Messages in this thread | | | Date | Wed, 28 Aug 2019 11:06:44 +0800 | From | Nick Hu <> | Subject | Re: [PATCH 1/2] riscv: Add memmove string operation. |
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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
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