x86/paravirt: Create a stack frame in PV_CALLEE_SAVE_REGS_THUNK

x86/paravirt: Create a stack frame in PV_CALLEE_SAVE_REGS_THUNK

A function created with the PV_CALLEE_SAVE_REGS_THUNK macro doesn't set
up a new stack frame before the call instruction, which breaks frame
pointer convention if CONFIG_FRAME_POINTER is enabled and can result in
a bad stack trace.  Also, the thunk functions aren't annotated as ELF
callable functions.

Create a stack frame when CONFIG_FRAME_POINTER is enabled and add the
ELF function type.

Signed-off-by: Josh Poimboeuf <[email protected]>
Reviewed-by: Borislav Petkov <[email protected]>
Cc: Alok Kataria <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Andy Lutomirski <[email protected]>
Cc: Arnaldo Carvalho de Melo <[email protected]>
Cc: Bernd Petrovitsch <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Brian Gerst <[email protected]>
Cc: Chris J Arges <[email protected]>
Cc: Chris Wright <[email protected]>
Cc: Denys Vlasenko <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Jeremy Fitzhardinge <[email protected]>
Cc: Jiri Slaby <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Michal Marek <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Pedro Alves <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rusty Russell <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: http://lkml.kernel.org/r/a2cad74e87c4aba7fd0f54a1af312e66a824a575.1453405861.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <[email protected]>