no_llseek, .read_iter = tty_read, .write_iter = redirected_tty_write, - .splice_write = iter_file_splice_write, .poll = tty_poll, .unlocked_ioctl = tty_ioctl, .compat_ioctl = tty_compat_ioctl,