util/nvmutil: harden pledge/unveil calls (OpenBSD)

*Open* files at the start, then unveil. The same overall
behaviour is observed. In the case that invalid arguments
are given, simply opening a file does not cause much
performance impact (if any).

Restrict operations as early as possible in code.

Bonus:

writeGbeFile also hardened; if flags is O_RDONLY, it aborts.

Signed-off-by: Leah Rowe <leah@libreboot.org>

0 files changed, 0 insertions, 0 deletions