Re: [PATCH 6.6] tpm: Lock TPM chip in tpm_pm_suspend() first

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

The upstream commit SHA1 provided is correct: 9265fed6db601ee2ec47577815387458ef4f047a

WARNING: Author mismatch between patch and upstream commit:
Backport author: bin.lan.cn@eng.windriver.com
Commit author: Jarkko Sakkinen <jarkko@kernel.org>


Status in newer kernel trees:
6.12.y | Present (exact SHA1)
6.11.y | Present (different SHA1: bc203fe416ab)
6.6.y | Not found

Note: The patch differs from the upstream commit:
---
1:  9265fed6db601 ! 1:  7fcb4bafb7f2d tpm: Lock TPM chip in tpm_pm_suspend() first
    @@ Metadata
      ## Commit message ##
         tpm: Lock TPM chip in tpm_pm_suspend() first
     
    +    [ Upstream commit 9265fed6db601ee2ec47577815387458ef4f047a ]
    +
         Setting TPM_CHIP_FLAG_SUSPENDED in the end of tpm_pm_suspend() can be racy
         according, as this leaves window for tpm_hwrng_read() to be called while
         the operation is in progress. The recent bug report gives also evidence of
    @@ Commit message
         Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
         Tested-by: Mike Seo <mikeseohyungjin@gmail.com>
         Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
    +    [ Don't call tpm2_end_auth_session() for this function does not exist
    +      in 6.6.y.]
    +    Signed-off-by: Bin Lan <bin.lan.cn@windriver.com>
     
      ## drivers/char/tpm/tpm-chip.c ##
     @@ drivers/char/tpm/tpm-chip.c: static int tpm_hwrng_read(struct hwrng *rng, void *data, size_t max, bool wait)
    @@ drivers/char/tpm/tpm-interface.c: int tpm_pm_suspend(struct device *dev)
      
     -	rc = tpm_try_get_ops(chip);
     -	if (!rc) {
    --		if (chip->flags & TPM_CHIP_FLAG_TPM2) {
    --			tpm2_end_auth_session(chip);
    +-		if (chip->flags & TPM_CHIP_FLAG_TPM2)
     -			tpm2_shutdown(chip, TPM2_SU_STATE);
    --		} else {
    +-		else
     -			rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
    --		}
     -
     -		tpm_put_ops(chip);
     +	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
    -+		tpm2_end_auth_session(chip);
     +		tpm2_shutdown(chip, TPM2_SU_STATE);
     +		goto suspended;
      	}
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Success   |