3 Commits

Author SHA1 Message Date
Sean Dooher
35c9baa11e [attributes] Add a facility for enforcing a Trusted Computing Base.
Introduce a function attribute 'enforce_tcb' that prevents the function
from calling other functions without the same attribute. This allows
isolating code that's considered to be somehow privileged so that it could not
use its privileges to exhibit arbitrary behavior.

Introduce an on-by-default warning '-Wtcb-enforcement' that warns
about violations of the above rule.

Introduce a function attribute 'enforce_tcb_leaf' that suppresses
the new warning within the function it is attached to. Such leaf functions
may implement common functionality between the trusted and the untrusted code
but they require extra careful audit with respect to their capabilities.

Fixes after a revert in 419ef38a50293c58078f830517f5e305068dbee6:
Fix a test.
Add workaround for GCC bug (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67274).
Attribute the patch appropriately!

Differential Revision: https://reviews.llvm.org/D91898
2021-01-11 10:20:51 -08:00
Nico Weber
419ef38a50 Revert "[attributes] Add a facility for enforcing a Trusted Computing Base."
This reverts commit c163aae45ef6b7f3bd99601195d3ce4aad5850c6.
Doesn't compile on some bots
(http://lab.llvm.org:8011/#/builders/98/builds/3387/steps/9/logs/stdio),
breaks tests on bots where it does compile
(http://45.33.8.238/linux/36843/step_7.txt).
2021-01-11 09:51:06 -05:00
Artem Dergachev
c163aae45e [attributes] Add a facility for enforcing a Trusted Computing Base.
Introduce a function attribute 'enforce_tcb' that prevents the function
from calling other functions without the same attribute. This allows
isolating code that's considered to be somehow privileged so that it could not
use its privileges to exhibit arbitrary behavior.

Introduce an on-by-default warning '-Wtcb-enforcement' that warns
about violations of the above rule.

Introduce a function attribute 'enforce_tcb_leaf' that suppresses
the new warning within the function it is attached to. Such leaf functions
may implement common functionality between the trusted and the untrusted code
but they require extra careful audit with respect to their capabilities.

Differential Revision: https://reviews.llvm.org/D91898
2021-01-11 06:39:42 -08:00