[PATCH 4/5] powerpc: Move barrier_nospec() out of allow_read_{from/write}_user()

[Christophe Leroy]

Move barrier_nospec() out of allow_read_from_user() and
allow_read_write_user() in order to allow reuse of those
functions when implementing masked user access.

Don't add it back in raw_copy_from_user() as it is already done
by callers of raw_copy_from_user().

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
 arch/powerpc/include/asm/kup.h     | 2 --
 arch/powerpc/include/asm/uaccess.h | 4 ++++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index 4c70be11b99a..4e2c79df4cdb 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -134,7 +134,6 @@ static __always_inline void kuap_assert_locked(void)
 
 static __always_inline void allow_read_from_user(const void __user *from)
 {
-	barrier_nospec();
 	allow_user_access(NULL, from, KUAP_READ);
 }
 
@@ -145,7 +144,6 @@ static __always_inline void allow_write_to_user(void __user *to)
 
 static __always_inline void allow_read_write_user(void __user *to, const void __user *from)
 {
-	barrier_nospec();
 	allow_user_access(to, from, KUAP_READ_WRITE);
 }
 
diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index dd5cf325ecde..89d53d4c2236 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -301,6 +301,7 @@ do {								\
 	__typeof__(sizeof(*(ptr))) __gu_size = sizeof(*(ptr));	\
 								\
 	might_fault();					\
+	barrier_nospec();					\
 	allow_read_from_user(__gu_addr);			\
 	__get_user_size_allowed(__gu_val, __gu_addr, __gu_size, __gu_err);	\
 	prevent_read_from_user(__gu_addr);			\
@@ -329,6 +330,7 @@ raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
 {
 	unsigned long ret;
 
+	barrier_nospec();
 	allow_read_write_user(to, from);
 	ret = __copy_tofrom_user(to, from, n);
 	prevent_read_write_user(to, from);
@@ -415,6 +417,7 @@ static __must_check __always_inline bool user_access_begin(const void __user *pt
 
 	might_fault();
 
+	barrier_nospec();
 	allow_read_write_user((void __user *)ptr, ptr);
 	return true;
 }
@@ -431,6 +434,7 @@ user_read_access_begin(const void __user *ptr, size_t len)
 
 	might_fault();
 
+	barrier_nospec();
 	allow_read_from_user(ptr);
 	return true;
 }
-- 
2.49.0