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, 3 insertions, 3 deletions

diff --git a/lib/libc/stdlib/abort.c b/lib/libc/stdlib/abort.c
index b137e49..022c6aa 100644
--- a/lib/libc/stdlib/abort.c
+++ b/lib/libc/stdlib/abort.c
@@ -61,7 +61,7 @@ abort()
 	 * any errors -- ISO C doesn't allow abort to return anyway.
 	 */
 	sigdelset(&act.sa_mask, SIGABRT);
-	(void)_sigprocmask(SIG_SETMASK, &act.sa_mask, NULL);
+	(void)__libc_sigprocmask(SIG_SETMASK, &act.sa_mask, NULL);
 	(void)raise(SIGABRT);
 
 	/*
@@ -71,9 +71,9 @@ abort()
 	act.sa_handler = SIG_DFL;
 	act.sa_flags = 0;
 	sigfillset(&act.sa_mask);
-	(void)_sigaction(SIGABRT, &act, NULL);
+	(void)__libc_sigaction(SIGABRT, &act, NULL);
 	sigdelset(&act.sa_mask, SIGABRT);
-	(void)_sigprocmask(SIG_SETMASK, &act.sa_mask, NULL);
+	(void)__libc_sigprocmask(SIG_SETMASK, &act.sa_mask, NULL);
 	(void)raise(SIGABRT);
 	exit(1);
 }