Fix known issues which blow up the process after dlopen("libthr.so")

(or loading a dso linked to libthr.so into process which was not
linked against threading library).

MFC r276630:
Remove interposing, fix malloc, reinstall signal handlers wrappers on
libthr load.

MFC r276681:
Avoid calling internal libc function through PLT or accessing data
though GOT.

MFC r277032:
Reduce the size of the interposing table and amount of
cancellation-handling code in the libthr.

MFC note:
r276646 ("do not erronously export 'openat' symbol from rtld") is not
applicable to stable/10 yet, since PATHFDS support was not merged.

1 files changed, 5 insertions, 1 deletions

diff --git a/lib/libc/gen/waitpid.c b/lib/libc/gen/waitpid.c
index b001837..5177591 100644
--- a/lib/libc/gen/waitpid.c
+++ b/lib/libc/gen/waitpid.c
@@ -40,10 +40,14 @@ __FBSDID("$FreeBSD$");
 #include <sys/resource.h>
 #include "un-namespace.h"
 
+#include "libc_private.h"
+
 pid_t
 __waitpid(pid_t pid, int *istat, int options)
 {
-	return (_wait4(pid, istat, options, (struct rusage *)0));
+
+	return (((pid_t (*)(pid_t, int *, int, struct rusage *))
+	    __libc_interposing[INTERPOS_wait4])(pid, istat, options, NULL));
 }
 
 __weak_reference(__waitpid, waitpid);