linux/arch/x86/kernel/ksysfs.c
Kees Cook 404f6aac9b x86: Apply more __ro_after_init and const
Guided by grsecurity's analogous __read_only markings in arch/x86,
this applies several uses of __ro_after_init to structures that are
only updated during __init, and const for some structures that are
never updated.  Additionally extends __init markings to some functions
that are only used during __init, and cleans up some missing C99 style
static initializers.

Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Brown <david.brown@linaro.org>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathias Krause <minipli@googlemail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: PaX Team <pageexec@freemail.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-hardening@lists.openwall.com
Link: http://lkml.kernel.org/r/20160808232906.GA29731@www.outflux.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-10 14:55:05 +02:00

341 lines
6.5 KiB
C

/*
* Architecture specific sysfs attributes in /sys/kernel
*
* Copyright (C) 2007, Intel Corp.
* Huang Ying <ying.huang@intel.com>
* Copyright (C) 2013, 2013 Red Hat, Inc.
* Dave Young <dyoung@redhat.com>
*
* This file is released under the GPLv2
*/
#include <linux/kobject.h>
#include <linux/string.h>
#include <linux/sysfs.h>
#include <linux/init.h>
#include <linux/stat.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <asm/io.h>
#include <asm/setup.h>
static ssize_t version_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return sprintf(buf, "0x%04x\n", boot_params.hdr.version);
}
static struct kobj_attribute boot_params_version_attr = __ATTR_RO(version);
static ssize_t boot_params_data_read(struct file *fp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t off, size_t count)
{
memcpy(buf, (void *)&boot_params + off, count);
return count;
}
static struct bin_attribute boot_params_data_attr = {
.attr = {
.name = "data",
.mode = S_IRUGO,
},
.read = boot_params_data_read,
.size = sizeof(boot_params),
};
static struct attribute *boot_params_version_attrs[] = {
&boot_params_version_attr.attr,
NULL,
};
static struct bin_attribute *boot_params_data_attrs[] = {
&boot_params_data_attr,
NULL,
};
static struct attribute_group boot_params_attr_group = {
.attrs = boot_params_version_attrs,
.bin_attrs = boot_params_data_attrs,
};
static int kobj_to_setup_data_nr(struct kobject *kobj, int *nr)
{
const char *name;
name = kobject_name(kobj);
return kstrtoint(name, 10, nr);
}
static int get_setup_data_paddr(int nr, u64 *paddr)
{
int i = 0;
struct setup_data *data;
u64 pa_data = boot_params.hdr.setup_data;
while (pa_data) {
if (nr == i) {
*paddr = pa_data;
return 0;
}
data = ioremap_cache(pa_data, sizeof(*data));
if (!data)
return -ENOMEM;
pa_data = data->next;
iounmap(data);
i++;
}
return -EINVAL;
}
static int __init get_setup_data_size(int nr, size_t *size)
{
int i = 0;
struct setup_data *data;
u64 pa_data = boot_params.hdr.setup_data;
while (pa_data) {
data = ioremap_cache(pa_data, sizeof(*data));
if (!data)
return -ENOMEM;
if (nr == i) {
*size = data->len;
iounmap(data);
return 0;
}
pa_data = data->next;
iounmap(data);
i++;
}
return -EINVAL;
}
static ssize_t type_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
int nr, ret;
u64 paddr;
struct setup_data *data;
ret = kobj_to_setup_data_nr(kobj, &nr);
if (ret)
return ret;
ret = get_setup_data_paddr(nr, &paddr);
if (ret)
return ret;
data = ioremap_cache(paddr, sizeof(*data));
if (!data)
return -ENOMEM;
ret = sprintf(buf, "0x%x\n", data->type);
iounmap(data);
return ret;
}
static ssize_t setup_data_data_read(struct file *fp,
struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf,
loff_t off, size_t count)
{
int nr, ret = 0;
u64 paddr;
struct setup_data *data;
void *p;
ret = kobj_to_setup_data_nr(kobj, &nr);
if (ret)
return ret;
ret = get_setup_data_paddr(nr, &paddr);
if (ret)
return ret;
data = ioremap_cache(paddr, sizeof(*data));
if (!data)
return -ENOMEM;
if (off > data->len) {
ret = -EINVAL;
goto out;
}
if (count > data->len - off)
count = data->len - off;
if (!count)
goto out;
ret = count;
p = ioremap_cache(paddr + sizeof(*data), data->len);
if (!p) {
ret = -ENOMEM;
goto out;
}
memcpy(buf, p + off, count);
iounmap(p);
out:
iounmap(data);
return ret;
}
static struct kobj_attribute type_attr = __ATTR_RO(type);
static struct bin_attribute data_attr __ro_after_init = {
.attr = {
.name = "data",
.mode = S_IRUGO,
},
.read = setup_data_data_read,
};
static struct attribute *setup_data_type_attrs[] = {
&type_attr.attr,
NULL,
};
static struct bin_attribute *setup_data_data_attrs[] = {
&data_attr,
NULL,
};
static struct attribute_group setup_data_attr_group = {
.attrs = setup_data_type_attrs,
.bin_attrs = setup_data_data_attrs,
};
static int __init create_setup_data_node(struct kobject *parent,
struct kobject **kobjp, int nr)
{
int ret = 0;
size_t size;
struct kobject *kobj;
char name[16]; /* should be enough for setup_data nodes numbers */
snprintf(name, 16, "%d", nr);
kobj = kobject_create_and_add(name, parent);
if (!kobj)
return -ENOMEM;
ret = get_setup_data_size(nr, &size);
if (ret)
goto out_kobj;
data_attr.size = size;
ret = sysfs_create_group(kobj, &setup_data_attr_group);
if (ret)
goto out_kobj;
*kobjp = kobj;
return 0;
out_kobj:
kobject_put(kobj);
return ret;
}
static void __init cleanup_setup_data_node(struct kobject *kobj)
{
sysfs_remove_group(kobj, &setup_data_attr_group);
kobject_put(kobj);
}
static int __init get_setup_data_total_num(u64 pa_data, int *nr)
{
int ret = 0;
struct setup_data *data;
*nr = 0;
while (pa_data) {
*nr += 1;
data = ioremap_cache(pa_data, sizeof(*data));
if (!data) {
ret = -ENOMEM;
goto out;
}
pa_data = data->next;
iounmap(data);
}
out:
return ret;
}
static int __init create_setup_data_nodes(struct kobject *parent)
{
struct kobject *setup_data_kobj, **kobjp;
u64 pa_data;
int i, j, nr, ret = 0;
pa_data = boot_params.hdr.setup_data;
if (!pa_data)
return 0;
setup_data_kobj = kobject_create_and_add("setup_data", parent);
if (!setup_data_kobj) {
ret = -ENOMEM;
goto out;
}
ret = get_setup_data_total_num(pa_data, &nr);
if (ret)
goto out_setup_data_kobj;
kobjp = kmalloc(sizeof(*kobjp) * nr, GFP_KERNEL);
if (!kobjp) {
ret = -ENOMEM;
goto out_setup_data_kobj;
}
for (i = 0; i < nr; i++) {
ret = create_setup_data_node(setup_data_kobj, kobjp + i, i);
if (ret)
goto out_clean_nodes;
}
kfree(kobjp);
return 0;
out_clean_nodes:
for (j = i - 1; j > 0; j--)
cleanup_setup_data_node(*(kobjp + j));
kfree(kobjp);
out_setup_data_kobj:
kobject_put(setup_data_kobj);
out:
return ret;
}
static int __init boot_params_ksysfs_init(void)
{
int ret;
struct kobject *boot_params_kobj;
boot_params_kobj = kobject_create_and_add("boot_params",
kernel_kobj);
if (!boot_params_kobj) {
ret = -ENOMEM;
goto out;
}
ret = sysfs_create_group(boot_params_kobj, &boot_params_attr_group);
if (ret)
goto out_boot_params_kobj;
ret = create_setup_data_nodes(boot_params_kobj);
if (ret)
goto out_create_group;
return 0;
out_create_group:
sysfs_remove_group(boot_params_kobj, &boot_params_attr_group);
out_boot_params_kobj:
kobject_put(boot_params_kobj);
out:
return ret;
}
arch_initcall(boot_params_ksysfs_init);