On Fri, Mar 3, 2017 at 3:33 PM, Alexander Potapenko glider@google.com wrote:
On Fri, Mar 3, 2017 at 3:30 PM, Arnd Bergmann arnd@arndb.de wrote:
On Fri, Mar 3, 2017 at 2:55 PM, Alexander Potapenko glider@google.com 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