From patchwork Sat Apr 6 13:52:01 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 13619832 Received: from bmailout3.hostsharing.net (bmailout3.hostsharing.net [176.9.242.62]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 576552C1A3; Sat, 6 Apr 2024 13:53:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=176.9.242.62 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712411588; cv=none; b=JkDPo/hgkErCJLHIK3A4aMJa8VQZwEWl0phz3RP7yq2d9WpbR2FO2e2EY8pDKclckjzBlAFrjR0WY2tD+Dq73GNa32Gy6PmZK3AoJx4iY8rvbE8zO7lSUlr1hPZd0dLK7jQMPDfuBjRZWHdIHzj7HiTIJINGOKbH6sJVUIsR6Hc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712411588; c=relaxed/simple; bh=KaB+H/QNRD1ZBpVagmhzPb+DI/HWOBbGyYx+42MjjhA=; h=Message-Id:In-Reply-To:References:From:Date:Subject:To:Cc; b=QACPOzWN+wOGQs43EFd28mp/05k0NeU6ez/KBaEgmxI19H6XqSjixDpKdKnTtC84c+TXFK0zPiu2vAZDLWxd+7LwageR0/JBDqaB+nD32zzDyWV6yZQgqdqPrD1PihWecEquxPgEEdudlwGBoc4n9xxL9mtN4n1gsCI1ntXj7dQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de; spf=pass smtp.mailfrom=wunner.de; arc=none smtp.client-ip=176.9.242.62 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=wunner.de Received: from h08.hostsharing.net (h08.hostsharing.net [IPv6:2a01:37:1000::53df:5f1c:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS RSA CA G1" (verified OK)) by bmailout3.hostsharing.net (Postfix) with ESMTPS id 71931100DA1BC; Sat, 6 Apr 2024 15:53:04 +0200 (CEST) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 483384E2B1B; Sat, 6 Apr 2024 15:53:04 +0200 (CEST) Message-Id: <5ed62b197a442ec6db53d8746d9d806dd0576e2d.1712410202.git.lukas@wunner.de> In-Reply-To: References: From: Lukas Wunner Date: Sat, 6 Apr 2024 15:52:01 +0200 Subject: [PATCH 1/2] sysfs: Add sysfs_bin_attr_simple_read() helper To: Greg Kroah-Hartman , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org Cc: Michael Ellerman , linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, Jean Delvare , Ard Biesheuvel , linux-efi@vger.kernel.org, Zhenyu Wang , Zhi Wang , intel-gvt-dev@lists.freedesktop.org, Daniel Lezcano , linux-pm@vger.kernel.org, Luis Chamberlain , linux-modules@vger.kernel.org Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: When drivers expose a bin_attribute in sysfs which is backed by a buffer in memory, a common pattern is to set the @private and @size members in struct bin_attribute to the buffer's location and size. The ->read() callback then merely consists of a single memcpy() call. It's not even necessary to perform bounds checks as these are already handled by sysfs_kf_bin_read(). However each driver is so far providing its own ->read() implementation. The pattern is sufficiently frequent to merit a public helper, so add sysfs_bin_attr_simple_read() as well as BIN_ATTR_SIMPLE_RO() and BIN_ATTR_SIMPLE_ADMIN_RO() macros to ease declaration of such bin_attributes and reduce LoC and .text section size. Signed-off-by: Lukas Wunner Reviewed-by: Greg Kroah-Hartman --- fs/sysfs/file.c | 27 +++++++++++++++++++++++++++ include/linux/sysfs.h | 15 +++++++++++++++ 2 files changed, 42 insertions(+) diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c index 6b7652f..289b57d 100644 --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -783,3 +783,30 @@ int sysfs_emit_at(char *buf, int at, const char *fmt, ...) return len; } EXPORT_SYMBOL_GPL(sysfs_emit_at); + +/** + * sysfs_bin_attr_simple_read - read callback to simply copy from memory. + * @file: attribute file which is being read. + * @kobj: object to which the attribute belongs. + * @attr: attribute descriptor. + * @buf: destination buffer. + * @off: offset in bytes from which to read. + * @count: maximum number of bytes to read. + * + * Simple ->read() callback for bin_attributes backed by a buffer in memory. + * The @private and @size members in struct bin_attribute must be set to the + * buffer's location and size before the bin_attribute is created in sysfs. + * + * Bounds check for @off and @count is done in sysfs_kf_bin_read(). + * Negative value check for @off is done in vfs_setpos() and default_llseek(). + * + * Returns number of bytes written to @buf. + */ +ssize_t sysfs_bin_attr_simple_read(struct file *file, struct kobject *kobj, + struct bin_attribute *attr, char *buf, + loff_t off, size_t count) +{ + memcpy(buf, attr->private + off, count); + return count; +} +EXPORT_SYMBOL_GPL(sysfs_bin_attr_simple_read); diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 326341c..a7d725f 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -371,6 +371,17 @@ struct bin_attribute bin_attr_##_name = __BIN_ATTR_ADMIN_RO(_name, _size) #define BIN_ATTR_ADMIN_RW(_name, _size) \ struct bin_attribute bin_attr_##_name = __BIN_ATTR_ADMIN_RW(_name, _size) +#define __BIN_ATTR_SIMPLE_RO(_name, _mode) { \ + .attr = { .name = __stringify(_name), .mode = _mode }, \ + .read = sysfs_bin_attr_simple_read, \ +} + +#define BIN_ATTR_SIMPLE_RO(_name) \ +struct bin_attribute bin_attr_##_name = __BIN_ATTR_SIMPLE_RO(_name, 0444) + +#define BIN_ATTR_SIMPLE_ADMIN_RO(_name) \ +struct bin_attribute bin_attr_##_name = __BIN_ATTR_SIMPLE_RO(_name, 0400) + struct sysfs_ops { ssize_t (*show)(struct kobject *, struct attribute *, char *); ssize_t (*store)(struct kobject *, struct attribute *, const char *, size_t); @@ -478,6 +489,10 @@ int sysfs_group_change_owner(struct kobject *kobj, __printf(3, 4) int sysfs_emit_at(char *buf, int at, const char *fmt, ...); +ssize_t sysfs_bin_attr_simple_read(struct file *file, struct kobject *kobj, + struct bin_attribute *attr, char *buf, + loff_t off, size_t count); + #else /* CONFIG_SYSFS */ static inline int sysfs_create_dir_ns(struct kobject *kobj, const void *ns) From patchwork Sat Apr 6 13:52:02 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lukas Wunner X-Patchwork-Id: 13619833 Received: from bmailout2.hostsharing.net (bmailout2.hostsharing.net [83.223.78.240]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1C96C2D05E; Sat, 6 Apr 2024 13:54:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=83.223.78.240 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712411661; cv=none; b=jBPrjJY2Psv4Resl/TlgFsetGc8sDS2uQOSSXsNHEa7QeyFTm8AlWF1kLHiK1xiZjY9hcPhx/CDcYXxSAZRfA4VMY/YBxHUfvnq+dEbkbY0mnFpa6/F/vMbqy6nv/LIbPo9pgwHer3bz51sqrAYst+tV+0EWyHsIMfLeoLU0yK8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712411661; c=relaxed/simple; bh=++C446erfBmkIadT7UESxN+hRSqQcV8WtV6QE89m0GM=; h=Message-Id:In-Reply-To:References:From:Date:Subject:To:Cc; b=Ri2tzIyzkDCL/JJtYu9lpo++jFAQJHcEbYk9RS5VZCXSXSqOCCPNc+vAWn87TIRjxtxSoiR9UOxRtANhN6xxiZ9EzQWC8TSsnoJCLZBPyiV7YVOHV4Wu0cEDi7fJAHL90K9tNnAeyBbzj0Z3Mkton1aBsnhEtWx6xYCL+FJH2E0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de; spf=pass smtp.mailfrom=wunner.de; arc=none smtp.client-ip=83.223.78.240 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=wunner.de Received: from h08.hostsharing.net (h08.hostsharing.net [IPv6:2a01:37:1000::53df:5f1c:0]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS RSA CA G1" (verified OK)) by bmailout2.hostsharing.net (Postfix) with ESMTPS id 879992800B3F1; Sat, 6 Apr 2024 15:54:16 +0200 (CEST) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 8084A9926B3; Sat, 6 Apr 2024 15:54:16 +0200 (CEST) Message-Id: <92ee0a0e83a5a3f3474845db6c8575297698933a.1712410202.git.lukas@wunner.de> In-Reply-To: References: From: Lukas Wunner Date: Sat, 6 Apr 2024 15:52:02 +0200 Subject: [PATCH 2/2] treewide: Use sysfs_bin_attr_simple_read() helper To: Greg Kroah-Hartman , "Rafael J. Wysocki" , linux-kernel@vger.kernel.org Cc: Michael Ellerman , linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, Jean Delvare , Ard Biesheuvel , linux-efi@vger.kernel.org, Zhenyu Wang , Zhi Wang , intel-gvt-dev@lists.freedesktop.org, Daniel Lezcano , linux-pm@vger.kernel.org, Luis Chamberlain , linux-modules@vger.kernel.org Precedence: bulk X-Mailing-List: linux-pm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Deduplicate ->read() callbacks of bin_attributes which are backed by a simple buffer in memory: Use the newly introduced sysfs_bin_attr_simple_read() helper instead, either by referencing it directly or by declaring such bin_attributes with BIN_ATTR_SIMPLE_RO() or BIN_ATTR_SIMPLE_ADMIN_RO(). Aside from a reduction of LoC, this shaves off a few bytes from vmlinux (304 bytes on an x86_64 allyesconfig). No functional change intended. Signed-off-by: Lukas Wunner Acked-by: Zhi Wang Acked-by: Michael Ellerman (powerpc) --- arch/powerpc/platforms/powernv/opal.c | 10 +-------- drivers/acpi/bgrt.c | 9 +------- drivers/firmware/dmi_scan.c | 12 ++-------- drivers/firmware/efi/rci2-table.c | 10 +-------- drivers/gpu/drm/i915/gvt/firmware.c | 26 +++++----------------- .../intel/int340x_thermal/int3400_thermal.c | 9 +------- init/initramfs.c | 10 +-------- kernel/module/sysfs.c | 13 +---------- 8 files changed, 14 insertions(+), 85 deletions(-) diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c index 45dd77e..5d0f35b 100644 --- a/arch/powerpc/platforms/powernv/opal.c +++ b/arch/powerpc/platforms/powernv/opal.c @@ -792,14 +792,6 @@ static int __init opal_sysfs_init(void) return 0; } -static ssize_t export_attr_read(struct file *fp, struct kobject *kobj, - struct bin_attribute *bin_attr, char *buf, - loff_t off, size_t count) -{ - return memory_read_from_buffer(buf, count, &off, bin_attr->private, - bin_attr->size); -} - static int opal_add_one_export(struct kobject *parent, const char *export_name, struct device_node *np, const char *prop_name) { @@ -826,7 +818,7 @@ static int opal_add_one_export(struct kobject *parent, const char *export_name, sysfs_bin_attr_init(attr); attr->attr.name = name; attr->attr.mode = 0400; - attr->read = export_attr_read; + attr->read = sysfs_bin_attr_simple_read; attr->private = __va(vals[0]); attr->size = vals[1]; diff --git a/drivers/acpi/bgrt.c b/drivers/acpi/bgrt.c index e4fb9e2..d1d9c92 100644 --- a/drivers/acpi/bgrt.c +++ b/drivers/acpi/bgrt.c @@ -29,14 +29,7 @@ BGRT_SHOW(xoffset, image_offset_x); BGRT_SHOW(yoffset, image_offset_y); -static ssize_t image_read(struct file *file, struct kobject *kobj, - struct bin_attribute *attr, char *buf, loff_t off, size_t count) -{ - memcpy(buf, attr->private + off, count); - return count; -} - -static BIN_ATTR_RO(image, 0); /* size gets filled in later */ +static BIN_ATTR_SIMPLE_RO(image); static struct attribute *bgrt_attributes[] = { &bgrt_attr_version.attr, diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c index 015c95a..3d0f773 100644 --- a/drivers/firmware/dmi_scan.c +++ b/drivers/firmware/dmi_scan.c @@ -746,16 +746,8 @@ static void __init dmi_scan_machine(void) pr_info("DMI not present or invalid.\n"); } -static ssize_t raw_table_read(struct file *file, struct kobject *kobj, - struct bin_attribute *attr, char *buf, - loff_t pos, size_t count) -{ - memcpy(buf, attr->private + pos, count); - return count; -} - -static BIN_ATTR(smbios_entry_point, S_IRUSR, raw_table_read, NULL, 0); -static BIN_ATTR(DMI, S_IRUSR, raw_table_read, NULL, 0); +static BIN_ATTR_SIMPLE_ADMIN_RO(smbios_entry_point); +static BIN_ATTR_SIMPLE_ADMIN_RO(DMI); static int __init dmi_init(void) { diff --git a/drivers/firmware/efi/rci2-table.c b/drivers/firmware/efi/rci2-table.c index de1a9a1..4fd45d6 100644 --- a/drivers/firmware/efi/rci2-table.c +++ b/drivers/firmware/efi/rci2-table.c @@ -40,15 +40,7 @@ struct rci2_table_global_hdr { static u32 rci2_table_len; unsigned long rci2_table_phys __ro_after_init = EFI_INVALID_TABLE_ADDR; -static ssize_t raw_table_read(struct file *file, struct kobject *kobj, - struct bin_attribute *attr, char *buf, - loff_t pos, size_t count) -{ - memcpy(buf, attr->private + pos, count); - return count; -} - -static BIN_ATTR(rci2, S_IRUSR, raw_table_read, NULL, 0); +static BIN_ATTR_SIMPLE_ADMIN_RO(rci2); static u16 checksum(void) { diff --git a/drivers/gpu/drm/i915/gvt/firmware.c b/drivers/gpu/drm/i915/gvt/firmware.c index 4dd52ac..5e66a26 100644 --- a/drivers/gpu/drm/i915/gvt/firmware.c +++ b/drivers/gpu/drm/i915/gvt/firmware.c @@ -50,21 +50,7 @@ struct gvt_firmware_header { #define dev_to_drm_minor(d) dev_get_drvdata((d)) -static ssize_t -gvt_firmware_read(struct file *filp, struct kobject *kobj, - struct bin_attribute *attr, char *buf, - loff_t offset, size_t count) -{ - memcpy(buf, attr->private + offset, count); - return count; -} - -static struct bin_attribute firmware_attr = { - .attr = {.name = "gvt_firmware", .mode = (S_IRUSR)}, - .read = gvt_firmware_read, - .write = NULL, - .mmap = NULL, -}; +static BIN_ATTR_SIMPLE_ADMIN_RO(gvt_firmware); static int expose_firmware_sysfs(struct intel_gvt *gvt) { @@ -107,10 +93,10 @@ static int expose_firmware_sysfs(struct intel_gvt *gvt) crc32_start = offsetof(struct gvt_firmware_header, version); h->crc32 = crc32_le(0, firmware + crc32_start, size - crc32_start); - firmware_attr.size = size; - firmware_attr.private = firmware; + bin_attr_gvt_firmware.size = size; + bin_attr_gvt_firmware.private = firmware; - ret = device_create_bin_file(&pdev->dev, &firmware_attr); + ret = device_create_bin_file(&pdev->dev, &bin_attr_gvt_firmware); if (ret) { vfree(firmware); return ret; @@ -122,8 +108,8 @@ static void clean_firmware_sysfs(struct intel_gvt *gvt) { struct pci_dev *pdev = to_pci_dev(gvt->gt->i915->drm.dev); - device_remove_bin_file(&pdev->dev, &firmware_attr); - vfree(firmware_attr.private); + device_remove_bin_file(&pdev->dev, &bin_attr_gvt_firmware); + vfree(bin_attr_gvt_firmware.private); } /** diff --git a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c index 427d370..6d4b51a 100644 --- a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c +++ b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c @@ -73,14 +73,7 @@ struct odvp_attr { struct device_attribute attr; }; -static ssize_t data_vault_read(struct file *file, struct kobject *kobj, - struct bin_attribute *attr, char *buf, loff_t off, size_t count) -{ - memcpy(buf, attr->private + off, count); - return count; -} - -static BIN_ATTR_RO(data_vault, 0); +static BIN_ATTR_SIMPLE_RO(data_vault); static struct bin_attribute *data_attributes[] = { &bin_attr_data_vault, diff --git a/init/initramfs.c b/init/initramfs.c index da79760..5193fae 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -575,15 +575,7 @@ static int __init initramfs_async_setup(char *str) #include #include -static ssize_t raw_read(struct file *file, struct kobject *kobj, - struct bin_attribute *attr, char *buf, - loff_t pos, size_t count) -{ - memcpy(buf, attr->private + pos, count); - return count; -} - -static BIN_ATTR(initrd, 0440, raw_read, NULL, 0); +static BIN_ATTR(initrd, 0440, sysfs_bin_attr_simple_read, NULL, 0); void __init reserve_initrd_mem(void) { diff --git a/kernel/module/sysfs.c b/kernel/module/sysfs.c index d964167..26efe13 100644 --- a/kernel/module/sysfs.c +++ b/kernel/module/sysfs.c @@ -146,17 +146,6 @@ struct module_notes_attrs { struct bin_attribute attrs[] __counted_by(notes); }; -static ssize_t module_notes_read(struct file *filp, struct kobject *kobj, - struct bin_attribute *bin_attr, - char *buf, loff_t pos, size_t count) -{ - /* - * The caller checked the pos and count against our size. - */ - memcpy(buf, bin_attr->private + pos, count); - return count; -} - static void free_notes_attrs(struct module_notes_attrs *notes_attrs, unsigned int i) { @@ -205,7 +194,7 @@ static void add_notes_attrs(struct module *mod, const struct load_info *info) nattr->attr.mode = 0444; nattr->size = info->sechdrs[i].sh_size; nattr->private = (void *)info->sechdrs[i].sh_addr; - nattr->read = module_notes_read; + nattr->read = sysfs_bin_attr_simple_read; ++nattr; } ++loaded;