[RFC][PATCH 13/14] arm: switch to csum_and_copy_from_user()

Al Viro
2020-03-27T23:31:37Z

Note that csum_partial_copy_from_user() is in assembler here,
so I'm leaving it alone and just providing the wrapper for
it. When/if we go for switching arm to user_access_{begin,end}()
(doing domain switches in those), somebody well need to look
into that one.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
arch/arm/include/asm/checksum.h | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/arch/arm/include/asm/checksum.h b/arch/arm/include/asm/checksum.h
index 20043e0ebb07..ed6073fee338 100644
--- a/arch/arm/include/asm/checksum.h
+++ b/arch/arm/include/asm/checksum.h
@@ -40,6 +40,20 @@ csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum);
__wsum
csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *err_ptr);

+#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
+static inline
+__wsum csum_and_copy_from_user (const void __user *src, void *dst,
+ int len, __wsum sum, int *err_ptr)
+{
+ if (access_ok(src, len))
+ return csum_partial_copy_from_user(src, dst, len, sum, err_ptr);
+
+ if (len)
+ *err_ptr = -EFAULT;
+
+ return sum;
+}
+
/*
* Fold a partial checksum without adding pseudo headers
*/
--
2.11.0