On Fri, Mar 3, 2017 at 3:33 PM, Alexander Potapenko <glider@xxxxxxxxxx> wrote: > On Fri, Mar 3, 2017 at 3:30 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: >> On Fri, Mar 3, 2017 at 2:55 PM, Alexander Potapenko <glider@xxxxxxxxxx> wrote: >> >> Would KMSAN also force local variables to be non-overlapping the way that >> asan-stack=1 and -fsanitize-address-use-after-scope do? As I understood it, >> KMSAN would add extra code for maintaining the uninit bits, but in an example >> like this > The thing is that KMSAN (and other tools that insert heavyweight > instrumentation) may cause heavy register spilling which will also > blow up the stack frames. In that case, I would expect a mostly distinct set of functions to have large stack frames with KMSAN, compared to the ones that need noinline_for_kasan. In most cases I patched, the called inline function is actually trivial, but invoked many times from the same caller. Arnd