xnu-3789.1.32.tar.gz

[apple/xnu.git] / osfmk / kern / sfi.c

diff --git a/osfmk/kern/sfi.c b/osfmk/kern/sfi.c
index b43fe2db1b3d63d5c2928551e9f5d957f30eceb6..8a67ec0344c72e0a53a146d16f717b8cb4670f2d 100644 (file)
--- a/osfmk/kern/sfi.c
+++ b/osfmk/kern/sfi.c
@@ -42,6 +42,8 @@
 #include <kern/timer_call.h>
 #include <kern/waitq.h>
 #include <kern/ledger.h>
+#include <kern/policy_internal.h>
+
 #include <pexpert/pexpert.h>
 
 #include <libkern/kernel_mach_header.h>
@@ -94,6 +96,8 @@ extern sched_call_t workqueue_get_sched_callback(void);
  *
  * The pset lock may also be taken, but not while any other locks are held.
  *
+ * The task and thread mutex may also be held while reevaluating sfi state.
+ *
  * splsched ---> sfi_lock ---> waitq ---> thread_lock
  *        \  \              \__ thread_lock (*)
  *         \  \__ pset_lock
@@ -738,13 +742,15 @@ sfi_class_id_t sfi_thread_classify(thread_t thread)
        task_t task = thread->task;
        boolean_t is_kernel_thread = (task == kernel_task);
        sched_mode_t thmode = thread->sched_mode;
-       int latency_qos = proc_get_effective_task_policy(task, TASK_POLICY_LATENCY_QOS);
-       int task_role = proc_get_effective_task_policy(task, TASK_POLICY_ROLE);
-       int thread_bg = proc_get_effective_thread_policy(thread, TASK_POLICY_DARWIN_BG);
-       int managed_task = proc_get_effective_task_policy(task, TASK_POLICY_SFI_MANAGED);
-       int thread_qos = proc_get_effective_thread_policy(thread, TASK_POLICY_QOS);
        boolean_t focal = FALSE;
 
+       int task_role       = proc_get_effective_task_policy(task, TASK_POLICY_ROLE);
+       int latency_qos     = proc_get_effective_task_policy(task, TASK_POLICY_LATENCY_QOS);
+       int managed_task    = proc_get_effective_task_policy(task, TASK_POLICY_SFI_MANAGED);
+
+       int thread_qos      = proc_get_effective_thread_policy(thread, TASK_POLICY_QOS);
+       int thread_bg       = proc_get_effective_thread_policy(thread, TASK_POLICY_DARWIN_BG);
+
        /* kernel threads never reach the user AST boundary, and are in a separate world for SFI */
        if (is_kernel_thread) {
                return SFI_CLASS_KERNEL;
@@ -928,7 +934,6 @@ void sfi_ast(thread_t thread)
        uint64_t        tid;
        thread_continue_t       continuation;
        sched_call_t    workq_callback = workqueue_get_sched_callback();
-       boolean_t       did_clear_wq = FALSE;
 
        s = splsched();
 
@@ -964,7 +969,8 @@ void sfi_ast(thread_t thread)
        /* Optimistically clear workq callback while thread is already locked */
        if (workq_callback && (thread->sched_call == workq_callback)) {
                thread_sched_call(thread, NULL);
-               did_clear_wq = TRUE;
+       } else {
+               workq_callback = NULL;
        }
        thread_unlock(thread);
 
@@ -991,15 +997,9 @@ void sfi_ast(thread_t thread)
        splx(s);
 
        if (did_wait) {
-               thread_block_reason(continuation, did_clear_wq ? workq_callback : NULL, AST_SFI);
-       } else {
-               if (did_clear_wq) {
-                       s = splsched();
-                       thread_lock(thread);
-                       thread_sched_call(thread, workq_callback);
-                       thread_unlock(thread);
-                       splx(s);
-               }
+               thread_block_reason(continuation, workq_callback, AST_SFI);
+       } else if (workq_callback) {
+               thread_reenable_sched_call(thread, workq_callback);
        }
 }