On Fri, Sep 23, 2022 at 10:42:38PM -0500, Gustavo A. R. Silva wrote:
> On Fri, Sep 23, 2022 at 08:07:41PM -0700, Kees Cook wrote:
> > To work around a misbehavior of the compiler's ability to see into
> > composite flexible array structs (as detailed in the coming memcpy()
> > hardening series[1]), split the memcpy() of the header and the payload
> > so no false positive run-time overflow warning will be generated. As it
> > turns out, this appears to actually reduce the text size:
Er, actually, I can't read/math. ;) It _does_ grow the text size. (That's
2_3_ not 22 at the start of the text size...) On examination, it appears
to unroll the already inlined memcpy further.
> >
> > $ size drivers/hv/vmbus_drv.o.before drivers/hv/vmbus_drv.o
> > text data bss dec hex filename
> > 22968 5239 232 28439 6f17 drivers/hv/vmbus_drv.o.before
> > 23032 5239 232 28503 6f57 drivers/hv/vmbus_drv.o
^
-Kees
--
Kees Cook
