From: Mark Wooding <mdw@ncipher.com>
Date: Wed, 20 Sep 2006 15:20:23 +0000 (+0100)
Subject: noise: Fix freewheel generator's use of setitimer(2).
X-Git-Tag: 2.1.1~31
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/catacomb/commitdiff_plain/ff98dc94cb5d9498cd92edd6b734ec863d763852?ds=inline;hp=-c

noise: Fix freewheel generator's use of setitimer(2).

If the old timer was turned off, don't accidentally turn it on.  While
on some Linux versions, this seems harmless enough, on others it causes
spurious SIGALRM signals to be sent to the process, which is terribly
unhelpful.
---

ff98dc94cb5d9498cd92edd6b734ec863d763852
diff --git a/noise.c b/noise.c
index 90889306..c122506f 100644
--- a/noise.c
+++ b/noise.c
@@ -390,7 +390,8 @@ int noise_freewheel(rand_pool *r)
 
 done:
   signal(SIGALRM, sigal);
-  TV_SUB(&oitv.it_value, &oitv.it_value, &itv.it_value);
+  if (oitv.it_value.tv_sec || oitv.it_value.tv_usec)
+    TV_SUB(&oitv.it_value, &oitv.it_value, &itv.it_value);
   setitimer(ITIMER_REAL, &oitv, 0);
   return (rc);
 }