COMPAT_SYSCALL_DEFINE: infrastructure

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 45 insertions, 0 deletions

diff --git a/arch/s390/include/asm/compat.h b/arch/s390/include/asm/compat.h
index 18cd6b592650..f8c6df6cd1f0 100644
--- a/arch/s390/include/asm/compat.h
+++ b/arch/s390/include/asm/compat.h
@@ -7,6 +7,9 @@
 #include <linux/sched.h>
 #include <linux/thread_info.h>
 
+#define __TYPE_IS_PTR(t) (!__builtin_types_compatible_p(typeof(0?(t)0:0ULL), u64))
+#define __SC_DELOUSE(t,v) (t)(__TYPE_IS_PTR(t) ? ((v) & 0x7fffffff) : (v))
+
 #define PSW32_MASK_PER          0x40000000UL
 #define PSW32_MASK_DAT          0x04000000UL
 #define PSW32_MASK_IO           0x02000000UL
diff --git a/include/linux/compat.h b/include/linux/compat.h
index 784ebfe63c48..a7877fa809fd 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -23,6 +23,48 @@
 #define COMPAT_USE_64BIT_TIME 0
 #endif
 
+#ifndef __SC_DELOUSE
+#define __SC_DELOUSE(t,v) ((t)(unsigned long)(v))
+#endif
+
+#define __SC_CCAST1(t1, a1)      __SC_DELOUSE(t1,a1)
+#define __SC_CCAST2(t2, a2, ...) __SC_DELOUSE(t2,a2), __SC_CCAST1(__VA_ARGS__)
+#define __SC_CCAST3(t3, a3, ...) __SC_DELOUSE(t3,a3), __SC_CCAST2(__VA_ARGS__)
+#define __SC_CCAST4(t4, a4, ...) __SC_DELOUSE(t4,a4), __SC_CCAST3(__VA_ARGS__)
+#define __SC_CCAST5(t5, a5, ...) __SC_DELOUSE(t5,a5), __SC_CCAST4(__VA_ARGS__)
+#define __SC_CCAST6(t6, a6, ...) __SC_DELOUSE(t6,a6), __SC_CCAST5(__VA_ARGS__)
+#define COMPAT_SYSCALL_DEFINE1(name, ...) \
+        COMPAT_SYSCALL_DEFINEx(1, _##name, __VA_ARGS__)
+#define COMPAT_SYSCALL_DEFINE2(name, ...) \
+        COMPAT_SYSCALL_DEFINEx(2, _##name, __VA_ARGS__)
+#define COMPAT_SYSCALL_DEFINE3(name, ...) \
+        COMPAT_SYSCALL_DEFINEx(3, _##name, __VA_ARGS__)
+#define COMPAT_SYSCALL_DEFINE4(name, ...) \
+        COMPAT_SYSCALL_DEFINEx(4, _##name, __VA_ARGS__)
+#define COMPAT_SYSCALL_DEFINE5(name, ...) \
+        COMPAT_SYSCALL_DEFINEx(5, _##name, __VA_ARGS__)
+#define COMPAT_SYSCALL_DEFINE6(name, ...) \
+        COMPAT_SYSCALL_DEFINEx(6, _##name, __VA_ARGS__)
+
+#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
+
+#define COMPAT_SYSCALL_DEFINEx(x, name, ...)                            \
+        asmlinkage long compat_sys##name(__SC_DECL##x(__VA_ARGS__));    \
+        static inline long C_SYSC##name(__SC_DECL##x(__VA_ARGS__));     \
+        asmlinkage long compat_SyS##name(__SC_LONG##x(__VA_ARGS__))     \
+        {                                                               \
+                return (long) C_SYSC##name(__SC_CCAST##x(__VA_ARGS__)); \
+        }                                                               \
+        SYSCALL_ALIAS(compat_sys##name, compat_SyS##name);              \
+        static inline long C_SYSC##name(__SC_DECL##x(__VA_ARGS__))
+
+#else /* CONFIG_HAVE_SYSCALL_WRAPPERS */
+
+#define COMPAT_SYSCALL_DEFINEx(x, name, ...)                            \
+        asmlinkage long compat_sys##name(__SC_DECL##x(__VA_ARGS__))
+
+#endif /* CONFIG_HAVE_SYSCALL_WRAPPERS */
+
 #define compat_jiffies_to_clock_t(x)    \
                 (((unsigned long)(x) * COMPAT_USER_HZ) / HZ)