win32: ash: sticky_free()

1 files changed, 15 insertions, 0 deletions

diff --git a/shell/ash.c b/shell/ash.c
index 2e47fd272..ba5811213 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -112,6 +112,8 @@ struct forkshell {
         struct strlist *strlist;
         pid_t pid;
 };
+static void sticky_free(void *p);
+#define free(p) sticky_free(p)
 static int spawn_forkshell(struct job *jp, struct forkshell *fs, int mode);
 #endif
 
@@ -13784,6 +13786,7 @@ forkshell_prepare(struct forkshell *fs)
 #undef exception_handler
 #undef trap
 #undef trap_ptr
+static void *sticky_mem_start, *sticky_mem_end;
 static void
 forkshell_init(const char *idstr)
 {
@@ -13802,6 +13805,9 @@ forkshell_init(const char *idstr)
         if (!fs)
                 bb_error_msg_and_die("Invalid forkshell memory");
 
+        /* this memory can't be freed */
+        sticky_mem_start = fs;
+        sticky_mem_end = (char *) fs + fs->size;
         /* pointer fixup */
         nodeptr = (int*)((char*)fs + fs->nodeptr_offset);
         while (*nodeptr) {
@@ -13838,6 +13844,15 @@ forkshell_init(const char *idstr)
         fs->fp(fs);
 }
 
+#undef free
+static void
+sticky_free(void *base)
+{
+        if (base >= sticky_mem_start && base < sticky_mem_end)
+                return;
+        free(base);
+}
+
 /*-
  * Copyright (c) 1989, 1991, 1993, 1994
  *      The Regents of the University of California.  All rights reserved.