linux/drivers/base/firmware_class.c
Linus Torvalds caca9510ff firmware loader: allow builtin firmware load even if usermodehelper is disabled
In commit a144c6a6c9 ("PM: Print a warning if firmware is requested
when tasks are frozen") we not only printed a warning if somebody tried
to load the firmware when tasks are frozen - we also failed the load.

But that check was done before the check for built-in firmware, and then
when we disallowed usermode helpers during bootup (commit 288d5abec8:
"Boot up with usermodehelper disabled"), that actually means that
built-in modules can no longer load their firmware even if the firmware
is built in too.  Which used to work, and some people depended on it for
the R100 driver.

So move the test for usermodehelper_is_disabled() down, to after
checking the built-in firmware.

This should fix:

	https://bugzilla.kernel.org/show_bug.cgi?id=40952

Reported-by: James Cloos <cloos@hjcloos.com>
Bisected-by: Elimar Riesebieter <riesebie@lxtec.de>
Cc: Michel Dänzer <michel@daenzer.net>
Cc: Rafael Wysocki <rjw@sisk.pl>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-08-24 15:55:30 -07:00

719 lines
17 KiB
C

/*
* firmware_class.c - Multi purpose firmware loading support
*
* Copyright (c) 2003 Manuel Estrada Sainz
*
* Please see Documentation/firmware_class/ for more information.
*
*/
#include <linux/capability.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/timer.h>
#include <linux/vmalloc.h>
#include <linux/interrupt.h>
#include <linux/bitops.h>
#include <linux/mutex.h>
#include <linux/kthread.h>
#include <linux/highmem.h>
#include <linux/firmware.h>
#include <linux/slab.h>
#define to_dev(obj) container_of(obj, struct device, kobj)
MODULE_AUTHOR("Manuel Estrada Sainz");
MODULE_DESCRIPTION("Multi purpose firmware loading support");
MODULE_LICENSE("GPL");
/* Builtin firmware support */
#ifdef CONFIG_FW_LOADER
extern struct builtin_fw __start_builtin_fw[];
extern struct builtin_fw __end_builtin_fw[];
static bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
{
struct builtin_fw *b_fw;
for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
if (strcmp(name, b_fw->name) == 0) {
fw->size = b_fw->size;
fw->data = b_fw->data;
return true;
}
}
return false;
}
static bool fw_is_builtin_firmware(const struct firmware *fw)
{
struct builtin_fw *b_fw;
for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
if (fw->data == b_fw->data)
return true;
return false;
}
#else /* Module case - no builtin firmware support */
static inline bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
{
return false;
}
static inline bool fw_is_builtin_firmware(const struct firmware *fw)
{
return false;
}
#endif
enum {
FW_STATUS_LOADING,
FW_STATUS_DONE,
FW_STATUS_ABORT,
};
static int loading_timeout = 60; /* In seconds */
/* fw_lock could be moved to 'struct firmware_priv' but since it is just
* guarding for corner cases a global lock should be OK */
static DEFINE_MUTEX(fw_lock);
struct firmware_priv {
struct completion completion;
struct firmware *fw;
unsigned long status;
struct page **pages;
int nr_pages;
int page_array_size;
struct timer_list timeout;
struct device dev;
bool nowait;
char fw_id[];
};
static struct firmware_priv *to_firmware_priv(struct device *dev)
{
return container_of(dev, struct firmware_priv, dev);
}
static void fw_load_abort(struct firmware_priv *fw_priv)
{
set_bit(FW_STATUS_ABORT, &fw_priv->status);
wmb();
complete(&fw_priv->completion);
}
static ssize_t firmware_timeout_show(struct class *class,
struct class_attribute *attr,
char *buf)
{
return sprintf(buf, "%d\n", loading_timeout);
}
/**
* firmware_timeout_store - set number of seconds to wait for firmware
* @class: device class pointer
* @attr: device attribute pointer
* @buf: buffer to scan for timeout value
* @count: number of bytes in @buf
*
* Sets the number of seconds to wait for the firmware. Once
* this expires an error will be returned to the driver and no
* firmware will be provided.
*
* Note: zero means 'wait forever'.
**/
static ssize_t firmware_timeout_store(struct class *class,
struct class_attribute *attr,
const char *buf, size_t count)
{
loading_timeout = simple_strtol(buf, NULL, 10);
if (loading_timeout < 0)
loading_timeout = 0;
return count;
}
static struct class_attribute firmware_class_attrs[] = {
__ATTR(timeout, S_IWUSR | S_IRUGO,
firmware_timeout_show, firmware_timeout_store),
__ATTR_NULL
};
static void fw_dev_release(struct device *dev)
{
struct firmware_priv *fw_priv = to_firmware_priv(dev);
int i;
for (i = 0; i < fw_priv->nr_pages; i++)
__free_page(fw_priv->pages[i]);
kfree(fw_priv->pages);
kfree(fw_priv);
module_put(THIS_MODULE);
}
static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct firmware_priv *fw_priv = to_firmware_priv(dev);
if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
return -ENOMEM;
if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
return -ENOMEM;
if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
return -ENOMEM;
return 0;
}
static struct class firmware_class = {
.name = "firmware",
.class_attrs = firmware_class_attrs,
.dev_uevent = firmware_uevent,
.dev_release = fw_dev_release,
};
static ssize_t firmware_loading_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct firmware_priv *fw_priv = to_firmware_priv(dev);
int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
return sprintf(buf, "%d\n", loading);
}
static void firmware_free_data(const struct firmware *fw)
{
int i;
vunmap(fw->data);
if (fw->pages) {
for (i = 0; i < PFN_UP(fw->size); i++)
__free_page(fw->pages[i]);
kfree(fw->pages);
}
}
/* Some architectures don't have PAGE_KERNEL_RO */
#ifndef PAGE_KERNEL_RO
#define PAGE_KERNEL_RO PAGE_KERNEL
#endif
/**
* firmware_loading_store - set value in the 'loading' control file
* @dev: device pointer
* @attr: device attribute pointer
* @buf: buffer to scan for loading control value
* @count: number of bytes in @buf
*
* The relevant values are:
*
* 1: Start a load, discarding any previous partial load.
* 0: Conclude the load and hand the data to the driver code.
* -1: Conclude the load with an error and discard any written data.
**/
static ssize_t firmware_loading_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct firmware_priv *fw_priv = to_firmware_priv(dev);
int loading = simple_strtol(buf, NULL, 10);
int i;
switch (loading) {
case 1:
mutex_lock(&fw_lock);
if (!fw_priv->fw) {
mutex_unlock(&fw_lock);
break;
}
firmware_free_data(fw_priv->fw);
memset(fw_priv->fw, 0, sizeof(struct firmware));
/* If the pages are not owned by 'struct firmware' */
for (i = 0; i < fw_priv->nr_pages; i++)
__free_page(fw_priv->pages[i]);
kfree(fw_priv->pages);
fw_priv->pages = NULL;
fw_priv->page_array_size = 0;
fw_priv->nr_pages = 0;
set_bit(FW_STATUS_LOADING, &fw_priv->status);
mutex_unlock(&fw_lock);
break;
case 0:
if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
vunmap(fw_priv->fw->data);
fw_priv->fw->data = vmap(fw_priv->pages,
fw_priv->nr_pages,
0, PAGE_KERNEL_RO);
if (!fw_priv->fw->data) {
dev_err(dev, "%s: vmap() failed\n", __func__);
goto err;
}
/* Pages are now owned by 'struct firmware' */
fw_priv->fw->pages = fw_priv->pages;
fw_priv->pages = NULL;
fw_priv->page_array_size = 0;
fw_priv->nr_pages = 0;
complete(&fw_priv->completion);
clear_bit(FW_STATUS_LOADING, &fw_priv->status);
break;
}
/* fallthrough */
default:
dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
/* fallthrough */
case -1:
err:
fw_load_abort(fw_priv);
break;
}
return count;
}
static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buffer, loff_t offset, size_t count)
{
struct device *dev = to_dev(kobj);
struct firmware_priv *fw_priv = to_firmware_priv(dev);
struct firmware *fw;
ssize_t ret_count;
mutex_lock(&fw_lock);
fw = fw_priv->fw;
if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
ret_count = -ENODEV;
goto out;
}
if (offset > fw->size) {
ret_count = 0;
goto out;
}
if (count > fw->size - offset)
count = fw->size - offset;
ret_count = count;
while (count) {
void *page_data;
int page_nr = offset >> PAGE_SHIFT;
int page_ofs = offset & (PAGE_SIZE-1);
int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
page_data = kmap(fw_priv->pages[page_nr]);
memcpy(buffer, page_data + page_ofs, page_cnt);
kunmap(fw_priv->pages[page_nr]);
buffer += page_cnt;
offset += page_cnt;
count -= page_cnt;
}
out:
mutex_unlock(&fw_lock);
return ret_count;
}
static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
{
int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT;
/* If the array of pages is too small, grow it... */
if (fw_priv->page_array_size < pages_needed) {
int new_array_size = max(pages_needed,
fw_priv->page_array_size * 2);
struct page **new_pages;
new_pages = kmalloc(new_array_size * sizeof(void *),
GFP_KERNEL);
if (!new_pages) {
fw_load_abort(fw_priv);
return -ENOMEM;
}
memcpy(new_pages, fw_priv->pages,
fw_priv->page_array_size * sizeof(void *));
memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
(new_array_size - fw_priv->page_array_size));
kfree(fw_priv->pages);
fw_priv->pages = new_pages;
fw_priv->page_array_size = new_array_size;
}
while (fw_priv->nr_pages < pages_needed) {
fw_priv->pages[fw_priv->nr_pages] =
alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
if (!fw_priv->pages[fw_priv->nr_pages]) {
fw_load_abort(fw_priv);
return -ENOMEM;
}
fw_priv->nr_pages++;
}
return 0;
}
/**
* firmware_data_write - write method for firmware
* @filp: open sysfs file
* @kobj: kobject for the device
* @bin_attr: bin_attr structure
* @buffer: buffer being written
* @offset: buffer offset for write in total data store area
* @count: buffer size
*
* Data written to the 'data' attribute will be later handed to
* the driver as a firmware image.
**/
static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buffer, loff_t offset, size_t count)
{
struct device *dev = to_dev(kobj);
struct firmware_priv *fw_priv = to_firmware_priv(dev);
struct firmware *fw;
ssize_t retval;
if (!capable(CAP_SYS_RAWIO))
return -EPERM;
mutex_lock(&fw_lock);
fw = fw_priv->fw;
if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
retval = -ENODEV;
goto out;
}
retval = fw_realloc_buffer(fw_priv, offset + count);
if (retval)
goto out;
retval = count;
while (count) {
void *page_data;
int page_nr = offset >> PAGE_SHIFT;
int page_ofs = offset & (PAGE_SIZE - 1);
int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
page_data = kmap(fw_priv->pages[page_nr]);
memcpy(page_data + page_ofs, buffer, page_cnt);
kunmap(fw_priv->pages[page_nr]);
buffer += page_cnt;
offset += page_cnt;
count -= page_cnt;
}
fw->size = max_t(size_t, offset, fw->size);
out:
mutex_unlock(&fw_lock);
return retval;
}
static struct bin_attribute firmware_attr_data = {
.attr = { .name = "data", .mode = 0644 },
.size = 0,
.read = firmware_data_read,
.write = firmware_data_write,
};
static void firmware_class_timeout(u_long data)
{
struct firmware_priv *fw_priv = (struct firmware_priv *) data;
fw_load_abort(fw_priv);
}
static struct firmware_priv *
fw_create_instance(struct firmware *firmware, const char *fw_name,
struct device *device, bool uevent, bool nowait)
{
struct firmware_priv *fw_priv;
struct device *f_dev;
int error;
fw_priv = kzalloc(sizeof(*fw_priv) + strlen(fw_name) + 1 , GFP_KERNEL);
if (!fw_priv) {
dev_err(device, "%s: kmalloc failed\n", __func__);
error = -ENOMEM;
goto err_out;
}
fw_priv->fw = firmware;
fw_priv->nowait = nowait;
strcpy(fw_priv->fw_id, fw_name);
init_completion(&fw_priv->completion);
setup_timer(&fw_priv->timeout,
firmware_class_timeout, (u_long) fw_priv);
f_dev = &fw_priv->dev;
device_initialize(f_dev);
dev_set_name(f_dev, "%s", dev_name(device));
f_dev->parent = device;
f_dev->class = &firmware_class;
dev_set_uevent_suppress(f_dev, true);
/* Need to pin this module until class device is destroyed */
__module_get(THIS_MODULE);
error = device_add(f_dev);
if (error) {
dev_err(device, "%s: device_register failed\n", __func__);
goto err_put_dev;
}
error = device_create_bin_file(f_dev, &firmware_attr_data);
if (error) {
dev_err(device, "%s: sysfs_create_bin_file failed\n", __func__);
goto err_del_dev;
}
error = device_create_file(f_dev, &dev_attr_loading);
if (error) {
dev_err(device, "%s: device_create_file failed\n", __func__);
goto err_del_bin_attr;
}
if (uevent)
dev_set_uevent_suppress(f_dev, false);
return fw_priv;
err_del_bin_attr:
device_remove_bin_file(f_dev, &firmware_attr_data);
err_del_dev:
device_del(f_dev);
err_put_dev:
put_device(f_dev);
err_out:
return ERR_PTR(error);
}
static void fw_destroy_instance(struct firmware_priv *fw_priv)
{
struct device *f_dev = &fw_priv->dev;
device_remove_file(f_dev, &dev_attr_loading);
device_remove_bin_file(f_dev, &firmware_attr_data);
device_unregister(f_dev);
}
static int _request_firmware(const struct firmware **firmware_p,
const char *name, struct device *device,
bool uevent, bool nowait)
{
struct firmware_priv *fw_priv;
struct firmware *firmware;
int retval = 0;
if (!firmware_p)
return -EINVAL;
*firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
if (!firmware) {
dev_err(device, "%s: kmalloc(struct firmware) failed\n",
__func__);
retval = -ENOMEM;
goto out;
}
if (fw_get_builtin_firmware(firmware, name)) {
dev_dbg(device, "firmware: using built-in firmware %s\n", name);
return 0;
}
if (WARN_ON(usermodehelper_is_disabled())) {
dev_err(device, "firmware: %s will not be loaded\n", name);
retval = -EBUSY;
goto out;
}
if (uevent)
dev_dbg(device, "firmware: requesting %s\n", name);
fw_priv = fw_create_instance(firmware, name, device, uevent, nowait);
if (IS_ERR(fw_priv)) {
retval = PTR_ERR(fw_priv);
goto out;
}
if (uevent) {
if (loading_timeout > 0)
mod_timer(&fw_priv->timeout,
round_jiffies_up(jiffies +
loading_timeout * HZ));
kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
}
wait_for_completion(&fw_priv->completion);
set_bit(FW_STATUS_DONE, &fw_priv->status);
del_timer_sync(&fw_priv->timeout);
mutex_lock(&fw_lock);
if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status))
retval = -ENOENT;
fw_priv->fw = NULL;
mutex_unlock(&fw_lock);
fw_destroy_instance(fw_priv);
out:
if (retval) {
release_firmware(firmware);
*firmware_p = NULL;
}
return retval;
}
/**
* request_firmware: - send firmware request and wait for it
* @firmware_p: pointer to firmware image
* @name: name of firmware file
* @device: device for which firmware is being loaded
*
* @firmware_p will be used to return a firmware image by the name
* of @name for device @device.
*
* Should be called from user context where sleeping is allowed.
*
* @name will be used as $FIRMWARE in the uevent environment and
* should be distinctive enough not to be confused with any other
* firmware image for this or any other device.
**/
int
request_firmware(const struct firmware **firmware_p, const char *name,
struct device *device)
{
return _request_firmware(firmware_p, name, device, true, false);
}
/**
* release_firmware: - release the resource associated with a firmware image
* @fw: firmware resource to release
**/
void release_firmware(const struct firmware *fw)
{
if (fw) {
if (!fw_is_builtin_firmware(fw))
firmware_free_data(fw);
kfree(fw);
}
}
/* Async support */
struct firmware_work {
struct work_struct work;
struct module *module;
const char *name;
struct device *device;
void *context;
void (*cont)(const struct firmware *fw, void *context);
bool uevent;
};
static int request_firmware_work_func(void *arg)
{
struct firmware_work *fw_work = arg;
const struct firmware *fw;
int ret;
if (!arg) {
WARN_ON(1);
return 0;
}
ret = _request_firmware(&fw, fw_work->name, fw_work->device,
fw_work->uevent, true);
fw_work->cont(fw, fw_work->context);
module_put(fw_work->module);
kfree(fw_work);
return ret;
}
/**
* request_firmware_nowait - asynchronous version of request_firmware
* @module: module requesting the firmware
* @uevent: sends uevent to copy the firmware image if this flag
* is non-zero else the firmware copy must be done manually.
* @name: name of firmware file
* @device: device for which firmware is being loaded
* @gfp: allocation flags
* @context: will be passed over to @cont, and
* @fw may be %NULL if firmware request fails.
* @cont: function will be called asynchronously when the firmware
* request is over.
*
* Asynchronous variant of request_firmware() for user contexts where
* it is not possible to sleep for long time. It can't be called
* in atomic contexts.
**/
int
request_firmware_nowait(
struct module *module, bool uevent,
const char *name, struct device *device, gfp_t gfp, void *context,
void (*cont)(const struct firmware *fw, void *context))
{
struct task_struct *task;
struct firmware_work *fw_work;
fw_work = kzalloc(sizeof (struct firmware_work), gfp);
if (!fw_work)
return -ENOMEM;
fw_work->module = module;
fw_work->name = name;
fw_work->device = device;
fw_work->context = context;
fw_work->cont = cont;
fw_work->uevent = uevent;
if (!try_module_get(module)) {
kfree(fw_work);
return -EFAULT;
}
task = kthread_run(request_firmware_work_func, fw_work,
"firmware/%s", name);
if (IS_ERR(task)) {
fw_work->cont(NULL, fw_work->context);
module_put(fw_work->module);
kfree(fw_work);
return PTR_ERR(task);
}
return 0;
}
static int __init firmware_class_init(void)
{
return class_register(&firmware_class);
}
static void __exit firmware_class_exit(void)
{
class_unregister(&firmware_class);
}
fs_initcall(firmware_class_init);
module_exit(firmware_class_exit);
EXPORT_SYMBOL(release_firmware);
EXPORT_SYMBOL(request_firmware);
EXPORT_SYMBOL(request_firmware_nowait);