[PATCH V2 01/12] tpm: Use durations returned from TPM

[Stefan Berger]

The TPM driver currently discards the durations values returned
from the TPM. The check of the response packet needs to consider that
the return_code field is 0 on success and the size of the expected
packet is equivalent to the header size + u32 length indicator for the
TPM_GetCapability() result + 3 timeout indicators of type u32.

v4:
- sysfs entry 'durations' is now a patch of its own
- the work-around for TPMs reporting durations in milliseconds is now in a
  patch of its own

v3:
- sysfs entry now called 'durations' to resemble TPM-speak (previously
  was called 'timeouts')

v2:
- adjusting all timeouts for TPM devices reporting timeouts in msec rather
  than usec
- also displaying in sysfs whether the timeouts are 'original' or 'adjusted'


Signed-off-by: Stefan Berger <stefanb@xxxxxxxxxxxxxxxxxx> 
Tested-by: Guillaume Chazarain <guichaz@xxxxxxxxx>

---
 drivers/char/tpm/tpm.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Index: linux-2.6/drivers/char/tpm/tpm.c
===================================================================
--- linux-2.6.orig/drivers/char/tpm/tpm.c
+++ linux-2.6/drivers/char/tpm/tpm.c
@@ -575,9 +575,11 @@ duration:
 	if (rc)
 		return;
 
-	if (be32_to_cpu(tpm_cmd.header.out.return_code)
-	    != 3 * sizeof(u32))
+	if (be32_to_cpu(tpm_cmd.header.out.return_code) != 0 ||
+	    be32_to_cpu(tpm_cmd.header.out.length)
+	    != sizeof(tpm_cmd.header.out) + sizeof(u32) + 3 * sizeof(u32))
 		return;
+
 	duration_cap = &tpm_cmd.params.getcap_out.cap.duration;
 	chip->vendor.duration[TPM_SHORT] =
 	    usecs_to_jiffies(be32_to_cpu(duration_cap->tpm_short));

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