From nobody Wed Feb 11 01:25:45 2026 Received: from mail-io1-f48.google.com (mail-io1-f48.google.com [209.85.166.48]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5A30715E1F6 for ; Tue, 2 Apr 2024 20:25:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.48 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712089536; cv=none; b=ZRdjrGMwlx2zVxdl+IlHJLjsZYp0WwawW0Yr96k77EgZzKymTGpsOV8bdS+hWmqxeZefHpBFr5lzhKPF4noN/Y1LszyQPXnZn87knKJZk5Ja8rzpMQahInGPOOAADVp5vcZLSvtal3T4Qqz36rWiI8OSJPXENowcxOBnU/z1Xxs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712089536; c=relaxed/simple; bh=lvxMY5xAb2LkORT4WJWhXdTw9IOcYUuS+QAu6zRgfeM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=P8+U9Pd5WcQRnh4DiQ1LclMnbv3h11R+kfDBVZMyP4fvhV19wOKmd6uNYm6BbBZymspYJrmab0a+ZH5yHopOP0xYg+Uwu448n05h8VSKmCDD5xKmPNc9QpL11HSf2bkt1FhRyXtRx0CutGVcTvhmmj8E7XIsTY0toAp0k6FFl90= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=rpSQ5AbF; arc=none smtp.client-ip=209.85.166.48 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="rpSQ5AbF" Received: by mail-io1-f48.google.com with SMTP id ca18e2360f4ac-7cc0e831e11so42169739f.1 for ; Tue, 02 Apr 2024 13:25:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1712089534; x=1712694334; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=wEISoDaReVBYlihnUfkRNegSHCa1fOWz9Nfv9lbetO4=; b=rpSQ5AbFmAhADrr5Wu0H8kGy+7W6gC8uCOb0gXT1WngH/NkwcM7sSOoAl3Gtf9+L2R +R6598YkJLVV31lhowcV+wut1UT/UbOtCWqQ3+lSPuKvn2Rs4p0OFcWgauEzemUbnqfT PkOtl/7AjqOBf3SgWreaLUAx3m95jvvm8kP3Ep3lyghYYbsuUZnmx5+9rabQFbUfSh4j m4sNnGto0z9th8Zdgb9qcenoZ65u49+KTUNWAkMKjUq09eVePvbfqSjJYOY5KeyIlqAM OIrf6P7V3w9jAAdHMa4b3LyPAsArfMrIudNLMMLxc+tzbI5xZuAu/i2wuHXR4fxGTrrR sd/Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1712089534; x=1712694334; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=wEISoDaReVBYlihnUfkRNegSHCa1fOWz9Nfv9lbetO4=; b=Vt07Xmrw07cGPv3xmK8siLnqrYJLVcfOtMr9UB3m4L7KBv6KbDo8JjIeA1/rxV8auA gqQoQNLaytT9uuOT25kXQ4j9A9vh8kM1zfFAbJB9nPG7qoeug2kxxmcqy7ZsJHJqop5i 332Zzak/cRz3Syspxaq3wbjCuQQ5Tzm+3d6+aba1+Ayr/xogvCJkyxDFl9yxwvLYeRvr 1eBytdsnA/wybvdYmf6SxayqedUL0CC8RheAxxCLfi3XMaQPjPVlUG2sHgeDNgUZzbNz 1Qd/10LbJpRAyIUMZZHRjE+luObNG/lTkqmq6r56NyTOwfvXpykVRXGAWgIjUkfkp/gX E1yA== X-Forwarded-Encrypted: i=1; AJvYcCUzfneuaMyix7FaIO4MJLwwwOUkm1MWEeATq+2wfzz7CbFwQb0dpunqqt4C3Usxo29FgbFzK4kJTyU5p3EpEYWr6BWcDecrDhwkaBin X-Gm-Message-State: AOJu0YwijemEYFxKhLtkUmIiryyqLDAEkd3vsXKgZwpVqAGd2UyM/7hK VvaJwsh60PK0mNb7en7zN3Ad1dhuJ31OXlr7RBgUDFFMuGL0KSJYPCQCB6kjcTE= X-Google-Smtp-Source: AGHT+IGJehSXeir2a4opOIryK4i/S+JB9yIPvNU+R1MfGhn5Hq5ofPKNTd0bOyXRTrjF2tYhZksXHA== X-Received: by 2002:a6b:6d16:0:b0:7d0:c0e7:b577 with SMTP id a22-20020a6b6d16000000b007d0c0e7b577mr7956587iod.2.1712089534576; Tue, 02 Apr 2024 13:25:34 -0700 (PDT) Received: from localhost.localdomain ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id u9-20020a02cbc9000000b0047ec029412fsm3445956jaq.12.2024.04.02.13.25.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 02 Apr 2024 13:25:33 -0700 (PDT) From: Jens Axboe To: linux-fsdevel@vger.kernel.org Cc: brauner@kernel.org, linux-kernel@vger.kernel.org, Jens Axboe Subject: [PATCH 3/3] signalfd: convert to ->read_iter() Date: Tue, 2 Apr 2024 14:18:23 -0600 Message-ID: <20240402202524.1514963-4-axboe@kernel.dk> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240402202524.1514963-1-axboe@kernel.dk> References: <20240402202524.1514963-1-axboe@kernel.dk> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Rather than use the older style ->read() hook, use ->read_iter() so that signalfd can support both O_NONBLOCK and IOCB_NOWAIT for non-blocking read attempts. Split the fd setup into two parts, so that signalfd can mark the file mode with FMODE_NOWAIT before installing it into the process table. Signed-off-by: Jens Axboe --- fs/signalfd.c | 44 ++++++++++++++++++++++++++++---------------- 1 file changed, 28 insertions(+), 16 deletions(-) diff --git a/fs/signalfd.c b/fs/signalfd.c index e20d1484c663..9b4ff83d816d 100644 --- a/fs/signalfd.c +++ b/fs/signalfd.c @@ -68,8 +68,7 @@ static __poll_t signalfd_poll(struct file *file, poll_tab= le *wait) /* * Copied from copy_siginfo_to_user() in kernel/signal.c */ -static int signalfd_copyinfo(struct signalfd_siginfo __user *uinfo, - kernel_siginfo_t const *kinfo) +static int signalfd_copyinfo(struct iov_iter *to, kernel_siginfo_t const *= kinfo) { struct signalfd_siginfo new; =20 @@ -146,10 +145,7 @@ static int signalfd_copyinfo(struct signalfd_siginfo _= _user *uinfo, break; } =20 - if (copy_to_user(uinfo, &new, sizeof(struct signalfd_siginfo))) - return -EFAULT; - - return sizeof(*uinfo); + return copy_to_iter(&new, sizeof(struct signalfd_siginfo), to); } =20 static ssize_t signalfd_dequeue(struct signalfd_ctx *ctx, kernel_siginfo_t= *info, @@ -199,25 +195,26 @@ static ssize_t signalfd_dequeue(struct signalfd_ctx *= ctx, kernel_siginfo_t *info * error code. The "count" parameter must be at least the size of a * "struct signalfd_siginfo". */ -static ssize_t signalfd_read(struct file *file, char __user *buf, size_t c= ount, - loff_t *ppos) +static ssize_t signalfd_read_iter(struct kiocb *iocb, struct iov_iter *to) { + struct file *file =3D iocb->ki_filp; struct signalfd_ctx *ctx =3D file->private_data; struct signalfd_siginfo __user *siginfo; - int nonblock =3D file->f_flags & O_NONBLOCK; + size_t count =3D iov_iter_count(to); ssize_t ret, total =3D 0; kernel_siginfo_t info; + bool nonblock; =20 count /=3D sizeof(struct signalfd_siginfo); if (!count) return -EINVAL; =20 - siginfo =3D (struct signalfd_siginfo __user *) buf; + nonblock =3D file->f_flags & O_NONBLOCK || iocb->ki_flags & IOCB_NOWAIT; do { ret =3D signalfd_dequeue(ctx, &info, nonblock); if (unlikely(ret <=3D 0)) break; - ret =3D signalfd_copyinfo(siginfo, &info); + ret =3D signalfd_copyinfo(to, &info); if (ret < 0) break; siginfo++; @@ -246,7 +243,7 @@ static const struct file_operations signalfd_fops =3D { #endif .release =3D signalfd_release, .poll =3D signalfd_poll, - .read =3D signalfd_read, + .read_iter =3D signalfd_read_iter, .llseek =3D noop_llseek, }; =20 @@ -265,20 +262,35 @@ static int do_signalfd4(int ufd, sigset_t *mask, int = flags) signotset(mask); =20 if (ufd =3D=3D -1) { + struct file *file; + ctx =3D kmalloc(sizeof(*ctx), GFP_KERNEL); if (!ctx) return -ENOMEM; =20 ctx->sigmask =3D *mask; =20 + ufd =3D get_unused_fd_flags(O_RDWR | + (flags & (O_CLOEXEC | O_NONBLOCK))); + if (ufd < 0) { + kfree(ctx); + return ufd; + } + + file =3D anon_inode_getfile("[signalfd]", &signalfd_fops, ctx, + O_RDWR | (flags & (O_CLOEXEC | O_NONBLOCK))); + if (IS_ERR(file)) { + put_unused_fd(ufd); + kfree(ctx); + return ufd; + } + file->f_mode |=3D FMODE_NOWAIT; + /* * When we call this, the initialization must be complete, since * anon_inode_getfd() will install the fd. */ - ufd =3D anon_inode_getfd("[signalfd]", &signalfd_fops, ctx, - O_RDWR | (flags & (O_CLOEXEC | O_NONBLOCK))); - if (ufd < 0) - kfree(ctx); + fd_install(ufd, file); } else { struct fd f =3D fdget(ufd); if (!f.file) --=20 2.43.0