[patch 27/34] Force link error if xchg/cmpxchg gets called with unsupported size.

Martin Schwidefsky
2007-10-04T11:36:06Z

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From: Heiko Carstens <heiko.carstens@de.ibm.com>

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
---

include/asm-s390/system.h | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)

Index: quilt-2.6/include/asm-s390/system.h
===================================================================
--- quilt-2.6.orig/include/asm-s390/system.h
+++ quilt-2.6/include/asm-s390/system.h
@@ -130,6 +130,8 @@ extern void pfault_fini(void);
__ret; \
})

+extern void __xchg_called_with_bad_pointer(void);
+
static inline unsigned long __xchg(unsigned long x, void * ptr, int size)
{
unsigned long addr, old;
@@ -150,8 +152,7 @@ static inline unsigned long __xchg(unsig
: "=&d" (old), "=m" (*(int *) addr)
: "d" (x << shift), "d" (~(255 << shift)), "a" (addr),
"m" (*(int *) addr) : "memory", "cc", "0");
- x = old >> shift;
- break;
+ return old >> shift;
case 2:
addr = (unsigned long) ptr;
shift = (2 ^ (addr & 2)) << 3;
@@ -166,8 +167,7 @@ static inline unsigned long __xchg(unsig
: "=&d" (old), "=m" (*(int *) addr)
: "d" (x << shift), "d" (~(65535 << shift)), "a" (addr),
"m" (*(int *) addr) : "memory", "cc", "0");
- x = old >> shift;
- break;
+ return old >> shift;
case 4:
asm volatile(
" l %0,0(%3)\n"
@@ -176,8 +176,7 @@ static inline unsigned long __xchg(unsig
: "=&d" (old), "=m" (*(int *) ptr)
: "d" (x), "a" (ptr), "m" (*(int *) ptr)
: "memory", "cc");
- x = old;
- break;
+ return old;
#ifdef __s390x__
case 8:
asm volatile(
@@ -187,11 +186,11 @@ static inline unsigned long __xchg(unsig
: "=&d" (old), "=m" (*(long *) ptr)
: "d" (x), "a" (ptr), "m" (*(long *) ptr)
: "memory", "cc");
- x = old;
- break;
+ return old;
#endif /* __s390x__ */
- }
- return x;
+ }
+ __xchg_called_with_bad_pointer();
+ return x;
}

/*
@@ -206,6 +205,8 @@ static inline unsigned long __xchg(unsig
((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
(unsigned long)(n),sizeof(*(ptr))))

+extern void __cmpxchg_called_with_bad_pointer(void);
+
static inline unsigned long
__cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size)
{
@@ -270,7 +271,8 @@ __cmpxchg(volatile void *ptr, unsigned l
return prev;
#endif /* __s390x__ */
}
- return old;
+ __cmpxchg_called_with_bad_pointer();
+ return old;
}

/*