powerpc: add machine check safe copy_to_user

Use memcpy_mcsafe() implementation to define copy_to_user_mcsafe() Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
ruscur · Jul 2, 2019 · 261bfef · 261bfef
1 parent d6a52d5
commit 261bfef
Show file tree

Hide file tree

Showing 2 changed files with 13 additions and 0 deletions.
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
@@ -134,6 +134,7 @@ config PPC
 	select ARCH_HAS_STRICT_KERNEL_RWX	if ((PPC_BOOK3S_64 || PPC32) && !RELOCATABLE && !HIBERNATION)
 	select ARCH_HAS_TICK_BROADCAST		if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAS_UACCESS_FLUSHCACHE	if PPC64
+	select ARCH_HAS_UACCESS_MCSAFE		if PPC64
 	select ARCH_HAS_UBSAN_SANITIZE_ALL
 	select ARCH_HAS_ZONE_DEVICE		if PPC_BOOK3S_64
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
@@ -386,6 +386,18 @@ static inline unsigned long raw_copy_to_user(void __user *to,
 	return ret;
 }
 
+static __always_inline unsigned long __must_check
+copy_to_user_mcsafe(void __user *to, const void *from, unsigned long n)
+{
+	if (likely(check_copy_size(from, n, true))) {
+		allow_write_to_user(to, n);
+		n = memcpy_mcsafe(to, from, n);
+		prevent_write_to_user(to, n);
+	}
+
+	return n;
+}
+
 extern unsigned long __clear_user(void __user *addr, unsigned long size);
 
 static inline unsigned long clear_user(void __user *addr, unsigned long size)