Bug #10866: A signal handler in signal.c can corrupt the value of errno.

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: 2.2.0
• Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN, 2.2: UNKNOWN

[sstewartgallus (Steven Stewart-Gallus)]

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

[normalperson (Eric Wong)]

Good catch! I'll commit in a little bit in case we missed something,
but I think that's the only signal handler.

• Status changed from Open to Closed
• % Done changed from 0 to 100

Applied in changeset r49746.

---

signal.c: preserve errno

• signal.c (sighandler): preserve errno
  Patch by Steven Stewart-Gallus [e-mail]
  [ruby-core:68172] [Bug #10866]