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

Tom Rix
2020-09-23T12:53:04Z

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@intel.com>
>>> Reviewed-by: Wu Hao <hao.wu@intel.com>
>>> ---
>>> .../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@intel.com>
>>> +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;