x86-64/arm64/powerpc: clean up and rename __copy_from_user_flushcachenocache-cleanup

This finishes the work on these odd functions that were only implemented
by a handful of architectures.

The 'flushcache' function was only used from the iterator code, and
let's make it do the same thing that the nontemporal version does:
remove the two underscores and add the user address checking.

Yes, yes, the user address checking is also done at iovec import time,
but we have long since walked away from the old double-underscore thing
where we try to avoid address checking overhead at access time, and
these functions shouldn't be so special and old-fashioned.

The arm64 version already did the address check, in fact, so there it's
just a matter of renaming it.  For powerpc and x86-64 we now do the
proper user access boilerplate.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

6 files changed, 17 insertions, 17 deletions

diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 6490930deef8..770bb5211b54 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -480,7 +480,7 @@ extern __must_check long strnlen_user(const char __user *str, long n);
 #ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
 extern unsigned long __must_check __copy_user_flushcache(void *to, const void __user *from, unsigned long n);
 
-static inline int __copy_from_user_flushcache(void *dst, const void __user *src, unsigned size)
+static inline size_t copy_from_user_flushcache(void *dst, const void __user *src, size_t size)
 {
 	kasan_check_write(dst, size);
 	return __copy_user_flushcache(dst, __uaccess_mask_ptr(src), size);
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 784a00e681fa..c4221dae9750 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -405,8 +405,7 @@ copy_mc_to_user(void __user *to, const void *from, unsigned long n)
 }
 #endif
 
-extern long __copy_from_user_flushcache(void *dst, const void __user *src,
-		unsigned size);
+extern size_t copy_from_user_flushcache(void *dst, const void __user *src, size_t size);
 
 static __must_check __always_inline bool user_access_begin(const void __user *ptr, size_t len)
 {
diff --git a/arch/powerpc/lib/pmem.c b/arch/powerpc/lib/pmem.c
index 4e724c4c01ad..0f0f2d851ac6 100644
--- a/arch/powerpc/lib/pmem.c
+++ b/arch/powerpc/lib/pmem.c
@@ -66,15 +66,16 @@ EXPORT_SYMBOL_GPL(arch_invalidate_pmem);
 /*
  * CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE symbols
  */
-long __copy_from_user_flushcache(void *dest, const void __user *src,
-		unsigned size)
+size_t copy_from_user_flushcache(void *dest, const void __user *src,
+				 size_t size)
 {
-	unsigned long copied, start = (unsigned long) dest;
+	unsigned long not_copied, start = (unsigned long) dest;
 
-	copied = __copy_from_user(dest, src, size);
+	src = mask_user_address(src);
+	not_copied = __copy_from_user(dest, src, size);
 	clean_pmem_range(start, start + size);
 
-	return copied;
+	return not_copied;
 }
 
 void memcpy_flushcache(void *dest, const void *src, size_t size)
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index 859d99c31c29..20de34cc9aa6 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -149,7 +149,7 @@ raw_copy_to_user(void __user *dst, const void *src, unsigned long size)
 
 #define copy_to_nontemporal copy_to_nontemporal
 extern size_t copy_to_nontemporal(void *dst, const void *src, size_t size);
-extern long __copy_user_flushcache(void *dst, const void __user *src, unsigned size);
+extern size_t copy_user_flushcache(void *dst, const void __user *src, size_t size);
 
 static inline int
 copy_from_user_inatomic_nontemporal(void *dst, const void __user *src,
@@ -164,11 +164,11 @@ copy_from_user_inatomic_nontemporal(void *dst, const void __user *src,
 	return ret;
 }
 
-static inline int
-__copy_from_user_flushcache(void *dst, const void __user *src, unsigned size)
+static inline size_t
+copy_from_user_flushcache(void *dst, const void __user *src, size_t size)
 {
 	kasan_check_write(dst, size);
-	return __copy_user_flushcache(dst, src, size);
+	return copy_user_flushcache(dst, src, size);
 }
 
 /*
diff --git a/arch/x86/lib/usercopy_64.c b/arch/x86/lib/usercopy_64.c
index 348c9275edce..c47d8cd0e243 100644
--- a/arch/x86/lib/usercopy_64.c
+++ b/arch/x86/lib/usercopy_64.c
@@ -43,14 +43,14 @@ void arch_wb_cache_pmem(void *addr, size_t size)
 }
 EXPORT_SYMBOL_GPL(arch_wb_cache_pmem);
 
-long __copy_user_flushcache(void *dst, const void __user *src, unsigned size)
+size_t copy_user_flushcache(void *dst, const void __user *src, size_t size)
 {
 	unsigned long flushed, dest = (unsigned long) dst;
-	long rc;
+	unsigned long rc;
 
-	stac();
+	src = masked_user_access_begin(src);
 	rc = copy_to_nontemporal(dst, (__force const void *)src, size);
-	clac();
+	user_access_end();
 
 	/*
 	 * copy_to_nontemporal() uses non-temporal stores for the bulk
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index b3a7642ced4f..3abbe7405be4 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -296,7 +296,7 @@ static __always_inline
 size_t copy_from_user_iter_flushcache(void __user *iter_from, size_t progress,
 				      size_t len, void *to, void *priv2)
 {
-	return __copy_from_user_flushcache(to + progress, iter_from, len);
+	return copy_from_user_flushcache(to + progress, iter_from, len);
 }
 
 static __always_inline