Re: [PATCH v12 2/3] selftests: tdx: Test TDX attestation GetReport support

On 9/8/22 8:48 PM, Huang, Kai wrote:

On Wed, 2022-09-07 at 17:27 -0700, Kuppuswamy Sathyanarayanan wrote:

...

+TEST(verify_report) +{

• __u8 reportdata[TDX_REPORTDATA_LEN];
• struct tdreport tdreport;
• struct tdx_report_req req;
• int devfd, i;
• devfd = open(TDX_GUEST_DEVNAME, O_RDWR | O_SYNC);
• ASSERT_LT(0, devfd);
• /* Generate sample report data */
• for (i = 0; i < TDX_REPORTDATA_LEN; i++)

• reportdata[i] = i;
  

• /* Initialize IOCTL request */
• req.subtype     = 0;
• req.reportdata  = (__u64)reportdata;
• req.rpd_len     = TDX_REPORTDATA_LEN;
• req.tdreport    = (__u64)&tdreport;
• req.tdr_len     = sizeof(tdreport);

'req' is a local variable, which isn't guaranteed to be zero. Looks you need to explicitly clear 'req' otherwise the req.reserved[7] may not be zero.

In the next version, I explicitly set it to 0. I could initialize the struct to 0. But doing it explicitly will show the expected values clearly.

memset(req.reserved, 0, sizeof(req.reserved));