d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Add a cv_wait to the TPM2.0 harvesting function

Browse Source 
Harvesting has to compete for the TPM chip with userspace.
Before this change the callout could hijack an unread buffer
causing a userspace call to the TPM to fail.

Submitted by: Kornel Duleba <mindal@semihalf.com>
Reviewed by: delphij
Obtained from: Semihalf
Sponsored by: Stormshield
Differential Revision: https://reviews.freebsd.org/D19712
This commit is contained in:
Marcin Wojtas 2019-04-03 08:22:58 +00:00
parent f806eb62a4
commit 3a3e5039b9
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=345842
1 changed files with 2 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
sys/dev/tpm/tpm20.c
View File

@ -263,6 +263,8 @@ tpm20_harvest(void *arg)
sc = arg;
sx_xlock(&sc->dev_lock);
while (sc->pending_data_length != 0)
cv_wait(&sc->buf_cv, &sc->dev_lock);
memcpy(sc->buf, cmd, sizeof(cmd));
result = sc->transmit(sc, sizeof(cmd));