On 20.01.21 18:25, Laszlo Ersek wrote: [...]
A simple grep for SIGUSR2 seems to indicate that SIGUSR2 is not used by system emulation for anything else, in practice. Is it possible to dedicate SIGUSR2 explicitly to coroutine-sigaltstack, and set up the action beforehand, from some init function that executes on a "central" thread, before qemu_coroutine_new() is ever called?
I wrote a patch to that effect, but just before sending I wondered whether SIGUSR2 cannot be registered by the “guest” in user-mode emulation, and whether that would then break coroutines from there on.
(I have no experience dealing with user-mode emulation, but it does look like the guest can just register handlers for any signal but SIGSEGV and SIGBUS.)
Max
