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    Subject[PATCH 4.7 167/184] score: fix copy_from_user() and friends
    Date
    4.7-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Al Viro <viro@zeniv.linux.org.uk>

    commit b615e3c74621e06cd97f86373ca90d43d6d998aa upstream.

    Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    arch/score/include/asm/uaccess.h | 41 +++++++++++++++++++--------------------
    1 file changed, 20 insertions(+), 21 deletions(-)

    --- a/arch/score/include/asm/uaccess.h
    +++ b/arch/score/include/asm/uaccess.h
    @@ -301,35 +301,34 @@ extern int __copy_tofrom_user(void *to,
    static inline unsigned long
    copy_from_user(void *to, const void *from, unsigned long len)
    {
    - unsigned long over;
    + unsigned long res = len;

    - if (access_ok(VERIFY_READ, from, len))
    - return __copy_tofrom_user(to, from, len);
    + if (likely(access_ok(VERIFY_READ, from, len)))
    + res = __copy_tofrom_user(to, from, len);

    - if ((unsigned long)from < TASK_SIZE) {
    - over = (unsigned long)from + len - TASK_SIZE;
    - return __copy_tofrom_user(to, from, len - over) + over;
    - }
    - return len;
    + if (unlikely(res))
    + memset(to + (len - res), 0, res);
    +
    + return res;
    }

    static inline unsigned long
    copy_to_user(void *to, const void *from, unsigned long len)
    {
    - unsigned long over;
    -
    - if (access_ok(VERIFY_WRITE, to, len))
    - return __copy_tofrom_user(to, from, len);
    + if (likely(access_ok(VERIFY_WRITE, to, len)))
    + len = __copy_tofrom_user(to, from, len);

    - if ((unsigned long)to < TASK_SIZE) {
    - over = (unsigned long)to + len - TASK_SIZE;
    - return __copy_tofrom_user(to, from, len - over) + over;
    - }
    return len;
    }

    -#define __copy_from_user(to, from, len) \
    - __copy_tofrom_user((to), (from), (len))
    +static inline unsigned long
    +__copy_from_user(void *to, const void *from, unsigned long len)
    +{
    + unsigned long left = __copy_tofrom_user(to, from, len);
    + if (unlikely(left))
    + memset(to + (len - left), 0, left);
    + return left;
    +}

    #define __copy_to_user(to, from, len) \
    __copy_tofrom_user((to), (from), (len))
    @@ -343,17 +342,17 @@ __copy_to_user_inatomic(void *to, const
    static inline unsigned long
    __copy_from_user_inatomic(void *to, const void *from, unsigned long len)
    {
    - return __copy_from_user(to, from, len);
    + return __copy_tofrom_user(to, from, len);
    }

    -#define __copy_in_user(to, from, len) __copy_from_user(to, from, len)
    +#define __copy_in_user(to, from, len) __copy_tofrom_user(to, from, len)

    static inline unsigned long
    copy_in_user(void *to, const void *from, unsigned long len)
    {
    if (access_ok(VERIFY_READ, from, len) &&
    access_ok(VERFITY_WRITE, to, len))
    - return copy_from_user(to, from, len);
    + return __copy_tofrom_user(to, from, len);
    }

    /*

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