Re: [PATCH v16 01/16] uaccess: add untagged_addr definition for other arches

Khalid Aziz
2019-06-03T17:05:51Z

On 6/3/19 10:55 AM, Andrey Konovalov wrote:
> To allow arm64 syscalls to accept tagged pointers from userspace, we must
> untag them when they are passed to the kernel. Since untagging is done in
> generic parts of the kernel, the untagged_addr macro needs to be defined
> for all architectures.
>
> Define it as a noop for architectures other than arm64.
>
> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
> Reviewed-by: Khalid Aziz <khalid.aziz@oracle.com>
> Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
> ---
> include/linux/mm.h | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index 0e8834ac32b7..949d43e9c0b6 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -99,6 +99,10 @@ extern int mmap_rnd_compat_bits __read_mostly;
> #include <asm/pgtable.h>
> #include <asm/processor.h>
>
> +#ifndef untagged_addr
> +#define untagged_addr(addr) (addr)
> +#endif
> +
> #ifndef __pa_symbol
> #define __pa_symbol(x) __pa(RELOC_HIDE((unsigned long)(x), 0))
> #endif
>

Andrey,

This patch has now become part of the other patch series Chris Hellwig
has sent out -
<https://lore.kernel.org/lkml/20190601074959.14036-1-hch@lst.de/>. Can
you coordinate with that patch series?

--
Khalid