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, 1 insertions, 0 deletions

diff --git a/lib/libc/sys/sigsuspend.c b/lib/libc/sys/sigsuspend.c
index 6e47368c49c3..1f980a117a1b 100644
--- a/lib/libc/sys/sigsuspend.c
+++ b/lib/libc/sys/sigsuspend.c
@@ -38,6 +38,7 @@ __FBSDID("$FreeBSD$");
 #include "libc_private.h"
 
 __weak_reference(__sys_sigsuspend, __sigsuspend);
+__weak_reference(sigsuspend, __libc_sigsuspend);
 
 #pragma weak sigsuspend
 int