Re: [PATCH V3] firmware loader: Fix the race FW_STATUS_DONE is followed by class_timeout
On Thu, Nov 8, 2012 at 7:14 PM, Chuansheng Liu wrote: > > There is a race as below when calling request_firmware(): > CPU1 CPU2 > write 0 > loading > mutex_lock(_lock) > ... > set_bit FW_STATUS_DONE class_timeout is coming >set_bit FW_STATUS_ABORT > complete_all > ... > mutex_unlock(_lock) > > In this time, the bit FW_STATUS_DONE and FW_STATUS_ABORT are set, > and request_firmware() will return failure due to condition in > _request_firmware_load(): > if (!buf->size || test_bit(FW_STATUS_ABORT, >status)) > retval = -ENOENT; > > But from the above scenerio, it should be a successful requesting. > So we need judge if the bit FW_STATUS_DONE is already set before > calling fw_load_abort() in timeout function. > > As Ming's proposal, we need change the timer into sched_work to > benefit from using _lock mutex also. > > Signed-off-by: liu chuansheng Acked-by: Ming Lei Thanks, -- Ming Lei -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH V3] firmware loader: Fix the race FW_STATUS_DONE is followed by class_timeout
On Thu, Nov 8, 2012 at 7:14 PM, Chuansheng Liu chuansheng@intel.com wrote: There is a race as below when calling request_firmware(): CPU1 CPU2 write 0 loading mutex_lock(fw_lock) ... set_bit FW_STATUS_DONE class_timeout is coming set_bit FW_STATUS_ABORT complete_all completion ... mutex_unlock(fw_lock) In this time, the bit FW_STATUS_DONE and FW_STATUS_ABORT are set, and request_firmware() will return failure due to condition in _request_firmware_load(): if (!buf-size || test_bit(FW_STATUS_ABORT, buf-status)) retval = -ENOENT; But from the above scenerio, it should be a successful requesting. So we need judge if the bit FW_STATUS_DONE is already set before calling fw_load_abort() in timeout function. As Ming's proposal, we need change the timer into sched_work to benefit from using fw_lock mutex also. Signed-off-by: liu chuansheng chuansheng@intel.com Acked-by: Ming Lei ming@canonical.com Thanks, -- Ming Lei -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH V3] firmware loader: Fix the race FW_STATUS_DONE is followed by class_timeout
There is a race as below when calling request_firmware():
CPU1 CPU2
write 0 > loading
mutex_lock(_lock)
...
set_bit FW_STATUS_DONE class_timeout is coming
set_bit FW_STATUS_ABORT
complete_all
...
mutex_unlock(_lock)
In this time, the bit FW_STATUS_DONE and FW_STATUS_ABORT are set,
and request_firmware() will return failure due to condition in
_request_firmware_load():
if (!buf->size || test_bit(FW_STATUS_ABORT, >status))
retval = -ENOENT;
But from the above scenerio, it should be a successful requesting.
So we need judge if the bit FW_STATUS_DONE is already set before
calling fw_load_abort() in timeout function.
As Ming's proposal, we need change the timer into sched_work to
benefit from using _lock mutex also.
Signed-off-by: liu chuansheng
---
drivers/base/firmware_class.c | 24
1 files changed, 16 insertions(+), 8 deletions(-)
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 8945f4e..b44ed35 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -143,7 +143,7 @@ struct fw_cache_entry {
};
struct firmware_priv {
- struct timer_list timeout;
+ struct delayed_work timeout_work;
bool nowait;
struct device dev;
struct firmware_buf *buf;
@@ -667,11 +667,18 @@ static struct bin_attribute firmware_attr_data = {
.write = firmware_data_write,
};
-static void firmware_class_timeout(u_long data)
+static void firmware_class_timeout_work(struct work_struct *work)
{
- struct firmware_priv *fw_priv = (struct firmware_priv *) data;
+ struct firmware_priv *fw_priv = container_of(work,
+ struct firmware_priv, timeout_work.work);
+ mutex_lock(_lock);
+ if (test_bit(FW_STATUS_DONE, &(fw_priv->buf->status))) {
+ mutex_unlock(_lock);
+ return;
+ }
fw_load_abort(fw_priv);
+ mutex_unlock(_lock);
}
static struct firmware_priv *
@@ -690,8 +697,8 @@ fw_create_instance(struct firmware *firmware, const char
*fw_name,
fw_priv->nowait = nowait;
fw_priv->fw = firmware;
- setup_timer(_priv->timeout,
- firmware_class_timeout, (u_long) fw_priv);
+ INIT_DELAYED_WORK(_priv->timeout_work,
+ firmware_class_timeout_work);
f_dev = _priv->dev;
@@ -858,7 +865,9 @@ static int _request_firmware_load(struct firmware_priv
*fw_priv, bool uevent,
dev_dbg(f_dev->parent, "firmware: direct-loading"
" firmware %s\n", buf->fw_id);
+ mutex_lock(_lock);
set_bit(FW_STATUS_DONE, >status);
+ mutex_unlock(_lock);
complete_all(>completion);
direct_load = 1;
goto handle_fw;
@@ -894,15 +903,14 @@ static int _request_firmware_load(struct firmware_priv
*fw_priv, bool uevent,
dev_set_uevent_suppress(f_dev, false);
dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id);
if (timeout != MAX_SCHEDULE_TIMEOUT)
- mod_timer(_priv->timeout,
- round_jiffies_up(jiffies + timeout));
+ schedule_delayed_work(_priv->timeout_work, timeout);
kobject_uevent(_priv->dev.kobj, KOBJ_ADD);
}
wait_for_completion(>completion);
- del_timer_sync(_priv->timeout);
+ cancel_delayed_work_sync(_priv->timeout_work);
handle_fw:
mutex_lock(_lock);
--
1.7.0.4
--
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[PATCH V3] firmware loader: Fix the race FW_STATUS_DONE is followed by class_timeout
There is a race as below when calling request_firmware():
CPU1 CPU2
write 0 loading
mutex_lock(fw_lock)
...
set_bit FW_STATUS_DONE class_timeout is coming
set_bit FW_STATUS_ABORT
complete_all completion
...
mutex_unlock(fw_lock)
In this time, the bit FW_STATUS_DONE and FW_STATUS_ABORT are set,
and request_firmware() will return failure due to condition in
_request_firmware_load():
if (!buf-size || test_bit(FW_STATUS_ABORT, buf-status))
retval = -ENOENT;
But from the above scenerio, it should be a successful requesting.
So we need judge if the bit FW_STATUS_DONE is already set before
calling fw_load_abort() in timeout function.
As Ming's proposal, we need change the timer into sched_work to
benefit from using fw_lock mutex also.
Signed-off-by: liu chuansheng chuansheng@intel.com
---
drivers/base/firmware_class.c | 24
1 files changed, 16 insertions(+), 8 deletions(-)
diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 8945f4e..b44ed35 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -143,7 +143,7 @@ struct fw_cache_entry {
};
struct firmware_priv {
- struct timer_list timeout;
+ struct delayed_work timeout_work;
bool nowait;
struct device dev;
struct firmware_buf *buf;
@@ -667,11 +667,18 @@ static struct bin_attribute firmware_attr_data = {
.write = firmware_data_write,
};
-static void firmware_class_timeout(u_long data)
+static void firmware_class_timeout_work(struct work_struct *work)
{
- struct firmware_priv *fw_priv = (struct firmware_priv *) data;
+ struct firmware_priv *fw_priv = container_of(work,
+ struct firmware_priv, timeout_work.work);
+ mutex_lock(fw_lock);
+ if (test_bit(FW_STATUS_DONE, (fw_priv-buf-status))) {
+ mutex_unlock(fw_lock);
+ return;
+ }
fw_load_abort(fw_priv);
+ mutex_unlock(fw_lock);
}
static struct firmware_priv *
@@ -690,8 +697,8 @@ fw_create_instance(struct firmware *firmware, const char
*fw_name,
fw_priv-nowait = nowait;
fw_priv-fw = firmware;
- setup_timer(fw_priv-timeout,
- firmware_class_timeout, (u_long) fw_priv);
+ INIT_DELAYED_WORK(fw_priv-timeout_work,
+ firmware_class_timeout_work);
f_dev = fw_priv-dev;
@@ -858,7 +865,9 @@ static int _request_firmware_load(struct firmware_priv
*fw_priv, bool uevent,
dev_dbg(f_dev-parent, firmware: direct-loading
firmware %s\n, buf-fw_id);
+ mutex_lock(fw_lock);
set_bit(FW_STATUS_DONE, buf-status);
+ mutex_unlock(fw_lock);
complete_all(buf-completion);
direct_load = 1;
goto handle_fw;
@@ -894,15 +903,14 @@ static int _request_firmware_load(struct firmware_priv
*fw_priv, bool uevent,
dev_set_uevent_suppress(f_dev, false);
dev_dbg(f_dev, firmware: requesting %s\n, buf-fw_id);
if (timeout != MAX_SCHEDULE_TIMEOUT)
- mod_timer(fw_priv-timeout,
- round_jiffies_up(jiffies + timeout));
+ schedule_delayed_work(fw_priv-timeout_work, timeout);
kobject_uevent(fw_priv-dev.kobj, KOBJ_ADD);
}
wait_for_completion(buf-completion);
- del_timer_sync(fw_priv-timeout);
+ cancel_delayed_work_sync(fw_priv-timeout_work);
handle_fw:
mutex_lock(fw_lock);
--
1.7.0.4
--
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