Hi Sato-san,
On Thu, Jul 16, 2015 at 7:15 AM, Yoshinori Sato
<ysato@xxxxxxxxxxxxxxxxxxxx> wrote:
> Current implemantation ptr argument evaluate 2 times.
> It'll be an unexpected result.
>
> Signed-off-by: Yoshinori Sato <ysato@xxxxxxxxxxxxxxxxxxxx>
Acked-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> ---
> include/asm-generic/uaccess.h | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
> index 72d8803..1b813fb 100644
> --- a/include/asm-generic/uaccess.h
> +++ b/include/asm-generic/uaccess.h
> @@ -163,9 +163,10 @@ static inline __must_check long __copy_to_user(void __user *to,
>
> #define put_user(x, ptr) \
> ({ \
> + __typeof__((ptr)) __p = (ptr); \
> might_fault(); \
> - access_ok(VERIFY_WRITE, ptr, sizeof(*ptr)) ? \
> - __put_user(x, ptr) : \
> + access_ok(VERIFY_WRITE, __p, sizeof(*__p)) ? \
> + __put_user(x, __p) : \
For safety, you may want to change "x" to "(x") while at it.
> -EFAULT; \
> })
>
> @@ -225,9 +226,10 @@ extern int __put_user_bad(void) __attribute__((noreturn));
>
> #define get_user(x, ptr) \
> ({ \
> + __typeof__((ptr)) __p = (ptr); \
> might_fault(); \
> - access_ok(VERIFY_READ, ptr, sizeof(*ptr)) ? \
> - __get_user(x, ptr) : \
> + access_ok(VERIFY_READ, __p, sizeof(*__p)) ? \
> + __get_user(x, __p) : \
Likewise.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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