Re: [PATCH v1 08/12] fpga: expose sec-mgr update errors

[Tom Rix]

On 9/22/20 4:42 PM, Russ Weight wrote:
>
> On 9/6/20 9:27 AM, Tom Rix wrote:
>> On 9/4/20 4:53 PM, Russ Weight wrote:
>>> Extend Intel Security Manager class driver to include
>>> an update/error sysfs node that can be read for error
>>> information when a secure update fails.
>>>
>>> Signed-off-by: Russ Weight <russell.h.weight@xxxxxxxxx>
>>> Reviewed-by: Wu Hao <hao.wu@xxxxxxxxx>
>>> ---
>>>  .../ABI/testing/sysfs-class-ifpga-sec-mgr     | 17 ++++++
>>>  drivers/fpga/ifpga-sec-mgr.c                  | 60 +++++++++++++++++--
>>>  include/linux/fpga/ifpga-sec-mgr.h            |  1 +
>>>  3 files changed, 73 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr b/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
>>> index 849ccb2802f8..e7b1b02bf7ee 100644
>>> --- a/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
>>> +++ b/Documentation/ABI/testing/sysfs-class-ifpga-sec-mgr
>>> @@ -97,3 +97,20 @@ Description:	Read-only. Returns a string describing the current
>>>  		programming. Userspace code can poll on this file,
>>>  		as it will be signaled by sysfs_notify() on each
>>>  		state change.
>>> +
>>> +What: 		/sys/class/ifpga_sec_mgr/ifpga_secX/update/error
>>> +Date:		Sep 2020
>>> +KernelVersion:  5.10
>>> +Contact:	Russ Weight <russell.h.weight@xxxxxxxxx>
>>> +Description:	Read-only. Returns a string describing the failure
>>> +		of a secure update. This string will be in the form
>>> +		of <STATUS>:<ERROR>, where <STATUS> will be one of
>>> +		the status strings described for the status sysfs
>>> +		file and <ERROR> will be one of the following:
>>> +		hw-error, timeout, user-abort, device-busy,
>>> +		invalid-file-size, read-write-error, flash-wearout,
>>> +		file-read-error.  The error sysfs file is only
>>> +		meaningful when the secure update engine is in the
>>> +		idle state. If this file is read while a secure
>>> +		update is in progress, then the read will fail with
>>> +		EBUSY.
>>> diff --git a/drivers/fpga/ifpga-sec-mgr.c b/drivers/fpga/ifpga-sec-mgr.c
>>> index 5fe3d85e2963..a7718bd8ee61 100644
>>> --- a/drivers/fpga/ifpga-sec-mgr.c
>>> +++ b/drivers/fpga/ifpga-sec-mgr.c
>>> @@ -146,10 +146,16 @@ static void update_progress(struct ifpga_sec_mgr *imgr,
>>>  	sysfs_notify(&imgr->dev.kobj, "update", "status");
>>>  }
>>>  
>>> +static void set_error(struct ifpga_sec_mgr *imgr, enum ifpga_sec_err err_code)
>>> +{
>>> +	imgr->err_state = imgr->progress;
>>> +	imgr->err_code = err_code;
>>> +}
>>> +
>>>  static void ifpga_sec_dev_error(struct ifpga_sec_mgr *imgr,
>>>  				enum ifpga_sec_err err_code)
>>>  {
>>> -	imgr->err_code = err_code;
>>> +	set_error(imgr, err_code);
>>>  	imgr->iops->cancel(imgr);
>>>  }
>>>  
>>> @@ -172,7 +178,7 @@ static void ifpga_sec_mgr_update(struct work_struct *work)
>>>  
>>>  	get_device(&imgr->dev);
>>>  	if (request_firmware(&fw, imgr->filename, &imgr->dev)) {
>>> -		imgr->err_code = IFPGA_SEC_ERR_FILE_READ;
>>> +		set_error(imgr, IFPGA_SEC_ERR_FILE_READ);
>>>  		goto idle_exit;
>>>  	}
>>>  
>>> @@ -180,7 +186,7 @@ static void ifpga_sec_mgr_update(struct work_struct *work)
>>>  	imgr->remaining_size = fw->size;
>>>  
>>>  	if (!try_module_get(imgr->dev.parent->driver->owner)) {
>>> -		imgr->err_code = IFPGA_SEC_ERR_BUSY;
>>> +		set_error(imgr, IFPGA_SEC_ERR_BUSY);
>>>  		goto release_fw_exit;
>>>  	}
>>>  
>>> @@ -266,16 +272,59 @@ static const char * const sec_mgr_prog_str[] = {
>>>  	"programming"		/* IFPGA_SEC_PROG_PROGRAMMING */
>>>  };
>>>  
>>> +static const char * const sec_mgr_err_str[] = {
>>> +	"none",			/* IFPGA_SEC_ERR_NONE */
>>> +	"hw-error",		/* IFPGA_SEC_ERR_HW_ERROR */
>>> +	"timeout",		/* IFPGA_SEC_ERR_TIMEOUT */
>>> +	"user-abort",		/* IFPGA_SEC_ERR_CANCELED */
>>> +	"device-busy",		/* IFPGA_SEC_ERR_BUSY */
>>> +	"invalid-file-size",	/* IFPGA_SEC_ERR_INVALID_SIZE */
>>> +	"read-write-error",	/* IFPGA_SEC_ERR_RW_ERROR */
>>> +	"flash-wearout",	/* IFPGA_SEC_ERR_WEAROUT */
>>> +	"file-read-error"	/* IFPGA_SEC_ERR_FILE_READ */
>>> +};
>>> +
>>> +static const char *sec_progress(enum ifpga_sec_prog prog)
>>> +{
>> A consistent api would have imgr as the parameter.
> There are two calls to this function: one passes imgr->progress, and one
> passes imgr->err_status. For this function, passing imgr alone would be
> insufficient.

ok.

Tom

>>> +	return (prog < IFPGA_SEC_PROG_MAX) ?
>>> +		sec_mgr_prog_str[prog] : "unknown-status";
>>> +}
>>> +
>>>  static ssize_t
>>>  status_show(struct device *dev, struct device_attribute *attr, char *buf)
>>>  {
>>>  	struct ifpga_sec_mgr *imgr = to_sec_mgr(dev);
>>>  
>>> -	return sprintf(buf, "%s\n", (imgr->progress < IFPGA_SEC_PROG_MAX) ?
>>> -		       sec_mgr_prog_str[imgr->progress] : "unknown-status");
>>> +	return sprintf(buf, "%s\n", sec_progress(imgr->progress));
>>>  }
>>>  static DEVICE_ATTR_RO(status);
>>>  
>>> +static ssize_t
>>> +error_show(struct device *dev, struct device_attribute *attr, char *buf)
>>> +{
>>> +	struct ifpga_sec_mgr *imgr = to_sec_mgr(dev);
>>> +	enum ifpga_sec_err err_code;
>>> +	const char *prog_str;
>>> +	int ret;
>>> +
>>> +	mutex_lock(&imgr->lock);
>>> +	if (imgr->progress != IFPGA_SEC_PROG_IDLE) {
>>> +		ret = -EBUSY;
>>> +	} else if (!imgr->err_code) {
>>> +		ret = 0;
>>> +	} else {
>>> +		err_code = imgr->err_code;
>>> +		prog_str = sec_progress(imgr->err_state);
>>> +		ret = sprintf(buf, "%s:%s\n", prog_str,
>>> +			      (err_code < IFPGA_SEC_ERR_MAX) ?
>>> +			      sec_mgr_err_str[err_code] : "unknown-error");
>> Should have sec_error() call to match the new sec_progress()
> OK - I'll add the sec_error() function.
>> Tom
>>
>>> +	}
>>> +	mutex_unlock(&imgr->lock);
>>> +
>>> +	return ret;
>>> +}
>>> +static DEVICE_ATTR_RO(error);
>>> +
>>>  static ssize_t filename_store(struct device *dev, struct device_attribute *attr,
>>>  			      const char *buf, size_t count)
>>>  {
>>> @@ -314,6 +363,7 @@ static DEVICE_ATTR_WO(filename);
>>>  static struct attribute *sec_mgr_update_attrs[] = {
>>>  	&dev_attr_filename.attr,
>>>  	&dev_attr_status.attr,
>>> +	&dev_attr_error.attr,
>>>  	NULL,
>>>  };
>>>  
>>> diff --git a/include/linux/fpga/ifpga-sec-mgr.h b/include/linux/fpga/ifpga-sec-mgr.h
>>> index 4da2864e251c..f04bf9e30c67 100644
>>> --- a/include/linux/fpga/ifpga-sec-mgr.h
>>> +++ b/include/linux/fpga/ifpga-sec-mgr.h
>>> @@ -181,6 +181,7 @@ struct ifpga_sec_mgr {
>>>  	const u8 *data;			/* pointer to update data */
>>>  	u32 remaining_size;		/* size remaining to transfer */
>>>  	enum ifpga_sec_prog progress;
>>> +	enum ifpga_sec_prog err_state;	/* progress state at time of failure */
>>>  	enum ifpga_sec_err err_code;	/* security manager error code */
>>>  	bool driver_unload;
>>>  	void *priv;