Document and tidy up one of the more arcane corners of signal
handling: why PRE(sys_sigreturn) has to construct a fake syscall
return value which, when written back to the guest state, leaves it
unchanged.  It's only taken me about 3 years to realise why :-)
Fixes to ppc platforms to follow.



git-svn-id: svn://svn.valgrind.org/valgrind/trunk@6650 a5019735-40e9-0310-863c-91ae7b9d1cf9
4 files changed