This set of patches fixes bugs which were preventing the
Debian sparc64 /bin/bash from running:
* the target_ucontext structure put the registers in the
wrong place (missing alignment specifier, mostly)
* the set_context and get_context traps weren't saving fp
and i7, which meant that guest code that did a longjmp would
crash shortly afterwards (SPARC64 uses these traps to
implement setjmp/longjmp)
* we were trying to stuff a 64-bit PC into a uint32_t in
sigreturn, which caused a SEGV on return from a signal handler
Review very much desired in particular from anybody who understands
SPARC register windows and how we handle them in linux-user for
patch 2! The other patches are straightforward.
This patchset is sufficient that I can at least chroot into
a Debian sparc64 chroot and run basic commands like 'ls' from
the shell prompt (together with Giuseppe Musacchio's patch that
fixes the stack_t struct).
There are clearly a bunch of other bugs in sparc signal handling
(starting with the fact that rt_frame support is simply not
implemented, but there are also some XXX/FIXME comments about TSTATE
save/restore in set/get_context and about the FPU state in the signal
frame code). There's also a Coverity issue about accessing off the
end of the sregs[] array in the target_mc_fpu struct -- the error is
actually harmless (we're accessing into the space in the union for
dregs[16..31] which is what we want to be doing) but I'll probably
put together a patch to make Coverity happier.