ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 780 insertions, 0 deletions

diff --git a/drivers/firmware/edd.c b/drivers/firmware/edd.c
new file mode 100644
index 000000000..f980c5b56
--- /dev/null
+++ b/drivers/firmware/edd.c
@@ -0,0 +1,780 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * linux/drivers/firmware/edd.c
+ *  Copyright (C) 2002, 2003, 2004 Dell Inc.
+ *  by Matt Domsch <Matt_Domsch@dell.com>
+ *  disk signature by Matt Domsch, Andrew Wilks, and Sandeep K. Shandilya
+ *  legacy CHS by Patrick J. LoPresti <patl@users.sourceforge.net>
+ *
+ * BIOS Enhanced Disk Drive Services (EDD)
+ * conformant to T13 Committee www.t13.org
+ *   projects 1572D, 1484D, 1386D, 1226DT
+ *
+ * This code takes information provided by BIOS EDD calls
+ * fn41 - Check Extensions Present and
+ * fn48 - Get Device Parameters with EDD extensions
+ * made in setup.S, copied to safe structures in setup.c,
+ * and presents it in sysfs.
+ *
+ * Please see http://linux.dell.com/edd/results.html for
+ * the list of BIOSs which have been reported to implement EDD.
+ */
+
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/stat.h>
+#include <linux/err.h>
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <linux/limits.h>
+#include <linux/device.h>
+#include <linux/pci.h>
+#include <linux/blkdev.h>
+#include <linux/edd.h>
+
+#define EDD_VERSION "0.16"
+#define EDD_DATE    "2004-Jun-25"
+
+MODULE_AUTHOR("Matt Domsch <Matt_Domsch@Dell.com>");
+MODULE_DESCRIPTION("sysfs interface to BIOS EDD information");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(EDD_VERSION);
+
+#define left (PAGE_SIZE - (p - buf) - 1)
+
+struct edd_device {
+	unsigned int index;
+	unsigned int mbr_signature;
+	struct edd_info *info;
+	struct kobject kobj;
+};
+
+struct edd_attribute {
+	struct attribute attr;
+	ssize_t(*show) (struct edd_device * edev, char *buf);
+	int (*test) (struct edd_device * edev);
+};
+
+/* forward declarations */
+static int edd_dev_is_type(struct edd_device *edev, const char *type);
+static struct pci_dev *edd_get_pci_dev(struct edd_device *edev);
+
+static struct edd_device *edd_devices[EDD_MBR_SIG_MAX];
+
+#define EDD_DEVICE_ATTR(_name,_mode,_show,_test) \
+struct edd_attribute edd_attr_##_name = { 	\
+	.attr = {.name = __stringify(_name), .mode = _mode },	\
+	.show	= _show,				\
+	.test	= _test,				\
+};
+
+static int
+edd_has_mbr_signature(struct edd_device *edev)
+{
+	return edev->index < min_t(unsigned char, edd.mbr_signature_nr, EDD_MBR_SIG_MAX);
+}
+
+static int
+edd_has_edd_info(struct edd_device *edev)
+{
+	return edev->index < min_t(unsigned char, edd.edd_info_nr, EDDMAXNR);
+}
+
+static inline struct edd_info *
+edd_dev_get_info(struct edd_device *edev)
+{
+	return edev->info;
+}
+
+static inline void
+edd_dev_set_info(struct edd_device *edev, int i)
+{
+	edev->index = i;
+	if (edd_has_mbr_signature(edev))
+		edev->mbr_signature = edd.mbr_signature[i];
+	if (edd_has_edd_info(edev))
+		edev->info = &edd.edd_info[i];
+}
+
+#define to_edd_attr(_attr) container_of(_attr,struct edd_attribute,attr)
+#define to_edd_device(obj) container_of(obj,struct edd_device,kobj)
+
+static ssize_t
+edd_attr_show(struct kobject * kobj, struct attribute *attr, char *buf)
+{
+	struct edd_device *dev = to_edd_device(kobj);
+	struct edd_attribute *edd_attr = to_edd_attr(attr);
+	ssize_t ret = -EIO;
+
+	if (edd_attr->show)
+		ret = edd_attr->show(dev, buf);
+	return ret;
+}
+
+static const struct sysfs_ops edd_attr_ops = {
+	.show = edd_attr_show,
+};
+
+static ssize_t
+edd_show_host_bus(struct edd_device *edev, char *buf)
+{
+	struct edd_info *info;
+	char *p = buf;
+	int i;
+
+	if (!edev)
+		return -EINVAL;
+	info = edd_dev_get_info(edev);
+	if (!info || !buf)
+		return -EINVAL;
+
+	for (i = 0; i < 4; i++) {
+		if (isprint(info->params.host_bus_type[i])) {
+			p += scnprintf(p, left, "%c", info->params.host_bus_type[i]);
+		} else {
+			p += scnprintf(p, left, " ");
+		}
+	}
+
+	if (!strncmp(info->params.host_bus_type, "ISA", 3)) {
+		p += scnprintf(p, left, "\tbase_address: %x\n",
+			     info->params.interface_path.isa.base_address);
+	} else if (!strncmp(info->params.host_bus_type, "PCIX", 4) ||
+		   !strncmp(info->params.host_bus_type, "PCI", 3) ||
+		   !strncmp(info->params.host_bus_type, "XPRS", 4)) {
+		p += scnprintf(p, left,
+			     "\t%02x:%02x.%d  channel: %u\n",
+			     info->params.interface_path.pci.bus,
+			     info->params.interface_path.pci.slot,
+			     info->params.interface_path.pci.function,
+			     info->params.interface_path.pci.channel);
+	} else if (!strncmp(info->params.host_bus_type, "IBND", 4) ||
+		   !strncmp(info->params.host_bus_type, "HTPT", 4)) {
+		p += scnprintf(p, left,
+			     "\tTBD: %llx\n",
+			     info->params.interface_path.ibnd.reserved);
+
+	} else {
+		p += scnprintf(p, left, "\tunknown: %llx\n",
+			     info->params.interface_path.unknown.reserved);
+	}
+	return (p - buf);
+}
+
+static ssize_t
+edd_show_interface(struct edd_device *edev, char *buf)
+{
+	struct edd_info *info;
+	char *p = buf;
+	int i;
+
+	if (!edev)
+		return -EINVAL;
+	info = edd_dev_get_info(edev);
+	if (!info || !buf)
+		return -EINVAL;
+
+	for (i = 0; i < 8; i++) {
+		if (isprint(info->params.interface_type[i])) {
+			p += scnprintf(p, left, "%c", info->params.interface_type[i]);
+		} else {
+			p += scnprintf(p, left, " ");
+		}
+	}
+	if (!strncmp(info->params.interface_type, "ATAPI", 5)) {
+		p += scnprintf(p, left, "\tdevice: %u  lun: %u\n",
+			     info->params.device_path.atapi.device,
+			     info->params.device_path.atapi.lun);
+	} else if (!strncmp(info->params.interface_type, "ATA", 3)) {
+		p += scnprintf(p, left, "\tdevice: %u\n",
+			     info->params.device_path.ata.device);
+	} else if (!strncmp(info->params.interface_type, "SCSI", 4)) {
+		p += scnprintf(p, left, "\tid: %u  lun: %llu\n",
+			     info->params.device_path.scsi.id,
+			     info->params.device_path.scsi.lun);
+	} else if (!strncmp(info->params.interface_type, "USB", 3)) {
+		p += scnprintf(p, left, "\tserial_number: %llx\n",
+			     info->params.device_path.usb.serial_number);
+	} else if (!strncmp(info->params.interface_type, "1394", 4)) {
+		p += scnprintf(p, left, "\teui: %llx\n",
+			     info->params.device_path.i1394.eui);
+	} else if (!strncmp(info->params.interface_type, "FIBRE", 5)) {
+		p += scnprintf(p, left, "\twwid: %llx lun: %llx\n",
+			     info->params.device_path.fibre.wwid,
+			     info->params.device_path.fibre.lun);
+	} else if (!strncmp(info->params.interface_type, "I2O", 3)) {
+		p += scnprintf(p, left, "\tidentity_tag: %llx\n",
+			     info->params.device_path.i2o.identity_tag);
+	} else if (!strncmp(info->params.interface_type, "RAID", 4)) {
+		p += scnprintf(p, left, "\tidentity_tag: %x\n",
+			     info->params.device_path.raid.array_number);
+	} else if (!strncmp(info->params.interface_type, "SATA", 4)) {
+		p += scnprintf(p, left, "\tdevice: %u\n",
+			     info->params.device_path.sata.device);
+	} else {
+		p += scnprintf(p, left, "\tunknown: %llx %llx\n",
+			     info->params.device_path.unknown.reserved1,
+			     info->params.device_path.unknown.reserved2);
+	}
+
+	return (p - buf);
+}
+
+/**
+ * edd_show_raw_data() - copies raw data to buffer for userspace to parse
+ * @edev: target edd_device
+ * @buf: output buffer
+ *
+ * Returns: number of bytes written, or -EINVAL on failure
+ */
+static ssize_t
+edd_show_raw_data(struct edd_device *edev, char *buf)
+{
+	struct edd_info *info;
+	ssize_t len = sizeof (info->params);
+	if (!edev)
+		return -EINVAL;
+	info = edd_dev_get_info(edev);
+	if (!info || !buf)
+		return -EINVAL;
+
+	if (!(info->params.key == 0xBEDD || info->params.key == 0xDDBE))
+		len = info->params.length;
+
+	/* In case of buggy BIOSs */
+	if (len > (sizeof(info->params)))
+		len = sizeof(info->params);
+
+	memcpy(buf, &info->params, len);
+	return len;
+}
+
+static ssize_t
+edd_show_version(struct edd_device *edev, char *buf)
+{
+	struct edd_info *info;
+	char *p = buf;
+	if (!edev)
+		return -EINVAL;
+	info = edd_dev_get_info(edev);
+	if (!info || !buf)
+		return -EINVAL;
+
+	p += scnprintf(p, left, "0x%02x\n", info->version);
+	return (p - buf);
+}
+
+static ssize_t
+edd_show_mbr_signature(struct edd_device *edev, char *buf)
+{
+	char *p = buf;
+	p += scnprintf(p, left, "0x%08x\n", edev->mbr_signature);
+	return (p - buf);
+}
+
+static ssize_t
+edd_show_extensions(struct edd_device *edev, char *buf)
+{
+	struct edd_info *info;
+	char *p = buf;
+	if (!edev)
+		return -EINVAL;
+	info = edd_dev_get_info(edev);
+	if (!info || !buf)
+		return -EINVAL;
+
+	if (info->interface_support & EDD_EXT_FIXED_DISK_ACCESS) {
+		p += scnprintf(p, left, "Fixed disk access\n");
+	}
+	if (info->interface_support & EDD_EXT_DEVICE_LOCKING_AND_EJECTING) {
+		p += scnprintf(p, left, "Device locking and ejecting\n");
+	}
+	if (info->interface_support & EDD_EXT_ENHANCED_DISK_DRIVE_SUPPORT) {
+		p += scnprintf(p, left, "Enhanced Disk Drive support\n");
+	}
+	if (info->interface_support & EDD_EXT_64BIT_EXTENSIONS) {
+		p += scnprintf(p, left, "64-bit extensions\n");
+	}
+	return (p - buf);
+}
+
+static ssize_t
+edd_show_info_flags(struct edd_device *edev, char *buf)
+{
+	struct edd_info *info;
+	char *p = buf;
+	if (!edev)
+		return -EINVAL;
+	info = edd_dev_get_info(edev);
+	if (!info || !buf)
+		return -EINVAL;
+
+	if (info->params.info_flags & EDD_INFO_DMA_BOUNDARY_ERROR_TRANSPARENT)
+		p += scnprintf(p, left, "DMA boundary error transparent\n");
+	if (info->params.info_flags & EDD_INFO_GEOMETRY_VALID)
+		p += scnprintf(p, left, "geometry valid\n");
+	if (info->params.info_flags & EDD_INFO_REMOVABLE)
+		p += scnprintf(p, left, "removable\n");
+	if (info->params.info_flags & EDD_INFO_WRITE_VERIFY)
+		p += scnprintf(p, left, "write verify\n");
+	if (info->params.info_flags & EDD_INFO_MEDIA_CHANGE_NOTIFICATION)
+		p += scnprintf(p, left, "media change notification\n");
+	if (info->params.info_flags & EDD_INFO_LOCKABLE)
+		p += scnprintf(p, left, "lockable\n");
+	if (info->params.info_flags & EDD_INFO_NO_MEDIA_PRESENT)
+		p += scnprintf(p, left, "no media present\n");
+	if (info->params.info_flags & EDD_INFO_USE_INT13_FN50)
+		p += scnprintf(p, left, "use int13 fn50\n");
+	return (p - buf);
+}
+
+static ssize_t
+edd_show_legacy_max_cylinder(struct edd_device *edev, char *buf)
+{
+	struct edd_info *info;
+	char *p = buf;
+	if (!edev)
+		return -EINVAL;
+	info = edd_dev_get_info(edev);
+	if (!info || !buf)
+		return -EINVAL;
+
+	p += scnprintf(p, left, "%u\n", info->legacy_max_cylinder);
+	return (p - buf);
+}
+
+static ssize_t
+edd_show_legacy_max_head(struct edd_device *edev, char *buf)
+{
+	struct edd_info *info;
+	char *p = buf;
+	if (!edev)
+		return -EINVAL;
+	info = edd_dev_get_info(edev);
+	if (!info || !buf)
+		return -EINVAL;
+
+	p += scnprintf(p, left, "%u\n", info->legacy_max_head);
+	return (p - buf);
+}
+
+static ssize_t
+edd_show_legacy_sectors_per_track(struct edd_device *edev, char *buf)
+{
+	struct edd_info *info;
+	char *p = buf;
+	if (!edev)
+		return -EINVAL;
+	info = edd_dev_get_info(edev);
+	if (!info || !buf)
+		return -EINVAL;
+
+	p += scnprintf(p, left, "%u\n", info->legacy_sectors_per_track);
+	return (p - buf);
+}
+
+static ssize_t
+edd_show_default_cylinders(struct edd_device *edev, char *buf)
+{
+	struct edd_info *info;
+	char *p = buf;
+	if (!edev)
+		return -EINVAL;
+	info = edd_dev_get_info(edev);
+	if (!info || !buf)
+		return -EINVAL;
+
+	p += scnprintf(p, left, "%u\n", info->params.num_default_cylinders);
+	return (p - buf);
+}
+
+static ssize_t
+edd_show_default_heads(struct edd_device *edev, char *buf)
+{
+	struct edd_info *info;
+	char *p = buf;
+	if (!edev)
+		return -EINVAL;
+	info = edd_dev_get_info(edev);
+	if (!info || !buf)
+		return -EINVAL;
+
+	p += scnprintf(p, left, "%u\n", info->params.num_default_heads);
+	return (p - buf);
+}
+
+static ssize_t
+edd_show_default_sectors_per_track(struct edd_device *edev, char *buf)
+{
+	struct edd_info *info;
+	char *p = buf;
+	if (!edev)
+		return -EINVAL;
+	info = edd_dev_get_info(edev);
+	if (!info || !buf)
+		return -EINVAL;
+
+	p += scnprintf(p, left, "%u\n", info->params.sectors_per_track);
+	return (p - buf);
+}
+
+static ssize_t
+edd_show_sectors(struct edd_device *edev, char *buf)
+{
+	struct edd_info *info;
+	char *p = buf;
+	if (!edev)
+		return -EINVAL;
+	info = edd_dev_get_info(edev);
+	if (!info || !buf)
+		return -EINVAL;
+
+	p += scnprintf(p, left, "%llu\n", info->params.number_of_sectors);
+	return (p - buf);
+}
+
+
+/*
+ * Some device instances may not have all the above attributes,
+ * or the attribute values may be meaningless (i.e. if
+ * the device is < EDD 3.0, it won't have host_bus and interface
+ * information), so don't bother making files for them.  Likewise
+ * if the default_{cylinders,heads,sectors_per_track} values
+ * are zero, the BIOS doesn't provide sane values, don't bother
+ * creating files for them either.
+ */
+
+static int
+edd_has_legacy_max_cylinder(struct edd_device *edev)
+{
+	struct edd_info *info;
+	if (!edev)
+		return 0;
+	info = edd_dev_get_info(edev);
+	if (!info)
+		return 0;
+	return info->legacy_max_cylinder > 0;
+}
+
+static int
+edd_has_legacy_max_head(struct edd_device *edev)
+{
+	struct edd_info *info;
+	if (!edev)
+		return 0;
+	info = edd_dev_get_info(edev);
+	if (!info)
+		return 0;
+	return info->legacy_max_head > 0;
+}
+
+static int
+edd_has_legacy_sectors_per_track(struct edd_device *edev)
+{
+	struct edd_info *info;
+	if (!edev)
+		return 0;
+	info = edd_dev_get_info(edev);
+	if (!info)
+		return 0;
+	return info->legacy_sectors_per_track > 0;
+}
+
+static int
+edd_has_default_cylinders(struct edd_device *edev)
+{
+	struct edd_info *info;
+	if (!edev)
+		return 0;
+	info = edd_dev_get_info(edev);
+	if (!info)
+		return 0;
+	return info->params.num_default_cylinders > 0;
+}
+
+static int
+edd_has_default_heads(struct edd_device *edev)
+{
+	struct edd_info *info;
+	if (!edev)
+		return 0;
+	info = edd_dev_get_info(edev);
+	if (!info)
+		return 0;
+	return info->params.num_default_heads > 0;
+}
+
+static int
+edd_has_default_sectors_per_track(struct edd_device *edev)
+{
+	struct edd_info *info;
+	if (!edev)
+		return 0;
+	info = edd_dev_get_info(edev);
+	if (!info)
+		return 0;
+	return info->params.sectors_per_track > 0;
+}
+
+static int
+edd_has_edd30(struct edd_device *edev)
+{
+	struct edd_info *info;
+	int i;
+	u8 csum = 0;
+
+	if (!edev)
+		return 0;
+	info = edd_dev_get_info(edev);
+	if (!info)
+		return 0;
+
+	if (!(info->params.key == 0xBEDD || info->params.key == 0xDDBE)) {
+		return 0;
+	}
+
+
+	/* We support only T13 spec */
+	if (info->params.device_path_info_length != 44)
+		return 0;
+
+	for (i = 30; i < info->params.device_path_info_length + 30; i++)
+		csum += *(((u8 *)&info->params) + i);
+
+	if (csum)
+		return 0;
+
+	return 1;
+}
+
+
+static EDD_DEVICE_ATTR(raw_data, 0444, edd_show_raw_data, edd_has_edd_info);
+static EDD_DEVICE_ATTR(version, 0444, edd_show_version, edd_has_edd_info);
+static EDD_DEVICE_ATTR(extensions, 0444, edd_show_extensions, edd_has_edd_info);
+static EDD_DEVICE_ATTR(info_flags, 0444, edd_show_info_flags, edd_has_edd_info);
+static EDD_DEVICE_ATTR(sectors, 0444, edd_show_sectors, edd_has_edd_info);
+static EDD_DEVICE_ATTR(legacy_max_cylinder, 0444,
+                       edd_show_legacy_max_cylinder,
+		       edd_has_legacy_max_cylinder);
+static EDD_DEVICE_ATTR(legacy_max_head, 0444, edd_show_legacy_max_head,
+		       edd_has_legacy_max_head);
+static EDD_DEVICE_ATTR(legacy_sectors_per_track, 0444,
+                       edd_show_legacy_sectors_per_track,
+		       edd_has_legacy_sectors_per_track);
+static EDD_DEVICE_ATTR(default_cylinders, 0444, edd_show_default_cylinders,
+		       edd_has_default_cylinders);
+static EDD_DEVICE_ATTR(default_heads, 0444, edd_show_default_heads,
+		       edd_has_default_heads);
+static EDD_DEVICE_ATTR(default_sectors_per_track, 0444,
+		       edd_show_default_sectors_per_track,
+		       edd_has_default_sectors_per_track);
+static EDD_DEVICE_ATTR(interface, 0444, edd_show_interface, edd_has_edd30);
+static EDD_DEVICE_ATTR(host_bus, 0444, edd_show_host_bus, edd_has_edd30);
+static EDD_DEVICE_ATTR(mbr_signature, 0444, edd_show_mbr_signature, edd_has_mbr_signature);
+
+/* These attributes are conditional and only added for some devices. */
+static struct edd_attribute * edd_attrs[] = {
+	&edd_attr_raw_data,
+	&edd_attr_version,
+	&edd_attr_extensions,
+	&edd_attr_info_flags,
+	&edd_attr_sectors,
+	&edd_attr_legacy_max_cylinder,
+	&edd_attr_legacy_max_head,
+	&edd_attr_legacy_sectors_per_track,
+	&edd_attr_default_cylinders,
+	&edd_attr_default_heads,
+	&edd_attr_default_sectors_per_track,
+	&edd_attr_interface,
+	&edd_attr_host_bus,
+	&edd_attr_mbr_signature,
+	NULL,
+};
+
+/**
+ *	edd_release - free edd structure
+ *	@kobj:	kobject of edd structure
+ *
+ *	This is called when the refcount of the edd structure
+ *	reaches 0. This should happen right after we unregister,
+ *	but just in case, we use the release callback anyway.
+ */
+
+static void edd_release(struct kobject * kobj)
+{
+	struct edd_device * dev = to_edd_device(kobj);
+	kfree(dev);
+}
+
+static const struct kobj_type edd_ktype = {
+	.release	= edd_release,
+	.sysfs_ops	= &edd_attr_ops,
+};
+
+static struct kset *edd_kset;
+
+
+/**
+ * edd_dev_is_type() - is this EDD device a 'type' device?
+ * @edev: target edd_device
+ * @type: a host bus or interface identifier string per the EDD spec
+ *
+ * Returns 1 (TRUE) if it is a 'type' device, 0 otherwise.
+ */
+static int
+edd_dev_is_type(struct edd_device *edev, const char *type)
+{
+	struct edd_info *info;
+	if (!edev)
+		return 0;
+	info = edd_dev_get_info(edev);
+
+	if (type && info) {
+		if (!strncmp(info->params.host_bus_type, type, strlen(type)) ||
+		    !strncmp(info->params.interface_type, type, strlen(type)))
+			return 1;
+	}
+	return 0;
+}
+
+/**
+ * edd_get_pci_dev() - finds pci_dev that matches edev
+ * @edev: edd_device
+ *
+ * Returns pci_dev if found, or NULL
+ */
+static struct pci_dev *
+edd_get_pci_dev(struct edd_device *edev)
+{
+	struct edd_info *info = edd_dev_get_info(edev);
+
+	if (edd_dev_is_type(edev, "PCI") || edd_dev_is_type(edev, "XPRS")) {
+		return pci_get_domain_bus_and_slot(0,
+				info->params.interface_path.pci.bus,
+				PCI_DEVFN(info->params.interface_path.pci.slot,
+				info->params.interface_path.pci.function));
+	}
+	return NULL;
+}
+
+static int
+edd_create_symlink_to_pcidev(struct edd_device *edev)
+{
+
+	struct pci_dev *pci_dev = edd_get_pci_dev(edev);
+	int ret;
+	if (!pci_dev)
+		return 1;
+	ret = sysfs_create_link(&edev->kobj,&pci_dev->dev.kobj,"pci_dev");
+	pci_dev_put(pci_dev);
+	return ret;
+}
+
+static inline void
+edd_device_unregister(struct edd_device *edev)
+{
+	kobject_put(&edev->kobj);
+}
+
+static void edd_populate_dir(struct edd_device * edev)
+{
+	struct edd_attribute * attr;
+	int error = 0;
+	int i;
+
+	for (i = 0; (attr = edd_attrs[i]) && !error; i++) {
+		if (!attr->test || attr->test(edev))
+			error = sysfs_create_file(&edev->kobj,&attr->attr);
+	}
+
+	if (!error) {
+		edd_create_symlink_to_pcidev(edev);
+	}
+}
+
+static int
+edd_device_register(struct edd_device *edev, int i)
+{
+	int error;
+
+	if (!edev)
+		return 1;
+	edd_dev_set_info(edev, i);
+	edev->kobj.kset = edd_kset;
+	error = kobject_init_and_add(&edev->kobj, &edd_ktype, NULL,
+				     "int13_dev%02x", 0x80 + i);
+	if (!error) {
+		edd_populate_dir(edev);
+		kobject_uevent(&edev->kobj, KOBJ_ADD);
+	}
+	return error;
+}
+
+static inline int edd_num_devices(void)
+{
+	return max_t(unsigned char,
+		     min_t(unsigned char, EDD_MBR_SIG_MAX, edd.mbr_signature_nr),
+		     min_t(unsigned char, EDDMAXNR, edd.edd_info_nr));
+}
+
+/**
+ * edd_init() - creates sysfs tree of EDD data
+ */
+static int __init
+edd_init(void)
+{
+	int i;
+	int rc=0;
+	struct edd_device *edev;
+
+	if (!edd_num_devices())
+		return -ENODEV;
+
+	printk(KERN_INFO "BIOS EDD facility v%s %s, %d devices found\n",
+	       EDD_VERSION, EDD_DATE, edd_num_devices());
+
+	edd_kset = kset_create_and_add("edd", NULL, firmware_kobj);
+	if (!edd_kset)
+		return -ENOMEM;
+
+	for (i = 0; i < edd_num_devices(); i++) {
+		edev = kzalloc_obj(*edev);
+		if (!edev) {
+			rc = -ENOMEM;
+			goto out;
+		}
+
+		rc = edd_device_register(edev, i);
+		if (rc) {
+			kfree(edev);
+			goto out;
+		}
+		edd_devices[i] = edev;
+	}
+
+	return 0;
+
+out:
+	while (--i >= 0)
+		edd_device_unregister(edd_devices[i]);
+	kset_unregister(edd_kset);
+	return rc;
+}
+
+static void __exit
+edd_exit(void)
+{
+	int i;
+	struct edd_device *edev;
+
+	for (i = 0; i < edd_num_devices(); i++) {
+		if ((edev = edd_devices[i]))
+			edd_device_unregister(edev);
+	}
+	kset_unregister(edd_kset);
+}
+
+late_initcall(edd_init);
+module_exit(edd_exit);