[RFC][PATCH 08/14] parisc: turn csum_partial_copy_from_user() into csum_and_copy_from_user()

Al Viro
2020-03-27T23:31:28Z

Already has the right semantics. Incidentally. failing copy_from_user()
zeroes the tail of destination - no need to repeat that manually

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
arch/parisc/include/asm/checksum.h | 3 ++-
arch/parisc/lib/checksum.c | 12 +++---------
2 files changed, 5 insertions(+), 10 deletions(-)

diff --git a/arch/parisc/include/asm/checksum.h b/arch/parisc/include/asm/checksum.h
index c1c22819a04d..7c69ce9634c7 100644
--- a/arch/parisc/include/asm/checksum.h
+++ b/arch/parisc/include/asm/checksum.h
@@ -26,11 +26,12 @@ extern __wsum csum_partial(const void *, int, __wsum);
*/
extern __wsum csum_partial_copy_nocheck(const void *, void *, int, __wsum);

+#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
/*
* this is a new version of the above that records errors it finds in *errp,
* but continues and zeros the rest of the buffer.
*/
-extern __wsum csum_partial_copy_from_user(const void __user *src,
+extern __wsum csum_and_copy_from_user(const void __user *src,
void *dst, int len, __wsum sum, int *errp);

/*
diff --git a/arch/parisc/lib/checksum.c b/arch/parisc/lib/checksum.c
index 256322c7b648..4e47c2ff2bcd 100644
--- a/arch/parisc/lib/checksum.c
+++ b/arch/parisc/lib/checksum.c
@@ -128,18 +128,12 @@ EXPORT_SYMBOL(csum_partial_copy_nocheck);
* Copy from userspace and compute checksum. If we catch an exception
* then zero the rest of the buffer.
*/
-__wsum csum_partial_copy_from_user(const void __user *src,
+__wsum csum_and_copy_from_user(const void __user *src,
void *dst, int len,
__wsum sum, int *err_ptr)
{
- int missing;
-
- missing = copy_from_user(dst, src, len);
- if (missing) {
- memset(dst + len - missing, 0, missing);
+ if (copy_from_user(dst, src, len))
*err_ptr = -EFAULT;
- }
-
return csum_partial(dst, len, sum);
}
-EXPORT_SYMBOL(csum_partial_copy_from_user);
+EXPORT_SYMBOL(csum_and_copy_from_user);
--
2.11.0