Hi Paul,
On Tue, Aug 27, 2019 at 05:33:11PM +0800, Andrey Ryabinin wrote:
>
>
> On 8/27/19 12:07 PM, Nick Hu wrote:
> > Hi Andrey
> >
> > On Thu, Aug 22, 2019 at 11:59:02PM +0800, Andrey Ryabinin wrote:
> >> On 8/7/19 10:19 AM, Nick Hu wrote:
> >>> There are some features which need this string operation for compilation,
> >>> like KASAN. So the purpose of this porting is for the features like KASAN
> >>> which cannot be compiled without it.
> >>>
> >>
> >> Compilation error can be fixed by diff bellow (I didn't test it).
> >> If you don't need memmove very early (before kasan_early_init()) than
> >> arch-specific not-instrumented memmove()
> >> isn't necessary to have.
> >>
> >> ---
> >> mm/kasan/common.c | 2 ++
> >> 1 file changed, 2 insertions(+)
> >>
> >> diff --git a/mm/kasan/common.c b/mm/kasan/common.c
> >> index 6814d6d6a023..897f9520bab3 100644
> >> --- a/mm/kasan/common.c
> >> +++ b/mm/kasan/common.c
> >> @@ -107,6 +107,7 @@ void *memset(void *addr, int c, size_t len)
> >> return __memset(addr, c, len);
> >> }
> >>
> >> +#ifdef __HAVE_ARCH_MEMMOVE
> >> #undef memmove
> >> void *memmove(void *dest, const void *src, size_t len)
> >> {
> >> @@ -115,6 +116,7 @@ void *memmove(void *dest, const void *src, size_t len)
> >>
> >> return __memmove(dest, src, len);
> >> }
> >> +#endif
> >>
> >> #undef memcpy
> >> void *memcpy(void *dest, const void *src, size_t len)
> >> --
> >> 2.21.0
> >>
> >>
> >>
> > I have confirmed that the string operations are not used before
> > kasan_early_init().
> > But I can't make sure whether other ARCHs would need it before
> > kasan_early_init().
> > Do you have any idea to check that? Should I cc all other ARCH maintainers?
>
>
> This doesn't affect other ARCHes in any way. If other arches have their own
> not-instrumented
> memmove implementation (and they do), they will continue to be able to use it
> early.
I prefer Andrey's method since porting the generic string operations with
newlib ones should
be a separated patch from KASAN.
Nick
