// SPDX-License-Identifier: GPL-2.0
/*
* main.c - Multi purpose firmware loading support
*
* Copyright (c) 2003 Manuel Estrada Sainz
*
* Please see Documentation/driver-api/firmware/ for more information.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/capability.h>
#include <linux/device.h>
#include <linux/kernel_read_file.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/initrd.h>
#include <linux/timer.h>
#include <linux/vmalloc.h>
#include <linux/interrupt.h>
#include <linux/bitops.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/highmem.h>
#include <linux/firmware.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/file.h>
#include <linux/list.h>
#include <linux/fs.h>
#include <linux/async.h>
#include <linux/pm.h>
#include <linux/suspend.h>
#include <linux/syscore_ops.h>
#include <linux/reboot.h>
#include <linux/security.h>
#include <linux/zstd.h>
#include <linux/xz.h>
#include <generated/utsrelease.h>
#include "../base.h"
#include "firmware.h"
#include "fallback.h"
MODULE_AUTHOR("Manuel Estrada Sainz");
MODULE_DESCRIPTION("Multi purpose firmware loading support");
MODULE_LICENSE("GPL");
struct firmware_cache {
/* firmware_buf instance will be added into the below list */
spinlock_t lock;
struct list_head head;
int state;
#ifdef CONFIG_FW_CACHE
/*
* Names of firmware images which have been cached successfully
* will be added into the below list so that device uncache
* helper can trace which firmware images have been cached
* before.
*/
spinlock_t name_lock;
struct list_head fw_names;
struct delayed_work work;
struct notifier_block pm_notify;
#endif
};
struct fw_cache_entry {
struct list_head list;
const char *name;
};
struct fw_name_devm {
unsigned long magic;
const char *name;
};
static inline struct fw_priv *to_fw_priv(struct kref *ref)
{
return container_of(ref, struct fw_priv, ref);
}
#define FW_LOADER_NO_CACHE 0
#define FW_LOADER_START_CACHE 1
/* fw_lock could be moved to 'struct fw_sysfs' but since it is just
* guarding for corner cases a global lock should be OK */
DEFINE_MUTEX(fw_lock);
struct firmware_cache fw_cache;
bool fw_load_abort_all;
void fw_state_init(struct fw_priv *fw_priv)
{
struct fw_state *fw_st = &fw_priv->fw_st;
init_completion(&fw_st->completion);
fw_st->status = FW_STATUS_UNKNOWN;
}
static inline int fw_state_wait(struct fw_priv *fw_priv)
{
return __fw_state_wait_common(fw_priv, MAX_SCHEDULE_TIMEOUT);
}
static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv);
static struct fw_priv *__allocate_fw_priv(const char *fw_name,
struct firmware_cache *fwc,
void *dbuf,
size_t size,
size_t offset,
u32 opt_flags)
{
struct fw_priv *fw_priv;
/* For a partial read, the buffer must be preallocated. */
if ((opt_flags & FW_OPT_PARTIAL) && !dbuf)
return NULL;
/* Only partial reads are allowed to use an offset. */
if (offset != 0 && !(opt_flags & FW_OPT_PARTIAL))
return NULL;
fw_priv = kzalloc(sizeof(*fw_priv), GFP_ATOMIC);
if (!fw_priv)
return NULL;
fw_priv->fw_name = kstrdup_const(fw_name, GFP_ATOMIC);
if (!fw_priv->fw_name) {
kfree(fw_priv);
return NULL;
}
kref_init(&fw_priv->ref);
fw_priv->fwc = fwc;
fw_priv->data = dbuf;
fw_priv->allocated_size = size;
fw_priv->offset = offset;
fw_priv->opt_flags = opt_flags;
fw_state_init(fw_priv);
#ifdef CONFIG_FW_LOADER_USER_HELPER
INIT_LIST_HEAD(&fw_priv->pending_list);
#endif
pr_debug("%s: fw-%s fw_priv=%p\n", __func__, fw_name, fw_priv);
return fw_priv;
}
static struct fw_priv *__lookup_fw_priv(const char *fw_name)
{
struct fw_priv *tmp;
struct firmware_cache *fwc = &fw_cache;
list_for_each_entry(tmp, &fwc->head, list)
if (!strcmp(tmp->fw_name, fw_name))
return tmp;
return NULL;
}
/* Returns 1 for batching firmware requests with the same name */
int alloc_lookup_fw_priv(const char *fw_name, struct firmware_cache *fwc,
struct fw_priv **fw_priv, void *dbuf, size_t size,
size_t offset, u32 opt_flags)
{
struct fw_priv *tmp;
spin_lock(&fwc->lock);
/*
* Do not merge requests that are marked to be non-cached or
* are performing partial reads.
*/
if (!(opt_flags & (FW_OPT_NOCACHE | FW_OPT_PARTIAL))) {
tmp = __lookup_fw_priv(fw_name);
if (tmp) {
kref_get(&tmp->ref);
spin_unlock(&fwc->lock);
*fw_priv = tmp;
pr_debug("batched request - sharing the same struct fw_priv and lookup for multiple requests\n");
return 1;
}
}
tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size, offset, opt_flags);
if (tmp) {
INIT_LIST_HEAD(&tmp->list);
if (!(opt_flags & FW_OPT_NOCACHE))
list_add(&tmp->list, &fwc->head);
}
spin_unlock(&fwc->lock);
*fw_priv = tmp;
return tmp ? 0 : -ENOMEM;
}
static void __free_fw_priv(struct kref *ref)
__releases(&fwc->lock)
{
struct fw_priv *fw_priv = to_fw_priv(ref);
struct firmware_cache *fwc = fw_priv->fwc;
pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
__func__, fw_priv->fw_name, fw_priv, fw_priv->data,
(unsigned int)fw_priv->size);
list_del(&fw_priv->list);
spin_unlock(&fwc->lock);
if (fw_is_paged_buf(fw_priv))
fw_free_paged_buf(fw_priv);
else if (!fw_priv->allocated_size)
vfree(fw_priv->data);
kfree_const(fw_priv->fw_name);
kfree(fw_priv);
}
void free_fw_priv(struct fw_priv *fw_priv)
{
struct firmware_cache *fwc = fw_priv->fwc;
spin_lock(&fwc->lock);
if (!kref_put(&fw_priv->ref, __free_fw_priv))
spin_unlock(&fwc->lock);
}
#ifdef CONFIG_FW_LOADER_PAGED_BUF
bool fw_is_paged_buf(struct fw_priv *fw_priv)
{
return fw_priv->is_paged_buf;
}
void fw_free_paged_buf(struct fw_priv *fw_priv)
{
int i;
if (!fw_priv->pages)
return;
vunmap(fw_priv->data);
for (i = 0; i < fw_priv->nr_pages; i++)
__free_page(fw_priv->pages[i]);
kvfree(fw_priv->pages);
fw_priv->pages = NULL;
fw_priv->page_array_size = 0;
fw_priv->nr_pages = 0;
fw_priv->data = NULL;
fw_priv->size = 0;
}
int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed)
{
/* 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 = kvmalloc_array(new_array_size, sizeof(void *),
GFP_KERNEL);
if (!new_pages)
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));
kvfree(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])
return -ENOMEM;
fw_priv->nr_pages++;
}
return 0;
}
int fw_map_paged_buf(struct fw_priv *fw_priv)
{
/* one pages buffer should be mapped/unmapped only once */
if (!fw_priv->pages)
return 0;
vunmap(fw_priv->data);
fw_priv->data = vmap(fw_priv->pages, fw_priv->nr_pages, 0,
PAGE_KERNEL_RO);
if (!fw_priv->data)
return -ENOMEM;
return 0;
}
#endif
/*
* ZSTD-compressed firmware support
*/
#ifdef CONFIG_FW_LOADER_COMPRESS_ZSTD
static int fw_decompress_zstd(struct device *dev, struct fw_priv *fw_priv,
size_t in_size, const void *in_buffer)
{
size_t len, out_size, workspace_size;
void *workspace, *out_buf;
zstd_dctx *ctx;
int err;
if (fw_priv->allocated_size) {
out_size = fw_priv->allocated_size;
out_buf = fw_priv->data;
} else {
zstd_frame_header params;
if (zstd_get_frame_header(¶ms, in_buffer, in_size) ||
params.frameContentSize == ZSTD_CONTENTSIZE_UNKNOWN) {
dev_dbg(dev, "%s: invalid zstd header\n", __func__);
return -EINVAL;
}
out_size = params.frameContentSize;
out_buf = vzalloc(out_size);
if (!out_buf)
return -ENOMEM;
}
workspace_size = zstd_dctx_workspace_bound();
workspace = kvzalloc(workspace_size, GFP_KERNEL);
if (!workspace) {
err = -ENOMEM;
goto error;
}
ctx = zstd_init_dctx(workspace, workspace_size);
if (!ctx) {
dev_dbg(dev, "%s: failed to initialize context\n", __func__);
err = -EINVAL;
goto error;
}
len = zstd_decompress_dctx(ctx, out_buf, out_size, in_buffer, in_size);
if (zstd_is_error(len)) {
dev_dbg(dev, "%s: failed to decompress: %d\n", __func__,
zstd_get_error_code(len));
err = -EINVAL;
goto error;
}
if (!fw_priv->allocated_size)
fw_priv->data = out_buf;
fw_priv->size = len;
err = 0;
error:
kvfree(workspace);
if (err && !fw_priv->allocated_size)
vfree(out_buf);
return err;
}
#endif /* CONFIG_FW_LOADER_COMPRESS_ZSTD */
/*
* XZ-compressed firmware support
*/
#ifdef CONFIG_FW_LOADER_COMPRESS_XZ
/* show an error and return the standard error code */
static int fw_decompress_xz_error(struct device *dev, enum xz_ret xz_ret)
{
if (xz_ret != XZ_STREAM_END) {
dev_warn(dev, "xz decompression failed (xz_ret=%d)\n", xz_ret);
return xz_ret == XZ_MEM_ERROR ? -ENOMEM : -EINVAL;
}
return 0;
}
/* single-shot decompression onto the pre-allocated buffer */
static int fw_decompress_xz_single(struct device *dev, struct fw_priv *fw_priv,
size_t in_size, const void *in_buffer)
{
struct xz_dec *xz_dec;
struct xz_buf xz_buf;
enum xz_ret xz_ret;
xz_dec = xz_dec_init(XZ_SINGLE, (u32)-1);
if (!xz_dec)
return -ENOMEM;
xz_buf.in_size = in_size;
xz_buf.in = in_buffer;
xz_buf.in_pos = 0;
xz_buf.out_size = fw_priv->allocated_size;
xz_buf.out = fw_priv->data;
xz_buf.out_pos = 0;
xz_ret = xz_dec_run(xz_dec, &xz_buf);
xz_dec_end(xz_dec);
fw_priv->size = xz_buf.out_pos;
return fw_decompress_xz_error(dev, xz_ret);
}
/* decompression on paged buffer and map it */
static int fw_decompress_xz_pages(struct device *dev, struct fw_priv *fw_priv,
size_t in_size, const void *in_buffer)
{
struct xz_dec *xz_dec;
struct xz_buf xz_buf;
enum xz_ret xz_ret;
struct page *page;
int err = 0;
xz_dec = xz_dec_init(XZ_DYNALLOC, (u32)-1);
if (!xz_dec)
return -ENOMEM;
xz_buf.in_size = in_size;
xz_buf.in = in_buffer;
xz_buf.in_pos = 0;
fw_priv->is_paged_buf = true;
fw_priv->size = 0;
do {
if (fw_grow_paged_buf(fw_priv, fw_priv->nr_pages + 1)) {
err = -ENOMEM;
goto out;
}
/* decompress onto the new allocated page */
page = fw_priv->pages[fw_priv->nr_pages - 1];
xz_buf.out = kmap_local_page(page);
xz_buf.out_pos = 0;
xz_buf.out_size = PAGE_SIZE;
xz_ret = xz_dec_run(xz_dec, &xz_buf);
kunmap_local(xz_buf.out);
fw_priv->size += xz_buf.out_pos;
/* partial decompression means either end or error */
if (xz_buf.out_pos != PAGE_SIZE)
break;
} while (xz_ret == XZ_OK);
err = fw_decompress_xz_error(dev, xz_ret);
if (!err)
err = fw_map_paged_buf(fw_priv);
out:
xz_dec_end(xz_dec);
return err;
}
static int fw_decompress_xz(struct device *dev, struct fw_priv *fw_priv,
size_t in_size, const void *in_buffer)
{
/* if the buffer is pre-allocated, we can perform in single-shot mode */
if (fw_priv->data)
return fw_decompress_xz_single(dev, fw_priv, in_size, in_buffer);
else
return fw_decompress_xz_pages(dev, fw_priv, in_size, in_buffer);
}
#endif /* CONFIG_FW_LOADER_COMPRESS_XZ */
/* direct firmware loading support */
static char fw_path_para[256];
static const char * const fw_path[] = {
fw_path_para,
"/lib/firmware/updates/" UTS_RELEASE,
"/lib/firmware/updates",
"/lib/firmware/" UTS_RELEASE,
"/lib/firmware"
};
/*
* Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
* from kernel command line because firmware_class is generally built in
* kernel instead of module.
*/
module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
static int
fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
const char *suffix,
int (*decompress)(struct device *dev,
struct fw_priv *fw_priv,
size_t in_size,
const void *in_buffer))
{
size_t size;
int i, len, maxlen = 0;
int rc = -ENOENT;
char *path, *nt = NULL;
size_t msize = INT_MAX;
void *buffer = NULL;
/* Already populated data member means we're loading into a buffer */
if (!decompress && fw_priv->data) {
buffer = fw_priv->data;
msize = fw_priv->allocated_size;
}
path = __getname();
if (!path)
return -ENOMEM;
wait_for_initramfs();
for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
size_t file_size = 0;
size_t *file_size_ptr = NULL;
/* skip the unset customized path */
if (!fw_path[i][0])
continue;
/* strip off \n from customized path */
maxlen = strlen(fw_path[i]);
if (i == 0) {
nt = strchr(fw_path[i], '\n');
if (nt)
maxlen = nt - fw_path[i];
}
len = snprintf(path, PATH_MAX, "%.*s/%s%s",
maxlen, fw_path[i],
fw_priv->fw_name, suffix);
if (len >= PATH_MAX) {
rc = -ENAMETOOLONG;
break;
}
fw_priv->size = 0;
/*
* The total file size is only examined when doing a partial
* read; the "full read" case needs to fail if the whole
* firmware was not completely loaded.
*/
if ((fw_priv->opt_flags & FW_OPT_PARTIAL) && buffer)
file_size_ptr = &file_size;
/* load firmware files from the mount namespace of init */
rc = kernel_read_file_from_path_initns(path, fw_priv->offset,
&buffer, msize,
file_size_ptr,
READING_FIRMWARE);
if (rc < 0) {
if (!(fw_priv->opt_flags & FW_OPT_NO_WARN)) {
if (rc != -ENOENT)
dev_warn(device,
"loading %s failed with error %d\n",
path, rc);
else
dev_dbg(device,
"loading %s failed for no such file or directory.\n",
path);
}
continue;
}
size = rc;
rc = 0;
dev_dbg(device, "Loading firmware from %s\n", path);
if (decompress) {
dev_dbg(device, "f/w decompressing %s\n",
fw_priv->fw_name);
rc = decompress(device, fw_priv, size, buffer);
/* discard the superfluous original content */
vfree(buffer);
buffer = NULL;
if (rc) {
fw_free_paged_buf(fw_priv);
continue;
}
} else {
dev_dbg(device, "direct-loading %s\n",
fw_priv->fw_name);
if (!fw_priv->data)
fw_priv->data = buffer;
fw_priv->size = size;
}
fw_state_done(fw_priv);
break;
}
__putname(path);
return rc;
}
/* firmware holds the ownership of pages */
static void firmware_free_data(const struct firmware *fw)
{
/* Loaded directly? */
if (!fw->priv) {
vfree(fw->data);
return;
}
free_fw_priv(fw->priv);
}
/* store the pages buffer info firmware from buf */
static void fw_set_page_data(struct fw_priv *fw_priv, struct firmware *fw)
{
fw->priv = fw_priv;
fw->size = fw_priv->size;
fw->data = fw_priv->data;
pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
__func__, fw_priv->fw_name, fw_priv, fw_priv->data,
(unsigned int)fw_priv->size);
}
#ifdef CONFIG_FW_CACHE
static void fw_name_devm_release(struct device *dev, void *res)
{
struct fw_name_devm *fwn = res;
if (fwn->magic == (unsigned long)&fw_cache)
pr_debug("%s: fw_name-%s devm-%p released\n",
__func__, fwn->name, res);
kfree_const(fwn->name);
}
static int fw_devm_match(struct device *dev, void *res,
void *match_data)
{
struct fw_name_devm *fwn = res;
return (fwn->magic == (unsigned long)&fw_cache) &&
!strcmp(fwn->name, match_data);
}
static struct fw_name_devm *fw_find_devm_name(struct device *dev,
const char *name)
{
struct fw_name_devm *fwn;
fwn = devres_find(dev, fw_name_devm_release,
fw_devm_match, (void *)name);
return fwn;
}
static bool fw_cache_is_setup(struct device *dev, const char *name)
{
struct fw_name_devm *fwn;
fwn = fw_find_devm_name(dev, name);
if (fwn)
return true;
return false;
}
/* add firmware name into devres list */
static int fw_add_devm_name(struct device *dev, const char *name)
{
struct fw_name_devm *fwn;
if (fw_cache_is_setup(dev, name))
return 0;
fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
GFP_KERNEL);
if (!fwn)
return -ENOMEM;
fwn->name = kstrdup_const(name, GFP_KERNEL);
if (!fwn->name) {
devres_free(fwn);
return -ENOMEM;
}
fwn->magic = (unsigned long)&fw_cache;
devres_add(dev, fwn);
return 0;
}
#else
static bool fw_cache_is_setup(struct device *dev, const char *name)
{
return false;
}
static int fw_add_devm_name(struct device *dev, const char *name)
{
return 0;
}
#endif
int assign_fw(struct firmware *fw, struct device *device)
{
struct fw_priv *fw_priv = fw->priv;
int ret;
mutex_lock(&fw_lock);
if (!fw_priv->size || fw_state_is_aborted(fw_priv)) {
mutex_unlock(&fw_lock);
return -ENOENT;
}
/*
* add firmware name into devres list so that we can auto cache
* and uncache firmware for device.
*
* device may has been deleted already, but the problem
* should be fixed in devres or driver core.
*/
/* don't cache firmware handled without uevent */
if (device && (fw_priv->opt_flags & FW_OPT_UEVENT) &&
!(fw_priv->opt_flags & FW_OPT_NOCACHE)) {
ret = fw_add_devm_name(device, fw_priv->fw_name);
if (ret) {
mutex_unlock(&fw_lock);
return ret;
}
}
/*
* After caching firmware image is started, let it piggyback
* on request firmware.
*/
if (!(fw_priv->opt_flags & FW_OPT_NOCACHE) &&
fw_priv->fwc->state == FW_LOADER_START_CACHE)
fw_cache_piggyback_on_request(fw_priv);
/* pass the pages buffer to driver at the last minute */
fw_set_page_data(fw_priv, fw);
mutex_unlock(&fw_lock);
return 0;
}
/* prepare firmware and firmware_buf structs;
* return 0 if a firmware is already assigned, 1 if need to load one,
* or a negative error code
*/
static int
_request_firmware_prepare(struct firmware **firmware_p, const char *name,
struct device *device, void *dbuf, size_t size,
size_t offset, u32 opt_flags)
{
struct firmware *firmware;
struct fw_priv *fw_priv;
int ret;
*firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
if (!firmware) {
dev_err(device, "%s: kmalloc(struct firmware) failed\n",
__func__);
return -ENOMEM;
}
if (firmware_request_builtin_buf(firmware, name, dbuf, size)) {
dev_dbg(device, "using built-in %s\n", name);
return 0; /* assigned */
}
ret = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size,
offset, opt_flags);
/*
* bind with 'priv' now to avoid warning in failure path
* of requesting firmware.
*/
firmware->priv = fw_priv;
if (ret > 0) {
ret = fw_state_wait(fw_priv);
if (!ret) {
fw_set_page_data(fw_priv, firmware);
return 0; /* assigned */
}
}
if (ret < 0)
return ret;
return 1; /* need to load */
}
/*
* Batched requests need only one wake, we need to do this step last due to the
* fallback mechanism. The buf is protected with kref_get(), and it won't be
* released until the last user calls release_firmware().
*
* Failed batched requests are possible as well, in such cases we just share
* the struct fw_priv and won't release it until all requests are woken
* and have gone through this same path.
*/
static void fw_abort_batch_reqs(struct firmware *fw)
{
struct fw_priv *fw_priv;
/* Loaded directly? */
if (!fw || !fw->priv)
return;
fw_priv = fw->priv;
mutex_lock(&fw_lock);
if (!fw_state_is_aborted(fw_priv))
fw_state_aborted(fw_priv);
mutex_unlock(&fw_lock);
}
#if defined(CONFIG_FW_LOADER_DEBUG)
#include <crypto/hash.h>
#include <crypto/sha2.h>
static void fw_log_firmware_info(const struct firmware *fw, const char *name, struct device *device)
{
struct shash_desc *shash;
struct crypto_shash *alg;
u8 *sha256buf;
char *outbuf;
alg = crypto_alloc_shash("sha256", 0, 0);
if (IS_ERR(alg))
return;
sha256buf = kmalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
outbuf = kmalloc(SHA256_BLOCK_SIZE + 1, GFP_KERNEL);
shash = kmalloc(sizeof(*shash) + crypto_shash_descsize(alg), GFP_KERNEL);
if (!sha256buf || !outbuf || !shash)
goto out_free;
shash->tfm = alg;
if (crypto_shash_digest(shash, fw->data, fw->size, sha256buf) < 0)
goto out_shash;
for (int i = 0; i < SHA256_DIGEST_SIZE; i++)
sprintf(&outbuf[i * 2], "%02x", sha256buf[i]);
outbuf[SHA256_BLOCK_SIZE] = 0;
dev_dbg(device, "Loaded FW: %s, sha256: %s\n", name, outbuf);
out_shash:
crypto_free_shash(alg);
out_free:
kfree(shash);
kfree(outbuf);
kfree(sha256buf);
}
#else
static void fw_log_firmware_info(const struct firmware *fw, const char *name,
struct device *device)
{}
#endif
/*
* Reject firmware file names with ".." path components.
* There are drivers that construct firmware file names from device-supplied
* strings, and we don't want some device to be able to tell us "I would like to
* be sent my firmware from ../../../etc/shadow, please".
*
* Search for ".." surrounded by either '/' or start/end of string.
*
* This intentionally only looks at the firmware name, not at the firmware base
* directory or at symlink contents.
*/
static bool name_contains_dotdot(const char *name)
{
size_t name_len = strlen(name);
return strcmp(name, "..") == 0 || strncmp(name, "../", 3) == 0 ||
strstr(name, "/../") != NULL ||
(name_len >= 3 && strcmp(name+name_len-3, "/..") == 0);
}
/* called from request_firmware() and request_firmware_work_func() */
static int
_request_firmware(const struct firmware **firmware_p, const char *name,
struct device *device, void *buf, size_t size,
size_t offset, u32 opt_flags)
{
struct firmware *fw = NULL;
struct cred *kern_cred = NULL;
const struct cred *old_cred;
bool nondirect = false;
int ret;
if (!firmware_p)
return -EINVAL;
if (!name || name[0] == '\0') {
ret = -EINVAL;
goto out;
}
if (name_contains_dotdot(name)) {
dev_warn(device,
"Firmware load for '%s' refused, path contains '..' component\n",
name);
ret = -EINVAL;
goto out;
}
ret = _request_firmware_prepare(&fw, name, device, buf, size,
offset, opt_flags);
if (ret <= 0) /* error or already assigned */
goto out;
/*
* We are about to try to access the firmware file. Because we may have been
* called by a driver when serving an unrelated request from userland, we use
* the kernel credentials to read the file.
*/
kern_cred = prepare_kernel_cred(&init_task);
if (!kern_cred) {
ret = -ENOMEM;
goto out;
}
old_cred = override_creds(kern_cred);
ret = fw_get_filesystem_firmware(device, fw->priv, "", NULL);
/* Only full reads can support decompression, platform, and sysfs. */
if (!(opt_flags & FW_OPT_PARTIAL))
nondirect = true;
#ifdef CONFIG_FW_LOADER_COMPRESS_ZSTD
if (ret == -ENOENT && nondirect)
ret = fw_get_filesystem_firmware(device, fw->priv, ".zst",
fw_decompress_zstd);
#endif
#ifdef CONFIG_FW_LOADER_COMPRESS_XZ
if (ret == -ENOENT && nondirect)
ret = fw_get_filesystem_firmware(device, fw->priv, ".xz",
fw_decompress_xz);
#endif
if (ret == -ENOENT && nondirect)
ret = firmware_fallback_platform(fw->priv);
if (ret) {
if (!(opt_flags & FW_OPT_NO_WARN))
dev_warn(device,
"Direct firmware load for %s failed with error %d\n",
name, ret);
if (nondirect)
ret = firmware_fallback_sysfs(fw, name, device,
opt_flags, ret);
} else
ret = assign_fw(fw, device);
revert_creds(old_cred);
put_cred(kern_cred);
out:
if (ret < 0) {
fw_abort_batch_reqs(fw);
release_firmware(fw);
fw = NULL;
} else {
fw_log_firmware_info(fw, name, device);
}
*firmware_p = fw;
return ret;
}
/**
* 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.
* It must not contain any ".." path components - "foo/bar..bin" is
* allowed, but "foo/../bar.bin" is not.
*
* Caller must hold the reference count of @device.
*
* The function can be called safely inside device's suspend and
* resume callback.
**/
int
request_firmware(const struct firmware **firmware_p, const char *name,
struct device *device)
{
int ret;
/* Need to pin this module until return */
__module_get(THIS_MODULE);
ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
FW_OPT_UEVENT);
module_put(THIS_MODULE);
return ret;
}
EXPORT_SYMBOL(request_firmware);
/**
* firmware_request_nowarn() - request for an optional fw module
* @firmware: pointer to firmware image
* @name: name of firmware file
* @device: device for which firmware is being loaded
*
* This function is similar in behaviour to request_firmware(), except it
* doesn't produce warning messages when the file is not found. The sysfs
* fallback mechanism is enabled if direct filesystem lookup fails. However,
* failures to find the firmware file with it are still suppressed. It is
* therefore up to the driver to check for the return value of this call and to
* decide when to inform the users of errors.
**/
int firmware_request_nowarn(const struct firmware **firmware, const char *name,
struct device *device)
{
int ret;
/* Need to pin this module until return */
__module_get(THIS_MODULE);
ret = _request_firmware(firmware, name, device, NULL, 0, 0,
FW_OPT_UEVENT | FW_OPT_NO_WARN);
module_put(THIS_MODULE);
return ret;
}
EXPORT_SYMBOL_GPL(firmware_request_nowarn);
/**
* request_firmware_direct() - load firmware directly without usermode helper
* @firmware_p: pointer to firmware image
* @name: name of firmware file
* @device: device for which firmware is being loaded
*
* This function works pretty much like request_firmware(), but this doesn't
* fall back to usermode helper even if the firmware couldn't be loaded
* directly from fs. Hence it's useful for loading optional firmwares, which
* aren't always present, without extra long timeouts of udev.
**/
int request_firmware_direct(const struct firmware **firmware_p,
const char *name, struct device *device)
{
int ret;
__module_get(THIS_MODULE);
ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
FW_OPT_UEVENT | FW_OPT_NO_WARN |
FW_OPT_NOFALLBACK_SYSFS);
module_put(THIS_MODULE);
return ret;
}
EXPORT_SYMBOL_GPL(request_firmware_direct);
/**
* firmware_request_platform() - request firmware with platform-fw fallback
* @firmware: pointer to firmware image
* @name: name of firmware file
* @device: device for which firmware is being loaded
*
* This function is similar in behaviour to request_firmware, except that if
* direct filesystem lookup fails, it will fallback to looking for a copy of the
* requested firmware embedded in the platform's main (e.g. UEFI) firmware.
**/
int firmware_request_platform(const struct firmware **firmware,
const char *name, struct device *device)
{
int ret;
/* Need to pin this module until return */
__module_get(THIS_MODULE);
ret = _request_firmware(firmware, name, device, NULL, 0, 0,
FW_OPT_UEVENT | FW_OPT_FALLBACK_PLATFORM);
module_put(THIS_MODULE);
return ret;
}
EXPORT_SYMBOL_GPL(firmware_request_platform);
/**
* firmware_request_cache() - cache firmware for suspend so resume can use it
* @name: name of firmware file
* @device: device for which firmware should be cached for
*
* There are some devices with an optimization that enables the device to not
* require loading firmware on system reboot. This optimization may still
* require the firmware present on resume from suspend. This routine can be
* used to ensure the firmware is present on resume from suspend in these
* situations. This helper is not compatible with drivers which use
* request_firmware_into_buf() or request_firmware_nowait() with no uevent set.
**/
int firmware_request_cache(struct device *device, const char *name)
{
int ret;
mutex_lock(&fw_lock);
ret = fw_add_devm_name(device, name);
mutex_unlock(&fw_lock);
return ret;
}
EXPORT_SYMBOL_GPL(firmware_request_cache);
/**
* request_firmware_into_buf() - load firmware into a previously allocated buffer
* @firmware_p: pointer to firmware image
* @name: name of firmware file
* @device: device for which firmware is being loaded and DMA region allocated
* @buf: address of buffer to load firmware into
* @size: size of buffer
*
* This function works pretty much like request_firmware(), but it doesn't
* allocate a buffer to hold the firmware data. Instead, the firmware
* is loaded directly into the buffer pointed to by @buf and the @firmware_p
* data member is pointed at @buf.
*
* This function doesn't cache firmware either.
*/
int
request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
struct device *device, void *buf, size_t size)
{
int ret;
if (fw_cache_is_setup(device, name))
return -EOPNOTSUPP;
__module_get(THIS_MODULE);
ret = _request_firmware(firmware_p, name, device, buf, size, 0,
FW_OPT_UEVENT | FW_OPT_NOCACHE);
module_put(THIS_MODULE);
return ret;
}
EXPORT_SYMBOL(request_firmware_into_buf);
/**
* request_partial_firmware_into_buf() - load partial firmware into a previously allocated buffer
* @firmware_p: pointer to firmware image
* @name: name of firmware file
* @device: device for which firmware is being loaded and DMA region allocated
* @buf: address of buffer to load firmware into
* @size: size of buffer
* @offset: offset into file to read
*
* This function works pretty much like request_firmware_into_buf except
* it allows a partial read of the file.
*/
int
request_partial_firmware_into_buf(const struct firmware **firmware_p,
const char *name, struct device *device,
void *buf, size_t size, size_t offset)
{
int ret;
if (fw_cache_is_setup(device, name))
return -EOPNOTSUPP;
__module_get(THIS_MODULE);
ret = _request_firmware(firmware_p, name, device, buf, size, offset,
FW_OPT_UEVENT | FW_OPT_NOCACHE |
FW_OPT_PARTIAL);
module_put(THIS_MODULE);
return ret;
}
EXPORT_SYMBOL(request_partial_firmware_into_buf);
/**
* 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 (!firmware_is_builtin(fw))
firmware_free_data(fw);
kfree(fw);
}
}
EXPORT_SYMBOL(release_firmware);
/* 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);
u32 opt_flags;
};
static void request_firmware_work_func(struct work_struct *work)
{
struct firmware_work *fw_work;
const struct firmware *fw;
fw_work = container_of(work, struct firmware_work, work);
_request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0, 0,
fw_work->opt_flags);
fw_work->cont(fw, fw_work->context);
put_device(fw_work->device); /* taken in request_firmware_nowait() */
module_put(fw_work->module);
kfree_const(fw_work->name);
kfree(fw_work);
}
static 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), bool nowarn)
{
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 = kstrdup_const(name, gfp);
if (!fw_work->name) {
kfree(fw_work);
return -ENOMEM;
}
fw_work->device = device;
fw_work->context = context;
fw_work->cont = cont;
fw_work->opt_flags = FW_OPT_NOWAIT |
(uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER) |
(nowarn ? FW_OPT_NO_WARN : 0);
if (!uevent && fw_cache_is_setup(device, name)) {
kfree_const(fw_work->name);
kfree(fw_work);
return -EOPNOTSUPP;
}
if (!try_module_get(module)) {
kfree_const(fw_work->name);
kfree(fw_work);
return -EFAULT;
}
get_device(fw_work->device);
INIT_WORK(&fw_work->work, request_firmware_work_func);
schedule_work(&fw_work->work);
return 0;
}
/**
* 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.
*
* Caller must hold the reference count of @device.
*
* Asynchronous variant of request_firmware() for user contexts:
* - sleep for as small periods as possible since it may
* increase kernel boot time of built-in device drivers
* requesting firmware in their ->probe() methods, if
* @gfp is GFP_KERNEL.
*
* - can't sleep at all if @gfp is GFP_ATOMIC.
**/
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))
{
return _request_firmware_nowait(module, uevent, name, device, gfp,
context, cont, false);
}
EXPORT_SYMBOL(request_firmware_nowait);
/**
* firmware_request_nowait_nowarn() - async version of request_firmware_nowarn
* @module: module requesting the firmware
* @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.
*
* Similar in function to request_firmware_nowait(), but doesn't print a warning
* when the firmware file could not be found and always sends a uevent to copy
* the firmware image.
*/
int firmware_request_nowait_nowarn(
struct module *module, const char *name,
struct device *device, gfp_t gfp, void *context,
void (*cont)(const struct firmware *fw, void *context))
{
return _request_firmware_nowait(module, FW_ACTION_UEVENT, name, device,
gfp, context, cont, true);
}
EXPORT_SYMBOL_GPL(firmware_request_nowait_nowarn);
#ifdef CONFIG_FW_CACHE
static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
/**
* cache_firmware() - cache one firmware image in kernel memory space
* @fw_name: the firmware image name
*
* Cache firmware in kernel memory so that drivers can use it when
* system isn't ready for them to request firmware image from userspace.
* Once it returns successfully, driver can use request_firmware or its
* nowait version to get the cached firmware without any interacting
* with userspace
*
* Return 0 if the firmware image has been cached successfully
* Return !0 otherwise
*
*/
static int cache_firmware(const char *fw_name)
{
int ret;
const struct firmware *fw;
pr_debug("%s: %s\n", __func__, fw_name);
ret = request_firmware(&fw, fw_name, NULL);
if (!ret)
kfree(fw);
pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
return ret;
}
static struct fw_priv *lookup_fw_priv(const char *fw_name)
{
struct fw_priv *tmp;
struct firmware_cache *fwc = &fw_cache;
spin_lock(&fwc->lock);
tmp = __lookup_fw_priv(fw_name);
spin_unlock(&fwc->lock);
return tmp;
}
/**
* uncache_firmware() - remove one cached firmware image
* @fw_name: the firmware image name
*
* Uncache one firmware image which has been cached successfully
* before.
*
* Return 0 if the firmware cache has been removed successfully
* Return !0 otherwise
*
*/
static int uncache_firmware(const char *fw_name)
{
struct fw_priv *fw_priv;
struct firmware fw;
pr_debug("%s: %s\n", __func__, fw_name);
if (firmware_request_builtin(&fw, fw_name))
return 0;
fw_priv = lookup_fw_priv(fw_name);
if (fw_priv) {
free_fw_priv(fw_priv);
return 0;
}
return -EINVAL;
}
static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
{
struct fw_cache_entry *fce;
fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
if (!fce)
goto exit;
fce->name = kstrdup_const(name, GFP_ATOMIC);
if (!fce->name) {
kfree(fce);
fce = NULL;
goto exit;
}
exit:
return fce;
}
static int __fw_entry_found(const char *name)
{
struct firmware_cache *fwc = &fw_cache;
struct fw_cache_entry *fce;
list_for_each_entry(fce, &fwc->fw_names, list) {
if (!strcmp(fce->name, name))
return 1;
}
return 0;
}
static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
{
const char *name = fw_priv->fw_name;
struct firmware_cache *fwc = fw_priv->fwc;
struct fw_cache_entry *fce;
spin_lock(&fwc->name_lock);
if (__fw_entry_found(name))
goto found;
fce = alloc_fw_cache_entry(name);
if (fce) {
list_add(&fce->list, &fwc->fw_names);
kref_get(&fw_priv->ref);
pr_debug("%s: fw: %s\n", __func__, name);
}
found:
spin_unlock(&fwc->name_lock);
}
static void free_fw_cache_entry(struct fw_cache_entry *fce)
{
kfree_const(fce->name);
kfree(fce);
}
static void __async_dev_cache_fw_image(void *fw_entry,
async_cookie_t cookie)
{
struct fw_cache_entry *fce = fw_entry;
struct firmware_cache *fwc = &fw_cache;
int ret;
ret = cache_firmware(fce->name);
if (ret) {
spin_lock(&fwc->name_lock);
list_del(&fce->list);
spin_unlock(&fwc->name_lock);
free_fw_cache_entry(fce);
}
}
/* called with dev->devres_lock held */
static void dev_create_fw_entry(struct device *dev, void *res,
void *data)
{
struct fw_name_devm *fwn = res;
const char *fw_name = fwn->name;
struct list_head *head = data;
struct fw_cache_entry *fce;
fce = alloc_fw_cache_entry(fw_name);
if (fce)
list_add(&fce->list, head);
}
static int devm_name_match(struct device *dev, void *res,
void *match_data)
{
struct fw_name_devm *fwn = res;
return (fwn->magic == (unsigned long)match_data);
}
static void dev_cache_fw_image(struct device *dev, void *data)
{
LIST_HEAD(todo);
struct fw_cache_entry *fce;
struct fw_cache_entry *fce_next;
struct firmware_cache *fwc = &fw_cache;
devres_for_each_res(dev, fw_name_devm_release,
devm_name_match, &fw_cache,
dev_create_fw_entry, &todo);
list_for_each_entry_safe(fce, fce_next, &todo, list) {
list_del(&fce->list);
spin_lock(&fwc->name_lock);
/* only one cache entry for one firmware */
if (!__fw_entry_found(fce->name)) {
list_add(&fce->list, &fwc->fw_names);
} else {
free_fw_cache_entry(fce);
fce = NULL;
}
spin_unlock(&fwc->name_lock);
if (fce)
async_schedule_domain(__async_dev_cache_fw_image,
(void *)fce,
&fw_cache_domain);
}
}
static void __device_uncache_fw_images(void)
{
struct firmware_cache *fwc = &fw_cache;
struct fw_cache_entry *fce;
spin_lock(&fwc->name_lock);
while (!list_empty(&fwc->fw_names)) {
fce = list_entry(fwc->fw_names.next,
struct fw_cache_entry, list);
list_del(&fce->list);
spin_unlock(&fwc->name_lock);
uncache_firmware(fce->name);
free_fw_cache_entry(fce);
spin_lock(&fwc->name_lock);
}
spin_unlock(&fwc->name_lock);
}
/**
* device_cache_fw_images() - cache devices' firmware
*
* If one device called request_firmware or its nowait version
* successfully before, the firmware names are recored into the
* device's devres link list, so device_cache_fw_images can call
* cache_firmware() to cache these firmwares for the device,
* then the device driver can load its firmwares easily at
* time when system is not ready to complete loading firmware.
*/
static void device_cache_fw_images(void)
{
struct firmware_cache *fwc = &fw_cache;
DEFINE_WAIT(wait);
pr_debug("%s\n", __func__);
/* cancel uncache work */
cancel_delayed_work_sync(&fwc->work);
fw_fallback_set_cache_timeout();
mutex_lock(&fw_lock);
fwc->state = FW_LOADER_START_CACHE;
dpm_for_each_dev(NULL, dev_cache_fw_image);
mutex_unlock(&fw_lock);
/* wait for completion of caching firmware for all devices */
async_synchronize_full_domain(&fw_cache_domain);
fw_fallback_set_default_timeout();
}
/**
* device_uncache_fw_images() - uncache devices' firmware
*
* uncache all firmwares which have been cached successfully
* by device_uncache_fw_images earlier
*/
static void device_uncache_fw_images(void)
{
pr_debug("%s\n", __func__);
__device_uncache_fw_images();
}
static void device_uncache_fw_images_work(struct work_struct *work)
{
device_uncache_fw_images();
}
/**
* device_uncache_fw_images_delay() - uncache devices firmwares
* @delay: number of milliseconds to delay uncache device firmwares
*
* uncache all devices's firmwares which has been cached successfully
* by device_cache_fw_images after @delay milliseconds.
*/
static void device_uncache_fw_images_delay(unsigned long delay)
{
queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
msecs_to_jiffies(delay));
}
static int fw_pm_notify(struct notifier_block *notify_block,
unsigned long mode, void *unused)
{
switch (mode) {
case PM_HIBERNATION_PREPARE:
case PM_SUSPEND_PREPARE:
case PM_RESTORE_PREPARE:
/*
* Here, kill pending fallback requests will only kill
* non-uevent firmware request to avoid stalling suspend.
*/
kill_pending_fw_fallback_reqs(false);
device_cache_fw_images();
break;
case PM_POST_SUSPEND:
case PM_POST_HIBERNATION:
case PM_POST_RESTORE:
/*
* In case that system sleep failed and syscore_suspend is
* not called.
*/
mutex_lock(&fw_lock);
fw_cache.state = FW_LOADER_NO_CACHE;
mutex_unlock(&fw_lock);
device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
break;
}
return 0;
}
/* stop caching firmware once syscore_suspend is reached */
static int fw_suspend(void)
{
fw_cache.state = FW_LOADER_NO_CACHE;
return 0;
}
static struct syscore_ops fw_syscore_ops = {
.suspend = fw_suspend,
};
static int __init register_fw_pm_ops(void)
{
int ret;
spin_lock_init(&fw_cache.name_lock);
INIT_LIST_HEAD(&fw_cache.fw_names);
INIT_DELAYED_WORK(&fw_cache.work,
device_uncache_fw_images_work);
fw_cache.pm_notify.notifier_call = fw_pm_notify;
ret = register_pm_notifier(&fw_cache.pm_notify);
if (ret)
return ret;
register_syscore_ops(&fw_syscore_ops);
return ret;
}
static inline void unregister_fw_pm_ops(void)
{
unregister_syscore_ops(&fw_syscore_ops);
unregister_pm_notifier(&fw_cache.pm_notify);
}
#else
static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
{
}
static inline int register_fw_pm_ops(void)
{
return 0;
}
static inline void unregister_fw_pm_ops(void)
{
}
#endif
static void __init fw_cache_init(void)
{
spin_lock_init(&fw_cache.lock);
INIT_LIST_HEAD(&fw_cache.head);
fw_cache.state = FW_LOADER_NO_CACHE;
}
static int fw_shutdown_notify(struct notifier_block *unused1,
unsigned long unused2, void *unused3)
{
/*
* Kill all pending fallback requests to avoid both stalling shutdown,
* and avoid a deadlock with the usermode_lock.
*/
kill_pending_fw_fallback_reqs(true);
return NOTIFY_DONE;
}
static struct notifier_block fw_shutdown_nb = {
.notifier_call = fw_shutdown_notify,
};
static int __init firmware_class_init(void)
{
int ret;
/* No need to unfold these on exit */
fw_cache_init();
ret = register_fw_pm_ops();
if (ret)
return ret;
ret = register_reboot_notifier(&fw_shutdown_nb);
if (ret)
goto out;
return register_sysfs_loader();
out:
unregister_fw_pm_ops();
return ret;
}
static void __exit firmware_class_exit(void)
{
unregister_fw_pm_ops();
unregister_reboot_notifier(&fw_shutdown_nb);
unregister_sysfs_loader();
}
fs_initcall(firmware_class_init);
module_exit(firmware_class_exit);
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