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From: Stefan Berger <stefanb@linux.ibm.com>
To: qemu-devel@nongnu.org
Cc: berrange@redhat.com, marcandre.lureau@gmail.com,
	Stefan Berger <stefanb@linux.ibm.com>
Subject: [PATCH v3 0/2] tpm: Resolve potential blocking-forever issue
Date: Wed, 16 Oct 2024 10:57:06 -0400	[thread overview]
Message-ID: <20241016145708.1166471-1-stefanb@linux.ibm.com> (raw)

In case swtpm was to return a control channel message with an error code it
would often return less bytes than the full response. In some cases the
current reading of the returned bytes would get stuck since more bytes are
expected. Therefore, pass a separate parameter indicating how many bytes to
expect in case of an error and read that many bytes in a first pass. Check
for an error code in the first 4 bytes. Read the rest in a 2nd pass.

   Stefan

v3:
  - 2/2: Pass size of return response for error as parameter

v2:
  - 2/2: Added special handling of CMD_GET_STATEBLOB



Stefan Berger (2):
  tpm: Use new ptm_cap_n structure for PTM_GET_CAPABILITY
  tpm_emulator: Read control channel response in 2 passes

 backends/tpm/tpm_emulator.c | 77 +++++++++++++++++++++++++++----------
 backends/tpm/tpm_ioctl.h    | 13 ++++++-
 backends/tpm/trace-events   |  2 +-
 3 files changed, 69 insertions(+), 23 deletions(-)

-- 
2.47.0



             reply	other threads:[~2024-10-16 14:57 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-16 14:57 Stefan Berger [this message]
2024-10-16 14:57 ` [PATCH v3 1/2] tpm: Use new ptm_cap_n structure for PTM_GET_CAPABILITY Stefan Berger
2024-10-16 15:03   ` Daniel P. Berrangé
2024-10-16 17:01     ` Stefan Berger
2024-10-16 14:57 ` [PATCH v3 2/2] tpm_emulator: Read control channel response in 2 passes Stefan Berger
2024-10-16 15:16   ` Daniel P. Berrangé

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