[PATCH 10/11] powerpc: use non-set_fs based maccess routines

Christoph Hellwig
2020-08-17T07:32:59Z

Provide __get_kernel_nofault and __put_kernel_nofault routines to
implement the maccess routines without messing with set_fs and without
opening up access to user space.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/powerpc/include/asm/uaccess.h | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 00699903f1efca..a31de40ac00b62 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -623,4 +623,20 @@ do { \
__put_user_goto(*(u8*)(_src + _i), (u8 __user *)(_dst + _i), e);\
} while (0)

+#define HAVE_GET_KERNEL_NOFAULT
+
+#define __get_kernel_nofault(dst, src, type, err_label) \
+do { \
+ int __kr_err; \
+ \
+ __get_user_size(*((type *)(dst)), (__force type __user *)(src), \
+ sizeof(type), __kr_err); \
+ if (unlikely(__kr_err)) \
+ goto err_label; \
+} while (0)
+
+#define __put_kernel_nofault(dst, src, type, err_label) \
+ __put_user_size_goto(*((type *)(src)), \
+ (__force type __user *)(dst), sizeof(type), err_label)
+
#endif /* _ARCH_POWERPC_UACCESS_H */
--
2.28.0