Hi, On Mon, 29 Feb 2016, Mikael Pettersson wrote:
> Well, almost. While it is true that a signal handler cannot > *accidentally* clobber the register state of the interrupted thread, it > can in fact access and update any part of that state via the ucontext_t > passed to it. Doing so is uncommon, but not unheard of and not even > that difficult -- I've done it myself in several different runtime > systems. Yeah, well, sure. That's not clobbering the registers directly though, but setting it up so that the kernel does it on return :) If you do that, you have to have a special sig-handler anyway, lest it clobbers other registers that are currently in use by the interrupted piece of code. > The code in a signal handler cannot assume that global register > variables are in sync with the interrupted thread, or that plain > assignments to them are reflected back, but that's not GCC's fault, nor > is it GCC's job to make that happen. And it's documented to not happen (reliably anyway), so all is fine. Ciai, Michael.
