2018-09-03 19:45:27

by Peter Huewe

Subject: [PATCH] tpm: Make SECURITYFS a weak dependency

While having SECURITYFS enabled for the tpm subsystem is beneficial in
most cases, it is not strictly necessary to have it enabled at all.
Especially on platforms without any boot firmware integration of the TPM
(e.g. raspberry pi) it does not add any value for the tpm subsystem,
as there is no eventlog present.

By turning it from 'select' to 'imply' it still gets selected per
default, but enables users who want to save some kb of ram by turning
SECURITYFS off.

Signed-off-by: Peter Huewe <[email protected]>
---
drivers/char/tpm/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
index 18c81cbe4704..536e55d3919f 100644
--- a/drivers/char/tpm/Kconfig
+++ b/drivers/char/tpm/Kconfig
@@ -5,7 +5,7 @@
menuconfig TCG_TPM
tristate "TPM Hardware Support"
depends on HAS_IOMEM
- select SECURITYFS
+ imply SECURITYFS
select CRYPTO
select CRYPTO_HASH_INFO
---help---
--
2.16.4

2018-09-05 11:30:16

by Jarkko Sakkinen

Subject: Re: [PATCH] tpm: Make SECURITYFS a weak dependency

On Mon, Sep 03, 2018 at 09:51:51PM +0200, Peter Huewe wrote:
> While having SECURITYFS enabled for the tpm subsystem is beneficial in
> most cases, it is not strictly necessary to have it enabled at all.
> Especially on platforms without any boot firmware integration of the TPM
> (e.g. raspberry pi) it does not add any value for the tpm subsystem,
> as there is no eventlog present.
>
> By turning it from 'select' to 'imply' it still gets selected per
> default, but enables users who want to save some kb of ram by turning
> SECURITYFS off.
>
> Signed-off-by: Peter Huewe <[email protected]>
> ---
> drivers/char/tpm/Kconfig | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig
> index 18c81cbe4704..536e55d3919f 100644
> --- a/drivers/char/tpm/Kconfig
> +++ b/drivers/char/tpm/Kconfig
> @@ -5,7 +5,7 @@
> menuconfig TCG_TPM
> tristate "TPM Hardware Support"
> depends on HAS_IOMEM
> - select SECURITYFS
> + imply SECURITYFS
> select CRYPTO
> select CRYPTO_HASH_INFO
> ---help---
> --
> 2.16.4
>

Reviewed-by: Jarkko Sakkinen <[email protected]>

/Jarkko