From nobody Tue Feb 10 03:00:05 2026 Received: from mail-il1-f172.google.com (mail-il1-f172.google.com [209.85.166.172]) (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 B09FD1494DE for ; Wed, 3 Apr 2024 14:04:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712153098; cv=none; b=HTanwEfBP8kOcAYuBK7f465PjYP9B0yd8kMZ7jBKzPxPoq5dyukeWslYneKqIc798rEExULNmpKXMLvGg96muzOVZclxENgbGFloI/coQx7+qenrw8Rn92HX3CJ87ktoL+nqWVVnSGpvrxox+6Xh2qrSwVdSLuK/Emu1HXo7lDI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712153098; c=relaxed/simple; bh=RYxshW62rNDqV/XwwfM71cdZpZnhqfyASR91PbgeFwI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dc+GXDYH/06mA3SGaJRCpQ/x6Bawdc6RbwsuBEvKYYSU7aOtqret/h4YJ/m6FS+RuAXoUVfpMdnfN6+qF79Vql0Hn/gJISO0PlIaMn8UNrre19DxwMb6NqHbzQZDd+oUjBGbBAcqlIsdFUMYX4C7vpjexPmEFvRhNf7M5Q7UZqc= 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=o7xE+H1r; arc=none smtp.client-ip=209.85.166.172 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="o7xE+H1r" Received: by mail-il1-f172.google.com with SMTP id e9e14a558f8ab-3688f1b7848so3864995ab.0 for ; Wed, 03 Apr 2024 07:04:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1712153096; x=1712757896; 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=7phpRQzKHUb5cKw5ojjkDKoDkjW2SeY3RKIXhDXMeoI=; b=o7xE+H1rwltHEdaNPiOdFytvVMA+f5fVW0FwhAv57WBI4XaC3HQK/NFMkgCBAGMzc8 1tSQRmE3JlGfMTbC7+KYX8MW8tUKP0QGCWTiqpCcLHlt+oj8+IAd5VacVRXZKrN8z+Hd PLSfvF3QpakKaefxy/MQN/5KUvGXB1wl4e6sIdYJoH5PXya/tRPANJ+HWtLDWDsn9ic3 NSsqrZTy83FQ6jT0ZuypCm5dYAw4GlyxADV9OgIn7qUdigSqJoNxmoXDSFjqahcxUZEz uE9STY8qpDskqs0KgsekQjBq06Eh1sKivD/oYnbWGAJ9oUFk1hXq+QeeicE/9mKld6x5 2skA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1712153096; x=1712757896; 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=7phpRQzKHUb5cKw5ojjkDKoDkjW2SeY3RKIXhDXMeoI=; b=bEEsvsjIL5NOisHyfP10uJ/MpBsQzgBOp/ZonGQztdDPWN6y3hhuA8STyUZ4ox5/fZ DmTWFHlmzSSxeXwqHhtJWqlZWRKl5yX94P8ot1sjhiaOMHOjibkVgB9Nx7zEwLD1DGXq fY1+tM7EV72Bt68xdxUYilySQh9c/GnuJDdWaHBvFWqV/sUXp0Knt5XyM23G3PLgkeJO w/JPIu0rZaSyAlqelGcOanxytnyJSu5jI5m6M0UbWu2DyLw9gNZkHYBwz+KKH8+5KPJp Lajg66D+Mo949Y4NyQu8PpTMLEIm1TrTTMHye+iAd6GR3mutyxBUMrvNgAkhHFv+GK0s CsWQ== X-Forwarded-Encrypted: i=1; AJvYcCXJK6FRJ+kW0jiFp4F/p79BDpTvytFVrNwJDdkYkIkQ+raYg7kvJVWcfJJka36xBw3LZSq6Y4GFdF3t9L75khFZx+5w8ZYHbNCDCXYz X-Gm-Message-State: AOJu0YyrJ2suIG8C7QFdm8rUjqW7xTqXhfnMaO5HvXw9G/HiRnlI6zXR WxL5ss+O+FVSTZ2+Kl3/okRjv7H8qcKVwaYFXbtzu9rB4bM2CNQiWVHZzX7BKew= X-Google-Smtp-Source: AGHT+IEBppmO1/3FbazzRqFUqPwmzgcKQdhokjBVL/E2xk7pqmtXNeh2uBIDR19/CXN3YT0AOJ1H0w== X-Received: by 2002:a05:6e02:2218:b0:365:2bd4:2f74 with SMTP id j24-20020a056e02221800b003652bd42f74mr17975633ilf.0.1712153095826; Wed, 03 Apr 2024 07:04:55 -0700 (PDT) Received: from localhost.localdomain ([96.43.243.2]) by smtp.gmail.com with ESMTPSA id a3-20020a056638164300b0047ef3ea2bdfsm2027098jat.78.2024.04.03.07.04.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 03 Apr 2024 07:04:54 -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: Wed, 3 Apr 2024 08:02:54 -0600 Message-ID: <20240403140446.1623931-4-axboe@kernel.dk> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240403140446.1623931-1-axboe@kernel.dk> References: <20240403140446.1623931-1-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 | 46 ++++++++++++++++++++++++++++------------------ 1 file changed, 28 insertions(+), 18 deletions(-) diff --git a/fs/signalfd.c b/fs/signalfd.c index e20d1484c663..72b6796a9a40 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, @@ -199,28 +195,27 @@ 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++; total +=3D ret; nonblock =3D 1; } while (--count); @@ -246,7 +241,7 @@ 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 +260,35 @@ 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