Messages in this thread | | | From | Nick Desaulniers <> | Date | Mon, 9 Sep 2019 14:06:36 -0700 | Subject | Re: [PATCH] arm64: fix unreachable code issue with cmpxchg |
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On Mon, Sep 9, 2019 at 1:21 PM Arnd Bergmann <arnd@arndb.de> wrote: > > On arm64 build with clang, sometimes the __cmpxchg_mb is not inlined > when CONFIG_OPTIMIZE_INLINING is set. > 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.
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de> > --- > arch/arm64/include/asm/cmpxchg.h | 15 ++++++++------- > 1 file changed, 8 insertions(+), 7 deletions(-) > > diff --git a/arch/arm64/include/asm/cmpxchg.h b/arch/arm64/include/asm/cmpxchg.h > index a1398f2f9994..fd64dc8a235f 100644 > --- a/arch/arm64/include/asm/cmpxchg.h > +++ b/arch/arm64/include/asm/cmpxchg.h > @@ -19,7 +19,7 @@ > * acquire+release for the latter. > */ > #define __XCHG_CASE(w, sfx, name, sz, mb, nop_lse, acq, acq_lse, rel, cl) \ > -static inline u##sz __xchg_case_##name##sz(u##sz x, volatile void *ptr) \ > +static __always_inline u##sz __xchg_case_##name##sz(u##sz x, volatile void *ptr)\ > { \ > u##sz ret; \ > unsigned long tmp; \ > @@ -62,7 +62,7 @@ __XCHG_CASE( , , mb_, 64, dmb ish, nop, , a, l, "memory") > #undef __XCHG_CASE > > #define __XCHG_GEN(sfx) \ > -static inline unsigned long __xchg##sfx(unsigned long x, \ > +static __always_inline unsigned long __xchg##sfx(unsigned long x, \ > volatile void *ptr, \ > int size) \ > { \ > @@ -103,8 +103,9 @@ __XCHG_GEN(_mb) > #define arch_xchg_release(...) __xchg_wrapper(_rel, __VA_ARGS__) > #define arch_xchg(...) __xchg_wrapper( _mb, __VA_ARGS__) > > -#define __CMPXCHG_CASE(name, sz) \ > -static inline u##sz __cmpxchg_case_##name##sz(volatile void *ptr, \ > +#define __CMPXCHG_CASE(name, sz) \ > +static __always_inline u##sz \ > +__cmpxchg_case_##name##sz(volatile void *ptr, \ > u##sz old, \ > u##sz new) \ > { \ > @@ -148,7 +149,7 @@ __CMPXCHG_DBL(_mb) > #undef __CMPXCHG_DBL > > #define __CMPXCHG_GEN(sfx) \ > -static inline unsigned long __cmpxchg##sfx(volatile void *ptr, \ > +static __always_inline unsigned long __cmpxchg##sfx(volatile void *ptr, \ > unsigned long old, \ > unsigned long new, \ > int size) \ > @@ -230,7 +231,7 @@ __CMPXCHG_GEN(_mb) > }) > > #define __CMPWAIT_CASE(w, sfx, sz) \ > -static inline void __cmpwait_case_##sz(volatile void *ptr, \ > +static __always_inline void __cmpwait_case_##sz(volatile void *ptr, \ > unsigned long val) \ > { \ > unsigned long tmp; \ > @@ -255,7 +256,7 @@ __CMPWAIT_CASE( , , 64); > #undef __CMPWAIT_CASE > > #define __CMPWAIT_GEN(sfx) \ > -static inline void __cmpwait##sfx(volatile void *ptr, \ > +static __always_inline void __cmpwait##sfx(volatile void *ptr, \ > unsigned long val, \ > int size) \ > { \ > -- > 2.20.0 > > -- > You received this message because you are subscribed to the Google Groups "Clang Built Linux" group. > To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20190909202153.144970-1-arnd%40arndb.de.
-- Thanks, ~Nick Desaulniers
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