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Fix signal stack namespace (bug 21584)
- From: Joseph Myers <joseph at codesourcery dot com>
- To: <libc-alpha at sourceware dot org>
- Date: Tue, 13 Jun 2017 21:09:47 +0000
- Subject: Fix signal stack namespace (bug 21584)
- Authentication-results: sourceware.org; auth=none
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.
2017-06-13 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].
diff --git a/signal/signal.h b/signal/signal.h
index 23cd8ef..8dfe849 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)
--
Joseph S. Myers
joseph@codesourcery.com