On 05/03/2017 06:37 PM, Jarkko Sakkinen wrote:
> On Fri, Apr 28, 2017 at 09:02:18AM -0400, Stefan Berger wrote:
>> Add an ioctl to request that the locality be prepended to every TPM
>> command.
> Don't really understand this change. Why locality is prenpended?

Commands can be executed under locality 0-3 and for some commands it is 
important to know which locality a user may have chosen. How else should 
we convey that locality to the TPM emulator ?

> Where is the ioctl declaration in this commit?

My bad, it's a flag that's being added here.

>
>> Signed-off-by: Stefan Berger <stef...@linux.vnet.ibm.com>
>> ---
>>   drivers/char/tpm/tpm_vtpm_proxy.c | 18 +++++++++++++-----
>>   include/uapi/linux/vtpm_proxy.h   |  4 +++-
>>   2 files changed, 16 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/char/tpm/tpm_vtpm_proxy.c 
>> b/drivers/char/tpm/tpm_vtpm_proxy.c
>> index 48b9818..6c90e02 100644
>> --- a/drivers/char/tpm/tpm_vtpm_proxy.c
>> +++ b/drivers/char/tpm/tpm_vtpm_proxy.c
>> @@ -52,7 +52,8 @@ struct proxy_dev {
>>   };
>>   
>>   /* all supported flags */
>> -#define VTPM_PROXY_FLAGS_ALL  (VTPM_PROXY_FLAG_TPM2)
>> +#define VTPM_PROXY_FLAGS_ALL  (VTPM_PROXY_FLAG_TPM2 | \
>> +                           VTPM_PROXY_FLAG_PREPEND_LOCALITY)
>>   
>>   static struct workqueue_struct *workqueue;
>>   
>> @@ -77,8 +78,9 @@ static ssize_t vtpm_proxy_fops_read(struct file *filp, 
>> char __user *buf,
>>                                  size_t count, loff_t *off)
>>   {
>>      struct proxy_dev *proxy_dev = filp->private_data;
>> -    size_t len;
>> -    int sig, rc;
>> +    size_t len, offset = 0;
>> +    int sig, rc = 0;
> One line per declaration:
>
> size_t len;
> size_t offset = 0;
> int sig;
> int rc = 0;
>
>> +    uint8_t locality;
>>   
>>      sig = wait_event_interruptible(proxy_dev->wq,
>>              proxy_dev->req_len != 0 ||
>> @@ -102,7 +104,13 @@ static ssize_t vtpm_proxy_fops_read(struct file *filp, 
>> char __user *buf,
>>              return -EIO;
>>      }
>>   
>> -    rc = copy_to_user(buf, proxy_dev->buffer, len);
>> +    if (proxy_dev->flags & VTPM_PROXY_FLAG_PREPEND_LOCALITY) {
>> +            locality = proxy_dev->chip->locality;
>> +            offset = sizeof(locality);
>> +            rc = copy_to_user(buf, &locality, offset);
>> +    }
>> +    if (!rc)
>> +            rc = copy_to_user(&buf[offset], proxy_dev->buffer, len);
>>      memset(proxy_dev->buffer, 0, len);
>>      proxy_dev->req_len = 0;
>>   
>> @@ -114,7 +122,7 @@ static ssize_t vtpm_proxy_fops_read(struct file *filp, 
>> char __user *buf,
>>      if (rc)
>>              return -EFAULT;
>>   
>> -    return len;
>> +    return offset + len;
>>   }
>>   
>>   /**
>> diff --git a/include/uapi/linux/vtpm_proxy.h 
>> b/include/uapi/linux/vtpm_proxy.h
>> index 83e64e7..512a29e 100644
>> --- a/include/uapi/linux/vtpm_proxy.h
>> +++ b/include/uapi/linux/vtpm_proxy.h
>> @@ -22,9 +22,11 @@
>>   /**
>>    * enum vtpm_proxy_flags - flags for the proxy TPM
>>    * @VTPM_PROXY_FLAG_TPM2:  the proxy TPM uses TPM 2.0 protocol
>> + * @VTPM_PROXY_PREPEND_LOCALITY:locality byte prepended on each command
>>    */
>>   enum vtpm_proxy_flags {
>> -    VTPM_PROXY_FLAG_TPM2    = 1,
>> +    VTPM_PROXY_FLAG_TPM2                    = 1,
>> +    VTPM_PROXY_FLAG_PREPEND_LOCALITY        = 2,
>>   };
>>   
>>   /**
>> -- 
>> 2.4.3
>>
> /Jarkko
>


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