Merge branch 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86/efi changes from Peter Anvin:
 "The bulk of these changes are cleaning up the efivars handling and
  breaking it up into a tree of files.  There are a number of fixes as
  well.

  The entire changeset is pretty big, but most of it is code movement.

  Several of these commits are quite new; the history got very messed up
  due to a mismerge with the urgent changes for rc8 which completely
  broke IA64, and so Ingo requested that we rebase it to straighten it
  out."

* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: remove "kfree(NULL)"
  efi: locking fix in efivar_entry_set_safe()
  efi, pstore: Read data from variable store before memcpy()
  efi, pstore: Remove entry from list when erasing
  efi, pstore: Initialise 'entry' before iterating
  efi: split efisubsystem from efivars
  efivarfs: Move to fs/efivarfs
  efivars: Move pstore code into the new EFI directory
  efivars: efivar_entry API
  efivars: Keep a private global pointer to efivars
  efi: move utf16 string functions to efi.h
  x86, efi: Make efi_memblock_x86_reserve_range more readable
  efivarfs: convert to use simple_open()

6 files changed, 587 insertions, 0 deletions

diff --git a/fs/efivarfs/Kconfig b/fs/efivarfs/Kconfig
new file mode 100644
index 000000000000..367bbb10c543
--- /dev/null
+++ b/fs/efivarfs/Kconfig
@@ -0,0 +1,12 @@
+config EFIVAR_FS
+        tristate "EFI Variable filesystem"
+        depends on EFI
+        help
+          efivarfs is a replacement filesystem for the old EFI
+          variable support via sysfs, as it doesn't suffer from the
+          same 1024-byte variable size limit.
+
+          To compile this file system support as a module, choose M
+          here. The module will be called efivarfs.
+
+          If unsure, say N.
diff --git a/fs/efivarfs/Makefile b/fs/efivarfs/Makefile
new file mode 100644
index 000000000000..955d478177d5
--- /dev/null
+++ b/fs/efivarfs/Makefile
@@ -0,0 +1,7 @@
+#
+# Makefile for the efivarfs filesystem
+#
+
+obj-$(CONFIG_EFIVAR_FS)         += efivarfs.o
+
+efivarfs-objs                   := inode.o file.o super.o
diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
new file mode 100644
index 000000000000..ede07fc7309f
--- /dev/null
+++ b/fs/efivarfs/file.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2012 Red Hat, Inc.
+ * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/efi.h>
+#include <linux/fs.h>
+
+#include "internal.h"
+
+static ssize_t efivarfs_file_write(struct file *file,
+                const char __user *userbuf, size_t count, loff_t *ppos)
+{
+        struct efivar_entry *var = file->private_data;
+        void *data;
+        u32 attributes;
+        struct inode *inode = file->f_mapping->host;
+        unsigned long datasize = count - sizeof(attributes);
+        ssize_t bytes = 0;
+        bool set = false;
+
+        if (count < sizeof(attributes))
+                return -EINVAL;
+
+        if (copy_from_user(&attributes, userbuf, sizeof(attributes)))
+                return -EFAULT;
+
+        if (attributes & ~(EFI_VARIABLE_MASK))
+                return -EINVAL;
+
+        data = kmalloc(datasize, GFP_KERNEL);
+        if (!data)
+                return -ENOMEM;
+
+        if (copy_from_user(data, userbuf + sizeof(attributes), datasize)) {
+                bytes = -EFAULT;
+                goto out;
+        }
+
+        bytes = efivar_entry_set_get_size(var, attributes, &datasize,
+                                          data, &set);
+        if (!set && bytes)
+                goto out;
+
+        if (bytes == -ENOENT) {
+                drop_nlink(inode);
+                d_delete(file->f_dentry);
+                dput(file->f_dentry);
+        } else {
+                mutex_lock(&inode->i_mutex);
+                i_size_write(inode, datasize + sizeof(attributes));
+                mutex_unlock(&inode->i_mutex);
+        }
+
+        bytes = count;
+
+out:
+        kfree(data);
+
+        return bytes;
+}
+
+static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
+                size_t count, loff_t *ppos)
+{
+        struct efivar_entry *var = file->private_data;
+        unsigned long datasize = 0;
+        u32 attributes;
+        void *data;
+        ssize_t size = 0;
+        int err;
+
+        err = efivar_entry_size(var, &datasize);
+        if (err)
+                return err;
+
+        data = kmalloc(datasize + sizeof(attributes), GFP_KERNEL);
+
+        if (!data)
+                return -ENOMEM;
+
+        size = efivar_entry_get(var, &attributes, &datasize,
+                                data + sizeof(attributes));
+        if (size)
+                goto out_free;
+
+        memcpy(data, &attributes, sizeof(attributes));
+        size = simple_read_from_buffer(userbuf, count, ppos,
+                                       data, datasize + sizeof(attributes));
+out_free:
+        kfree(data);
+
+        return size;
+}
+
+const struct file_operations efivarfs_file_operations = {
+        .open   = simple_open,
+        .read   = efivarfs_file_read,
+        .write  = efivarfs_file_write,
+        .llseek = no_llseek,
+};
diff --git a/fs/efivarfs/inode.c b/fs/efivarfs/inode.c
new file mode 100644
index 000000000000..640e289d522e
--- /dev/null
+++ b/fs/efivarfs/inode.c
@@ -0,0 +1,173 @@
+/*
+ * Copyright (C) 2012 Red Hat, Inc.
+ * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/efi.h>
+#include <linux/fs.h>
+#include <linux/ctype.h>
+
+#include "internal.h"
+
+struct inode *efivarfs_get_inode(struct super_block *sb,
+                                const struct inode *dir, int mode, dev_t dev)
+{
+        struct inode *inode = new_inode(sb);
+
+        if (inode) {
+                inode->i_ino = get_next_ino();
+                inode->i_mode = mode;
+                inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+                switch (mode & S_IFMT) {
+                case S_IFREG:
+                        inode->i_fop = &efivarfs_file_operations;
+                        break;
+                case S_IFDIR:
+                        inode->i_op = &efivarfs_dir_inode_operations;
+                        inode->i_fop = &simple_dir_operations;
+                        inc_nlink(inode);
+                        break;
+                }
+        }
+        return inode;
+}
+
+/*
+ * Return true if 'str' is a valid efivarfs filename of the form,
+ *
+ *      VariableName-12345678-1234-1234-1234-1234567891bc
+ */
+bool efivarfs_valid_name(const char *str, int len)
+{
+        static const char dashes[EFI_VARIABLE_GUID_LEN] = {
+                [8] = 1, [13] = 1, [18] = 1, [23] = 1
+        };
+        const char *s = str + len - EFI_VARIABLE_GUID_LEN;
+        int i;
+
+        /*
+         * We need a GUID, plus at least one letter for the variable name,
+         * plus the '-' separator
+         */
+        if (len < EFI_VARIABLE_GUID_LEN + 2)
+                return false;
+
+        /* GUID must be preceded by a '-' */
+        if (*(s - 1) != '-')
+                return false;
+
+        /*
+         * Validate that 's' is of the correct format, e.g.
+         *
+         *      12345678-1234-1234-1234-123456789abc
+         */
+        for (i = 0; i < EFI_VARIABLE_GUID_LEN; i++) {
+                if (dashes[i]) {
+                        if (*s++ != '-')
+                                return false;
+                } else {
+                        if (!isxdigit(*s++))
+                                return false;
+                }
+        }
+
+        return true;
+}
+
+static void efivarfs_hex_to_guid(const char *str, efi_guid_t *guid)
+{
+        guid->b[0] = hex_to_bin(str[6]) << 4 | hex_to_bin(str[7]);
+        guid->b[1] = hex_to_bin(str[4]) << 4 | hex_to_bin(str[5]);
+        guid->b[2] = hex_to_bin(str[2]) << 4 | hex_to_bin(str[3]);
+        guid->b[3] = hex_to_bin(str[0]) << 4 | hex_to_bin(str[1]);
+        guid->b[4] = hex_to_bin(str[11]) << 4 | hex_to_bin(str[12]);
+        guid->b[5] = hex_to_bin(str[9]) << 4 | hex_to_bin(str[10]);
+        guid->b[6] = hex_to_bin(str[16]) << 4 | hex_to_bin(str[17]);
+        guid->b[7] = hex_to_bin(str[14]) << 4 | hex_to_bin(str[15]);
+        guid->b[8] = hex_to_bin(str[19]) << 4 | hex_to_bin(str[20]);
+        guid->b[9] = hex_to_bin(str[21]) << 4 | hex_to_bin(str[22]);
+        guid->b[10] = hex_to_bin(str[24]) << 4 | hex_to_bin(str[25]);
+        guid->b[11] = hex_to_bin(str[26]) << 4 | hex_to_bin(str[27]);
+        guid->b[12] = hex_to_bin(str[28]) << 4 | hex_to_bin(str[29]);
+        guid->b[13] = hex_to_bin(str[30]) << 4 | hex_to_bin(str[31]);
+        guid->b[14] = hex_to_bin(str[32]) << 4 | hex_to_bin(str[33]);
+        guid->b[15] = hex_to_bin(str[34]) << 4 | hex_to_bin(str[35]);
+}
+
+static int efivarfs_create(struct inode *dir, struct dentry *dentry,
+                          umode_t mode, bool excl)
+{
+        struct inode *inode;
+        struct efivar_entry *var;
+        int namelen, i = 0, err = 0;
+
+        if (!efivarfs_valid_name(dentry->d_name.name, dentry->d_name.len))
+                return -EINVAL;
+
+        inode = efivarfs_get_inode(dir->i_sb, dir, mode, 0);
+        if (!inode)
+                return -ENOMEM;
+
+        var = kzalloc(sizeof(struct efivar_entry), GFP_KERNEL);
+        if (!var) {
+                err = -ENOMEM;
+                goto out;
+        }
+
+        /* length of the variable name itself: remove GUID and separator */
+        namelen = dentry->d_name.len - EFI_VARIABLE_GUID_LEN - 1;
+
+        efivarfs_hex_to_guid(dentry->d_name.name + namelen + 1,
+                        &var->var.VendorGuid);
+
+        for (i = 0; i < namelen; i++)
+                var->var.VariableName[i] = dentry->d_name.name[i];
+
+        var->var.VariableName[i] = '\0';
+
+        inode->i_private = var;
+
+        efivar_entry_add(var, &efivarfs_list);
+        d_instantiate(dentry, inode);
+        dget(dentry);
+out:
+        if (err) {
+                kfree(var);
+                iput(inode);
+        }
+        return err;
+}
+
+static int efivarfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+        struct efivar_entry *var = dentry->d_inode->i_private;
+
+        if (efivar_entry_delete(var))
+                return -EINVAL;
+
+        drop_nlink(dentry->d_inode);
+        dput(dentry);
+        return 0;
+};
+
+/*
+ * Handle negative dentry.
+ */
+static struct dentry *efivarfs_lookup(struct inode *dir, struct dentry *dentry,
+                                      unsigned int flags)
+{
+        if (dentry->d_name.len > NAME_MAX)
+                return ERR_PTR(-ENAMETOOLONG);
+        d_add(dentry, NULL);
+        return NULL;
+}
+
+const struct inode_operations efivarfs_dir_inode_operations = {
+        .lookup = efivarfs_lookup,
+        .unlink = efivarfs_unlink,
+        .create = efivarfs_create,
+};
diff --git a/fs/efivarfs/internal.h b/fs/efivarfs/internal.h
new file mode 100644
index 000000000000..b5ff16addb7c
--- /dev/null
+++ b/fs/efivarfs/internal.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2012 Red Hat, Inc.
+ * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef EFIVAR_FS_INTERNAL_H
+#define EFIVAR_FS_INTERNAL_H
+
+#include <linux/list.h>
+
+extern const struct file_operations efivarfs_file_operations;
+extern const struct inode_operations efivarfs_dir_inode_operations;
+extern bool efivarfs_valid_name(const char *str, int len);
+extern struct inode *efivarfs_get_inode(struct super_block *sb,
+                        const struct inode *dir, int mode, dev_t dev);
+
+extern struct list_head efivarfs_list;
+
+#endif /* EFIVAR_FS_INTERNAL_H */
diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
new file mode 100644
index 000000000000..525a2a1ac16c
--- /dev/null
+++ b/fs/efivarfs/super.c
@@ -0,0 +1,268 @@
+/*
+ * Copyright (C) 2012 Red Hat, Inc.
+ * Copyright (C) 2012 Jeremy Kerr <jeremy.kerr@canonical.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/ctype.h>
+#include <linux/efi.h>
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/pagemap.h>
+#include <linux/ucs2_string.h>
+
+#include "internal.h"
+
+LIST_HEAD(efivarfs_list);
+
+static void efivarfs_evict_inode(struct inode *inode)
+{
+        clear_inode(inode);
+}
+
+static const struct super_operations efivarfs_ops = {
+        .statfs = simple_statfs,
+        .drop_inode = generic_delete_inode,
+        .evict_inode = efivarfs_evict_inode,
+        .show_options = generic_show_options,
+};
+
+static struct super_block *efivarfs_sb;
+
+/*
+ * Compare two efivarfs file names.
+ *
+ * An efivarfs filename is composed of two parts,
+ *
+ *      1. A case-sensitive variable name
+ *      2. A case-insensitive GUID
+ *
+ * So we need to perform a case-sensitive match on part 1 and a
+ * case-insensitive match on part 2.
+ */
+static int efivarfs_d_compare(const struct dentry *parent, const struct inode *pinode,
+                              const struct dentry *dentry, const struct inode *inode,
+                              unsigned int len, const char *str,
+                              const struct qstr *name)
+{
+        int guid = len - EFI_VARIABLE_GUID_LEN;
+
+        if (name->len != len)
+                return 1;
+
+        /* Case-sensitive compare for the variable name */
+        if (memcmp(str, name->name, guid))
+                return 1;
+
+        /* Case-insensitive compare for the GUID */
+        return strncasecmp(name->name + guid, str + guid, EFI_VARIABLE_GUID_LEN);
+}
+
+static int efivarfs_d_hash(const struct dentry *dentry,
+                           const struct inode *inode, struct qstr *qstr)
+{
+        unsigned long hash = init_name_hash();
+        const unsigned char *s = qstr->name;
+        unsigned int len = qstr->len;
+
+        if (!efivarfs_valid_name(s, len))
+                return -EINVAL;
+
+        while (len-- > EFI_VARIABLE_GUID_LEN)
+                hash = partial_name_hash(*s++, hash);
+
+        /* GUID is case-insensitive. */
+        while (len--)
+                hash = partial_name_hash(tolower(*s++), hash);
+
+        qstr->hash = end_name_hash(hash);
+        return 0;
+}
+
+/*
+ * Retaining negative dentries for an in-memory filesystem just wastes
+ * memory and lookup time: arrange for them to be deleted immediately.
+ */
+static int efivarfs_delete_dentry(const struct dentry *dentry)
+{
+        return 1;
+}
+
+static struct dentry_operations efivarfs_d_ops = {
+        .d_compare = efivarfs_d_compare,
+        .d_hash = efivarfs_d_hash,
+        .d_delete = efivarfs_delete_dentry,
+};
+
+static struct dentry *efivarfs_alloc_dentry(struct dentry *parent, char *name)
+{
+        struct dentry *d;
+        struct qstr q;
+        int err;
+
+        q.name = name;
+        q.len = strlen(name);
+
+        err = efivarfs_d_hash(NULL, NULL, &q);
+        if (err)
+                return ERR_PTR(err);
+
+        d = d_alloc(parent, &q);
+        if (d)
+                return d;
+
+        return ERR_PTR(-ENOMEM);
+}
+
+static int efivarfs_callback(efi_char16_t *name16, efi_guid_t vendor,
+                             unsigned long name_size, void *data)
+{
+        struct super_block *sb = (struct super_block *)data;
+        struct efivar_entry *entry;
+        struct inode *inode = NULL;
+        struct dentry *dentry, *root = sb->s_root;
+        unsigned long size = 0;
+        char *name;
+        int len, i;
+        int err = -ENOMEM;
+
+        entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+        if (!entry)
+                return err;
+
+        memcpy(entry->var.VariableName, name16, name_size);
+        memcpy(&(entry->var.VendorGuid), &vendor, sizeof(efi_guid_t));
+
+        len = ucs2_strlen(entry->var.VariableName);
+
+        /* name, plus '-', plus GUID, plus NUL*/
+        name = kmalloc(len + 1 + EFI_VARIABLE_GUID_LEN + 1, GFP_KERNEL);
+        if (!name)
+                goto fail;
+
+        for (i = 0; i < len; i++)
+                name[i] = entry->var.VariableName[i] & 0xFF;
+
+        name[len] = '-';
+
+        efi_guid_unparse(&entry->var.VendorGuid, name + len + 1);
+
+        name[len + EFI_VARIABLE_GUID_LEN+1] = '\0';
+
+        inode = efivarfs_get_inode(sb, root->d_inode, S_IFREG | 0644, 0);
+        if (!inode)
+                goto fail_name;
+
+        dentry = efivarfs_alloc_dentry(root, name);
+        if (IS_ERR(dentry)) {
+                err = PTR_ERR(dentry);
+                goto fail_inode;
+        }
+
+        /* copied by the above to local storage in the dentry. */
+        kfree(name);
+
+        efivar_entry_size(entry, &size);
+        efivar_entry_add(entry, &efivarfs_list);
+
+        mutex_lock(&inode->i_mutex);
+        inode->i_private = entry;
+        i_size_write(inode, size + sizeof(entry->var.Attributes));
+        mutex_unlock(&inode->i_mutex);
+        d_add(dentry, inode);
+
+        return 0;
+
+fail_inode:
+        iput(inode);
+fail_name:
+        kfree(name);
+fail:
+        kfree(entry);
+        return err;
+}
+
+static int efivarfs_destroy(struct efivar_entry *entry, void *data)
+{
+        efivar_entry_remove(entry);
+        kfree(entry);
+        return 0;
+}
+
+static int efivarfs_fill_super(struct super_block *sb, void *data, int silent)
+{
+        struct inode *inode = NULL;
+        struct dentry *root;
+        int err;
+
+        efivarfs_sb = sb;
+
+        sb->s_maxbytes          = MAX_LFS_FILESIZE;
+        sb->s_blocksize         = PAGE_CACHE_SIZE;
+        sb->s_blocksize_bits    = PAGE_CACHE_SHIFT;
+        sb->s_magic             = EFIVARFS_MAGIC;
+        sb->s_op                = &efivarfs_ops;
+        sb->s_d_op              = &efivarfs_d_ops;
+        sb->s_time_gran         = 1;
+
+        inode = efivarfs_get_inode(sb, NULL, S_IFDIR | 0755, 0);
+        if (!inode)
+                return -ENOMEM;
+        inode->i_op = &efivarfs_dir_inode_operations;
+
+        root = d_make_root(inode);
+        sb->s_root = root;
+        if (!root)
+                return -ENOMEM;
+
+        INIT_LIST_HEAD(&efivarfs_list);
+
+        err = efivar_init(efivarfs_callback, (void *)sb, false,
+                          true, &efivarfs_list);
+        if (err)
+                __efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL, NULL);
+
+        return err;
+}
+
+static struct dentry *efivarfs_mount(struct file_system_type *fs_type,
+                                    int flags, const char *dev_name, void *data)
+{
+        return mount_single(fs_type, flags, data, efivarfs_fill_super);
+}
+
+static void efivarfs_kill_sb(struct super_block *sb)
+{
+        kill_litter_super(sb);
+        efivarfs_sb = NULL;
+
+        /* Remove all entries and destroy */
+        __efivar_entry_iter(efivarfs_destroy, &efivarfs_list, NULL, NULL);
+}
+
+static struct file_system_type efivarfs_type = {
+        .name    = "efivarfs",
+        .mount   = efivarfs_mount,
+        .kill_sb = efivarfs_kill_sb,
+};
+
+static __init int efivarfs_init(void)
+{
+        if (!efi_enabled(EFI_RUNTIME_SERVICES))
+                return 0;
+
+        if (!efivars_kobject())
+                return 0;
+
+        return register_filesystem(&efivarfs_type);
+}
+
+MODULE_AUTHOR("Matthew Garrett, Jeremy Kerr");
+MODULE_DESCRIPTION("EFI Variable Filesystem");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_FS("efivarfs");
+
+module_init(efivarfs_init);