Hi Bill, On Mon, 5 Oct 2026, at 12:25, Bill Wendling wrote: > Code that runs outside the kernel proper, such as the EFI stub, gets > nothing out of the counted_by annotations: the bounds checks they feed > (FORTIFY_SOURCE, UBSAN_BOUNDS) are already disabled there. > > The annotations can also break the build. A __counted_by_ptr() that > names a member declared after the pointer needs Clang's > '-fexperimental-late-parse-attributes', which the top-level Makefile > adds to 'KBUILD_CFLAGS'. The x86 EFI stub builds its own cflags and does > not get that flag, so it fails as soon as such a struct is pulled in > through a common header. > > Overriding the macros from a Makefile doesn't work: > 'compiler_types.h' is pulled in with '-include', which is processed > after all -D/-U options, so it re-establishes the definitions. Follow > the '__NO_FORTIFY' precedent instead: let a build define > '__NO_COUNTED_BY' or '__NO_COUNTED_BY_PTR' to turn the corresponding > annotation into a no-op. The two are kept separate but parallel so they > can be folded together once all supported compilers handle > '__counted_by' on pointers. >
I'd prefer a single macro here - if there is ever a case where we need to turn off one but not the other, we can revisit. Otherwise, this looks good to me - thanks.
