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m68k: Fix xchg/cmpxchg to fail to link if given an inappropriate pointer

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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 <dhowells@redhat.com>
Acked-by: Greg Ungerer <gerg@uclinux.org>
cc: linux-m68k@lists.linux-m68k.org
This commit is contained in:
David Howells 2012-03-28 18:30:02 +01:00
parent c9034c3a1d
commit 2501cf768e
1 changed files with 16 additions and 4 deletions
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20
arch/m68k/include/asm/system.h
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@ -68,6 +68,8 @@ asmlinkage void resume(void);
struct __xchg_dummy { unsigned long a[100]; }; struct __xchg_dummy { unsigned long a[100]; };
#define __xg(x) ((volatile struct __xchg_dummy *)(x)) #define __xg(x) ((volatile struct __xchg_dummy *)(x))
extern unsigned long __invalid_xchg_size(unsigned long, volatile void *, int);
#ifndef CONFIG_RMW_INSNS #ifndef CONFIG_RMW_INSNS
static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size) 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; x = tmp;
break; break;
default: default:
BUG(); tmp = __invalid_xchg_size(x, ptr, size);
break;
} }
local_irq_restore(flags); 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) static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
{ {
switch (size) { switch (size) {
case 1: case 1:
__asm__ __volatile__ __asm__ __volatile__
("moveb %2,%0\n\t" ("moveb %2,%0\n\t"
"1:\n\t" "1:\n\t"
@ -110,7 +113,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz
"jne 1b" "jne 1b"
: "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory"); : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
break; break;
case 2: case 2:
__asm__ __volatile__ __asm__ __volatile__
("movew %2,%0\n\t" ("movew %2,%0\n\t"
"1:\n\t" "1:\n\t"
@ -118,7 +121,7 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz
"jne 1b" "jne 1b"
: "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory"); : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
break; break;
case 4: case 4:
__asm__ __volatile__ __asm__ __volatile__
("movel %2,%0\n\t" ("movel %2,%0\n\t"
"1:\n\t" "1:\n\t"
@ -126,6 +129,9 @@ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int siz
"jne 1b" "jne 1b"
: "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory"); : "=&d" (x) : "d" (x), "m" (*__xg(ptr)) : "memory");
break; break;
default:
x = __invalid_xchg_size(x, ptr, size);
break;
} }
return x; 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)) #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, * Atomic compare and exchange. Compare OLD with MEM, if identical,
* store NEW in MEM. Return the initial value in MEM. Success is * 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" (old), "=m" (*(int *)p)
: "d" (new), "0" (old), "m" (*(int *)p)); : "d" (new), "0" (old), "m" (*(int *)p));
break; break;
default:
old = __invalid_cmpxchg_size(p, old, new, size);
break;
} }
return old; return old;
} }