linux-user: Implement gethostname

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 038aefe..89c74ad 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -8868,6 +8868,19 @@
         break;
     }
 #endif
+#ifdef TARGET_NR_gethostname
+    case TARGET_NR_gethostname:
+    {
+        char *name = lock_user(VERIFY_WRITE, arg1, arg2, 0);
+        if (name) {
+            ret = get_errno(gethostname(name, arg2));
+            unlock_user(name, arg1, arg2);
+        } else {
+            ret = -TARGET_EFAULT;
+        }
+        break;
+    }
+#endif
     default:
     unimplemented:
         gemu_log("qemu: Unsupported syscall: %d\n", num);