On 10/6/20 10:00 AM, Dave Martin wrote: > On Tue, Oct 06, 2020 at 08:33:47AM -0700, Dave Hansen wrote: >> On 10/6/20 8:25 AM, Dave Martin wrote: >>> Or are people reporting real stack overruns on x86 today? >> We have real overruns. We have ~2800 bytes of XSAVE (regisiter) state >> mostly from AVX-512, and a 2048 byte MINSIGSTKSZ. > Right. Out of interest, do you believe that's a direct consequence of > the larger kernel-generated signal frame, or does the expansion of > userspace stack frames play a role too? The kernel-generated signal frame is entirely responsible for the ~2800 bytes that I'm talking about. I'm sure there are some systems where userspace plays a role, but those are much less of a worry at the moment, since the kernel-induced overflows mean an instant crash that userspace has no recourse for.
