new file mode 100644
@@ -0,0 +1,45 @@
+#include <sys/cdefs.h>
+#include <sys/param.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+uintptr_t __stack_chk_guard = 0;
+
+void
+__attribute__((__constructor__))
+__stack_chk_init (void)
+{
+ if (__stack_chk_guard != 0)
+ return;
+
+#if defined(__CYGWIN__) || defined(__rtems__)
+ arc4random_buf(&__stack_chk_guard, sizeof(__stack_chk_guard));
+#else
+ /* If getentropy is not available, use the "terminator canary". */
+ ((unsigned char *)&__stack_chk_guard)[0] = 0;
+ ((unsigned char *)&__stack_chk_guard)[1] = 0;
+ ((unsigned char *)&__stack_chk_guard)[2] = '\n';
+ ((unsigned char *)&__stack_chk_guard)[3] = 255;
+#endif
+}
+
+void
+__attribute__((__noreturn__))
+__stack_chk_fail (void)
+{
+ char msg[] = "*** stack smashing detected ***: terminated\n";
+ write (2, msg, strlen (msg));
+ raise (SIGABRT);
+ _exit (127);
+}
+
+#ifdef __ELF__
+void
+__attribute__((visibility ("hidden")))
+__stack_chk_fail_local (void)
+{
+ __stack_chk_fail();
+}
+#endif
Compiling with any of the -fstack-protector* flags requires the __stack_chk_guard data import (which needs to be initialized) and the __stack_chk_fail{,_local} functions. While GCC's own libssp can provide these, it is better that we provide these ourselves. The implementation is custom due to being OS-specific. Signed-off-by: Yaakov Selkowitz <yselkowi@redhat.com> --- newlib/libc/ssp/stack_protector.c | 45 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 newlib/libc/ssp/stack_protector.c -- 2.15.0