[PATCH] D20913: [asan] add primitives that allow coroutine implementations

[Dmitry Vyukov via llvm-commits]

dvyukov added a comment.

I see that folly always uses main thread stack as scheduler stack: always switches main->fiber/fiber->main, but not fiber1->fiber2. Some programs avoid the excessive switch by doing fiber1->fiber2. We need to make sure that we support that pattern as well.

I wonder if it can interfere with signals (without altstack). Namely, a signal arrives when asan has setup fiber stack, but the actual switch did not happen (SP is still pointing to the old stack). Then signal handler executes something that causes __asan_handle_no_return. Seems that we can get the same crash. Need tests.


http://reviews.llvm.org/D20913