[v8,1/8] arm64: add type casts to untagged_addr macro
diff mbox series

Message ID 4a4063a3e074608b99cf22ab447fecc36d056251.1541687720.git.andreyknvl@google.com
State New
Headers show
Series
  • arm64: untag user pointers passed to the kernel
Related show

Commit Message

Andrey Konovalov Nov. 8, 2018, 2:36 p.m. UTC
This patch makes the untagged_addr macro accept all kinds of address types
(void *, unsigned long, etc.) and allows not to specify type casts in each
place where it is used. This is done by using __typeof__.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 arch/arm64/include/asm/uaccess.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Catalin Marinas Nov. 29, 2018, 6:22 p.m. UTC | #1
On Thu, Nov 08, 2018 at 03:36:08PM +0100, Andrey Konovalov wrote:
> This patch makes the untagged_addr macro accept all kinds of address types
> (void *, unsigned long, etc.) and allows not to specify type casts in each
> place where it is used. This is done by using __typeof__.
> 
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> ---
>  arch/arm64/include/asm/uaccess.h | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
> index 07c34087bd5e..c1325271e368 100644
> --- a/arch/arm64/include/asm/uaccess.h
> +++ b/arch/arm64/include/asm/uaccess.h
> @@ -101,7 +101,8 @@ static inline unsigned long __range_ok(const void __user *addr, unsigned long si
>   * up with a tagged userland pointer. Clear the tag to get a sane pointer to
>   * pass on to access_ok(), for instance.
>   */
> -#define untagged_addr(addr)		sign_extend64(addr, 55)
> +#define untagged_addr(addr)		\
> +	((__typeof__(addr))sign_extend64((__u64)(addr), 55))

Nitpick: same comment as here (use u64):

http://lkml.kernel.org/r/20181123173739.osgvnnhmptdgtlnl@lakrids.cambridge.arm.com

Acked-by: Catalin Marinas <catalin.marinas@arm.com>

(not acking the whole series just yet, only specific patches to remember
what I reviewed)
Andrey Konovalov Dec. 6, 2018, 12:34 p.m. UTC | #2
On Thu, Nov 29, 2018 at 7:22 PM Catalin Marinas <catalin.marinas@arm.com> wrote:
>
> On Thu, Nov 08, 2018 at 03:36:08PM +0100, Andrey Konovalov wrote:
> > This patch makes the untagged_addr macro accept all kinds of address types
> > (void *, unsigned long, etc.) and allows not to specify type casts in each
> > place where it is used. This is done by using __typeof__.
> >
> > Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> > ---
> >  arch/arm64/include/asm/uaccess.h | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
> > index 07c34087bd5e..c1325271e368 100644
> > --- a/arch/arm64/include/asm/uaccess.h
> > +++ b/arch/arm64/include/asm/uaccess.h
> > @@ -101,7 +101,8 @@ static inline unsigned long __range_ok(const void __user *addr, unsigned long si
> >   * up with a tagged userland pointer. Clear the tag to get a sane pointer to
> >   * pass on to access_ok(), for instance.
> >   */
> > -#define untagged_addr(addr)          sign_extend64(addr, 55)
> > +#define untagged_addr(addr)          \
> > +     ((__typeof__(addr))sign_extend64((__u64)(addr), 55))
>
> Nitpick: same comment as here (use u64):
>
> http://lkml.kernel.org/r/20181123173739.osgvnnhmptdgtlnl@lakrids.cambridge.arm.com

Will do in v9.

>
> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
>
> (not acking the whole series just yet, only specific patches to remember
> what I reviewed)

OK.

Thanks!

Patch
diff mbox series

diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 07c34087bd5e..c1325271e368 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -101,7 +101,8 @@  static inline unsigned long __range_ok(const void __user *addr, unsigned long si
  * up with a tagged userland pointer. Clear the tag to get a sane pointer to
  * pass on to access_ok(), for instance.
  */
-#define untagged_addr(addr)		sign_extend64(addr, 55)
+#define untagged_addr(addr)		\
+	((__typeof__(addr))sign_extend64((__u64)(addr), 55))
 
 #define access_ok(type, addr, size)	__range_ok(addr, size)
 #define user_addr_max			get_fs