commit 705b5cedcdfaa3c5b8b6c2718010f2c8c162855d
author Earle F. Philhower, III <earlephilhower@yahoo.com> Fri Jun 17 07:50:53 2022 -0700
committer GitHub <noreply@github.com> Fri Jun 17 09:50:53 2022 -0500
tree 015149b628befa4f41188ebf5a4915a06696a631
parent bdd97466357549c20d79e4740913f09e1656652f

Wrap realloc() call with malloc_mutex in multicore (#864)

Protect against heap corruption by mutex-protecting the realloc() call
(like malloc/free are already).

Fixes #863
Fixes https://github.com/maxgerhardt/platform-raspberrypi/issues/7
Fixes https://github.com/earlephilhower/arduino-pico/issues/614

src/rp2_common/pico_malloc/CMakeLists.txt

diff --git a/src/rp2_common/pico_malloc/CMakeLists.txt b/src/rp2_common/pico_malloc/CMakeLists.txt
index deeb30f..57ac267 100644
--- a/src/rp2_common/pico_malloc/CMakeLists.txt
+++ b/src/rp2_common/pico_malloc/CMakeLists.txt
@@ -10,6 +10,7 @@
 
     pico_wrap_function(pico_malloc malloc)
     pico_wrap_function(pico_malloc calloc)
+    pico_wrap_function(pico_malloc realloc)
     pico_wrap_function(pico_malloc free)
 
     target_link_libraries(pico_malloc INTERFACE pico_sync)

src/rp2_common/pico_malloc/pico_malloc.c

diff --git a/src/rp2_common/pico_malloc/pico_malloc.c b/src/rp2_common/pico_malloc/pico_malloc.c
index 4928a8e..a053986 100644
--- a/src/rp2_common/pico_malloc/pico_malloc.c
+++ b/src/rp2_common/pico_malloc/pico_malloc.c
@@ -16,6 +16,7 @@
 
 extern void *__real_malloc(size_t size);
 extern void *__real_calloc(size_t count, size_t size);
+extern void *__real_realloc(void *mem, size_t size);
 extern void __real_free(void *mem);
 
 extern char __StackLimit; /* Set by linker.  */
@@ -62,6 +63,23 @@
     return rc;
 }
 
+void *__wrap_realloc(void *mem, size_t size) {
+#if PICO_USE_MALLOC_MUTEX
+    mutex_enter_blocking(&malloc_mutex);
+#endif
+    void *rc = __real_realloc(mem, size);
+#if PICO_USE_MALLOC_MUTEX
+    mutex_exit(&malloc_mutex);
+#endif
+#if PICO_DEBUG_MALLOC
+    if (!rc || ((uint8_t *)rc) + size > (uint8_t*)PICO_DEBUG_MALLOC_LOW_WATER) {
+        printf("realloc %p %d->%p\n", mem, (uint) size, rc);
+    }
+#endif
+    check_alloc(rc, size);
+    return rc;
+}
+
 void __wrap_free(void *mem) {
 #if PICO_USE_MALLOC_MUTEX
     mutex_enter_blocking(&malloc_mutex);