Hi, While working on a vdso for Linux/m68k I stumbled again on a problem, I already had with the fallback unwind handler in gcc, where I'd like to hear some opinions. I'm looking at the i386 unwind handler and that doesn't bother to restore any fp registers. On m68k it's a little more difficult as the fp register are saved/restored conditionally. There are also a few fp control register on the stack, which are currently not restored via unwind.
The question maybe here is what really needs to restored via the signal frame? If it's only for exception handling call clobbered registers wouldn't really need to be restored (often they are even immediately overwritten again to setup the exception handler) and even call saved register don't really need to restored as that should already be done via the frame of the signal handler itself (and depends on SA_SIGINFO anyway). So is there really any need to restore in the signal frame more than return address and frame address? AFAICT that should be enough for exception handling, but maybe there is something else... bye, Roman
