2 files changed, 27 insertions, 3 deletions

diff --git a/kernel/Kconfig.preempt b/kernel/Kconfig.preempt
index 0669b70fa6a3..9fdba03dc1fc 100644
--- a/kernel/Kconfig.preempt
+++ b/kernel/Kconfig.preempt
@@ -52,8 +52,23 @@ config PREEMPT
 
 endchoice
 
+config PREEMPT_RCU
+        bool "Preemptible RCU"
+        depends on PREEMPT
+        default n
+        help
+          This option reduces the latency of the kernel by making certain
+          RCU sections preemptible. Normally RCU code is non-preemptible, if
+          this option is selected then read-only RCU sections become
+          preemptible. This helps latency, but may expose bugs due to
+          now-naive assumptions about each RCU read-side critical section
+          remaining on a given CPU through its execution.
+
+          Say N if you are unsure.
+
 config RCU_TRACE
         bool "Enable tracing for RCU - currently stats in debugfs"
+        depends on PREEMPT_RCU
         select DEBUG_FS
         default y
         help
diff --git a/kernel/module.c b/kernel/module.c
index be4807fb90e4..5d437bffd8dc 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2178,10 +2178,20 @@ sys_init_module(void __user *umod,
                 wake_up(&module_wq);
                 return ret;
         }
+        if (ret > 0) {
+                printk(KERN_WARNING "%s: '%s'->init suspiciously returned %d, "
+                                    "it should follow 0/-E convention\n"
+                       KERN_WARNING "%s: loading module anyway...\n",
+                       __func__, mod->name, ret,
+                       __func__);
+                dump_stack();
+        }
 
-        /* Now it's a first class citizen! */
-        mutex_lock(&module_mutex);
+        /* Now it's a first class citizen!  Wake up anyone waiting for it. */
         mod->state = MODULE_STATE_LIVE;
+        wake_up(&module_wq);
+
+        mutex_lock(&module_mutex);
         /* Drop initial reference. */
         module_put(mod);
         unwind_remove_table(mod->unwind_info, 1);
@@ -2190,7 +2200,6 @@ sys_init_module(void __user *umod,
         mod->init_size = 0;
         mod->init_text_size = 0;
         mutex_unlock(&module_mutex);
-        wake_up(&module_wq);
 
         return 0;
 }