From patchwork series 401925

https://patchwork.ozlabs.org//project/linuxppc-dev/list/?series=401925

Author: Fox Snowpatch

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];
 

drivers/acpi/bgrt.c

@@ -29,14 +29,7 @@ BGRT_SHOW(type, image_type);
 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,

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)
 {

drivers/firmware/efi/rci2-table.c

@@ -40,15 +40,7 @@ static u8 *rci2_base;
 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)
 {

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);
 }
 
 /**

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,

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);

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_emit(char *buf, const char *fmt, ...);
 __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)

init/initramfs.c

@@ -575,15 +575,7 @@ extern unsigned long __initramfs_size;
 #include <linux/initrd.h>
 #include <linux/kexec.h>
 
-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)
 {

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;