From 4a392932f1909364e606fa893cea3ce14e0c8122 Mon Sep 17 00:00:00 2001
From: Felipe Neves <felipe.neves@espressif.com>
Date: Tue, 12 Nov 2019 14:01:27 +0800
Subject: [PATCH] heap/heap_caps: added special case for esp32s2 when handling
 memory allocated (and aliased) from IRAM

---
 components/heap/heap_caps.c            | 14 +++++++++++++-
 components/heap/multi_heap_poisoning.c | 14 ++++++++++++++
 components/heap/test/test_realloc.c    |  3 +--
 3 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/components/heap/heap_caps.c b/components/heap/heap_caps.c
index 9e2ddd3a41..28cb7bf4d1 100644
--- a/components/heap/heap_caps.c
+++ b/components/heap/heap_caps.c
@@ -107,6 +107,7 @@ IRAM_ATTR void *heap_caps_malloc( size_t size, uint32_t caps )
                         //we need to 'invert' it (lowest address in DRAM == highest address in IRAM and vice-versa) and
                         //add a pointer to the DRAM equivalent before the address we're going to return.
                         ret = multi_heap_malloc(heap->heap, size + 4);  // int overflow checked above
+
                         if (ret != NULL) {
                             return dram_alloc_to_iram_addr(ret, size + 4);  // int overflow checked above
                         }
@@ -287,8 +288,18 @@ IRAM_ATTR void *heap_caps_realloc( void *ptr, size_t size, int caps)
         return NULL;
     }
 
-    heap_t *heap = find_containing_heap(ptr);
+#if CONFIG_IDF_TARGET_ESP32S2BETA
+    //On esp32s2 the pointer to heap 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];
+        //printf("[HEAP_CAPS_MALLOC]: obtained pointer that was aliased: %p \n", (void *)ptr);
+    }
+#endif
 
+    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
@@ -308,6 +319,7 @@ 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 = multi_heap_get_allocated_size(heap->heap, ptr);
         assert(old_size > 0);
         memcpy(new_p, ptr, MIN(size, old_size));
diff --git a/components/heap/multi_heap_poisoning.c b/components/heap/multi_heap_poisoning.c
index a896043abb..559ad18d2e 100644
--- a/components/heap/multi_heap_poisoning.c
+++ b/components/heap/multi_heap_poisoning.c
@@ -21,6 +21,7 @@
 #include <sys/param.h>
 #include <multi_heap.h>
 #include "multi_heap_internal.h"
+#include "heap_private.h"
 
 /* Note: Keep platform-specific parts in this header, this source
    file should depend on libc only */
@@ -268,7 +269,20 @@ 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);
     }
 #endif
diff --git a/components/heap/test/test_realloc.c b/components/heap/test/test_realloc.c
index 290ee3da6e..763cddab62 100644
--- a/components/heap/test/test_realloc.c
+++ b/components/heap/test/test_realloc.c
@@ -31,7 +31,6 @@ TEST_CASE("realloc move data to a new heap type", "[heap]")
 
     char *a = malloc(64);
     memcpy(a, buf, 64);
-
     // move data from 'a' to IRAM
     char *b = heap_caps_realloc(a, 64, MALLOC_CAP_EXEC);
     TEST_ASSERT_NOT_NULL(b);
@@ -40,7 +39,7 @@ TEST_CASE("realloc move data to a new heap type", "[heap]")
     TEST_ASSERT_EQUAL_HEX32_ARRAY(buf, b, 64/sizeof(uint32_t));
 
     // Move data back to DRAM
-    char *c = heap_caps_realloc(b, 48, MALLOC_CAP_8BIT);
+    char *c = heap_caps_realloc(b, 48, MALLOC_CAP_8BIT);    
     TEST_ASSERT_NOT_NULL(c);
     TEST_ASSERT_NOT_EQUAL(b, c);
     TEST_ASSERT(heap_caps_check_integrity(MALLOC_CAP_INVALID, true));