On Thu Aug 10, 2023 at 6:08 PM EEST, Limonciello, Mario wrote:
>
>
> On 8/10/2023 10:07 AM, Jarkko Sakkinen wrote:
> > On Tue Aug 8, 2023 at 7:12 AM EEST, Mario Limonciello wrote:
> >> The same checks are repeated in 3 places to decide whether to use
> >> hwrng. Consolidate these into a helper.
> >>
> >> Also this fixes a case that one of them was missing a check in the
> >> cleanup path.
> >>
> >> Fixes: 554b841d4703 ("tpm: Disable RNG for all AMD fTPMs")
> >> Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxx>
> >> ---
> >> drivers/char/tpm/tpm-chip.c | 19 ++++++++++++++-----
> >> 1 file changed, 14 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/drivers/char/tpm/tpm-chip.c b/drivers/char/tpm/tpm-chip.c
> >> index e904aae9771be..ea6b4013bc38f 100644
> >> --- a/drivers/char/tpm/tpm-chip.c
> >> +++ b/drivers/char/tpm/tpm-chip.c
> >> @@ -521,10 +521,20 @@ static int tpm_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait)
> >> return tpm_get_random(chip, data, max);
> >> }
> >>
> >> +static bool tpm_is_hwrng_enabled(struct tpm_chip *chip)
> >> +{
> >> + if (!IS_ENABLED(CONFIG_HW_RANDOM_TPM))
> >> + return false;
> >> + if (tpm_is_firmware_upgrade(chip))
> >> + return false;
> >> + if (chip->flags & TPM_CHIP_FLAG_HWRNG_DISABLED)
> >> + return false;
> >> + return true;
> >> +}
> >> +
> >> static int tpm_add_hwrng(struct tpm_chip *chip)
> >> {
> >> - if (!IS_ENABLED(CONFIG_HW_RANDOM_TPM) || tpm_is_firmware_upgrade(chip) ||
> >> - chip->flags & TPM_CHIP_FLAG_HWRNG_DISABLED)
> >> + if (!tpm_is_hwrng_enabled(chip))
> >> return 0;
> >>
> >> snprintf(chip->hwrng_name, sizeof(chip->hwrng_name),
> >> @@ -629,7 +639,7 @@ int tpm_chip_register(struct tpm_chip *chip)
> >> return 0;
> >>
> >> out_hwrng:
> >> - if (IS_ENABLED(CONFIG_HW_RANDOM_TPM) && !tpm_is_firmware_upgrade(chip))
> >> + if (tpm_is_hwrng_enabled(chip))
> >> hwrng_unregister(&chip->hwrng);
> >> out_ppi:
> >> tpm_bios_log_teardown(chip);
> >> @@ -654,8 +664,7 @@ EXPORT_SYMBOL_GPL(tpm_chip_register);
> >> void tpm_chip_unregister(struct tpm_chip *chip)
> >> {
> >> tpm_del_legacy_sysfs(chip);
> >> - if (IS_ENABLED(CONFIG_HW_RANDOM_TPM) && !tpm_is_firmware_upgrade(chip) &&
> >> - !(chip->flags & TPM_CHIP_FLAG_HWRNG_DISABLED))
> >> + if (tpm_is_hwrng_enabled(chip))
> >> hwrng_unregister(&chip->hwrng);
> >> tpm_bios_log_teardown(chip);
> >> if (chip->flags & TPM_CHIP_FLAG_TPM2 && !tpm_is_firmware_upgrade(chip))
> >
> > Given my previous queries: should I apply this or revert and apply v3?
> >
> > BR, Jarkko
>
> Linus picked it up already directly.
I came two days behind, sorry.
BR, Jarkko
