nptl: Install SIGSETXID handler with SA_ONSTACK [BZ #27914]

The signal is sent to all threads, some of which may have switched
to very small stacks.  If they have also installed an alternate
signal stack, SA_ONSTACK makes this work.  The Go runtime needs this:

  runtime: C.setuid/C.setgid smashes Go stack
  <https://github.com/golang/go/issues/9400>

Doing this for SIGCANCEL is less obviously beneficial and needs further
testing.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

0 files changed, 0 insertions, 0 deletions