This is a note to let you know that I've just added the patch titled
tpm: Add a helper for checking hwrng enabled
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tpm-add-a-helper-for-checking-hwrng-enabled.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From cacc6e22932f373a91d7be55a9b992dc77f4c59b Mon Sep 17 00:00:00 2001
From: Mario Limonciello <mario.limonciello@xxxxxxx>
Date: Mon, 7 Aug 2023 23:12:29 -0500
Subject: tpm: Add a helper for checking hwrng enabled
From: Mario Limonciello <mario.limonciello@xxxxxxx>
commit cacc6e22932f373a91d7be55a9b992dc77f4c59b upstream.
The same checks are repeated in three 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>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/char/tpm/tpm-chip.c | 19 ++++++++++++++-----
1 file changed, 14 insertions(+), 5 deletions(-)
--- a/drivers/char/tpm/tpm-chip.c
+++ b/drivers/char/tpm/tpm-chip.c
@@ -518,10 +518,20 @@ static int tpm_hwrng_read(struct hwrng *
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),
@@ -626,7 +636,7 @@ int tpm_chip_register(struct tpm_chip *c
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);
@@ -651,8 +661,7 @@ 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))
Patches currently in stable-queue which might be from mario.limonciello@xxxxxxx are
queue-6.1/tpm-disable-rng-for-all-amd-ftpms.patch
queue-6.1/tpm-add-a-helper-for-checking-hwrng-enabled.patch
