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=1793631747; b=j7VvM6Z3Foks5Lnd9ob5OloWIo4QgAjSiEHz6MaCWqz2ENhTtQKnCM7IUdzr6D8jr4Ai zOs6Fzrb9X03XsIptaVzFj8I/vkzHuReS0al5FZGd3uOcN0Z1BY23VPHvFXrXyBc0wTVG MIp9aZ2jZPaoROBe5+yJ681Xg716CKwY50Z0+qG9eSjFZEeUEYndfD3yOMi22R0xb9S1q lwNJvJRzeQz7BSsn1Gomw5jKeNMrjR4B/K6TAeHYTQVcsj8hi8187CoXc5k1gcdewiH8l Xq8XcjXhgR0HnrxGre1xn7fDODuXAPq0Gkivaz9lksUQ/Pki4qb3BRmrYLurX+Hr0Nw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793631747; 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=qVgyj+FYQ9g7uHqmkN/6kOivRqdCDmjAyQM7m79vY9A=; b=IRM5bhtxYRwjXUC22HQ/rKiGL+D5DVaqE7bYug2By8IbGQV0Jyvo0nPrkurSZpRv1GDD 5E9jH0Oi9Ut6NloD9ZU/8RjFIbBz6e0RF2/IPlI5dpZIYH/kJrRk6N1Jq8BKFEc8CqUGF EVv7ARW65jbnG8SnqJa2e3lHbTTWby4cztx3FxJPdbMLwSP8K+EYOS9Sno6KDvt6VI3K8 XaBSdg0n+8QwmZ9jqhw5npLyyWIExN88XJTfGhdqVh8tTlZxHOF4vvuAVr8wa5BMPpyei te0eoz71bLdQPja+MNvNjNDFVF29LbEjIt0dI2LAHkpLjjWwtFyEqnt5xlYoYqSUv3g== 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="d/TU5Bzo"; 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 70D956070CAC; Mon, 2 Nov 2026 15:02:27 +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=d/TU5Bzo Received: by smtp.kernel.org (Postfix) with ESMTPSA id 174411F00A17; Mon, 2 Nov 2026 15:02:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793631747; bh=qVgyj+FYQ9g7uHqmkN/6kOivRqdCDmjAyQM7m79vY9A=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=d/TU5BzoI0BtvHfYzajrrcPl1GXVCryRY1Ut48y/GJIvjjd3K9tAkOPoaubnTH8Cj sK1647iQobp60ZY24tDMaAx9NsKxFNjymF5IY5h/cKkK9nGKkyHoV7CZDZf8JNbRww IRIPJfTF97vUVSY7NrIvF3mdu1MbBY5I5i7z+xiQlEEZ26yJHEdd7bH89Gqlbow2Ks Vg0J9epC20U9E4NUHIBDGai+NMTOFT3rd71sgkTUJULyeOxAVxvB4aiLpCaS0sj7+K C1HjOmzglPQcf1LCUAmDC0bN3L5TxoShuNDSEnm0bhASQBWbCYoW6wiUfo3S3aSY11 bUEfQJ+ZWGIIw== From: Christian Brauner Date: Mon, 02 Nov 2026 16:01:29 +0100 Subject: [PATCH RFC 02/22] ARM: alignment: let procfs copy in writes X-Mailing-List: linux-raid@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-v1-2-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 to /proc/cpu/alignment before it pins the entry, and take the mode from that copy. Writes larger than PAGE_SIZE - 1 bytes fail with -EINVAL now. Signed-off-by: Christian Brauner (Amutable) --- arch/arm/mm/alignment.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c index 3e5e30968634..11ceefdfa388 100644 --- a/arch/arm/mm/alignment.c +++ b/arch/arm/mm/alignment.c @@ -144,14 +144,13 @@ static int alignment_proc_show(struct seq_file *m, void *v) return 0; } -static ssize_t alignment_proc_write(struct file *file, const char __user *buffer, +static ssize_t alignment_proc_write(struct file *file, char *buffer, size_t count, loff_t *pos) { char mode; if (count > 0) { - if (get_user(mode, buffer)) - return -EFAULT; + mode = buffer[0]; if (mode >= '0' && mode <= '5') ai_usermode = safe_usermode(mode - '0', true); } @@ -160,7 +159,7 @@ static ssize_t alignment_proc_write(struct file *file, const char __user *buffer static const struct proc_ops alignment_proc_ops = { .proc_show = alignment_proc_show, - .proc_write = alignment_proc_write, + .proc_write_buf = alignment_proc_write, }; #endif /* CONFIG_PROC_FS */ -- 2.53.0