Skip to content
Snippets Groups Projects
user avatar
Jarkko Sakkinen authored
The initial HMAC session feature added TPM bus encryption and/or integrity
protection to various in-kernel TPM operations. This can cause performance
bottlenecks with IMA, as it heavily utilizes PCR extend operations.

In order to mitigate this performance issue, introduce a kernel
command-line parameter to the TPM driver for disabling the integrity
protection for PCR extend operations (i.e. TPM2_PCR_Extend).

Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Link: https://lore.kernel.org/linux-integrity/20241015193916.59964-1-zohar@linux.ibm.com/


Fixes: 6519fea6 ("tpm: add hmac checks to tpm2_pcr_extend()")
Tested-by: default avatarMimi Zohar <zohar@linux.ibm.com>
Co-developed-by: default avatarRoberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: default avatarRoberto Sassu <roberto.sassu@huawei.com>
Co-developed-by: default avatarMimi Zohar <zohar@linux.ibm.com>
Signed-off-by: default avatarMimi Zohar <zohar@linux.ibm.com>
Signed-off-by: default avatarJarkko Sakkinen <jarkko@kernel.org>
27184f89
History
Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.