heap: fix wrong memory region check

A memory region starts from REGION_START and ends at
(REGION_START+SIZE-1).

Prior to this change, the check assumes a to-be-added region starting from REGION_START is invalid. Let's take an easy example:

A memory region:  0x1000~0x10ff
new added region: 0x1000~0x1020

This will be valid.

Valid conditions and invalid conditions are illustrated in the code comment

components/heap/heap_caps_init.c

@@ -1,16 +1,8 @@
-// Copyright 2015-2016 Espressif Systems (Shanghai) PTE LTD
+/*
-//
+ * SPDX-FileCopyrightText: 2015-2022 Espressif Systems (Shanghai) CO LTD
-// Licensed under the Apache License, Version 2.0 (the "License");
+ *
-// you may not use this file except in compliance with the License.
+ * SPDX-License-Identifier: Apache-2.0
-// You may obtain a copy of the License at
+ */
-
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
 #include "heap_private.h"
 #include <assert.h>
 #include <string.h>
@@ -180,28 +172,38 @@ esp_err_t heap_caps_add_region_with_caps(const uint32_t caps[], intptr_t start,
     //Check if region overlaps the start and/or end of an existing region. If so, the
     //region is invalid (or maybe added twice)
     /*
-     *  assume that in on region, start must be less than end (cannot equal to) !!
+     *  We assume that in any region, the "start" must be stictly less than the end.
-     *  Specially, the 4th scenario can be allowed. For example, allocate memory from heap,
+     *  Specially, the 3rd scenario can be allowed. For example, allocate memory from heap,
      *  then change the capability and call this function to create a new region for special
      *  application.
-     *  In the following chart, 'start = start' and 'end = end' is contained in 3rd scenario.
+     *  In the following chart, 'start = start' and 'end = end' is contained in 4th scenario.
      *  This all equal scenario is incorrect because the same region cannot be add twice. For example,
      *  add the .bss memory to region twice, if not do the check, it will cause exception.
      *
      *  the existing heap region                                  s(tart)                e(nd)
      *                                                            |----------------------|
-     *  1.add region  [Correct]   (s1<s && e1<=s)           |-----|
+     *
-     *  2.add region  [Incorrect] (s2<=s && s<e2<=e)        |---------------|
+     *  1.add region  (e1<s)                                |-----|                                      correct: bool condition_1 = end < heap->start;
-     *  3.add region  [Incorrect] (s3<=s && e<e3)           |-------------------------------------|
+     *
-     *  4 add region  [Correct]   (s<s4<e && s<e4<=e)                  |-------|
+     *  2.add region  (s2<s && e2>=s)                       |-----------------|                          wrong:   bool condition_2 = start < heap->start && end >= heap->start;
-     *  5.add region  [Incorrect] (s<s5<e && e<e5)                     |----------------------------|
+     *                                                      |---------------------------------|          wrong
-     *  6.add region  [Correct]   (e<=s6 && e<e6)                                        |----|
+     *
+     *  3.add region  (s3>=s && e3<e)                             |---------------|                      correct: bool condition_3 = start >= heap->start && end < heap->end;
+     *                                                                  |--------------|                 correct
+     *
+     *  4.add region  (s4<e && e4>=e)                             |----------------------|               wrong:   bool condition_4 = start < heap->end && end >= heap->end;
+     *                                                                  |---------------------|          wrong
+     *
+     *  5.add region  (s5>=e)                                                            |----|          correct: bool condition_5 = start >= heap->end;
      */
 
     heap_t *heap;
     SLIST_FOREACH(heap, &registered_heaps, next) {
-        if ((start <= heap->start && end > heap->start)
+        bool condition_2 = start < heap->start && end >= heap->start;       //if 1, wrong
-                || (start < heap->end && end > heap->end)) {
+        bool condition_4 = start < heap->end && end >= heap->end;           //if 1, wrong
+        bool wrong_region = condition_2 || condition_4;
+
+        if (wrong_region) {
             return ESP_FAIL;
         }
     }

tools/ci/check_copyright_ignore.txt

@@ -999,7 +999,6 @@ components/hal/twai_hal_iram.c
 components/hal/uart_hal.c
 components/hal/uart_hal_iram.c
 components/hal/usb_hal.c
-components/heap/heap_caps_init.c
 components/heap/heap_private.h
 components/heap/heap_task_info.c
 components/heap/heap_tlsf.c