Solve the static problem of user mode locking under high concurrency.

kernel/base/ipc/los_futex.c

@@ -465,41 +465,29 @@ STATIC INT32 OsFindAndInsertToHash(FutexNode *node)
     return ret;
 }
 
-STATIC INT32 OsFutexWaitParmaCheck(const UINT32 *userVaddr, UINT32 flags, UINT32 val, UINT32 absTime)
+STATIC INT32 OsFutexWaitParamCheck(const UINT32 *userVaddr, UINT32 flags, UINT32 absTime)
 {
     UINTPTR futexKey = (UINTPTR)userVaddr;
-    UINT32 lockVal;
-    INT32 ret;
 
     if (OS_INT_ACTIVE) {
         return LOS_EINTR;
     }
 
     if (flags) {
-        PRINT_ERR("Futex wait parma check failed! error flags: 0x%x\n", flags);
+        PRINT_ERR("Futex wait param check failed! error flags: 0x%x\n", flags);
         return LOS_EINVAL;
     }
 
     if ((futexKey % sizeof(INT32)) || (futexKey < OS_FUTEX_KEY_BASE) || (futexKey >= OS_FUTEX_KEY_MAX)) {
-        PRINT_ERR("Futex wait parma check failed! error futex key: 0x%x\n", futexKey);
+        PRINT_ERR("Futex wait param check failed! error futex key: 0x%x\n", futexKey);
         return LOS_EINVAL;
     }
 
     if (!absTime) {
-        PRINT_ERR("Futex wait parma check failed! error absTime: %u\n", absTime);
-        return LOS_EINVAL;
-    }
-
-    ret = LOS_ArchCopyFromUser(&lockVal, userVaddr, sizeof(UINT32));
-    if (ret) {
-        PRINT_ERR("Futex wait parma check failed! copy from user failed!\n");
+        PRINT_ERR("Futex wait param check failed! error absTime: %u\n", absTime);
         return LOS_EINVAL;
     }
 
-    if (lockVal != val) {
-        return LOS_EBADF;
-    }
-
     return LOS_OK;
 }
 
@@ -542,10 +530,10 @@ STATIC INT32 OsFutexInserTaskToHash(LosTaskCB **taskCB, FutexNode **node, const
     return LOS_OK;
 }
 
-STATIC INT32 OsFutexWaitTask(const UINT32 timeOut, const UINT32 *userVaddr)
+STATIC INT32 OsFutexWaitTask(const UINT32 timeOut, const UINT32 *userVaddr, UINT32 val)
 {
     INT32 futexRet;
-    UINT32 intSave;
+    UINT32 intSave, lockVal;
     LosTaskCB *taskCB = NULL;
     FutexNode *node = NULL;
     UINTPTR futexKey = (UINTPTR)userVaddr;
@@ -556,7 +544,19 @@ STATIC INT32 OsFutexWaitTask(const UINT32 timeOut, const UINT32 *userVaddr)
         return LOS_EINVAL;
     }
 
+    if (LOS_ArchCopyFromUser(&lockVal, userVaddr, sizeof(UINT32))) {
+        PRINT_ERR("Futex wait param check failed! copy from user failed!\n");
+        futexRet = LOS_EINVAL;
+	goto EXIT_ERR;
+    }
+
+    if (lockVal != val) {
+        futexRet = LOS_EBADF;
+	goto EXIT_ERR;
+    }
+
     if (OsFutexInserTaskToHash(&taskCB, &node, futexKey)) {
+        futexRet = LOS_NOK;
         goto EXIT_ERR;
     }
     SCHEDULER_LOCK(intSave);
@@ -564,10 +564,6 @@ STATIC INT32 OsFutexWaitTask(const UINT32 timeOut, const UINT32 *userVaddr)
     OsPercpuGet()->taskLockCnt++;
     LOS_SpinUnlock(&g_taskSpin);
 
-#ifdef LOS_FUTEX_DEBUG
-    OsFutexHashShow();
-#endif
-
     futexRet = OsFutexUnlock(&hashNode->listLock);
     if (futexRet) {
         OsPercpuGet()->taskLockCnt--;
@@ -594,12 +590,9 @@ STATIC INT32 OsFutexWaitTask(const UINT32 timeOut, const UINT32 *userVaddr)
     return LOS_OK;
 
 EXIT_ERR:
-    futexRet = OsFutexUnlock(&hashNode->listLock);
+    (VOID)OsFutexUnlock(&hashNode->listLock);
 EXIT_UNLOCK_ERR:
-    if (futexRet) {
-        return futexRet;
-    }
-    return LOS_NOK;
+    return futexRet;
 }
 
 INT32 OsFutexWait(const UINT32 *userVaddr, UINT32 flags, UINT32 val, UINT32 absTime)
@@ -607,7 +600,7 @@ INT32 OsFutexWait(const UINT32 *userVaddr, UINT32 flags, UINT32 val, UINT32 absT
     INT32 ret;
     UINT32 timeOut = LOS_WAIT_FOREVER;
 
-    ret = OsFutexWaitParmaCheck(userVaddr, flags, val, absTime);
+    ret = OsFutexWaitParamCheck(userVaddr, flags, absTime);
     if (ret) {
         return ret;
     }
@@ -615,7 +608,7 @@ INT32 OsFutexWait(const UINT32 *userVaddr, UINT32 flags, UINT32 val, UINT32 absT
         timeOut = OsFutexGetTick(absTime);
     }
 
-    return OsFutexWaitTask(timeOut, userVaddr);
+    return OsFutexWaitTask(timeOut, userVaddr, val);
 }
 
 /* Check to see if the task to be awakened has timed out