On Mon, 2019-05-06 at 18:30 +0200, 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@xxxxxxx> > Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx> > --- > include/linux/mm.h | 4 ++++ > 1 file changed, 4 insertions(+) As discussed in the other thread Chris started, there is a generic need to untag addresses in kernel and this patch gets us ready for that. Reviewed-by: Khalid Aziz <khalid.aziz@xxxxxxxxxx> > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 6b10c21630f5..44041df804a6 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
