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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=WlfLyMWw; 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 10C01606CA14; Wed, 4 Nov 2026 19:53:36 +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=WlfLyMWw Received: by smtp.kernel.org (Postfix) with ESMTPSA id 665591F000C1; Wed, 4 Nov 2026 19:53:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793822016; bh=dsg9KbFNlQBgwAedsKmZy7BqjgWqOw9kCQlCnQdMJZA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=WlfLyMWw9PMWft6v3dWdKtEemNCAsc/h/WCr0nG5tqlw1sEQtAckqBhAP9iFKJgWf 27ncRmg1m8lM73l7BGvThX+mkSAof45Ljqmi9lCmiTMRbF9fM1X3/mBBhBzPydmlAO DeHW3949SPOMNs+43V9Xli1roY8qLNOykPE7+vV4aJTQWW190ZkX74Zo7Zh8U+HHhP d/XnnzDuQDPFQtiKceof0EppiONyIpR9s/hpjh94Xmy2AYlTdqUDnq8Cy13OVzhv5Y x7sNbPQYQHvpSi8Y3OICpdiWEC+Zjh63M8mM9daa/pACN3UkdTLxiq8kpclsKBgWoi 4kSRU+9L7gicQ== 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 15/30] profiling: let procfs copy out reads of /proc/profile Date: Wed, 4 Nov 2026 20:53:22 +0100 Message-ID: <20261104-work-procfs-fs-v2-15-319e0f9a8aae@kernel.org> In-Reply-To: <20261104-work-procfs-fs-v2-0-319e0f9a8aae@kernel.org> References: <20261104-work-procfs-fs-v2-0-319e0f9a8aae@kernel.org> 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" X-Mailer: b4 0.17-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=2059; i=brauner@kernel.org; h=from:subject:message-id; bh=gnVLSy2PYfESjxmb08z8Yz7ZqLCo2VlJ7LnvjQbbWNo=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWS97rF59HT+zup9O3ZGTf/0yHBfocWfFwsvSv5eJLh9v abrT7/nUzpKWRjEuBhkxRRZHNpNwuWW81RsNsrUgJnDygQyhIGLUwAmUvSD4Z/pxPOtqj0nL7pp FThnlOS/03fdYCfgm5H+M+Bo0z2DeWIM/9O8Ilp05sv4X7J9I23pz7LGW/N/3/7A04qK/L5CxZM 1uQA= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Content-Transfer-Encoding: 8bit Fill the buffer procfs hands to ->proc_read_buf() instead of reading straight into userspace. readprofile reads the whole file in one go, so ask for PROC_ENTRY_FULL_READS and procfs fills such a read in pieces. The file is read through ->read_iter() now, so sendfile() and splice() work on it like on the other converted entries. Signed-off-by: Christian Brauner (Amutable) --- kernel/profile.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/kernel/profile.c b/kernel/profile.c index dc2db66a77d2..64f6a45834b1 100644 --- a/kernel/profile.c +++ b/kernel/profile.c @@ -142,7 +142,6 @@ void profile_tick(int type) #ifdef CONFIG_PROC_FS #include #include -#include /* * This function accesses profiling information. The returned data is @@ -151,7 +150,7 @@ void profile_tick(int type) * get meaningful info out of these data. */ static ssize_t -read_profile(struct file *file, char __user *buf, size_t count, loff_t *ppos) +read_profile(struct file *file, char *buf, size_t count, loff_t *ppos) { unsigned long p = *ppos; ssize_t read; @@ -165,13 +164,11 @@ read_profile(struct file *file, char __user *buf, size_t count, loff_t *ppos) read = 0; while (p < sizeof(unsigned int) && count > 0) { - if (put_user(*((char *)(&sample_step)+p), buf)) - return -EFAULT; + *buf = *((char *)(&sample_step)+p); buf++; p++; count--; read++; } pnt = (char *)prof_buffer + p - sizeof(atomic_t); - if (copy_to_user(buf, (void *)pnt, count)) - return -EFAULT; + memcpy(buf, pnt, count); read += count; *ppos += read; return read; @@ -206,7 +203,8 @@ static ssize_t write_profile(struct file *file, char *buf, size_t count, } static const struct proc_ops profile_proc_ops = { - .proc_read = read_profile, + .proc_flags = PROC_ENTRY_FULL_READS, + .proc_read_buf = read_profile, .proc_write_buf = write_profile, .proc_lseek = default_llseek, }; -- 2.53.0