Re: [PATCH] arm64: fix unreachable code issue with cmpxchg

From: Nathan Chancellor
Date: Mon Sep 09 2019 - 23:43:21 EST

On Mon, Sep 09, 2019 at 10:21:35PM +0200, Arnd Bergmann wrote:
> On arm64 build with clang, sometimes the __cmpxchg_mb is not inlined
> Clang then fails a compile-time assertion, because it cannot tell at
> compile time what the size of the argument is:
> mm/memcontrol.o: In function `__cmpxchg_mb':
> memcontrol.c:(.text+0x1a4c): undefined reference to `__compiletime_assert_175'
> memcontrol.c:(.text+0x1a4c): relocation truncated to fit: R_AARCH64_CALL26 against undefined symbol `__compiletime_assert_175'
> Mark all of the cmpxchg() style functions as __always_inline to
> ensure that the compiler can see the result.
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Tested-by: Nathan Chancellor <natechancellor@xxxxxxxxx>