On Wed, May 16, 2018 at 6:45 PM Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> wrote: > On 05/16/2018 06:34 PM, Alexander Potapenko wrote: > > stackdepot used to call memcpy(), which compiler tools normally > > instrument, therefore every lookup used to unnecessarily call instrumented > > code. This is somewhat ok in the case of KASAN, but under KMSAN a lot of > > time was spent in the instrumentation. > > > > (A similar change has been previously committed for memcmp()) > > > > Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> > > Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx> > > Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> > > --- > > lib/stackdepot.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/lib/stackdepot.c b/lib/stackdepot.c > > index e513459a5601..d48c744fa750 100644 > > --- a/lib/stackdepot.c > > +++ b/lib/stackdepot.c > > @@ -140,7 +140,7 @@ static struct stack_record *depot_alloc_stack(unsigned long *entries, int size, > > stack->handle.slabindex = depot_index; > > stack->handle.offset = depot_offset >> STACK_ALLOC_ALIGN; > > stack->handle.valid = 1; > > - memcpy(stack->entries, entries, size * sizeof(unsigned long)); > > + __memcpy(stack->entries, entries, size * sizeof(unsigned long)); > This has no effect. Since the whole file is not instrumented memcpy automagically replaced with __memcpy. You're right, we just didn't have the code defining memcpy() to __memcpy() in KMSAN. I'll fix that instead. -- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg
