From 31145f38fa3e1649fe357efd03a50e8c4882b0b0 Mon Sep 17 00:00:00 2001
From: Felipe Neves <felipe.neves@espressif.com>
Date: Tue, 19 Nov 2019 15:36:22 -0300
Subject: [PATCH] heap_caps: added special case for realloc when previous area
 is an diram_iram ptr, this will force a malloc/copy/free

---
 components/heap/heap_caps.c            | 37 ++++++++++++++++++++------
 components/heap/multi_heap_poisoning.c | 21 ++-------------
 2 files changed, 31 insertions(+), 27 deletions(-)

diff --git a/components/heap/heap_caps.c b/components/heap/heap_caps.c
index 316612cf6f..2661bcb611 100644
--- a/components/heap/heap_caps.c
+++ b/components/heap/heap_caps.c
@@ -275,6 +275,10 @@ IRAM_ATTR void heap_caps_free( void *ptr)
 
 IRAM_ATTR void *heap_caps_realloc( void *ptr, size_t size, int caps)
 {
+    bool ptr_in_diram_case = false;
+    heap_t *heap = NULL;
+    void *dram_ptr = NULL;
+    
     if (ptr == NULL) {
         return heap_caps_malloc(size, caps);
     }
@@ -288,23 +292,32 @@ IRAM_ATTR void *heap_caps_realloc( void *ptr, size_t size, int caps)
         return NULL;
     }
 
-    //On esp32s2 the pointer to heap may be aliased, we need to 
+    //The pointer to memory may be aliased, we need to 
     //recover it before to manage a new allocation:
     if(esp_ptr_in_diram_iram((void *)ptr)) {
-        //pointer must be already aliased, otherwise just ignore this part:
         uint32_t *dram_addr = (uint32_t *)ptr;
-        ptr = (void *)dram_addr[-1];
+        dram_ptr  = (void *)dram_addr[-1];
+        
         //printf("[HEAP_CAPS_MALLOC]: obtained pointer that was aliased: %p \n", (void *)ptr);
+        
+        heap = find_containing_heap(dram_ptr);
+        assert(heap != NULL && "realloc() pointer is outside heap areas");
+        
+        //with pointers that reside on diram space, we avoid to 
+        //to use realloc implementation due to address translation issues,
+        //instead force a malloc/copy/free
+        ptr_in_diram_case = true;
+    
+    } else {
+        heap = find_containing_heap(ptr);
+        assert(heap != NULL && "realloc() pointer is outside heap areas");
     }
 
-    heap_t *heap = find_containing_heap(ptr);
-    assert(heap != NULL && "realloc() pointer is outside heap areas");
-
     // are the existing heap's capabilities compatible with the
     // requested ones?
     bool compatible_caps = (caps & get_all_caps(heap)) == caps;
 
-    if (compatible_caps) {
+    if (compatible_caps && !ptr_in_diram_case) {
         // try to reallocate this memory within the same heap
         // (which will resize the block if it can)
         void *r = multi_heap_realloc(heap->heap, ptr, size);
@@ -317,8 +330,16 @@ IRAM_ATTR void *heap_caps_realloc( void *ptr, size_t size, int caps)
     // in a different heap with requested capabilities.
     void *new_p = heap_caps_malloc(size, caps);
     if (new_p != NULL) {
+        size_t old_size = 0;
+
+        //If we're dealing with aliased ptr, information regarding its containing
+        //heap can only be obtained with translated address.
+        if(ptr_in_diram_case) {
+            old_size = multi_heap_get_allocated_size(heap->heap, dram_ptr);
+        } else {
+            old_size = multi_heap_get_allocated_size(heap->heap, ptr);
+        }
 
-        size_t old_size = multi_heap_get_allocated_size(heap->heap, ptr);
         assert(old_size > 0);
         memcpy(new_p, ptr, MIN(size, old_size));
         heap_caps_free(ptr);
diff --git a/components/heap/multi_heap_poisoning.c b/components/heap/multi_heap_poisoning.c
index 3717b6c299..ffe885150d 100644
--- a/components/heap/multi_heap_poisoning.c
+++ b/components/heap/multi_heap_poisoning.c
@@ -21,10 +21,6 @@
 #include <sys/param.h>
 #include <multi_heap.h>
 #include "multi_heap_internal.h"
-#if CONFIG_IDF_TARGET_ESP32S2BETA
-    #include "heap_private.h"
-#endif
-
 
 /* Note: Keep platform-specific parts in this header, this source
    file should depend on libc only */
@@ -272,21 +268,8 @@ void *multi_heap_realloc(multi_heap_handle_t heap, void *p, size_t size)
     new_head = multi_heap_malloc_impl(heap, size + POISON_OVERHEAD);
     if (new_head != NULL) {
         result = poison_allocated_region(new_head, size);
-
-#if CONFIG_IDF_TARGET_ESP32S2BETA
-        //We may need to deal with aliased heap pointers. here too, 
-        //mainly because the heap canary is located before the
-        //the slot reserved to preserve original DRAM address
-        //so the original user data is actually p + 4 ahead :
-        if(esp_ptr_in_diram_dram((void *)p)) {
-            memcpy(result, p + sizeof(intptr_t), MIN(size, orig_alloc_size));
-        } else {
-            memcpy(result, p , MIN(size, orig_alloc_size));
-        }
-#else 
-        memcpy(result, p, MIN(size, orig_alloc_size));
-#endif        
-        multi_heap_free(heap, p);
+        memcpy(result, p, MIN(size, orig_alloc_size));      
+        multi_heap_free(heap, p);        
     }
 #endif