From 21f8859dd08fd231198eda4095061837d527b926 Mon Sep 17 00:00:00 2001
From: Joseph Myers <joseph@codesourcery.com>
Date: Mon, 19 Jun 2017 12:00:13 +0000
Subject: [PATCH] Fix signal stack namespace (bug 21584).

In POSIX.1:2008, various signal stack symbols - sigaltstack, SS_*,
SIGSTKSZ, MINSIGSTKSZ - are all XSI-shaded.  glibc wrongly makes them
visible for non-XSI POSIX.  This patch fixes the conditionals, leaving
the symbols available for __USE_MISC as it seems likely some of them
are widely used and should be visible by default.  (Note that stack_t
is *not* XSI-shaded and so the conditionals on that are correctly
unchanged.)

Tested for x86_64.

	[BZ #21584]
	* signal/signal.h: Make includes of <bits/sigstack.h> and
	<bits/ss_flags.h> conditional on [__USE_XOPEN_EXTENDED ||
	__USE_MISC].
	(sigaltstack): Make declaration conditional on
	[__USE_XOPEN_EXTENDED || __USE_MISC].
---
 ChangeLog       |  7 +++++++
 signal/signal.h | 10 ++++++----
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 0aa7bfe3be..b8d9d58403 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2017-06-19  Joseph Myers  <joseph@codesourcery.com>
 
+	[BZ #21584]
+	* signal/signal.h: Make includes of <bits/sigstack.h> and
+	<bits/ss_flags.h> conditional on [__USE_XOPEN_EXTENDED ||
+	__USE_MISC].
+	(sigaltstack): Make declaration conditional on
+	[__USE_XOPEN_EXTENDED || __USE_MISC].
+
 	[BZ #21575]
 	* resource/bits/types/struct_rusage.h: New file.
 	* include/bits/types/struct_rusage.h: Likewise.
diff --git a/signal/signal.h b/signal/signal.h
index 23cd8efb14..8dfe849890 100644
--- a/signal/signal.h
+++ b/signal/signal.h
@@ -301,20 +301,22 @@ extern int sigreturn (struct sigcontext *__scp) __THROW;
    calls be restarted after signal SIG.  */
 extern int siginterrupt (int __sig, int __interrupt) __THROW;
 
-# include <bits/sigstack.h>
 # include <bits/types/stack_t.h>
-# include <bits/ss_flags.h>
 # if defined __USE_XOPEN || defined __USE_XOPEN2K8
 /* This will define `ucontext_t' and `mcontext_t'.  */
 #  include <sys/ucontext.h>
 # endif
+#endif /* Use POSIX.1-2008 or X/Open Unix.  */
+
+#if defined __USE_XOPEN_EXTENDED || defined __USE_MISC
+# include <bits/sigstack.h>
+# include <bits/ss_flags.h>
 
 /* Alternate signal handler stack interface.
    This interface should always be preferred over `sigstack'.  */
 extern int sigaltstack (const stack_t *__restrict __ss,
 			stack_t *__restrict __oss) __THROW;
-
-#endif /* Use POSIX.1-2008 or X/Open Unix.  */
+#endif /* __USE_XOPEN_EXTENDED || __USE_MISC */
 
 #if ((defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K8)	\
      || defined __USE_MISC)