On Tue, Aug 01, 2023 at 11:43:29AM +0200, Ricardo Cañuelo wrote:
The lkdtm selftest config fragment enables CONFIG_UBSAN_TRAP to make the ARRAY_BOUNDS test kill the calling process when an out-of-bound access is detected by UBSAN. However, after this [1] commit, UBSAN is triggered under many new scenarios that weren't detected before, such as in struct definitions with fixed-size trailing arrays used as flexible arrays. As a result, CONFIG_UBSAN_TRAP=y has become a very aggressive option to enable except for specific situations.
Yeah, that's fair. We need to actually get these issues reported and TRAP doesn't help with that.
`make kselftest-merge` applies CONFIG_UBSAN_TRAP=y to the kernel config for all selftests, which makes many of them fail because of system hangs during boot.
This change removes the config option from the lkdtm kselftest and also the ARRAY_BOUNDS test to skip it rather than have it failing. If out-of-bound array accesses need to be checked, there's CONFIG_TEST_UBSAN for that.
I *think* instead, we can turn off TRAP but retain the ARRAY_BOUNDS kselftest by looking for either WARN or TRAP results:
-ARRAY_BOUNDS +ARRAY_BOUNDS call trace:|UBSAN: array-index-out-of-bounds
Can test that and send a v2?
-Kees