From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793632070; b=ia1M7GP+uaZFHs5ac8tBoa1+n2lrYA4SxBJpjaLdNHIEFquzHJc/1re9CYQ0LT9Krx8j 3hwjdv7TG49JjjGCUZRe4QJ/y1yluO9Jvpn+Pe/f0jM94P8T2UXUix1q18DTfvQ4us54R p1cxHTqhnDaUrxREefabW3StB5UlQJA7ZihqXHlHzjkG/qc2GurOkNvveEasjzPj6SJPj YU8TFooxLDcjjRjt2A4BGrddiLLclbvpi6O3nA9pq0aRF2hpKTA3wG5jrObGZqDkO9BrV k7I1g85br3sTec1Q99NRsKVKvPrsFnEk8mY1JM/s7y5U4wResNhNJCt92QgmEppuwsg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793632070; h=Received:DKIM-Signature:From:Date:Subject:MIME-Version:Content-Type: Content-Transfer-Encoding:Message-Id:References:In-Reply-To:To:Cc: X-Mailer; bh=lzi0v2Iw6r5Nf2GLOsMSQBwdPNX93e2TzGzGfD3oQvk=; b=dCqC+geZgYa+16mFGtApa1HOqzz9b5NuIwVHT56mBNo6IlopgiFvWjFHhhqyGaGCKJY/ GZbh/wyHMAuBDjq6/djbUyYyRvvD8Gf3KvE7gN4bwXcByYqKfDIGQgYSjumcUitg815Nh 9ObIyVO/zNXU75lrQtRimuz+4iqToLA1XQHzDfwAoLnqQ8RFJcdrU6GRbmmHBotIwEdHy TQHHJyx1qKV3rqy2Jx1wxFV3S9RSbiEZglNM9aG03RGG/f20CGDsSxpx5t0SOaO6NmeNr JeRvke48lc+kWLgSuxexZwK3vDdd4Az5273sm+yeY+3qE0TTUK+9+hgldp9jdK/Ri7A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=kIoUwWZI; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BC56760A34CD; Mon, 2 Nov 2026 15:07:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=kIoUwWZI Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9C6921F00A18; Mon, 2 Nov 2026 15:07:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793632069; bh=lzi0v2Iw6r5Nf2GLOsMSQBwdPNX93e2TzGzGfD3oQvk=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=kIoUwWZIZJmPIDGcbCqUMn+ysgkkYH4B9KIOKwQcxHvHBenqGMDwfSExIyruQhbFw GSvSuGXqLlsS/+2bX4zY15r68FSJdvY7PhgxxV9bnP9Q3PrAcl12NmKthDnezkWdzA YQcdsHreaTBVFGkt5/ixU0O685iwRTrAmT2xH295OHXHJaGkHJFEIXEMqGqXCeqbKp nkpHGaPfZ7GY12qU7tMKJN88syBFW289W+duXDc1qru1IIyFkTan4orRc22NIVl3pP G9JHqYUFv0jVxFqVlQXSQgnsHBo0FeNBeFWC+sINyeJMsGIfziINB34GYCGOVyuJWO tkxpbHP0pDc6g== From: Christian Brauner Date: Mon, 02 Nov 2026 16:01:45 +0100 Subject: [PATCH RFC 18/22] macintosh/via-pmu: let procfs copy in writes to the options file X-Mailing-List: linux-debuggers@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261102-work-procfs-arch-v1-18-c9492ab08480@kernel.org> References: <20261102-work-procfs-arch-v1-0-c9492ab08480@kernel.org> In-Reply-To: <20261102-work-procfs-arch-v1-0-c9492ab08480@kernel.org> To: linux-fsdevel@vger.kernel.org Cc: Linus Torvalds , Jann Horn , Josef Bacik , Chris Mason , Jeff Layton , NeilBrown , Eric Dumazet , Thomas Gleixner , Al Viro , Jonathan Corbet , Christoph Hellwig , Greg Kroah-Hartman , Joel Granados , Kees Cook , Jan Kara , Jan Kara , linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-acpi@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-s390@vger.kernel.org, linux-scsi@vger.kernel.org, linux-um@lists.infradead.org, linux-wireless@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, ntfs3@lists.linux.dev, platform-driver-x86@vger.kernel.org, coreteam@netfilter.org, kexec@lists.infradead.org, linux-pci@vger.kernel.org, linux-sound@vger.kernel.org, netfilter-devel@vger.kernel.org, dri-devel@lists.freedesktop.org, ibm-acpi-devel@lists.sourceforge.net, jfs-discussion@lists.sourceforge.net, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-cifs@vger.kernel.org, linux-fbdev@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-mm@kvack.org, linux-sh@vger.kernel.org, linux-usb@vger.kernel.org, samba-technical@lists.samba.org, sparclinux@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-doc@vger.kernel.org, linux-serial@vger.kernel.org, linux-atm-general@lists.sourceforge.net, Takashi Iwai , linux-input@vger.kernel.org, linux-raid@vger.kernel.org, linux-ext4@vger.kernel.org, linux-modules@vger.kernel.org, linux-debuggers@vger.kernel.org, "Christian Brauner (Amutable)" , Chuck Lever X-Mailer: b4 0.17-dev Implement ->proc_write_buf() so procfs copies in what is written before it pins the entry, and parse the option from that copy. Writes larger than PAGE_SIZE - 1 bytes fail with -EINVAL now. Signed-off-by: Christian Brauner (Amutable) --- drivers/macintosh/via-pmu.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/macintosh/via-pmu.c b/drivers/macintosh/via-pmu.c index 49f929ae10e4..079c085be5d2 100644 --- a/drivers/macintosh/via-pmu.c +++ b/drivers/macintosh/via-pmu.c @@ -913,7 +913,7 @@ static int pmu_options_proc_show(struct seq_file *m, void *v) } static ssize_t pmu_options_proc_write(struct file *file, - const char __user *buffer, size_t count, loff_t *pos) + char *buffer, size_t count, loff_t *pos) { char tmp[33]; char *label, *val; @@ -923,8 +923,7 @@ static ssize_t pmu_options_proc_write(struct file *file, return -EINVAL; if (count > 32) count = 32; - if (copy_from_user(tmp, buffer, count)) - return -EFAULT; + memcpy(tmp, buffer, count); tmp[count] = 0; label = tmp; @@ -958,7 +957,7 @@ static ssize_t pmu_options_proc_write(struct file *file, static const struct proc_ops pmu_options_proc_ops = { .proc_show = pmu_options_proc_show, - .proc_write = pmu_options_proc_write, + .proc_write_buf = pmu_options_proc_write, }; #endif -- 2.53.0