From 29524a9d42f683ca7b67f07f1ac3f6049c8675cc Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Thu, 6 Jul 2017 15:35:24 -0700 Subject: compiler, clang: always inline when CONFIG_OPTIMIZE_INLINING is disabled commit 9a04dbcfb33b4012d0ce8c0282f1e3ca694675b1 upstream. The motivation for commit abb2ea7dfd82 ("compiler, clang: suppress warning for unused static inline functions") was to suppress clang's warnings about unused static inline functions. For configs without CONFIG_OPTIMIZE_INLINING enabled, such as any non-x86 architecture, `inline' in the kernel implies that __attribute__((always_inline)) is used. Some code depends on that behavior, see https://lkml.org/lkml/2017/6/13/918: net/built-in.o: In function `__xchg_mb': arch/arm64/include/asm/cmpxchg.h:99: undefined reference to `__compiletime_assert_99' arch/arm64/include/asm/cmpxchg.h:99: undefined reference to `__compiletime_assert_99 The full fix would be to identify these breakages and annotate the functions with __always_inline instead of `inline'. But since we are late in the 4.12-rc cycle, simply carry forward the forced inlining behavior and work toward moving arm64, and other architectures, toward CONFIG_OPTIMIZE_INLINING behavior. Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1706261552200.1075@chino.kir.corp.google.com Signed-off-by: David Rientjes Reported-by: Sodagudi Prasad Tested-by: Sodagudi Prasad Tested-by: Matthias Kaehlcke Cc: Mark Rutland Cc: Will Deacon Cc: Catalin Marinas Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- include/linux/compiler-clang.h | 8 -------- 1 file changed, 8 deletions(-) (limited to 'include/linux/compiler-clang.h') diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index 8a97da12ea26..01225b0059b1 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -16,14 +16,6 @@ */ #define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__) -/* - * GCC does not warn about unused static inline functions for - * -Wunused-function. This turns out to avoid the need for complex #ifdef - * directives. Suppress the warning in clang as well. - */ -#undef inline -#define inline inline __attribute__((unused)) notrace - /* Clang doesn't have a way to turn it off per-function, yet. */ #ifdef __noretpoline #undef __noretpoline -- cgit v1.2.3