hurd: handle EINTR during critical sections

During critical sections, signal handling is deferred and thus RPCs return
EINTR, even if SA_RESTART is set. We thus have to restart the whole critical
section in that case.

This also adds HURD_CRITICAL_UNLOCK in the cases where one wants to
break the section in the middle.

1 files changed, 4 insertions, 0 deletions

diff --git a/hurd/hurd/signal.h b/hurd/hurd/signal.h
index 37b7dec5a0..db9a02f000 100644
--- a/hurd/hurd/signal.h
+++ b/hurd/hurd/signal.h
@@ -277,6 +277,10 @@ _hurd_critical_section_unlock (void *our_lock)
   { void *__hurd_critical__ = _hurd_critical_section_lock ()
 #define HURD_CRITICAL_END \
       _hurd_critical_section_unlock (__hurd_critical__); } while (0)
+
+/* This one can be used inside the C scoping level, for early exits.  */
+#define HURD_CRITICAL_UNLOCK \
+      _hurd_critical_section_unlock (__hurd_critical__);
 
 /* Initialize the signal code, and start the signal thread.
    Arguments give the "init ints" from exec_startup.  */