On Tue, May 14, 2024 at 4:55 AM Marco Elver <elver@xxxxxxxxxx> wrote: > > On Mon, 13 May 2024 at 20:48, Kees Cook <keescook@xxxxxxxxxxxx> wrote: > > > > In the future can you CC the various maintainers of the affected > > tooling? :) > > > > On Mon, May 06, 2024 at 10:35:41PM +0900, Masahiro Yamada wrote: > > > > > > This patch set removes many instances of the following variables: > > > > > > - OBJECT_FILES_NON_STANDARD > > > - KASAN_SANITIZE > > > - UBSAN_SANITIZE > > > - KCSAN_SANITIZE > > > - KMSAN_SANITIZE > > > - GCOV_PROFILE > > > - KCOV_INSTRUMENT > > > > > > Such tools are intended only for kernel space objects, most of which > > > are listed in obj-y, lib-y, or obj-m. > > I welcome the simplification, but see below. > > > This is a reasonable assertion, and the changes really simplify things > > now and into the future. Thanks for finding such a clean solution! I > > note that it also immediately fixes the issue noticed and fixed here: > > https://lore.kernel.org/all/20240513122754.1282833-1-roberto.sassu@xxxxxxxxxxxxxxx/ > > > > > The best guess is, objects in $(obj-y), $(lib-y), $(obj-m) can opt in > > > such tools. Otherwise, not. > > > > > > This works in most places. > > > > I am worried about the use of "guess" and "most", though. :) Before, we > > had some clear opt-out situations, and now it's more of a side-effect. I > > think this is okay, but I'd really like to know more about your testing. > > > > It seems like you did build testing comparing build flags, since you > > call out some of the explicit changes in patch 2, quoting: > > > > > - include arch/mips/vdso/vdso-image.o into UBSAN, GCOV, KCOV > > > - include arch/sparc/vdso/vdso-image-*.o into UBSAN > > > - include arch/sparc/vdso/vma.o into UBSAN > > > - include arch/x86/entry/vdso/extable.o into KASAN, KCSAN, UBSAN, GCOV, KCOV > > > - include arch/x86/entry/vdso/vdso-image-*.o into KASAN, KCSAN, UBSAN, GCOV, KCOV > > > - include arch/x86/entry/vdso/vdso32-setup.o into KASAN, KCSAN, UBSAN, GCOV, KCOV > > > - include arch/x86/entry/vdso/vma.o into GCOV, KCOV > > > - include arch/x86/um/vdso/vma.o into KASAN, GCOV, KCOV > > > > I would agree that these cases are all likely desirable. > > > > Did you find any cases where you found that instrumentation was _removed_ > > where not expected? > > In addition, did you boot test these kernels? No. I didn't. > While I currently don't > recall if the vdso code caused us problems (besides the linking > problem for non-kernel objects), anything that is opted out from > instrumentation in arch/ code needs to be carefully tested if it > should be opted back into instrumentation. We had many fun hours > debugging boot hangs or other recursion issues due to instrumented > arch code. As I replied to Kees, I checked the diff of .*.cmd files. I believe checking the compiler flags for every object is comprehensive testing. If the same set of compiler flags is passed, the same build artifact is generated. -- Best Regards Masahiro Yamada
