diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 10 | ||||
| -rw-r--r-- | drivers/char/tpm/tpm.c | 47 |
2 files changed, 50 insertions, 7 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index d80930d58dae..e0df679c3902 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -99,6 +99,7 @@ parameter is applicable: SWSUSP Software suspend (hibernation) is enabled. SUSPEND System suspend states are enabled. FTRACE Function tracing enabled. + TPM TPM drivers are enabled. TS Appropriate touchscreen support is enabled. UMS USB Mass Storage support is enabled. USB USB support is enabled. @@ -2619,6 +2620,15 @@ and is between 256 and 4096 characters. It is defined in the file tp720= [HW,PS2] + tpm_suspend_pcr=[HW,TPM] + Format: integer pcr id + Specify that at suspend time, the tpm driver + should extend the specified pcr with zeros, + as a workaround for some chips which fail to + flush the last written pcr on TPM_SaveState. + This will guarantee that all the other pcrs + are saved. + trace_buf_size=nn[KMG] [FTRACE] will set tracing buffer size. diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c index f06bb37defb1..5c447c991bd5 100644 --- a/drivers/char/tpm/tpm.c +++ b/drivers/char/tpm/tpm.c @@ -1067,6 +1067,27 @@ void tpm_remove_hardware(struct device *dev) } EXPORT_SYMBOL_GPL(tpm_remove_hardware); +#define TPM_ORD_SAVESTATE cpu_to_be32(152) +#define SAVESTATE_RESULT_SIZE 10 + +static struct tpm_input_header savestate_header = { + .tag = TPM_TAG_RQU_COMMAND, + .length = cpu_to_be32(10), + .ordinal = TPM_ORD_SAVESTATE +}; + +/* Bug workaround - some TPM's don't flush the most + * recently changed pcr on suspend, so force the flush + * with an extend to the selected _unused_ non-volatile pcr. + */ +static int tpm_suspend_pcr; +static int __init tpm_suspend_setup(char *str) +{ + get_option(&str, &tpm_suspend_pcr); + return 1; +} +__setup("tpm_suspend_pcr=", tpm_suspend_setup); + /* * We are about to suspend. Save the TPM state * so that it can be restored. @@ -1074,17 +1095,29 @@ EXPORT_SYMBOL_GPL(tpm_remove_hardware); int tpm_pm_suspend(struct device *dev, pm_message_t pm_state) { struct tpm_chip *chip = dev_get_drvdata(dev); - u8 savestate[] = { - 0, 193, /* TPM_TAG_RQU_COMMAND */ - 0, 0, 0, 10, /* blob length (in bytes) */ - 0, 0, 0, 152 /* TPM_ORD_SaveState */ - }; + struct tpm_cmd_t cmd; + int rc; + + u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 }; if (chip == NULL) return -ENODEV; - tpm_transmit(chip, savestate, sizeof(savestate)); - return 0; + /* for buggy tpm, flush pcrs with extend to selected dummy */ + if (tpm_suspend_pcr) { + cmd.header.in = pcrextend_header; + cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr); + memcpy(cmd.params.pcrextend_in.hash, dummy_hash, + TPM_DIGEST_SIZE); + rc = transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, + "extending dummy pcr before suspend"); + } + + /* now do the actual savestate */ + cmd.header.in = savestate_header; + rc = transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, + "sending savestate before suspend"); + return rc; } EXPORT_SYMBOL_GPL(tpm_pm_suspend); |