1 files changed, 37 insertions, 1 deletions

diff --git a/unix/alloc.c b/unix/alloc.c
index cb866c78a2..44a84437ec 100644
--- a/unix/alloc.c
+++ b/unix/alloc.c
@@ -24,16 +24,29 @@
  * THE SOFTWARE.
  */
 
+#include <stdio.h>
 #include <stdint.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sys/mman.h>
 
-#include "mpconfigport.h"
+#include "py/mpstate.h"
+#include "py/gc.h"
 
 #if defined(__OpenBSD__) || defined(__MACH__)
 #define MAP_ANONYMOUS MAP_ANON
 #endif
 
+// The memory allocated here is not on the GC heap (and it may contain pointers
+// that need to be GC'd) so we must somehow trace this memory.  We do it by
+// keeping a linked list of all mmap'd regions, and tracing them explicitly.
+
+typedef struct _mmap_region_t {
+    void *ptr;
+    size_t len;
+    struct _mmap_region_t *next;
+} mmap_region_t;
+
 void mp_unix_alloc_exec(mp_uint_t min_size, void **ptr, mp_uint_t *size) {
     // size needs to be a multiple of the page size
     *size = (min_size + 0xfff) & (~0xfff);
@@ -41,8 +54,31 @@ void mp_unix_alloc_exec(mp_uint_t min_size, void **ptr, mp_uint_t *size) {
     if (*ptr == MAP_FAILED) {
         *ptr = NULL;
     }
+
+    // add new link to the list of mmap'd regions
+    mmap_region_t *rg = m_new_obj(mmap_region_t);
+    rg->ptr = *ptr;
+    rg->len = min_size;
+    rg->next = MP_STATE_VM(mmap_region_head);
+    MP_STATE_VM(mmap_region_head) = rg;
 }
 
 void mp_unix_free_exec(void *ptr, mp_uint_t size) {
     munmap(ptr, size);
+
+    // unlink the mmap'd region from the list
+    for (mmap_region_t **rg = (mmap_region_t**)&MP_STATE_VM(mmap_region_head); *rg != NULL; *rg = (*rg)->next) {
+        if ((*rg)->ptr == ptr) {
+            mmap_region_t *next = (*rg)->next;
+            m_del_obj(mmap_region_t, *rg);
+            *rg = next;
+            return;
+        }
+    }
+}
+
+void mp_unix_mark_exec(void) {
+    for (mmap_region_t *rg = MP_STATE_VM(mmap_region_head); rg != NULL; rg = rg->next) {
+        gc_collect_root(rg->ptr, rg->len / sizeof(mp_uint_t));
+    }
 }