To integrate tpm_event_log with IMA subsystem, tpm_crb and tpm_crb_ffa driver should be built as built-in (CONFIG_TCG_CRB=y && CONFIG_TCG_CRB_FFA=y).
However, this could make failure for ima_init() gets tpm chip when each initcall function deployed like: 0000000000000888 l .initcall6.init 0000000000000000 crb_acpi_driver_init 000000000000088c l .initcall6.init 0000000000000000 tpm_crb_ffa_driver_init If crb_api_driver_init() is called first, probing tpm device using CRB over FFA method is deferred since tpm_crb_ffa_driver_init() isn't called yet. Deferred probe of the tpm device will be probed by system workqueue in proper time after deferred_probe_initcall() registers the work. However, ima_init() could be called first if they're deployed like: 000000000000012c l .initcall7.init 0000000000000000 init_ima 000000000000016c l .initcall7.init 0000000000000000 deferred_probe_initcall7 In this situation, ima_init() failed to find tpm device and it failed to generate boot_aggregate with PCR values. That's why kernel prints log this situation though tpm device exists: [ 3.080786] ima: No TPM chip found, activating TPM-bypass! To resolve this, call ffa_register() in tpm_crb_ffa_init() when it was built with built-in so that ima can generate boot_aggregate log with PCR values properly. Signed-off-by: Yeoreum Yun <[email protected]> --- drivers/char/tpm/tpm_crb_ffa.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-) diff --git a/drivers/char/tpm/tpm_crb_ffa.c b/drivers/char/tpm/tpm_crb_ffa.c index 4ead61f01299..2ef29b66fa5d 100644 --- a/drivers/char/tpm/tpm_crb_ffa.c +++ b/drivers/char/tpm/tpm_crb_ffa.c @@ -115,6 +115,7 @@ struct tpm_crb_ffa { }; static struct tpm_crb_ffa *tpm_crb_ffa; +static struct ffa_driver tpm_crb_ffa_driver; static int tpm_crb_ffa_to_linux_errno(int errno) { @@ -168,13 +169,22 @@ static int tpm_crb_ffa_to_linux_errno(int errno) */ int tpm_crb_ffa_init(void) { - if (!tpm_crb_ffa) - return -ENOENT; + int ret = 0; - if (IS_ERR_VALUE(tpm_crb_ffa)) - return -ENODEV; + if (IS_MODULE(CONFIG_TCG_ARM_CRB_FFA)) { + if (!tpm_crb_ffa) + ret = -ENOENT; - return 0; + if (IS_ERR_VALUE(tpm_crb_ffa)) + ret = -ENODEV; + + return ret; + } + + ret = ffa_register(&tpm_crb_ffa_driver); + BUG_ON(!ret && !tpm_crb_ffa); + + return ret; } EXPORT_SYMBOL_GPL(tpm_crb_ffa_init); @@ -369,7 +379,9 @@ static struct ffa_driver tpm_crb_ffa_driver = { .id_table = tpm_crb_ffa_device_id, }; +#ifdef MODULE module_ffa_driver(tpm_crb_ffa_driver); +#endif MODULE_AUTHOR("Arm"); MODULE_DESCRIPTION("TPM CRB FFA driver"); -- LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}
