compat: provide compat_ptr() on all architectures

In order to avoid needless #ifdef CONFIG_COMPAT checks,
move the compat_ptr() definition to linux/compat.h
where it can be seen by any file regardless of the
architecture.

Only s390 needs a special definition, this can use the
self-#define trick we have elsewhere.
Reviewed-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm64/include/asm/compat.h

@@ -114,23 +114,6 @@ typedef u32		compat_sigset_word;
 
 #define COMPAT_OFF_T_MAX	0x7fffffff
 
-/*
- * A pointer passed in from user mode. This should not
- * be used for syscall parameters, just declare them
- * as pointers because the syscall entry code will have
- * appropriately converted them already.
- */
-
-static inline void __user *compat_ptr(compat_uptr_t uptr)
-{
-	return (void __user *)(unsigned long)uptr;
-}
-
-static inline compat_uptr_t ptr_to_compat(void __user *uptr)
-{
-	return (u32)(unsigned long)uptr;
-}
-
 #define compat_user_stack_pointer() (user_stack_pointer(task_pt_regs(current)))
 #define COMPAT_MINSIGSTKSZ	2048
 

arch/mips/include/asm/compat.h

@@ -100,24 +100,6 @@ typedef u32		compat_sigset_word;
 
 #define COMPAT_OFF_T_MAX	0x7fffffff
 
-/*
- * A pointer passed in from user mode. This should not
- * be used for syscall parameters, just declare them
- * as pointers because the syscall entry code will have
- * appropriately converted them already.
- */
-
-static inline void __user *compat_ptr(compat_uptr_t uptr)
-{
-	/* cast to a __user pointer via "unsigned long" makes sparse happy */
-	return (void __user *)(unsigned long)(long)uptr;
-}
-
-static inline compat_uptr_t ptr_to_compat(void __user *uptr)
-{
-	return (u32)(unsigned long)uptr;
-}
-
 static inline void __user *arch_compat_alloc_user_space(long len)
 {
 	struct pt_regs *regs = (struct pt_regs *)

arch/parisc/include/asm/compat.h

@@ -173,23 +173,6 @@ struct compat_shmid64_ds {
 #define COMPAT_ELF_NGREG 80
 typedef compat_ulong_t compat_elf_gregset_t[COMPAT_ELF_NGREG];
 
-/*
- * A pointer passed in from user mode. This should not
- * be used for syscall parameters, just declare them
- * as pointers because the syscall entry code will have
- * appropriately converted them already.
- */
-
-static inline void __user *compat_ptr(compat_uptr_t uptr)
-{
-	return (void __user *)(unsigned long)uptr;
-}
-
-static inline compat_uptr_t ptr_to_compat(void __user *uptr)
-{
-	return (u32)(unsigned long)uptr;
-}
-
 static __inline__ void __user *arch_compat_alloc_user_space(long len)
 {
 	struct pt_regs *regs = &current->thread.regs;

arch/powerpc/include/asm/compat.h

@@ -96,23 +96,6 @@ typedef u32		compat_sigset_word;
 
 #define COMPAT_OFF_T_MAX	0x7fffffff
 
-/*
- * A pointer passed in from user mode. This should not
- * be used for syscall parameters, just declare them
- * as pointers because the syscall entry code will have
- * appropriately converted them already.
- */
-
-static inline void __user *compat_ptr(compat_uptr_t uptr)
-{
-	return (void __user *)(unsigned long)uptr;
-}
-
-static inline compat_uptr_t ptr_to_compat(void __user *uptr)
-{
-	return (u32)(unsigned long)uptr;
-}
-
 static inline void __user *arch_compat_alloc_user_space(long len)
 {
 	struct pt_regs *regs = current->thread.regs;

arch/powerpc/oprofile/backtrace.c

@@ -9,7 +9,7 @@
 #include <linux/sched.h>
 #include <asm/processor.h>
 #include <linux/uaccess.h>
-#include <asm/compat.h>
+#include <linux/compat.h>
 #include <asm/oprofile_impl.h>
 
 #define STACK_SP(STACK)		*(STACK)

arch/s390/include/asm/compat.h

@@ -177,11 +177,7 @@ static inline void __user *compat_ptr(compat_uptr_t uptr)
 {
 	return (void __user *)(unsigned long)(uptr & 0x7fffffffUL);
 }
-
-static inline compat_uptr_t ptr_to_compat(void __user *uptr)
-{
-	return (u32)(unsigned long)uptr;
-}
+#define compat_ptr(uptr) compat_ptr(uptr)
 
 #ifdef CONFIG_COMPAT
 

arch/sparc/include/asm/compat.h

@@ -125,23 +125,6 @@ typedef u32		compat_sigset_word;
 
 #define COMPAT_OFF_T_MAX	0x7fffffff
 
-/*
- * A pointer passed in from user mode. This should not
- * be used for syscall parameters, just declare them
- * as pointers because the syscall entry code will have
- * appropriately converted them already.
- */
-
-static inline void __user *compat_ptr(compat_uptr_t uptr)
-{
-	return (void __user *)(unsigned long)uptr;
-}
-
-static inline compat_uptr_t ptr_to_compat(void __user *uptr)
-{
-	return (u32)(unsigned long)uptr;
-}
-
 #ifdef CONFIG_COMPAT
 static inline void __user *arch_compat_alloc_user_space(long len)
 {

arch/x86/include/asm/compat.h

@@ -177,23 +177,6 @@ typedef struct user_regs_struct compat_elf_gregset_t;
 	(!!(task_pt_regs(current)->orig_ax & __X32_SYSCALL_BIT))
 #endif
 
-/*
- * A pointer passed in from user mode. This should not
- * be used for syscall parameters, just declare them
- * as pointers because the syscall entry code will have
- * appropriately converted them already.
- */
-
-static inline void __user *compat_ptr(compat_uptr_t uptr)
-{
-	return (void __user *)(unsigned long)uptr;
-}
-
-static inline compat_uptr_t ptr_to_compat(void __user *uptr)
-{
-	return (u32)(unsigned long)uptr;
-}
-
 static inline void __user *arch_compat_alloc_user_space(long len)
 {
 	compat_uptr_t sp;

include/linux/compat.h

@@ -958,4 +958,22 @@ static inline bool in_compat_syscall(void) { return false; }
 
 #endif /* CONFIG_COMPAT */
 
+/*
+ * A pointer passed in from user mode. This should not
+ * be used for syscall parameters, just declare them
+ * as pointers because the syscall entry code will have
+ * appropriately converted them already.
+ */
+#ifndef compat_ptr
+static inline void __user *compat_ptr(compat_uptr_t uptr)
+{
+	return (void __user *)(unsigned long)uptr;
+}
+#endif
+
+static inline compat_uptr_t ptr_to_compat(void __user *uptr)
+{
+	return (u32)(unsigned long)uptr;
+}
+
 #endif /* _LINUX_COMPAT_H */