forked from Minki/linux
33c0c9bdf7
class_create is actually defined at the header. Fix the markup there and add a new one at the right place. While here, also fix some markups for functions that have different names between their prototypes and kernel-doc comments. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/2fb6efd6a1f90d69ff73bf579566079cbb051e15.1603469755.git.mchehab+huawei@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
659 lines
16 KiB
C
659 lines
16 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/types.h>
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#include <linux/kconfig.h>
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#include <linux/list.h>
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#include <linux/slab.h>
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#include <linux/security.h>
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#include <linux/highmem.h>
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#include <linux/umh.h>
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#include <linux/sysctl.h>
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#include <linux/vmalloc.h>
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#include <linux/module.h>
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#include "fallback.h"
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#include "firmware.h"
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/*
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* firmware fallback mechanism
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*/
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MODULE_IMPORT_NS(FIRMWARE_LOADER_PRIVATE);
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extern struct firmware_fallback_config fw_fallback_config;
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/* These getters are vetted to use int properly */
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static inline int __firmware_loading_timeout(void)
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{
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return fw_fallback_config.loading_timeout;
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}
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/* These setters are vetted to use int properly */
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static void __fw_fallback_set_timeout(int timeout)
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{
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fw_fallback_config.loading_timeout = timeout;
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}
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/*
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* use small loading timeout for caching devices' firmware because all these
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* firmware images have been loaded successfully at lease once, also system is
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* ready for completing firmware loading now. The maximum size of firmware in
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* current distributions is about 2M bytes, so 10 secs should be enough.
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*/
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void fw_fallback_set_cache_timeout(void)
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{
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fw_fallback_config.old_timeout = __firmware_loading_timeout();
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__fw_fallback_set_timeout(10);
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}
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/* Restores the timeout to the value last configured during normal operation */
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void fw_fallback_set_default_timeout(void)
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{
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__fw_fallback_set_timeout(fw_fallback_config.old_timeout);
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}
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static long firmware_loading_timeout(void)
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{
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return __firmware_loading_timeout() > 0 ?
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__firmware_loading_timeout() * HZ : MAX_JIFFY_OFFSET;
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}
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static inline bool fw_sysfs_done(struct fw_priv *fw_priv)
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{
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return __fw_state_check(fw_priv, FW_STATUS_DONE);
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}
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static inline bool fw_sysfs_loading(struct fw_priv *fw_priv)
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{
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return __fw_state_check(fw_priv, FW_STATUS_LOADING);
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}
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static inline int fw_sysfs_wait_timeout(struct fw_priv *fw_priv, long timeout)
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{
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return __fw_state_wait_common(fw_priv, timeout);
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}
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struct fw_sysfs {
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bool nowait;
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struct device dev;
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struct fw_priv *fw_priv;
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struct firmware *fw;
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};
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static struct fw_sysfs *to_fw_sysfs(struct device *dev)
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{
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return container_of(dev, struct fw_sysfs, dev);
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}
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static void __fw_load_abort(struct fw_priv *fw_priv)
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{
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/*
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* There is a small window in which user can write to 'loading'
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* between loading done and disappearance of 'loading'
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*/
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if (fw_sysfs_done(fw_priv))
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return;
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list_del_init(&fw_priv->pending_list);
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fw_state_aborted(fw_priv);
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}
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static void fw_load_abort(struct fw_sysfs *fw_sysfs)
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{
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struct fw_priv *fw_priv = fw_sysfs->fw_priv;
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__fw_load_abort(fw_priv);
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}
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static LIST_HEAD(pending_fw_head);
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void kill_pending_fw_fallback_reqs(bool only_kill_custom)
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{
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struct fw_priv *fw_priv;
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struct fw_priv *next;
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mutex_lock(&fw_lock);
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list_for_each_entry_safe(fw_priv, next, &pending_fw_head,
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pending_list) {
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if (!fw_priv->need_uevent || !only_kill_custom)
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__fw_load_abort(fw_priv);
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}
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mutex_unlock(&fw_lock);
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}
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static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
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char *buf)
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{
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return sysfs_emit(buf, "%d\n", __firmware_loading_timeout());
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}
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/**
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* timeout_store() - set number of seconds to wait for firmware
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* @class: device class pointer
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* @attr: device attribute pointer
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* @buf: buffer to scan for timeout value
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* @count: number of bytes in @buf
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*
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* Sets the number of seconds to wait for the firmware. Once
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* this expires an error will be returned to the driver and no
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* firmware will be provided.
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*
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* Note: zero means 'wait forever'.
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**/
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static ssize_t timeout_store(struct class *class, struct class_attribute *attr,
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const char *buf, size_t count)
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{
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int tmp_loading_timeout = simple_strtol(buf, NULL, 10);
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if (tmp_loading_timeout < 0)
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tmp_loading_timeout = 0;
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__fw_fallback_set_timeout(tmp_loading_timeout);
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return count;
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}
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static CLASS_ATTR_RW(timeout);
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static struct attribute *firmware_class_attrs[] = {
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&class_attr_timeout.attr,
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NULL,
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};
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ATTRIBUTE_GROUPS(firmware_class);
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static void fw_dev_release(struct device *dev)
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{
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struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
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kfree(fw_sysfs);
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}
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static int do_firmware_uevent(struct fw_sysfs *fw_sysfs, struct kobj_uevent_env *env)
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{
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if (add_uevent_var(env, "FIRMWARE=%s", fw_sysfs->fw_priv->fw_name))
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return -ENOMEM;
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if (add_uevent_var(env, "TIMEOUT=%i", __firmware_loading_timeout()))
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return -ENOMEM;
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if (add_uevent_var(env, "ASYNC=%d", fw_sysfs->nowait))
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return -ENOMEM;
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return 0;
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}
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static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
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{
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struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
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int err = 0;
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mutex_lock(&fw_lock);
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if (fw_sysfs->fw_priv)
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err = do_firmware_uevent(fw_sysfs, env);
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mutex_unlock(&fw_lock);
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return err;
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}
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static struct class firmware_class = {
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.name = "firmware",
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.class_groups = firmware_class_groups,
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.dev_uevent = firmware_uevent,
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.dev_release = fw_dev_release,
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};
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int register_sysfs_loader(void)
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{
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return class_register(&firmware_class);
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}
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void unregister_sysfs_loader(void)
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{
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class_unregister(&firmware_class);
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}
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static ssize_t firmware_loading_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
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int loading = 0;
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mutex_lock(&fw_lock);
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if (fw_sysfs->fw_priv)
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loading = fw_sysfs_loading(fw_sysfs->fw_priv);
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mutex_unlock(&fw_lock);
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return sysfs_emit(buf, "%d\n", loading);
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}
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/**
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* firmware_loading_store() - set value in the 'loading' control file
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* @dev: device pointer
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* @attr: device attribute pointer
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* @buf: buffer to scan for loading control value
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* @count: number of bytes in @buf
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*
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* The relevant values are:
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*
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* 1: Start a load, discarding any previous partial load.
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* 0: Conclude the load and hand the data to the driver code.
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* -1: Conclude the load with an error and discard any written data.
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**/
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static ssize_t firmware_loading_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
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struct fw_priv *fw_priv;
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ssize_t written = count;
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int loading = simple_strtol(buf, NULL, 10);
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mutex_lock(&fw_lock);
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fw_priv = fw_sysfs->fw_priv;
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if (fw_state_is_aborted(fw_priv))
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goto out;
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switch (loading) {
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case 1:
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/* discarding any previous partial load */
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if (!fw_sysfs_done(fw_priv)) {
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fw_free_paged_buf(fw_priv);
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fw_state_start(fw_priv);
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}
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break;
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case 0:
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if (fw_sysfs_loading(fw_priv)) {
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int rc;
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/*
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* Several loading requests may be pending on
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* one same firmware buf, so let all requests
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* see the mapped 'buf->data' once the loading
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* is completed.
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* */
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rc = fw_map_paged_buf(fw_priv);
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if (rc)
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dev_err(dev, "%s: map pages failed\n",
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__func__);
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else
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rc = security_kernel_post_load_data(fw_priv->data,
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fw_priv->size,
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LOADING_FIRMWARE, "blob");
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/*
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* Same logic as fw_load_abort, only the DONE bit
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* is ignored and we set ABORT only on failure.
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*/
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list_del_init(&fw_priv->pending_list);
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if (rc) {
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fw_state_aborted(fw_priv);
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written = rc;
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} else {
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fw_state_done(fw_priv);
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}
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break;
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}
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fallthrough;
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default:
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dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
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fallthrough;
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case -1:
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fw_load_abort(fw_sysfs);
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break;
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}
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out:
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mutex_unlock(&fw_lock);
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return written;
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}
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static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
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static void firmware_rw_data(struct fw_priv *fw_priv, char *buffer,
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loff_t offset, size_t count, bool read)
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{
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if (read)
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memcpy(buffer, fw_priv->data + offset, count);
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else
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memcpy(fw_priv->data + offset, buffer, count);
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}
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static void firmware_rw(struct fw_priv *fw_priv, char *buffer,
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loff_t offset, size_t count, bool read)
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{
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while (count) {
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void *page_data;
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int page_nr = offset >> PAGE_SHIFT;
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int page_ofs = offset & (PAGE_SIZE-1);
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int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
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page_data = kmap(fw_priv->pages[page_nr]);
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if (read)
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memcpy(buffer, page_data + page_ofs, page_cnt);
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else
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memcpy(page_data + page_ofs, buffer, page_cnt);
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kunmap(fw_priv->pages[page_nr]);
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buffer += page_cnt;
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offset += page_cnt;
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count -= page_cnt;
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}
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}
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static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr,
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char *buffer, loff_t offset, size_t count)
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{
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struct device *dev = kobj_to_dev(kobj);
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struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
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struct fw_priv *fw_priv;
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ssize_t ret_count;
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mutex_lock(&fw_lock);
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fw_priv = fw_sysfs->fw_priv;
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if (!fw_priv || fw_sysfs_done(fw_priv)) {
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ret_count = -ENODEV;
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goto out;
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}
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if (offset > fw_priv->size) {
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ret_count = 0;
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goto out;
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}
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if (count > fw_priv->size - offset)
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count = fw_priv->size - offset;
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ret_count = count;
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if (fw_priv->data)
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firmware_rw_data(fw_priv, buffer, offset, count, true);
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else
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firmware_rw(fw_priv, buffer, offset, count, true);
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out:
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mutex_unlock(&fw_lock);
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return ret_count;
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}
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static int fw_realloc_pages(struct fw_sysfs *fw_sysfs, int min_size)
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{
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int err;
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err = fw_grow_paged_buf(fw_sysfs->fw_priv,
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PAGE_ALIGN(min_size) >> PAGE_SHIFT);
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if (err)
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fw_load_abort(fw_sysfs);
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return err;
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}
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/**
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* firmware_data_write() - write method for firmware
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* @filp: open sysfs file
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* @kobj: kobject for the device
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* @bin_attr: bin_attr structure
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* @buffer: buffer being written
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* @offset: buffer offset for write in total data store area
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* @count: buffer size
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*
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* Data written to the 'data' attribute will be later handed to
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* the driver as a firmware image.
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**/
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static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr,
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char *buffer, loff_t offset, size_t count)
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{
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struct device *dev = kobj_to_dev(kobj);
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struct fw_sysfs *fw_sysfs = to_fw_sysfs(dev);
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struct fw_priv *fw_priv;
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ssize_t retval;
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if (!capable(CAP_SYS_RAWIO))
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return -EPERM;
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mutex_lock(&fw_lock);
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fw_priv = fw_sysfs->fw_priv;
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if (!fw_priv || fw_sysfs_done(fw_priv)) {
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retval = -ENODEV;
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goto out;
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}
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if (fw_priv->data) {
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if (offset + count > fw_priv->allocated_size) {
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retval = -ENOMEM;
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goto out;
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}
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firmware_rw_data(fw_priv, buffer, offset, count, false);
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retval = count;
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} else {
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retval = fw_realloc_pages(fw_sysfs, offset + count);
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if (retval)
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goto out;
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retval = count;
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firmware_rw(fw_priv, buffer, offset, count, false);
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}
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fw_priv->size = max_t(size_t, offset + count, fw_priv->size);
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out:
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mutex_unlock(&fw_lock);
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return retval;
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}
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static struct bin_attribute firmware_attr_data = {
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.attr = { .name = "data", .mode = 0644 },
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.size = 0,
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.read = firmware_data_read,
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.write = firmware_data_write,
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};
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static struct attribute *fw_dev_attrs[] = {
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&dev_attr_loading.attr,
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NULL
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};
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static struct bin_attribute *fw_dev_bin_attrs[] = {
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&firmware_attr_data,
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NULL
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};
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static const struct attribute_group fw_dev_attr_group = {
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.attrs = fw_dev_attrs,
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.bin_attrs = fw_dev_bin_attrs,
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};
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static const struct attribute_group *fw_dev_attr_groups[] = {
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&fw_dev_attr_group,
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NULL
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};
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static struct fw_sysfs *
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fw_create_instance(struct firmware *firmware, const char *fw_name,
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struct device *device, u32 opt_flags)
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{
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struct fw_sysfs *fw_sysfs;
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struct device *f_dev;
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fw_sysfs = kzalloc(sizeof(*fw_sysfs), GFP_KERNEL);
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if (!fw_sysfs) {
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fw_sysfs = ERR_PTR(-ENOMEM);
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goto exit;
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}
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fw_sysfs->nowait = !!(opt_flags & FW_OPT_NOWAIT);
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fw_sysfs->fw = firmware;
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f_dev = &fw_sysfs->dev;
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device_initialize(f_dev);
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dev_set_name(f_dev, "%s", fw_name);
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f_dev->parent = device;
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f_dev->class = &firmware_class;
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f_dev->groups = fw_dev_attr_groups;
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exit:
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return fw_sysfs;
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}
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/**
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* fw_load_sysfs_fallback() - load a firmware via the sysfs fallback mechanism
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* @fw_sysfs: firmware sysfs information for the firmware to load
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* @timeout: timeout to wait for the load
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*
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* In charge of constructing a sysfs fallback interface for firmware loading.
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**/
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static int fw_load_sysfs_fallback(struct fw_sysfs *fw_sysfs, long timeout)
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{
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int retval = 0;
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struct device *f_dev = &fw_sysfs->dev;
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struct fw_priv *fw_priv = fw_sysfs->fw_priv;
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/* fall back on userspace loading */
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if (!fw_priv->data)
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fw_priv->is_paged_buf = true;
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dev_set_uevent_suppress(f_dev, true);
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retval = device_add(f_dev);
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if (retval) {
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dev_err(f_dev, "%s: device_register failed\n", __func__);
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goto err_put_dev;
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}
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mutex_lock(&fw_lock);
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list_add(&fw_priv->pending_list, &pending_fw_head);
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mutex_unlock(&fw_lock);
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if (fw_priv->opt_flags & FW_OPT_UEVENT) {
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fw_priv->need_uevent = true;
|
|
dev_set_uevent_suppress(f_dev, false);
|
|
dev_dbg(f_dev, "firmware: requesting %s\n", fw_priv->fw_name);
|
|
kobject_uevent(&fw_sysfs->dev.kobj, KOBJ_ADD);
|
|
} else {
|
|
timeout = MAX_JIFFY_OFFSET;
|
|
}
|
|
|
|
retval = fw_sysfs_wait_timeout(fw_priv, timeout);
|
|
if (retval < 0 && retval != -ENOENT) {
|
|
mutex_lock(&fw_lock);
|
|
fw_load_abort(fw_sysfs);
|
|
mutex_unlock(&fw_lock);
|
|
}
|
|
|
|
if (fw_state_is_aborted(fw_priv)) {
|
|
if (retval == -ERESTARTSYS)
|
|
retval = -EINTR;
|
|
else
|
|
retval = -EAGAIN;
|
|
} else if (fw_priv->is_paged_buf && !fw_priv->data)
|
|
retval = -ENOMEM;
|
|
|
|
device_del(f_dev);
|
|
err_put_dev:
|
|
put_device(f_dev);
|
|
return retval;
|
|
}
|
|
|
|
static int fw_load_from_user_helper(struct firmware *firmware,
|
|
const char *name, struct device *device,
|
|
u32 opt_flags)
|
|
{
|
|
struct fw_sysfs *fw_sysfs;
|
|
long timeout;
|
|
int ret;
|
|
|
|
timeout = firmware_loading_timeout();
|
|
if (opt_flags & FW_OPT_NOWAIT) {
|
|
timeout = usermodehelper_read_lock_wait(timeout);
|
|
if (!timeout) {
|
|
dev_dbg(device, "firmware: %s loading timed out\n",
|
|
name);
|
|
return -EBUSY;
|
|
}
|
|
} else {
|
|
ret = usermodehelper_read_trylock();
|
|
if (WARN_ON(ret)) {
|
|
dev_err(device, "firmware: %s will not be loaded\n",
|
|
name);
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
fw_sysfs = fw_create_instance(firmware, name, device, opt_flags);
|
|
if (IS_ERR(fw_sysfs)) {
|
|
ret = PTR_ERR(fw_sysfs);
|
|
goto out_unlock;
|
|
}
|
|
|
|
fw_sysfs->fw_priv = firmware->priv;
|
|
ret = fw_load_sysfs_fallback(fw_sysfs, timeout);
|
|
|
|
if (!ret)
|
|
ret = assign_fw(firmware, device);
|
|
|
|
out_unlock:
|
|
usermodehelper_read_unlock();
|
|
|
|
return ret;
|
|
}
|
|
|
|
static bool fw_force_sysfs_fallback(u32 opt_flags)
|
|
{
|
|
if (fw_fallback_config.force_sysfs_fallback)
|
|
return true;
|
|
if (!(opt_flags & FW_OPT_USERHELPER))
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
static bool fw_run_sysfs_fallback(u32 opt_flags)
|
|
{
|
|
int ret;
|
|
|
|
if (fw_fallback_config.ignore_sysfs_fallback) {
|
|
pr_info_once("Ignoring firmware sysfs fallback due to sysctl knob\n");
|
|
return false;
|
|
}
|
|
|
|
if ((opt_flags & FW_OPT_NOFALLBACK_SYSFS))
|
|
return false;
|
|
|
|
/* Also permit LSMs and IMA to fail firmware sysfs fallback */
|
|
ret = security_kernel_load_data(LOADING_FIRMWARE, true);
|
|
if (ret < 0)
|
|
return false;
|
|
|
|
return fw_force_sysfs_fallback(opt_flags);
|
|
}
|
|
|
|
/**
|
|
* firmware_fallback_sysfs() - use the fallback mechanism to find firmware
|
|
* @fw: pointer to firmware image
|
|
* @name: name of firmware file to look for
|
|
* @device: device for which firmware is being loaded
|
|
* @opt_flags: options to control firmware loading behaviour, as defined by
|
|
* &enum fw_opt
|
|
* @ret: return value from direct lookup which triggered the fallback mechanism
|
|
*
|
|
* This function is called if direct lookup for the firmware failed, it enables
|
|
* a fallback mechanism through userspace by exposing a sysfs loading
|
|
* interface. Userspace is in charge of loading the firmware through the sysfs
|
|
* loading interface. This sysfs fallback mechanism may be disabled completely
|
|
* on a system by setting the proc sysctl value ignore_sysfs_fallback to true.
|
|
* If this is false we check if the internal API caller set the
|
|
* @FW_OPT_NOFALLBACK_SYSFS flag, if so it would also disable the fallback
|
|
* mechanism. A system may want to enforce the sysfs fallback mechanism at all
|
|
* times, it can do this by setting ignore_sysfs_fallback to false and
|
|
* force_sysfs_fallback to true.
|
|
* Enabling force_sysfs_fallback is functionally equivalent to build a kernel
|
|
* with CONFIG_FW_LOADER_USER_HELPER_FALLBACK.
|
|
**/
|
|
int firmware_fallback_sysfs(struct firmware *fw, const char *name,
|
|
struct device *device,
|
|
u32 opt_flags,
|
|
int ret)
|
|
{
|
|
if (!fw_run_sysfs_fallback(opt_flags))
|
|
return ret;
|
|
|
|
if (!(opt_flags & FW_OPT_NO_WARN))
|
|
dev_warn(device, "Falling back to sysfs fallback for: %s\n",
|
|
name);
|
|
else
|
|
dev_dbg(device, "Falling back to sysfs fallback for: %s\n",
|
|
name);
|
|
return fw_load_from_user_helper(fw, name, device, opt_flags);
|
|
}
|