[Bug sanitizer/94307] Provide a way to declare the *SAN exception handler -fsanitize-undefined-trap-on-error

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94307

--- Comment #3 from Martin Liška <marxin at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #1)
> But isn't the default without -fsanitize-undefined-trap-on-error already
> calling
> a library routine that the kernel could override?

They don't want to implement all the:
        call    __ubsan_handle_add_overflow
        call    __ubsan_handle_divrem_overflow
        call    __ubsan_handle_dynamic_type_cache_miss
        call    __ubsan_handle_invalid_builtin
        call    __ubsan_handle_load_invalid_value
        call    __ubsan_handle_mul_overflow
        call    __ubsan_handle_negate_overflow
        call    __ubsan_handle_nonnull_arg
        call    __ubsan_handle_out_of_bounds
        call    __ubsan_handle_pointer_overflow
        call    __ubsan_handle_shift_out_of_bounds
        call    __ubsan_handle_sub_overflow
        call    __ubsan_handle_type_mismatch_v1
...
run-time entry points.