From: sstewartgallus00@...
Date: 2015-02-18T17:46:37+00:00
Subject: [ruby-core:68172] [Ruby trunk - Bug #10866] [Open] A signal handler in signal.c can corrupt the value of errno.

Issue #10866 has been reported by Steven Stewart-Gallus.

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Bug #10866: A signal handler in signal.c can corrupt the value of errno.
https://bugs.ruby-lang.org/issues/10866

* Author: Steven Stewart-Gallus
* Status: Open
* Priority: Normal
* Assignee: 
* ruby -v: 2.2.0
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN
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A signal handler in signal.c can corrupt the value of errno.  This is
common mistake.  It should save and restore errno as in the following
patch.  I think this is the only signal handler used but I am not that
familiar with the code.

Index: signal.c
===================================================================
--- signal.c	(revision 49641)
+++ signal.c	(working copy)
@@ -688,11 +688,15 @@
 static RETSIGTYPE
 sighandler(int sig)
 {
+    int old_errnum = errno;
+
     signal_enque(sig);
     rb_thread_wakeup_timer_thread();
 #if !defined(BSD_SIGNAL) && !defined(POSIX_SIGNAL)
     ruby_signal(sig, sighandler);
 #endif
+
+    errno = old_errnum;
 }
 
 int




-- 
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