From 2501cf768e4009a06287a5ee842fd93dd4fd690e Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 28 Mar 2012 18:30:02 +0100 Subject: [PATCH] m68k: Fix xchg/cmpxchg to fail to link if given an inappropriate pointer Fix the m68k versions of xchg() and cmpxchg() to fail to link if given an inappropriately sized pointer rather than BUG()'ing at runtime. Signed-off-by: David Howells Acked-by: Greg Ungerer cc: linux-m68k@lists.linux-m68k.org --- arch/m68k/include/asm/system.h | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/arch/m68k/include/asm/system.h b/arch/m68k/include/asm/system.h index 47b01f4726bc..a10c4d1241de 100644 --- a/arch/m68k/include/asm/system.h +++ b/arch/m68k/include/asm/system.h @@ -68,6 +68,8 @@ asmlinkage void resume(void); struct __xchg_dummy { unsigned long a[100]; }; #define __xg(x) ((volatile struct __xchg_dummy *)(x)) +extern unsigned long __invalid_xchg_size(unsigned long, volatile void *, int); + #ifndef CONFIG_RMW_INSNS static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size) { @@ -92,7 +94,8 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz x = tmp; break; default: - BUG(); + tmp = __invalid_xchg_size(x, ptr, size); + break; } local_irq_restore(flags); @@ -102,7 +105,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size) { switch (size) { - case 1: + case 1: __asm__ __volatile__ ("moveb %2,%0\n\t" "1:\n\t" @@ -110,7 +113,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz "jne 1b" : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory"); break; - case 2: + case 2: __asm__ __volatile__ ("movew %2,%0\n\t" "1:\n\t" @@ -118,7 +121,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz "jne 1b" : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory"); break; - case 4: + case 4: __asm__ __volatile__ ("movel %2,%0\n\t" "1:\n\t" @@ -126,6 +129,9 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz "jne 1b" : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory"); break; + default: + x = __invalid_xchg_size(x, ptr, size); + break; } return x; } @@ -135,6 +141,9 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n)) +extern unsigned long __invalid_cmpxchg_size(volatile void *, + unsigned long, unsigned long, int); + /* * Atomic compare and exchange. Compare OLD with MEM, if identical, * store NEW in MEM. Return the initial value in MEM. Success is @@ -162,6 +171,9 @@ static inline unsigned long __cmpxchg(volatile void *p, unsigned long old, : "=d" (old), "=m" (*(int *)p) : "d" (new), "0" (old), "m" (*(int *)p)); break; + default: + old = __invalid_cmpxchg_size(p, old, new, size); + break; } return old; } -- 2.20.1