Enable -D_FORTIFY_SOURCE=2 and fix resulting diagnostics

Author: jepler

src/Makefile

@@ -244,7 +244,7 @@ INCLUDE += $(LIBTIRPC_CFLAGS)
 # Compilation options.	Perhaps some of these should come from Makefile.inc? (CXXFLAGS now does)
 INTEGER_OVERFLOW_FLAGS := -fwrapv
 OPT := -Os $(INTEGER_OVERFLOW_FLAGS)
-DEBUG := $(DEBUG) -g -Wall -Wno-stringop-truncation
+DEBUG := $(DEBUG) -g -Wall -Wno-stringop-truncation -D_FORTIFY_SOURCE=2
 CFLAGS := $(INCLUDE) $(OPT) $(DEBUG) $(EXTRA_DEBUG) -DULAPI -std=gnu11 -Werror=implicit-function-declaration $(CFLAGS) $(CPPFLAGS)
 CXXFLAGS := $(INCLUDE) $(EXTRA_DEBUG) -DULAPI $(DEBUG) $(OPT) -Werror=overloaded-virtual $(CXXFLAGS) $(CPPFLAGS)
 CXXFLAGS += -std=gnu++17

src/hal/user_comps/sendkeys.c

@@ -62,7 +62,7 @@ void emit(int fd, int type, int code, int val)
    ie.type = type;
    ie.code = code;
    ie.value = val;
-   write(fd, &ie, sizeof(ie));
+   if (write(fd, &ie, sizeof(ie)) != sizeof(ie)) { perror("write(input_event)"); }
 }
 
 static void exit_handler(int sig) {
@@ -219,7 +219,6 @@ int init(int argc, char* argv[]){
 }
 
 int main(int argc, char* argv[]) {
-    struct uinput_user_dev uidev;
     int i, j;
 
     signal(SIGINT, exit_handler);
@@ -246,24 +245,28 @@ int main(int argc, char* argv[]) {
             if (! *hal->init) continue;
             if (*hal->init && ! param->inited) {
                 param->fd = open("/dev/uinput", O_WRONLY | O_NONBLOCK);
-                if (param->fd < 0) rtapi_print_msg(RTAPI_MSG_ERR, 
-                    "Cannot open /dev/uinput. Suggest chmod 666 /dev/uinput\n");
+                if (param->fd < 0) {
+                    rtapi_print_msg(RTAPI_MSG_ERR,
+                        "Cannot open /dev/uinput. Suggest chmod 666 /dev/uinput\n");
+                    abort();
+                }
                 ioctl(param->fd, UI_SET_EVBIT, EV_KEY);
                 for (j = 0; j < param->num_events; j++){
                     if (hal->event[j] > 0 && hal->event[j] < KEY_MAX){
                         ioctl(param->fd, UI_SET_KEYBIT, hal->event[j]);
                         rtapi_print("SET_EVBIT %i\n", hal->event[j]);
                     }
                 }
+                struct uinput_user_dev uidev;
                 memset(&uidev, 0, sizeof(uidev));
                 strcpy(uidev.name, "linuxcnc-hal");
                 uidev.id.bustype = BUS_USB;
                 uidev.id.vendor  = 0x1;
                 uidev.id.product = 0x1;
                 uidev.id.version = 1;
 
-                write(param->fd, &uidev, sizeof(uidev));
-                ioctl(param->fd, UI_DEV_CREATE);
+                if (write(param->fd, &uidev, sizeof(uidev)) != sizeof(uidev)) { perror("write(uinput_user_dev)"); abort(); }
+                if (ioctl(param->fd, UI_DEV_CREATE) < 0) { perror("ioctl(UI_DEV_CREATE)"); abort(); }
                 param->inited = 1;
             }
             if (*hal->keycode != param->oldcode) {

src/rtapi/uspace_rtapi_app.cc

@@ -523,14 +523,14 @@ int main(int argc, char **argv) {
                 "    sudo env RTAPI_UID=`id -u` RTAPI_FIFO_PATH=$HOME/.rtapi_fifo gdb " EMC2_BIN_DIR "/rtapi_app\n");
             exit(1);
         }
-        setreuid(fallback_uid, 0);
+        if (setreuid(fallback_uid, 0) != 0) { perror("setreuid"); abort(); }
         fprintf(stderr,
             "Running with fallback_uid.  getuid()=%d geteuid()=%d\n",
             getuid(), geteuid());
     }
     ruid = getuid();
     euid = geteuid();
-    setresuid(euid, euid, ruid);
+    if (setresuid(euid, euid, ruid) != 0) { perror("setresuid"); abort(); }
 #ifdef __linux__
     setfsuid(ruid);
 #endif