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-rw-r--r--drivers/base/firmware_class.c51
-rw-r--r--include/linux/kmod.h1
-rw-r--r--kernel/kmod.c58
3 files changed, 76 insertions, 34 deletions
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 6029067..72c644b 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -81,6 +81,11 @@ enum {
static int loading_timeout = 60; /* In seconds */
+static inline long firmware_loading_timeout(void)
+{
+ return loading_timeout > 0 ? loading_timeout * HZ : MAX_SCHEDULE_TIMEOUT;
+}
+
/* 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);
@@ -541,31 +546,22 @@ static void _request_firmware_cleanup(const struct firmware **firmware_p)
static int _request_firmware(const struct firmware *firmware,
const char *name, struct device *device,
- bool uevent, bool nowait)
+ bool uevent, bool nowait, long timeout)
{
struct firmware_priv *fw_priv;
- int retval;
-
- retval = usermodehelper_read_trylock();
- if (WARN_ON(retval)) {
- dev_err(device, "firmware: %s will not be loaded\n", name);
- return retval;
- }
+ int retval = 0;
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 (IS_ERR(fw_priv))
+ return PTR_ERR(fw_priv);
if (uevent) {
- if (loading_timeout > 0)
+ if (timeout != MAX_SCHEDULE_TIMEOUT)
mod_timer(&fw_priv->timeout,
- round_jiffies_up(jiffies +
- loading_timeout * HZ));
+ round_jiffies_up(jiffies + timeout));
kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
}
@@ -582,9 +578,6 @@ static int _request_firmware(const struct firmware *firmware,
mutex_unlock(&fw_lock);
fw_destroy_instance(fw_priv);
-
-out:
- usermodehelper_read_unlock();
return retval;
}
@@ -613,7 +606,14 @@ request_firmware(const struct firmware **firmware_p, const char *name,
if (ret <= 0)
return ret;
- ret = _request_firmware(*firmware_p, name, device, true, false);
+ ret = usermodehelper_read_trylock();
+ if (WARN_ON(ret)) {
+ dev_err(device, "firmware: %s will not be loaded\n", name);
+ } else {
+ ret = _request_firmware(*firmware_p, name, device, true, false,
+ firmware_loading_timeout());
+ usermodehelper_read_unlock();
+ }
if (ret)
_request_firmware_cleanup(firmware_p);
@@ -648,6 +648,7 @@ static int request_firmware_work_func(void *arg)
{
struct firmware_work *fw_work = arg;
const struct firmware *fw;
+ long timeout;
int ret;
if (!arg) {
@@ -659,8 +660,16 @@ static int request_firmware_work_func(void *arg)
if (ret <= 0)
goto out;
- ret = _request_firmware(fw, fw_work->name, fw_work->device,
- fw_work->uevent, true);
+ timeout = usermodehelper_read_lock_wait(firmware_loading_timeout());
+ if (timeout) {
+ ret = _request_firmware(fw, fw_work->name, fw_work->device,
+ fw_work->uevent, true, timeout);
+ usermodehelper_read_unlock();
+ } else {
+ dev_dbg(fw_work->device, "firmware: %s loading timed out\n",
+ fw_work->name);
+ ret = -EAGAIN;
+ }
if (ret)
_request_firmware_cleanup(&fw);
diff --git a/include/linux/kmod.h b/include/linux/kmod.h
index 97d22c3..b087377 100644
--- a/include/linux/kmod.h
+++ b/include/linux/kmod.h
@@ -115,6 +115,7 @@ extern void usermodehelper_init(void);
extern int usermodehelper_disable(void);
extern void usermodehelper_enable(void);
extern int usermodehelper_read_trylock(void);
+extern long usermodehelper_read_lock_wait(long timeout);
extern void usermodehelper_read_unlock(void);
#endif /* __LINUX_KMOD_H__ */
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 4079ac1..da7fcca 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -334,6 +334,12 @@ static atomic_t running_helpers = ATOMIC_INIT(0);
static DECLARE_WAIT_QUEUE_HEAD(running_helpers_waitq);
/*
+ * Used by usermodehelper_read_lock_wait() to wait for usermodehelper_disabled
+ * to become 'false'.
+ */
+static DECLARE_WAIT_QUEUE_HEAD(usermodehelper_disabled_waitq);
+
+/*
* Time to wait for running_helpers to become zero before the setting of
* usermodehelper_disabled in usermodehelper_disable() fails
*/
@@ -352,6 +358,33 @@ int usermodehelper_read_trylock(void)
}
EXPORT_SYMBOL_GPL(usermodehelper_read_trylock);
+long usermodehelper_read_lock_wait(long timeout)
+{
+ DEFINE_WAIT(wait);
+
+ if (timeout < 0)
+ return -EINVAL;
+
+ down_read(&umhelper_sem);
+ for (;;) {
+ prepare_to_wait(&usermodehelper_disabled_waitq, &wait,
+ TASK_UNINTERRUPTIBLE);
+ if (!usermodehelper_disabled)
+ break;
+
+ up_read(&umhelper_sem);
+
+ timeout = schedule_timeout(timeout);
+ if (!timeout)
+ break;
+
+ down_read(&umhelper_sem);
+ }
+ finish_wait(&usermodehelper_disabled_waitq, &wait);
+ return timeout;
+}
+EXPORT_SYMBOL_GPL(usermodehelper_read_lock_wait);
+
void usermodehelper_read_unlock(void)
{
up_read(&umhelper_sem);
@@ -359,6 +392,17 @@ void usermodehelper_read_unlock(void)
EXPORT_SYMBOL_GPL(usermodehelper_read_unlock);
/**
+ * usermodehelper_enable - allow new helpers to be started again
+ */
+void usermodehelper_enable(void)
+{
+ down_write(&umhelper_sem);
+ usermodehelper_disabled = 0;
+ wake_up(&usermodehelper_disabled_waitq);
+ up_write(&umhelper_sem);
+}
+
+/**
* usermodehelper_disable - prevent new helpers from being started
*/
int usermodehelper_disable(void)
@@ -381,22 +425,10 @@ int usermodehelper_disable(void)
if (retval)
return 0;
- down_write(&umhelper_sem);
- usermodehelper_disabled = 0;
- up_write(&umhelper_sem);
+ usermodehelper_enable();
return -EAGAIN;
}
-/**
- * usermodehelper_enable - allow new helpers to be started again
- */
-void usermodehelper_enable(void)
-{
- down_write(&umhelper_sem);
- usermodehelper_disabled = 0;
- up_write(&umhelper_sem);
-}
-
static void helper_lock(void)
{
atomic_inc(&running_helpers);