Poll works!

kernel_module/test/poll.c

@@ -6,32 +6,29 @@
 #include <unistd.h> /* read */
 
 int main(int argc, char **argv) {
-    char buf[1024];
-    int fd, n;
+    char buf[1024], path[1024];
+    int fd, i, n;
     short revents;
     struct pollfd pfd;
 
     fd = open(argv[1], O_RDONLY | O_NONBLOCK);
+    if (fd == -1) {
+        perror("open");
+        exit(EXIT_FAILURE);
+    }
     pfd.fd = fd;
     pfd.events = POLLIN;
     while (1) {
         puts("loop");
-        poll(&pfd, 1, -1);
+        i = poll(&pfd, 1, -1);
+        if (i == -1) {
+            perror("poll");
+            exit(EXIT_FAILURE);
+        }
         revents = pfd.revents;
         if (revents & POLLIN) {
             n = read(pfd.fd, buf, sizeof(buf));
             printf("POLLIN n=%d buf=%.*s\n", n, n, buf);
         }
-        if (revents & POLLHUP) {
-            printf("POLLHUP\n");
-            close(pfd.fd);
-            break;
-        }
-        if (revents & POLLNVAL) {
-            printf("POLLNVAL\n");
-        }
-        if (revents & POLLERR) {
-            printf("POLLERR\n");
-        }
     }
 }