This makes them harder to miss for spammy apps when UBSAN is not deadly.
Don't commit to making the warnln red at the momment, because that would
probably be a nuisance if stderr is not a tty.
This is the same strategy that LLVM's compiler-rt uses to make sure that
each UBSAN error is only reported once, when UBSAN is *not* deadly.
Otherwise, each time we head through a UB codepath, we will log the same
error over and over. That behavior just adds noise to the logs and makes
it nearly impossible to run binaires that have some common code path
with flagged UB in them.
compiler-rt goes the extra step to make sure the "clear" action is
atomic, but we don't really have that many multi-threaded apps gettting
tested with UBSAN yet, so we can add that later.
The first time we want to print a UBSAN violation, the UBSAN runtime
in userspace will get the UBSAN_OPTIONS environment variable to check if
it contains the string "halt_on_error=1". This is clearly not robust to
invalid options or adding more options, but it gets the job done at the
moment. :^)
Take Kernel/UBSanitizer.cpp and make a copy in LibSanitizer.
We can use LibSanitizer to hold other sanitizers as people implement
them :^).
To enable UBSAN for LibC, DynamicLoader, and other low level system
libraries, LibUBSanitizer is built as a serenity_libc, and has a static
version for LibCStatic to use. The approach is the same as that taken in
Note that this means now UBSAN is enabled for code generators, Lagom,
Kernel, and Userspace with -DENABLE_UNDEFINED_SANTIZER=ON. In userspace
however, UBSAN is not deadly (yet).
Co-authored-by: ForLoveOfCats <ForLoveOfCats@vivaldi.net>
