From 10d8b1480e6966ba03cd3afad3b5d6eb5e341fae Mon Sep 17 00:00:00 2001 From: pan xinhui Date: Tue, 23 Feb 2016 19:05:01 +0800 Subject: [PATCH] powerpc: Use BUILD_BUG_ON_MSG() for unsupported {cmp}xchg sizes __xchg_called_with_bad_pointer() can't tell us which code uses {cmp}xchg with an unsupported size, and no error is reported until the link stage. To make such problems easier to debug, use BUILD_BUG_ON_MSG() instead. Signed-off-by: pan xinhui [mpe: Tweak change log wording & add relaxed/acquire] Signed-off-by: Michael Ellerman fixup --- arch/powerpc/include/asm/cmpxchg.h | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) diff --git a/arch/powerpc/include/asm/cmpxchg.h b/arch/powerpc/include/asm/cmpxchg.h index cae4fa85250c..44efe739b6b9 100644 --- a/arch/powerpc/include/asm/cmpxchg.h +++ b/arch/powerpc/include/asm/cmpxchg.h @@ -5,6 +5,7 @@ #include #include #include +#include /* * Atomic exchange @@ -83,12 +84,6 @@ __xchg_u64_relaxed(u64 *p, unsigned long val) } #endif -/* - * This function doesn't exist, so you'll get a linker error - * if something tries to do an invalid xchg(). - */ -extern void __xchg_called_with_bad_pointer(void); - static __always_inline unsigned long __xchg_local(volatile void *ptr, unsigned long x, unsigned int size) { @@ -100,7 +95,7 @@ __xchg_local(volatile void *ptr, unsigned long x, unsigned int size) return __xchg_u64_local(ptr, x); #endif } - __xchg_called_with_bad_pointer(); + BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg"); return x; } @@ -115,7 +110,7 @@ __xchg_relaxed(void *ptr, unsigned long x, unsigned int size) return __xchg_u64_relaxed(ptr, x); #endif } - __xchg_called_with_bad_pointer(); + BUILD_BUG_ON_MSG(1, "Unsupported size for __xchg_local"); return x; } #define xchg_local(ptr,x) \ @@ -316,10 +311,6 @@ __cmpxchg_u64_acquire(u64 *p, unsigned long old, unsigned long new) } #endif -/* This function doesn't exist, so you'll get a linker error - if something tries to do an invalid cmpxchg(). */ -extern void __cmpxchg_called_with_bad_pointer(void); - static __always_inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, unsigned int size) @@ -332,7 +323,7 @@ __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, return __cmpxchg_u64(ptr, old, new); #endif } - __cmpxchg_called_with_bad_pointer(); + BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg"); return old; } @@ -348,7 +339,7 @@ __cmpxchg_local(volatile void *ptr, unsigned long old, unsigned long new, return __cmpxchg_u64_local(ptr, old, new); #endif } - __cmpxchg_called_with_bad_pointer(); + BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg_local"); return old; } @@ -364,7 +355,7 @@ __cmpxchg_relaxed(void *ptr, unsigned long old, unsigned long new, return __cmpxchg_u64_relaxed(ptr, old, new); #endif } - __cmpxchg_called_with_bad_pointer(); + BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg_relaxed"); return old; } @@ -380,7 +371,7 @@ __cmpxchg_acquire(void *ptr, unsigned long old, unsigned long new, return __cmpxchg_u64_acquire(ptr, old, new); #endif } - __cmpxchg_called_with_bad_pointer(); + BUILD_BUG_ON_MSG(1, "Unsupported size for __cmpxchg_acquire"); return old; } #define cmpxchg(ptr, o, n) \ -- 2.20.1