On Wed, May 13, 2020 at 03:15:55PM +0200, Marco Elver wrote: > So far so good, except: both __no_sanitize_or_inline and > __no_kcsan_or_inline *do* avoid KCSAN instrumenting plain accesses, it > just doesn't avoid explicit kcsan_check calls, like those in > READ/WRITE_ONCE if KCSAN is enabled for the compilation unit. That's > just because macros won't be redefined just for __no_sanitize > functions. Similarly, READ_ONCE_NOCHECK does work as expected, and its > access is unchecked. > > This will have the expected result: > __no_sanitize_or_inline void foo(void) { x++; } // no data races reported > > This will not work as expected: > __no_sanitize_or_inline void foo(void) { READ_ONCE(x); } // data > races are reported > > All this could be fixed if GCC devs would finally take my patch to > make -fsanitize=thread distinguish volatile [1], but then we have to > wait ~years for the new compilers to reach us. So please don't hold > your breath for this one any time soon. > [1] https://gcc.gnu.org/pipermail/gcc-patches/2020-April/544452.html
Right, but that does not address the much larger issue of the attribute vs inline tranwreck :/ Also, could not this compiler instrumentation live as a kernel specific GCC-plugin instead of being part of GCC proper? Because in that case, we'd have much better control over it.