Re: GCC's -fsplit-stack disturbing Mach's vm_allocate

2013-06-21 Thread Roland McGrath
Split-stack is fundamentally incompatible with __hurd_threadvar_location et al (and cthreads). We won't ever be able to use split-stack until we change to a proper thread-pointer-based implementation (i.e. segment-register based stuff for i386).

Re: GCC's -fsplit-stack disturbing Mach's vm_allocate

2013-06-21 Thread Richard Braun
On Sat, Jun 22, 2013 at 12:52:03AM +0200, Thomas Schwinge wrote: > But anyway, what is the split-stack run-time/startup code doing so that > it makes vm_allocate behave erratically? Isn't vm_allocate a real system > call after all, but relies on some threadvar state? It's now too late to > figure

GCC's -fsplit-stack disturbing Mach's vm_allocate

2013-06-21 Thread Thomas Schwinge
Hi! This is tracked down from the GCC Go testsuite, where every execution test would fail à la: mmap errno 1073741846 fatal error: mmap That is EINVAL (but that actually is a straw man, as it should turn out), and mmap has been invoked from [GCC]/libbacktrace/mmap.c:backtrace_alloc (but