Commit Graph

4 Commits

Author SHA1 Message Date
Aaron Ballman e765e0bc8e Use functions with prototypes when appropriate; NFC
A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,

  void func();

becomes

  void func(void);

This is the first batch of tests being updated (there are a significant
number of other tests left to be updated).
2022-02-03 16:42:27 -05:00
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 c163aae45e.
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