From d0aef615acb0b1cb3c1662a7d2562ea7bef471ec Mon Sep 17 00:00:00 2001 From: "Marvin.Haeuser@outlook.com" Date: Fri, 4 Aug 2017 03:52:08 +0800 Subject: [PATCH] MdePkg/BaseLib: Add IsNodeInList() function. This patch adds IsNodeInList() to BaseLib, which verifies the given Node is part of the doubly-linked List provided. V2: - Rename "List" to "FirstEntry" and "Node" to "SecondEntry" to clarify that "FirstEntry" does not need to be the doubly-linked list's head node. V3: - Remove ASSERTs from IsNodeInList() which are present in InternalBaseLibIsListValid(). Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Marvin Haeuser Reviewed-by: Liming Gao --- MdePkg/Include/Library/BaseLib.h | 27 ++++++++++ MdePkg/Library/BaseLib/BaseLibInternals.h | 28 ---------- MdePkg/Library/BaseLib/LinkedList.c | 66 ++++++++++++++++++++++- 3 files changed, 92 insertions(+), 29 deletions(-) diff --git a/MdePkg/Include/Library/BaseLib.h b/MdePkg/Include/Library/BaseLib.h index 791849b804..40b96b761a 100644 --- a/MdePkg/Include/Library/BaseLib.h +++ b/MdePkg/Include/Library/BaseLib.h @@ -2868,6 +2868,33 @@ PathCleanUpDirectories( #define INITIALIZE_LIST_HEAD_VARIABLE(ListHead) {&(ListHead), &(ListHead)} +/** + Checks whether FirstEntry and SecondEntry are part of the same doubly-linked + list. + + If FirstEntry is NULL, then ASSERT(). + If FirstEntry->ForwardLink is NULL, then ASSERT(). + If FirstEntry->BackLink is NULL, then ASSERT(). + If SecondEntry is NULL, then ASSERT(); + If PcdMaximumLinkedListLength is not zero, and List contains more than + PcdMaximumLinkedListLength nodes, then ASSERT(). + + @param FirstEntry A pointer to a node in a linked list. + @param SecondEntry A pointer to the node to locate. + + @retval TRUE SecondEntry is in the same doubly-linked list as FirstEntry. + @retval FALSE SecondEntry isn't in the same doubly-linked list as FirstEntry, + or FirstEntry is invalid. + +**/ +BOOLEAN +EFIAPI +IsNodeInList ( + IN CONST LIST_ENTRY *FirstEntry, + IN CONST LIST_ENTRY *SecondEntry + ); + + /** Initializes the head node of a doubly linked list, and returns the pointer to the head node of the doubly linked list. diff --git a/MdePkg/Library/BaseLib/BaseLibInternals.h b/MdePkg/Library/BaseLib/BaseLibInternals.h index ea387ce37d..9dca97a0dc 100644 --- a/MdePkg/Library/BaseLib/BaseLibInternals.h +++ b/MdePkg/Library/BaseLib/BaseLibInternals.h @@ -339,34 +339,6 @@ InternalSwitchStack ( ); -/** - Worker function that locates the Node in the List. - - By searching the List, finds the location of the Node in List. At the same time, - verifies the validity of this list. - - If List is NULL, then ASSERT(). - If List->ForwardLink is NULL, then ASSERT(). - If List->backLink is NULL, then ASSERT(). - If Node is NULL, then ASSERT(); - If PcdMaximumLinkedListLength is not zero, and prior to insertion the number - of nodes in ListHead, including the ListHead node, is greater than or - equal to PcdMaximumLinkedListLength, then ASSERT(). - - @param List A pointer to a node in a linked list. - @param Node A pointer to one nod. - - @retval TRUE Node is in List. - @retval FALSE Node isn't in List, or List is invalid. - -**/ -BOOLEAN -EFIAPI -IsNodeInList ( - IN CONST LIST_ENTRY *List, - IN CONST LIST_ENTRY *Node - ); - /** Worker function that returns a bit field from Operand. diff --git a/MdePkg/Library/BaseLib/LinkedList.c b/MdePkg/Library/BaseLib/LinkedList.c index ba373f4b7b..af27b0dd9a 100644 --- a/MdePkg/Library/BaseLib/LinkedList.c +++ b/MdePkg/Library/BaseLib/LinkedList.c @@ -1,7 +1,7 @@ /** @file Linked List Library Functions. - Copyright (c) 2006 - 2013, Intel Corporation. All rights reserved.
+ Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.
This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this distribution. The full text of the license may be found at @@ -112,6 +112,70 @@ InternalBaseLibIsNodeInList ( return TRUE; } +/** + Checks whether FirstEntry and SecondEntry are part of the same doubly-linked + list. + + If FirstEntry is NULL, then ASSERT(). + If FirstEntry->ForwardLink is NULL, then ASSERT(). + If FirstEntry->BackLink is NULL, then ASSERT(). + If SecondEntry is NULL, then ASSERT(); + If PcdMaximumLinkedListLength is not zero, and List contains more than + PcdMaximumLinkedListLength nodes, then ASSERT(). + + @param FirstEntry A pointer to a node in a linked list. + @param SecondEntry A pointer to the node to locate. + + @retval TRUE SecondEntry is in the same doubly-linked list as FirstEntry. + @retval FALSE SecondEntry isn't in the same doubly-linked list as FirstEntry, + or FirstEntry is invalid. + +**/ +BOOLEAN +EFIAPI +IsNodeInList ( + IN CONST LIST_ENTRY *FirstEntry, + IN CONST LIST_ENTRY *SecondEntry + ) +{ + UINTN Count; + CONST LIST_ENTRY *Ptr; + + // + // ASSERT List not too long + // + ASSERT (InternalBaseLibIsListValid (FirstEntry)); + + ASSERT (SecondEntry != NULL); + + Count = 0; + Ptr = FirstEntry; + + // + // Check to see if SecondEntry is a member of FirstEntry. + // Exit early if the number of nodes in List >= PcdMaximumLinkedListLength + // + do { + Ptr = Ptr->ForwardLink; + if (PcdGet32 (PcdMaximumLinkedListLength) > 0) { + Count++; + + // + // Return if the linked list is too long + // + if (Count == PcdGet32 (PcdMaximumLinkedListLength)) { + return (BOOLEAN)(Ptr == SecondEntry); + } + } + + if (Ptr == SecondEntry) { + return TRUE; + } + } while (Ptr != FirstEntry); + + return FALSE; +} + /** Initializes the head node of a doubly-linked list, and returns the pointer to the head node of the doubly-linked list. -- 2.39.2