Switch libc from using _sig{procmask,action,suspend} symbols, which

are aliases for the syscall stubs and are plt-interposed, to the
libc-private aliases of internally interposed sigprocmask() etc.

Since e.g. _sigaction is not interposed by libthr, calling signal()
removes thr_sighandler() from the handler slot etc.  The result was
breaking signal semantic and rtld locking.

The added __libc_sigprocmask and other symbols are hidden, they are
not exported and cannot be called through PLT.  The setjmp/longjmp
functions for x86 were changed to use direct calls, and since
PIC_PROLOGUE only needed for functional PLT indirection on i386, it is
removed as well.

The PowerPC bug of calling the syscall directly in the setjmp/longjmp
implementation is kept as is.

Reported by:	Pete French <petefrench@ingresso.co.uk>
Tested by:	Michiel Boland <boland37@xs4all.nl>
Reviewed by:	jilles (previous version)
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week

1 files changed, 4 insertions, 3 deletions

diff --git a/lib/libc/stdio/tmpfile.c b/lib/libc/stdio/tmpfile.c
index c67d1e4..e5a2be1 100644
--- a/lib/libc/stdio/tmpfile.c
+++ b/lib/libc/stdio/tmpfile.c
@@ -46,9 +46,10 @@ __FBSDID("$FreeBSD$");
 #include <string.h>
 #include <paths.h>
 #include "un-namespace.h"
+#include "libc_private.h"
 
 FILE *
-tmpfile()
+tmpfile(void)
 {
 	sigset_t set, oset;
 	FILE *fp;
@@ -69,7 +70,7 @@ tmpfile()
 		return (NULL);
 
 	sigfillset(&set);
-	(void)_sigprocmask(SIG_BLOCK, &set, &oset);
+	(void)__libc_sigprocmask(SIG_BLOCK, &set, &oset);
 
 	fd = mkstemp(buf);
 	if (fd != -1)
@@ -77,7 +78,7 @@ tmpfile()
 
 	free(buf);
 
-	(void)_sigprocmask(SIG_SETMASK, &oset, NULL);
+	(void)__libc_sigprocmask(SIG_SETMASK, &oset, NULL);
 
 	if (fd == -1)
 		return (NULL);