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smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=YJCSbelw; 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 CAF6860A6F6E; Mon, 2 Nov 2026 15:23:31 +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=YJCSbelw Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9111F1F00A1B; Mon, 2 Nov 2026 15:23:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793633011; bh=yr3akMspnIWFpqWJkjrAgv6glOgJhJX8fSAifemHFwA=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=YJCSbelwTMu+lkg0XhQdoj8LyLuu8oZ2pe/iy53Q06xxAeDwqlvsnJcfvKWPrL8nO 1LPsdJ6f92UxNgYIH2elZX5cKB2Bn/cwnYbrr5FGX2EiostBzZYZDEJohQQBKlZ100 p7HUnoW1j6UUmYnSxVo38pqZI9irmD68pXikF1kIKMo2LkpHXgXPDrrJi4p7Z6BTEm Ho/gXdwOiakESPZcb3mkuegm2OWR2/e5jdgZUaERpTqlL7W8/AYhca74N335/39sZi ng2uaNbyx5FiMaSAp2/TUfphsXmLg87fQ3ClWdiErCTiRsq4P0nmjoEgLpLSQ0erqr l9l+F4V475wRA== From: Christian Brauner Date: Mon, 02 Nov 2026 16:07:21 +0100 Subject: [PATCH RFC 11/27] latencytop: let procfs copy in writes to /proc/latency_stats X-Mailing-List: linux-modules@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-fs-v1-11-d09a996317b3@kernel.org> References: <20261102-work-procfs-fs-v1-0-d09a996317b3@kernel.org> In-Reply-To: <20261102-work-procfs-fs-v1-0-d09a996317b3@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 X-Developer-Signature: v=1; a=openpgp-sha256; l=1161; i=brauner@kernel.org; h=from:subject:message-id; bh=9/PXHkkWFBWwJpiw0GjnsftfBxXIsWStv0RQuWJfsao=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWS9WG6Uxf1FUCLiA19Y3u9pcme5JklFv7e+/n/G+vrUZ 5GZL6Y4dJSyMIhxMciKKbI4tJuEyy3nqdhslKkBM4eVCWQIAxenAEwkpIORYdf3e/NXsH6/4133 rv1C3AUbjW+79J6LeEzq8giUbOXbd4uRYa5Xn0HazZ7z2x9NiNU/Zf+6XrKpZKKX2K/DOgyTKn0 MWQE= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Implement ->proc_write_buf() so procfs copies in what is written before it pins the entry. The write only clears the statistics and doesn't look at what was written anyway. Writes larger than PAGE_SIZE - 1 bytes fail with -EINVAL now. Signed-off-by: Christian Brauner (Amutable) --- kernel/latencytop.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/kernel/latencytop.c b/kernel/latencytop.c index b764f47606d3..35f73ca07656 100644 --- a/kernel/latencytop.c +++ b/kernel/latencytop.c @@ -267,8 +267,7 @@ static int lstats_show(struct seq_file *m, void *v) } static ssize_t -lstats_write(struct file *file, const char __user *buf, size_t count, - loff_t *offs) +lstats_write(struct file *file, char *buf, size_t count, loff_t *offs) { clear_global_latency_tracing(); @@ -277,7 +276,7 @@ lstats_write(struct file *file, const char __user *buf, size_t count, static const struct proc_ops lstats_proc_ops = { .proc_show = lstats_show, - .proc_write = lstats_write, + .proc_write_buf = lstats_write, }; static int __init init_lstats_procfs(void) -- 2.53.0