[lttng-dev] [PATCH urcu] Fix uatomic sign cast (v2)
Mathieu Desnoyers
mathieu.desnoyers at efficios.com
Mon Mar 26 11:26:03 EDT 2012
* Mathieu Desnoyers (mathieu.desnoyers at efficios.com) wrote:
> Passing an unsigned int to uatomic_sub does not honor sign extend to
> long, as we should be allowed by assume.
>
> Fix this by introducing caa_cast_long_keep_sign(), which casts either to
> long or unsigned long depending on the signedness of the argument
> received. It is used in uatomic_sub before applying the "-" operator,
> since this operator needs to operate on the "long" type size (since sign
> extension might not be performed if the argument received is unsigned).
FYI, this fix is now committed to urcu master branch as:
commit e56d99bf2046a163875df80bab5195f38606dfde
Thanks,
Mathieu
>
> Changelog since v1:
> - cast_long_keep_sign -> caa_cast_long_keep_sign
>
> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
> ---
> tests/test_uatomic.c | 4 +++
> urcu/compiler.h | 5 ++++
> urcu/uatomic/generic.h | 59 ++++++++++++++++++++++++++-----------------------
> urcu/uatomic/ppc.h | 18 ++++++++------
> urcu/uatomic/s390.h | 13 +++++-----
> urcu/uatomic/sparc64.h | 7 +++--
> urcu/uatomic/x86.h | 42 ++++++++++++++++++----------------
> 7 files changed, 84 insertions(+), 64 deletions(-)
>
> Index: userspace-rcu/tests/test_uatomic.c
> ===================================================================
> --- userspace-rcu.orig/tests/test_uatomic.c
> +++ userspace-rcu/tests/test_uatomic.c
> @@ -62,6 +62,10 @@ do { \
> assert(uatomic_read(ptr) == 122); \
> v = uatomic_sub_return(ptr, 1); \
> assert(v == 121); \
> + uatomic_sub(ptr, (unsigned int) 2); \
> + assert(uatomic_read(ptr) == 119); \
> + uatomic_inc(ptr); \
> + uatomic_inc(ptr); \
> assert(uatomic_read(ptr) == 121); \
> uatomic_and(ptr, 129); \
> assert(uatomic_read(ptr) == 1); \
> Index: userspace-rcu/urcu/compiler.h
> ===================================================================
> --- userspace-rcu.orig/urcu/compiler.h
> +++ userspace-rcu/urcu/compiler.h
> @@ -86,4 +86,9 @@
> #define URCU_FORCE_CAST(type, arg) ((type) (arg))
> #endif
>
> +#define caa_is_signed_type(type) (((type) (-1)) < 0)
> +
> +#define caa_cast_long_keep_sign(v) \
> + (caa_is_signed_type(__typeof__(v)) ? (long) (v) : (unsigned long) (v))
> +
> #endif /* _URCU_COMPILER_H */
> Index: userspace-rcu/urcu/uatomic/generic.h
> ===================================================================
> --- userspace-rcu.orig/urcu/uatomic/generic.h
> +++ userspace-rcu/urcu/uatomic/generic.h
> @@ -81,9 +81,10 @@ unsigned long _uatomic_cmpxchg(void *add
> }
>
>
> -#define uatomic_cmpxchg(addr, old, _new) \
> - ((__typeof__(*(addr))) _uatomic_cmpxchg((addr), (unsigned long)(old),\
> - (unsigned long)(_new), \
> +#define uatomic_cmpxchg(addr, old, _new) \
> + ((__typeof__(*(addr))) _uatomic_cmpxchg((addr), \
> + caa_cast_long_keep_sign(old), \
> + caa_cast_long_keep_sign(_new),\
> sizeof(*(addr))))
>
>
> @@ -119,8 +120,8 @@ void _uatomic_and(void *addr, unsigned l
>
> #define uatomic_and(addr, v) \
> (_uatomic_and((addr), \
> - (unsigned long)(v), \
> - sizeof(*(addr))))
> + caa_cast_long_keep_sign(v), \
> + sizeof(*(addr))))
> #endif
>
> /* uatomic_or */
> @@ -156,8 +157,8 @@ void _uatomic_or(void *addr, unsigned lo
>
> #define uatomic_or(addr, v) \
> (_uatomic_or((addr), \
> - (unsigned long)(v), \
> - sizeof(*(addr))))
> + caa_cast_long_keep_sign(v), \
> + sizeof(*(addr))))
> #endif
>
> /* uatomic_add_return */
> @@ -188,10 +189,10 @@ unsigned long _uatomic_add_return(void *
> }
>
>
> -#define uatomic_add_return(addr, v) \
> - ((__typeof__(*(addr))) _uatomic_add_return((addr), \
> - (unsigned long)(v), \
> - sizeof(*(addr))))
> +#define uatomic_add_return(addr, v) \
> + ((__typeof__(*(addr))) _uatomic_add_return((addr), \
> + caa_cast_long_keep_sign(v), \
> + sizeof(*(addr))))
> #endif /* #ifndef uatomic_add_return */
>
> #ifndef uatomic_xchg
> @@ -253,7 +254,8 @@ unsigned long _uatomic_exchange(void *ad
> }
>
> #define uatomic_xchg(addr, v) \
> - ((__typeof__(*(addr))) _uatomic_exchange((addr), (unsigned long)(v), \
> + ((__typeof__(*(addr))) _uatomic_exchange((addr), \
> + caa_cast_long_keep_sign(v), \
> sizeof(*(addr))))
> #endif /* #ifndef uatomic_xchg */
>
> @@ -322,10 +324,10 @@ void _uatomic_and(void *addr, unsigned l
> _uatomic_link_error();
> }
>
> -#define uatomic_and(addr, v) \
> - (_uatomic_and((addr), \
> - (unsigned long)(v), \
> - sizeof(*(addr))))
> +#define uatomic_and(addr, v) \
> + (_uatomic_and((addr), \
> + caa_cast_long_keep_sign(v), \
> + sizeof(*(addr))))
> #endif /* #ifndef uatomic_and */
>
> #ifndef uatomic_or
> @@ -393,10 +395,10 @@ void _uatomic_or(void *addr, unsigned lo
> _uatomic_link_error();
> }
>
> -#define uatomic_or(addr, v) \
> - (_uatomic_or((addr), \
> - (unsigned long)(v),\
> - sizeof(*(addr))))
> +#define uatomic_or(addr, v) \
> + (_uatomic_or((addr), \
> + caa_cast_long_keep_sign(v), \
> + sizeof(*(addr))))
> #endif /* #ifndef uatomic_or */
>
> #ifndef uatomic_add_return
> @@ -469,10 +471,10 @@ unsigned long _uatomic_add_return(void *
> return 0;
> }
>
> -#define uatomic_add_return(addr, v) \
> - ((__typeof__(*(addr))) _uatomic_add_return((addr), \
> - (unsigned long)(v), \
> - sizeof(*(addr))))
> +#define uatomic_add_return(addr, v) \
> + ((__typeof__(*(addr))) _uatomic_add_return((addr), \
> + caa_cast_long_keep_sign(v), \
> + sizeof(*(addr))))
> #endif /* #ifndef uatomic_add_return */
>
> #ifndef uatomic_xchg
> @@ -546,7 +548,8 @@ unsigned long _uatomic_exchange(void *ad
> }
>
> #define uatomic_xchg(addr, v) \
> - ((__typeof__(*(addr))) _uatomic_exchange((addr), (unsigned long)(v), \
> + ((__typeof__(*(addr))) _uatomic_exchange((addr), \
> + caa_cast_long_keep_sign(v), \
> sizeof(*(addr))))
> #endif /* #ifndef uatomic_xchg */
>
> @@ -558,8 +561,10 @@ unsigned long _uatomic_exchange(void *ad
> #define uatomic_add(addr, v) (void)uatomic_add_return((addr), (v))
> #endif
>
> -#define uatomic_sub_return(addr, v) uatomic_add_return((addr), -(v))
> -#define uatomic_sub(addr, v) uatomic_add((addr), -(v))
> +#define uatomic_sub_return(addr, v) \
> + uatomic_add_return((addr), -(caa_cast_long_keep_sign(v)))
> +#define uatomic_sub(addr, v) \
> + uatomic_add((addr), -(caa_cast_long_keep_sign(v)))
>
> #ifndef uatomic_inc
> #define uatomic_inc(addr) uatomic_add((addr), 1)
> Index: userspace-rcu/urcu/uatomic/ppc.h
> ===================================================================
> --- userspace-rcu.orig/urcu/uatomic/ppc.h
> +++ userspace-rcu/urcu/uatomic/ppc.h
> @@ -100,7 +100,8 @@ unsigned long _uatomic_exchange(void *ad
> }
>
> #define uatomic_xchg(addr, v) \
> - ((__typeof__(*(addr))) _uatomic_exchange((addr), (unsigned long)(v), \
> + ((__typeof__(*(addr))) _uatomic_exchange((addr), \
> + caa_cast_long_keep_sign(v), \
> sizeof(*(addr))))
> /* cmpxchg */
>
> @@ -159,9 +160,10 @@ unsigned long _uatomic_cmpxchg(void *add
> }
>
>
> -#define uatomic_cmpxchg(addr, old, _new) \
> - ((__typeof__(*(addr))) _uatomic_cmpxchg((addr), (unsigned long)(old),\
> - (unsigned long)(_new), \
> +#define uatomic_cmpxchg(addr, old, _new) \
> + ((__typeof__(*(addr))) _uatomic_cmpxchg((addr), \
> + caa_cast_long_keep_sign(old), \
> + caa_cast_long_keep_sign(_new),\
> sizeof(*(addr))))
>
> /* uatomic_add_return */
> @@ -215,10 +217,10 @@ unsigned long _uatomic_add_return(void *
> }
>
>
> -#define uatomic_add_return(addr, v) \
> - ((__typeof__(*(addr))) _uatomic_add_return((addr), \
> - (unsigned long)(v), \
> - sizeof(*(addr))))
> +#define uatomic_add_return(addr, v) \
> + ((__typeof__(*(addr))) _uatomic_add_return((addr), \
> + caa_cast_long_keep_sign(v), \
> + sizeof(*(addr))))
>
> #ifdef __cplusplus
> }
> Index: userspace-rcu/urcu/uatomic/s390.h
> ===================================================================
> --- userspace-rcu.orig/urcu/uatomic/s390.h
> +++ userspace-rcu/urcu/uatomic/s390.h
> @@ -106,8 +106,9 @@ unsigned long _uatomic_exchange(volatile
> }
>
> #define uatomic_xchg(addr, v) \
> - (__typeof__(*(addr))) _uatomic_exchange((addr), (unsigned long)(v), \
> - sizeof(*(addr)))
> + (__typeof__(*(addr))) _uatomic_exchange((addr), \
> + caa_cast_long_keep_sign(v), \
> + sizeof(*(addr)))
>
> /* cmpxchg */
>
> @@ -145,10 +146,10 @@ unsigned long _uatomic_cmpxchg(void *add
> return 0;
> }
>
> -#define uatomic_cmpxchg(addr, old, _new) \
> - (__typeof__(*(addr))) _uatomic_cmpxchg((addr), \
> - (unsigned long)(old), \
> - (unsigned long)(_new), \
> +#define uatomic_cmpxchg(addr, old, _new) \
> + (__typeof__(*(addr))) _uatomic_cmpxchg((addr), \
> + caa_cast_long_keep_sign(old), \
> + caa_cast_long_keep_sign(_new),\
> sizeof(*(addr)))
>
> #ifdef __cplusplus
> Index: userspace-rcu/urcu/uatomic/sparc64.h
> ===================================================================
> --- userspace-rcu.orig/urcu/uatomic/sparc64.h
> +++ userspace-rcu/urcu/uatomic/sparc64.h
> @@ -66,9 +66,10 @@ unsigned long _uatomic_cmpxchg(void *add
> }
>
>
> -#define uatomic_cmpxchg(addr, old, _new) \
> - ((__typeof__(*(addr))) _uatomic_cmpxchg((addr), (unsigned long)(old),\
> - (unsigned long)(_new), \
> +#define uatomic_cmpxchg(addr, old, _new) \
> + ((__typeof__(*(addr))) _uatomic_cmpxchg((addr), \
> + caa_cast_long_keep_sign(old), \
> + caa_cast_long_keep_sign(_new), \
> sizeof(*(addr))))
>
> #ifdef __cplusplus
> Index: userspace-rcu/urcu/uatomic/x86.h
> ===================================================================
> --- userspace-rcu.orig/urcu/uatomic/x86.h
> +++ userspace-rcu/urcu/uatomic/x86.h
> @@ -102,8 +102,9 @@ unsigned long __uatomic_cmpxchg(void *ad
> }
>
> #define _uatomic_cmpxchg(addr, old, _new) \
> - ((__typeof__(*(addr))) __uatomic_cmpxchg((addr), (unsigned long)(old),\
> - (unsigned long)(_new), \
> + ((__typeof__(*(addr))) __uatomic_cmpxchg((addr), \
> + caa_cast_long_keep_sign(old), \
> + caa_cast_long_keep_sign(_new),\
> sizeof(*(addr))))
>
> /* xchg */
> @@ -163,7 +164,8 @@ unsigned long __uatomic_exchange(void *a
> }
>
> #define _uatomic_xchg(addr, v) \
> - ((__typeof__(*(addr))) __uatomic_exchange((addr), (unsigned long)(v), \
> + ((__typeof__(*(addr))) __uatomic_exchange((addr), \
> + caa_cast_long_keep_sign(v), \
> sizeof(*(addr))))
>
> /* uatomic_add_return */
> @@ -226,10 +228,10 @@ unsigned long __uatomic_add_return(void
> return 0;
> }
>
> -#define _uatomic_add_return(addr, v) \
> - ((__typeof__(*(addr))) __uatomic_add_return((addr), \
> - (unsigned long)(v), \
> - sizeof(*(addr))))
> +#define _uatomic_add_return(addr, v) \
> + ((__typeof__(*(addr))) __uatomic_add_return((addr), \
> + caa_cast_long_keep_sign(v), \
> + sizeof(*(addr))))
>
> /* uatomic_and */
>
> @@ -283,7 +285,7 @@ void __uatomic_and(void *addr, unsigned
> }
>
> #define _uatomic_and(addr, v) \
> - (__uatomic_and((addr), (unsigned long)(v), sizeof(*(addr))))
> + (__uatomic_and((addr), caa_cast_long_keep_sign(v), sizeof(*(addr))))
>
> /* uatomic_or */
>
> @@ -337,7 +339,7 @@ void __uatomic_or(void *addr, unsigned l
> }
>
> #define _uatomic_or(addr, v) \
> - (__uatomic_or((addr), (unsigned long)(v), sizeof(*(addr))))
> + (__uatomic_or((addr), caa_cast_long_keep_sign(v), sizeof(*(addr))))
>
> /* uatomic_add */
>
> @@ -391,7 +393,7 @@ void __uatomic_add(void *addr, unsigned
> }
>
> #define _uatomic_add(addr, v) \
> - (__uatomic_add((addr), (unsigned long)(v), sizeof(*(addr))))
> + (__uatomic_add((addr), caa_cast_long_keep_sign(v), sizeof(*(addr))))
>
>
> /* uatomic_inc */
> @@ -517,7 +519,7 @@ extern unsigned long _compat_uatomic_set
> unsigned long _new, int len);
> #define compat_uatomic_set(addr, _new) \
> ((__typeof__(*(addr))) _compat_uatomic_set((addr), \
> - (unsigned long)(_new), \
> + caa_cast_long_keep_sign(_new), \
> sizeof(*(addr))))
>
>
> @@ -525,35 +527,35 @@ extern unsigned long _compat_uatomic_xch
> unsigned long _new, int len);
> #define compat_uatomic_xchg(addr, _new) \
> ((__typeof__(*(addr))) _compat_uatomic_xchg((addr), \
> - (unsigned long)(_new), \
> + caa_cast_long_keep_sign(_new), \
> sizeof(*(addr))))
>
> extern unsigned long _compat_uatomic_cmpxchg(void *addr, unsigned long old,
> unsigned long _new, int len);
> #define compat_uatomic_cmpxchg(addr, old, _new) \
> ((__typeof__(*(addr))) _compat_uatomic_cmpxchg((addr), \
> - (unsigned long)(old), \
> - (unsigned long)(_new), \
> + caa_cast_long_keep_sign(old), \
> + caa_cast_long_keep_sign(_new), \
> sizeof(*(addr))))
>
> extern void _compat_uatomic_and(void *addr, unsigned long _new, int len);
> #define compat_uatomic_and(addr, v) \
> (_compat_uatomic_and((addr), \
> - (unsigned long)(v), \
> + caa_cast_long_keep_sign(v), \
> sizeof(*(addr))))
>
> extern void _compat_uatomic_or(void *addr, unsigned long _new, int len);
> #define compat_uatomic_or(addr, v) \
> (_compat_uatomic_or((addr), \
> - (unsigned long)(v), \
> + caa_cast_long_keep_sign(v), \
> sizeof(*(addr))))
>
> extern unsigned long _compat_uatomic_add_return(void *addr,
> unsigned long _new, int len);
> -#define compat_uatomic_add_return(addr, v) \
> - ((__typeof__(*(addr))) _compat_uatomic_add_return((addr), \
> - (unsigned long)(v), \
> - sizeof(*(addr))))
> +#define compat_uatomic_add_return(addr, v) \
> + ((__typeof__(*(addr))) _compat_uatomic_add_return((addr), \
> + caa_cast_long_keep_sign(v), \
> + sizeof(*(addr))))
>
> #define compat_uatomic_add(addr, v) \
> ((void)compat_uatomic_add_return((addr), (v)))
> --
> Mathieu Desnoyers
> Operating System Efficiency R&D Consultant
> EfficiOS Inc.
> http://www.efficios.com
>
> _______________________________________________
> lttng-dev mailing list
> lttng-dev at lists.lttng.org
> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
--
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com
More information about the lttng-dev
mailing list