svn commit: r307971 - head/sys/mips/include

[Konstantin Belousov]

On Fri, Oct 28, 2016 at 09:59:26AM -0700, John Baldwin wrote:
> Well, we could perhaps patch those to use SA_SIGINFO instead, but if it's
> a non-trivial amount of effort I'm not going to bother.  I'm surprised that
> some of those would use sigcontext.  Both mono and go post-date SA_SIGINFO
> being standardized and supported on FreeBSD AFAIK.  Supporting sigcontext
> just means extra BSD-specific code in those applications compared to using
> SA_SIGINFO. :-/

For libunwind, I can see a rationale for struct sigcontext use.  It seems
that on Linux, rt_sigreturn(2) syscall takes struct sigcontext *, and not
struct ucontext *, as the argument.  This is not unreasonable, because
the additional ucontext fields make no sense for sigreturn, for us they
are copied into kernel AS but are also unused.

So my FreeBSD port followed the existing Linux code.  And I started wondering
should we change our sigreturn(2) to take sigcontext * instead of ucontext *.