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=1793632106; b=nBIS3VMfaidub5VxShCKfRasTeR9nhMGZmsp+NDYP+n6PfEiAzK2QG2V6xpg8aUC1Esn vr6yaLcKf1SRyNhMbIvltcaS/sfz5fs612m8py/nlLbFc14s0KON4t3mUAbh3bnOvU3+C B6lsyByLpFb3iWCoJxqGW4QL98RTILGrqM15TF0YBiibD37qWeBbbAI5yIn+joGPPFEUa NZRRAC+9t6Kt0wdZcGCFwck6CEqsE/QAQn5slei52RBTsH2+epLtsbM7TRnEJPt2AURXk 9Ao/KeSFQ91PfLDhKg496gJKEDYDEMJy0dd+CidHEWK/BZue9L/V8UEMNGhfpLpsIkA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793632106; 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=Dp7sSooWMguSrSQWYm7n5WBM775aoRxhTJFL+eJzfGM=; b=I6usm73on+qllaEe4kw5ExEATjUS4/4RPMwip0mBwEKcvOfDUuQvtZhaNSk+qhZ1MJEi UfKl6rmKCvHE1zgnyHpg9DjcTruXsLRz8hCBdrExa0hJsKQNM2XnLCfKzR0h1bDnoMU/l uLELdByPZnhmAb7A1tZUJPDWoKLHXb5HKjGpG+D7UvoJpkcICZfb2dbGIJVjLfL2l8WXW Kxg+p2HjyHGz40heNbkjkjPqA73AgjdRP4xCII2feSoyt+3JETnKgEOleOMuOsdwG6/dm c/1Yhv7YLCCaqvOicoeomnab9lUyO7D+71W6TSHMmvv2LP+RwjimqP7e6pBTmwgWEqA== 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=eyNIQCxY; 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 8D0D5606B1CB; Mon, 2 Nov 2026 15:08:26 +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=eyNIQCxY Received: by smtp.kernel.org (Postfix) with ESMTPSA id 79E931F00A20; Mon, 2 Nov 2026 15:08:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793632106; bh=Dp7sSooWMguSrSQWYm7n5WBM775aoRxhTJFL+eJzfGM=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=eyNIQCxYEcRLLrGyZcPtIprIvg2rkuSpaKrMvW58hJQxt/VyWt7hS3Qal6zoUQ/gl 0f9cCCPMX1bOMUh9BIWeFK5f4ATpN0EM/aPUrffzJ9XwWlsu4eKD6ZgzUlwDjfLjwL Uvn00wNomN8/SMqh9jXER44dMwsdR9yWd6JSqBhqRXPHK14atBxuYmQ+rYaoEBUKUD vDmMOPV29JIfjjL6fBW6U6eWYBA/B7Lc6f6IJGDxAZNs993WFUAYbhkuu/ueCEe0L/ Yqu69q4QgN/VaqD5PYjScQjBFfvU4mejG6swjL58FVzjyKA2XiENQnp0sJJnQeShIQ zmvRe7kDYECMg== From: Christian Brauner Date: Mon, 02 Nov 2026 16:01:47 +0100 Subject: [PATCH RFC 20/22] platform/x86: toshiba_acpi: let procfs copy in writes X-Mailing-List: linux-input@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-v1-20-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() for the files in /proc/acpi/toshiba so procfs copies in what is written before it pins the entry, and parse what was written from that copy. Commands longer than PAGE_SIZE - 1 bytes are rejected now. Signed-off-by: Christian Brauner (Amutable) --- drivers/platform/x86/toshiba_acpi.c | 36 ++++++++++++------------------------ 1 file changed, 12 insertions(+), 24 deletions(-) diff --git a/drivers/platform/x86/toshiba_acpi.c b/drivers/platform/x86/toshiba_acpi.c index 560e62da05a9..895e321ada03 100644 --- a/drivers/platform/x86/toshiba_acpi.c +++ b/drivers/platform/x86/toshiba_acpi.c @@ -1478,7 +1478,7 @@ static int set_lcd_status(struct backlight_device *bd) return set_lcd_brightness(dev, bd->props.brightness); } -static ssize_t lcd_proc_write(struct file *file, const char __user *buf, +static ssize_t lcd_proc_write(struct file *file, char *buf, size_t count, loff_t *pos) { struct toshiba_acpi_dev *dev = pde_data(file_inode(file)); @@ -1488,8 +1488,7 @@ static ssize_t lcd_proc_write(struct file *file, const char __user *buf, int value; len = min(count, sizeof(cmd) - 1); - if (copy_from_user(cmd, buf, len)) - return -EFAULT; + memcpy(cmd, buf, len); cmd[len] = '\0'; levels = dev->backlight_dev->props.max_brightness + 1; @@ -1505,7 +1504,7 @@ static ssize_t lcd_proc_write(struct file *file, const char __user *buf, static const struct proc_ops lcd_proc_ops = { .proc_show = lcd_proc_show, - .proc_write = lcd_proc_write, + .proc_write_buf = lcd_proc_write, }; /* Video-Out */ @@ -1541,24 +1540,17 @@ static int video_proc_show(struct seq_file *m, void *v) return 0; } -static ssize_t video_proc_write(struct file *file, const char __user *buf, +static ssize_t video_proc_write(struct file *file, char *buf, size_t count, loff_t *pos) { struct toshiba_acpi_dev *dev = pde_data(file_inode(file)); - char *buffer; - char *cmd; + char *buffer = buf; int lcd_out = -1, crt_out = -1, tv_out = -1; int remain = count; int value; int ret; u32 video_out; - cmd = memdup_user_nul(buf, count); - if (IS_ERR(cmd)) - return PTR_ERR(cmd); - - buffer = cmd; - /* * Scan expression. Multiple expressions may be delimited with ; * NOTE: To keep scanning simple, invalid fields are ignored. @@ -1577,8 +1569,6 @@ static ssize_t video_proc_write(struct file *file, const char __user *buf, } while (remain && *(buffer - 1) != ';'); } - kfree(cmd); - ret = get_video_status(dev, &video_out); if (!ret) { unsigned int new_video_out = video_out; @@ -1602,7 +1592,7 @@ static ssize_t video_proc_write(struct file *file, const char __user *buf, static const struct proc_ops video_proc_ops = { .proc_show = video_proc_show, - .proc_write = video_proc_write, + .proc_write_buf = video_proc_write, }; /* Fan status */ @@ -1644,7 +1634,7 @@ static int fan_proc_show(struct seq_file *m, void *v) return 0; } -static ssize_t fan_proc_write(struct file *file, const char __user *buf, +static ssize_t fan_proc_write(struct file *file, char *buf, size_t count, loff_t *pos) { struct toshiba_acpi_dev *dev = pde_data(file_inode(file)); @@ -1653,8 +1643,7 @@ static ssize_t fan_proc_write(struct file *file, const char __user *buf, int value; len = min(count, sizeof(cmd) - 1); - if (copy_from_user(cmd, buf, len)) - return -EFAULT; + memcpy(cmd, buf, len); cmd[len] = '\0'; if (sscanf(cmd, " force_on : %i", &value) != 1 || @@ -1671,7 +1660,7 @@ static ssize_t fan_proc_write(struct file *file, const char __user *buf, static const struct proc_ops fan_proc_ops = { .proc_show = fan_proc_show, - .proc_write = fan_proc_write, + .proc_write_buf = fan_proc_write, }; /* Fan RPM */ @@ -1707,7 +1696,7 @@ static int keys_proc_show(struct seq_file *m, void *v) return 0; } -static ssize_t keys_proc_write(struct file *file, const char __user *buf, +static ssize_t keys_proc_write(struct file *file, char *buf, size_t count, loff_t *pos) { struct toshiba_acpi_dev *dev = pde_data(file_inode(file)); @@ -1716,8 +1705,7 @@ static ssize_t keys_proc_write(struct file *file, const char __user *buf, int value; len = min(count, sizeof(cmd) - 1); - if (copy_from_user(cmd, buf, len)) - return -EFAULT; + memcpy(cmd, buf, len); cmd[len] = '\0'; if (sscanf(cmd, " hotkey_ready : %i", &value) == 1 && value == 0) @@ -1730,7 +1718,7 @@ static ssize_t keys_proc_write(struct file *file, const char __user *buf, static const struct proc_ops keys_proc_ops = { .proc_show = keys_proc_show, - .proc_write = keys_proc_write, + .proc_write_buf = keys_proc_write, }; static int __maybe_unused version_proc_show(struct seq_file *m, void *v) -- 2.53.0