On Tue, Jul 23, 2019 at 12:50 PM Peter Zijlstra <pet...@infradead.org> wrote: > On Fri, Jul 19, 2019 at 01:36:00PM +0200, Arnd Bergmann wrote: > > --- a/include/linux/wait.h > > +++ b/include/linux/wait.h > > @@ -70,8 +70,17 @@ extern void __init_waitqueue_head(struct wait_queue_head > > *wq_head, const char *n > > #ifdef CONFIG_LOCKDEP > > # define __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) \ > > ({ init_waitqueue_head(&name); name; }) > > -# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \ > > +# if defined(__clang__) && __clang_major__ <= 9 > > +/* work around https://bugs.llvm.org/show_bug.cgi?id=42604 */ > > +# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) > > \ > > + _Pragma("clang diagnostic push") > > \ > > + _Pragma("clang diagnostic ignored \"-Wuninitialized\"") > > \ > > + struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) > > \ > > + _Pragma("clang diagnostic pop") > > +# else > > +# define DECLARE_WAIT_QUEUE_HEAD_ONSTACK(name) \ > > struct wait_queue_head name = __WAIT_QUEUE_HEAD_INIT_ONSTACK(name) > > +# endif > > While this is indeed much better than before; do we really want to do > this? That is, since clang-9 release will not need this, we're basically > doing the above for pre-release compilers only.
Kernelci currently builds arch/arm and arch/arm64 kernels with clang-8, and probably won't change to clang-9 until after that is released, presumably in September. Anyone doing x86 builds would use a clang-9 snapshot today because of the asm-goto support, but so far the fix has not been merged there either. I think the chances of it getting fixed before the release are fairly good, but I don't know how long it will actually take. Arnd