X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/4bd07ac2140668789aa3ee8ec4dde4a3e0a3bba5..d9a64523371fa019c4575bb400cbbc3a50ac9903:/osfmk/kern/sync_sema.c

diff --git a/osfmk/kern/sync_sema.c b/osfmk/kern/sync_sema.c
index 4304559e6..98f33ba8d 100644
--- a/osfmk/kern/sync_sema.c
+++ b/osfmk/kern/sync_sema.c
@@ -66,6 +66,8 @@ static unsigned int semaphore_event;
 zone_t semaphore_zone;
 unsigned int semaphore_max;
 
+os_refgrp_decl(static, sema_refgrp, "semaphore", NULL);
+
 /* Forward declarations */
 
 
@@ -184,7 +186,7 @@ semaphore_create(
 	 * Initialize the semaphore values.
 	 */
 	s->port	= IP_NULL;
-	s->ref_count = 1;
+	os_ref_init(&s->ref_count, &sema_refgrp);
 	s->count = value;
 	s->active = TRUE;
 	s->owner = task;
@@ -280,11 +282,12 @@ semaphore_destroy(
 
 	if (semaphore->owner != task) {
 		semaphore_unlock(semaphore);
+		semaphore_dereference(semaphore);
 		splx(spl_level);
 		task_unlock(task);
 		return KERN_INVALID_ARGUMENT;
 	}
-			
+
 	semaphore_destroy_internal(task, semaphore);
 	/* semaphore unlocked */
 
@@ -687,7 +690,8 @@ semaphore_wait_internal(
 		thread_t	self = current_thread();
 
 		wait_semaphore->count = -1;  /* we don't keep an actual count */
-		thread_lock(self);
+
+		thread_set_pending_block_hint(self, kThreadWaitSemaphore);
 		(void)waitq_assert_wait64_locked(
 					&wait_semaphore->waitq,
 					SEMAPHORE_EVENT,
@@ -695,7 +699,6 @@ semaphore_wait_internal(
 					TIMEOUT_URGENCY_USER_NORMAL,
 					deadline, TIMEOUT_NO_LEEWAY,
 					self);
-		thread_unlock(self);
 	}
 	semaphore_unlock(wait_semaphore);
 	splx(spl_level);
@@ -1105,7 +1108,7 @@ void
 semaphore_reference(
 	semaphore_t		semaphore)
 {
-	(void)hw_atomic_add(&semaphore->ref_count, 1);
+	os_ref_retain(&semaphore->ref_count);
 }
 
 /*
@@ -1124,8 +1127,9 @@ semaphore_dereference(
 	if (semaphore == NULL)
 		return;
 
-	if (hw_atomic_sub(&semaphore->ref_count, 1) != 0)
+	if (os_ref_release(&semaphore->ref_count) > 0) {
 		return;
+	}
 
 	/*
 	 * Last ref, clean up the port [if any]
@@ -1173,4 +1177,15 @@ semaphore_dereference(
 	zfree(semaphore_zone, semaphore);
 }
 
+#define WAITQ_TO_SEMA(wq) ((semaphore_t) ((uintptr_t)(wq) - offsetof(struct semaphore, waitq)))
+void
+kdp_sema_find_owner(struct waitq * waitq, __assert_only event64_t event, thread_waitinfo_t * waitinfo)
+{
+	semaphore_t sem = WAITQ_TO_SEMA(waitq);
+	assert(event == SEMAPHORE_EVENT);
+	assert(kdp_is_in_zone(sem, "semaphores"));
 
+	waitinfo->context = VM_KERNEL_UNSLIDE_OR_PERM(sem->port);
+	if (sem->owner)
+		waitinfo->owner = pid_from_task(sem->owner);
+}