2011-03-30 16:17:46

by Stefan Berger

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

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 <[email protected]>
Tested-by: Guillaume Chazarain <[email protected]>

---
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));