Am 10. Januar 2021 20:44:15 MEZ schrieb Joel Peshkin joel.peshkin@broadcom.com:
Hi Heinrich,
Thank you for your comments. I have 2 questions about how to proceed....
- Unit test
I can add a function that can be used to trigger an overrun, but I am not sure where to include it as the stack protector prints the error message and then resets uboot so it wouldn't fir in a unit test suite.
I could add a CONFIG_STACKPROTECTOR_TEST_FAIL to add a "test_stackprotector fail" command to the CLI and you could call the underlying stackprot_test_fail() from code hacked into SPL and TPL
Additonally to the test command you will nedd a Python test (in /test/py/tests/) to excercise it.
- Standalone/EFI
What we did for our own standalone code was to add the KBUILD_CFLAGS += -fno-stack-protector to the Makefile for our specific standalone. The problem is there is no generic place from which all standalone/EFI is called, so I could just leave this for maintainers of specific standalone/EPI programs to add IF they are enabling STACKPROTECTOR (If they don't enable it, they don't need to do anything) or I could add KBUILD_CFLAGS += -fno-stack-protector to both
This would lead to contradictory arguments on the GCC command line.
lib/efi_setlftest/Makefile and lib/efi_loader/Makefile
Have a look at CFLAGS_REMOVE in aforementioned Makefiles.
Best regards
Heinrich
What would you suggest?
Regards,
Joel