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s390: Replace weird use of PTR_RET.

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Saves repeating "(void __force *)__uptr" but it's less clear.  Using
the output of PTR_RET() to determine the error rather than just
testing IS_ERR() is odd.

For example, I *assume* __gptr_to_uptr() never returns NULL?  Because
the __ret would be 0 for the old code.  The new version is clearer, IMHO:
it would try to get_user() on that address.

If you hate this variant, I can just s/PTR_RET/PTR_ERR_OR_ZERO/ instead.

Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
This commit is contained in:
Rusty Russell 2013-07-15 11:21:32 +09:30
parent 8c6ffba0ed
commit 228b82211b
1 changed files with 8 additions and 4 deletions
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12
arch/s390/kvm/gaccess.h
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@ -42,9 +42,11 @@ static inline void __user *__gptr_to_uptr(struct kvm_vcpu *vcpu,
({ \
__typeof__(gptr) __uptr = __gptr_to_uptr(vcpu, gptr, 1);\
int __mask = sizeof(__typeof__(*(gptr))) - 1; \
int __ret = PTR_RET((void __force *)__uptr); \
int __ret; \
\
if (!__ret) { \
if (IS_ERR((void __force *)__uptr)) { \
__ret = PTR_ERR((void __force *)__uptr); \
} else { \
BUG_ON((unsigned long)__uptr & __mask); \
__ret = get_user(x, __uptr); \
} \
@ -55,9 +57,11 @@ static inline void __user *__gptr_to_uptr(struct kvm_vcpu *vcpu,
({ \
__typeof__(gptr) __uptr = __gptr_to_uptr(vcpu, gptr, 1);\
int __mask = sizeof(__typeof__(*(gptr))) - 1; \
int __ret = PTR_RET((void __force *)__uptr); \
int __ret; \
\
if (!__ret) { \
if (IS_ERR((void __force *)__uptr)) { \
__ret = PTR_ERR((void __force *)__uptr); \
} else { \
BUG_ON((unsigned long)__uptr & __mask); \
__ret = put_user(x, __uptr); \
} \