[PATCH] tpm: Remove dead NULL check in tpm2_flush_space()

[PATCH] tpm: Remove dead NULL check in tpm2_flush_space()

[Gunnar Kudrjavets]

The 'space' pointer in tpm2_flush_space() is assigned from
&chip->work_space, which is the address of an embedded struct member
within struct tpm_chip. This address can never be NULL, making the
NULL check dead code. The new code follows the existing pattern
established by the other callers in tpm2-space.c which also assign
from &chip->work_space without a NULL check. Remove the dead code
to avoid confusion.

Fixes: e3aaebcbb7c6 ("tpm: Clean up TPM space after command failure")
Signed-off-by: Gunnar Kudrjavets <gunnarku@amazon.com>
Assisted-by: Kiro:claude-opus-4.6
Reviewed-by: Justinien Bouron <jbouron@amazon.com>
---
 drivers/char/tpm/tpm2-space.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
index 60354cd53b5c..1eec72eb8208 100644
--- a/drivers/char/tpm/tpm2-space.c
+++ b/drivers/char/tpm/tpm2-space.c
@@ -169,9 +169,6 @@ void tpm2_flush_space(struct tpm_chip *chip)
 	struct tpm_space *space = &chip->work_space;
 	int i;
 
-	if (!space)
-		return;
-
 	for (i = 0; i < ARRAY_SIZE(space->context_tbl); i++)
 		if (space->context_tbl[i] && ~space->context_tbl[i])
 			tpm2_flush_context(chip, space->context_tbl[i]);

base-commit: 949692da7211572fac419b2986b6abc0cd1aeb76
-- 
2.47.3

Re: [PATCH] tpm: Remove dead NULL check in tpm2_flush_space()

[Paul Menzel]

Dear Gunnar,


Thank you for your patch.

Am 27.04.26 um 18:32 schrieb Gunnar Kudrjavets:
> The 'space' pointer in tpm2_flush_space() is assigned from
> &chip->work_space, which is the address of an embedded struct member
> within struct tpm_chip. This address can never be NULL, making the
> NULL check dead code. The new code follows the existing pattern
> established by the other callers in tpm2-space.c which also assign
> from &chip->work_space without a NULL check. Remove the dead code
> to avoid confusion.
> 
> Fixes: e3aaebcbb7c6 ("tpm: Clean up TPM space after command failure")
> Signed-off-by: Gunnar Kudrjavets <gunnarku@amazon.com>
> Assisted-by: Kiro:claude-opus-4.6
> Reviewed-by: Justinien Bouron <jbouron@amazon.com>
> ---
>   drivers/char/tpm/tpm2-space.c | 3 ---
>   1 file changed, 3 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm2-space.c b/drivers/char/tpm/tpm2-space.c
> index 60354cd53b5c..1eec72eb8208 100644
> --- a/drivers/char/tpm/tpm2-space.c
> +++ b/drivers/char/tpm/tpm2-space.c
> @@ -169,9 +169,6 @@ void tpm2_flush_space(struct tpm_chip *chip)
>   	struct tpm_space *space = &chip->work_space;
>   	int i;
>   
> -	if (!space)
> -		return;
> -
>   	for (i = 0; i < ARRAY_SIZE(space->context_tbl); i++)
>   		if (space->context_tbl[i] && ~space->context_tbl[i])
>   			tpm2_flush_context(chip, space->context_tbl[i]);

gemini/gemini-3.1-pro-preview made a comment [1]. No idea, if it’s valid.


Kind regards,

Paul


[1]: 
https://sashiko.dev/#/patchset/20260427163238.20230-1-gunnarku%40amazon.com

Re: [PATCH] tpm: Remove dead NULL check in tpm2_flush_space()

[Gunnar Kudrjavets]

On Sun, Apr 27, 2026 at 10:49 PM Paul Menzel <pmenzel@molgen.mpg.de> wrote:
> gemini/gemini-3.1-pro-preview made a comment [1]. No idea, if it's valid.

Thanks for forwarding, Paul. AFAICS, the comment is a false positive.

My theory is that Gemini conflates two different variables named
'space':

1. The 'space' parameter passed to tpm_dev_transmit(). This *can* be
   NULL (it is NULL for /dev/tpm0 clients).

2. The local 'space' variable inside tpm2_flush_space(). This is
   assigned from &chip->work_space and can *never* be NULL.

The removed NULL check was testing case (2), not case (1).

Regards,
Gunnar

Re: [PATCH] tpm: Remove dead NULL check in tpm2_flush_space()

[Paul Menzel]

Dear Gunnar,


Am 28.04.26 um 00:57 schrieb Gunnar Kudrjavets:
> On Sun, Apr 27, 2026 at 10:49 PM Paul Menzel <pmenzel@molgen.mpg.de> wrote:
>> gemini/gemini-3.1-pro-preview made a comment [1]. No idea, if it's valid.
> 
> Thanks for forwarding, Paul. AFAICS, the comment is a false positive.
> 
> My theory is that Gemini conflates two different variables named
> 'space':
> 
> 1. The 'space' parameter passed to tpm_dev_transmit(). This *can* be
>     NULL (it is NULL for /dev/tpm0 clients).
> 
> 2. The local 'space' variable inside tpm2_flush_space(). This is
>     assigned from &chip->work_space and can *never* be NULL.
> 
> The removed NULL check was testing case (2), not case (1).

Thank you for quickly looking into this. Sorry for the noise.


Kind regards,

Paul