libsandbox: lock main syscall code with a mutex

Since the main sandbox code maintains state with global variables (like
sbcontext), make sure we use a pthread mutex to prevent multiple threads
from corrupting each other.  In the non-threaded case this shouldn't be
a problem as the C library provides redirection stubs in its own code.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/headers.h b/headers.h
index b690056..74fd7b7 100644
--- a/headers.h
+++ b/headers.h
@@ -36,6 +36,9 @@
 #ifdef HAVE_MEMORY_H
 # include <memory.h>
 #endif
+#ifdef HAVE_PTHREAD_H
+# include <pthread.h>
+#endif
 #ifdef HAVE_SIGINFO_H
 # include <siginfo.h>
 #endif