add injection targets

targets/syscalls.c

@@ -0,0 +1,35 @@
+#include <errno.h>
+#include <sys/stat.h>
+
+extern char _end; /* provided by linker script */
+static char *heap_ptr = &_end;
+
+void *sbrk(int incr) {
+  char *prev = heap_ptr;
+  heap_ptr += incr;
+  return prev;
+}
+
+int write(int fd, const char *buf, int len) { return len; }
+
+int read(int fd, char *buf, int len) { return 0; }
+int close(int fd) { return -1; }
+int fstat(int fd, struct stat *st) {
+  st->st_mode = S_IFCHR;
+  return 0;
+}
+int isatty(int fd) { return 1; }
+int lseek(int fd, int offset, int whence) { return 0; }
+void _exit(int status) {
+  while (1)
+    ;
+}
+void exit(int status) {
+  while (1)
+    ;
+}
+int kill(int pid, int sig) {
+  errno = EINVAL;
+  return -1;
+}
+int getpid(void) { return 1; }