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Wed, 4 Nov 2026 19:36:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793820981; bh=qVgyj+FYQ9g7uHqmkN/6kOivRqdCDmjAyQM7m79vY9A=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=g53FbUkZCSWNwnfejXhy6s2nelprEnvO5Q4YohPFBJHS+h/+Bis4YhN2/N/AQPc6j fzYwibXDmXurtiMkWQn5u+VqbndlNGJtHCg2mWpnoK5k3yXNh3AEwdUXjS/Wn8YgAp DsbkdUjLTcZjtiVPGmJw8p0/O2ZWUM6qG/u1JQ1LS7FQsul73LZQiypnKRi3hmBJNn pWa+EONoOhGPwjSkAXUgj9sc5Wf8Ushz0fe45yGX+M0rWNNO/OogEaHlzCPeH+AsK7 UOZddBvu39FXQ3nOy8HZZvj2XFYHPYSGv2QlAmtdpAP6TIhnKozmF8NTYKArJ9/gig pdBxHcmOh0+mA== From: Christian Brauner 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 Subject: [PATCH RESEND v2 02/23] ARM: alignment: let procfs copy in writes Date: Wed, 4 Nov 2026 20:36:07 +0100 Message-ID: <20261104-work-procfs-arch-v2-2-2aeb952c9597@kernel.org> In-Reply-To: <20261104-work-procfs-arch-v2-0-2aeb952c9597@kernel.org> References: <20261104-work-procfs-arch-v2-0-2aeb952c9597@kernel.org> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" X-Mailer: b4 0.17-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1378; i=brauner@kernel.org; h=from:subject:message-id; bh=zhi1nqFEpiSFVRrnQoKgWCc9KudbEGTZB0sdbQtmzK0=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWS97njXfbbxoNI5d7tgS3+dmRcrGv6d2Z0Tv6xkukLGh 2eO1xfe6ihlYRDjYpAVU2RxaDcJl1vOU7HZKFMDZg4rE8gQBi5OAZiITgLDX+mF5S+vT7n7/+IW 5t66y78vbZh5fg+zoqqy103BXpsgljCGf/rni1NaxQ39Co13b8868UXRoW/v43tTZjz4Lhnc/Iu pmREA X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Content-Transfer-Encoding: 8bit X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" X-Spam-Status: No, score=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 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