X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Ftalloc%2Ftalloc.c;h=ed958a8e5f25fdbeebf83f30b1ea8fef82d018bc;hp=1424748eef7fa9a5b49caabd9fb095914b51cd50;hb=d1cea3ebf96f61b5bbac1e74975700770e06add6;hpb=f933b8c3246e3fbfe362cb1db73a4ef774725709

diff --git a/ccan/talloc/talloc.c b/ccan/talloc/talloc.c
index 1424748e..ed958a8e 100644
--- a/ccan/talloc/talloc.c
+++ b/ccan/talloc/talloc.c
@@ -43,7 +43,7 @@
 #define ALWAYS_REALLOC 0
 
 
-#define MAX_TALLOC_SIZE 0x10000000
+#define MAX_TALLOC_SIZE 0x7FFFFFFF
 #define TALLOC_MAGIC 0xe814ec70
 #define TALLOC_FLAG_FREE 0x01
 #define TALLOC_FLAG_LOOP 0x02
@@ -469,7 +469,7 @@ static void *__talloc_steal(const void *new_ctx, const void *ptr)
 /* 
    internal talloc_free call
 */
-static inline int _talloc_free(void *ptr)
+static inline int _talloc_free(const void *ptr)
 {
 	struct talloc_chunk *tc;
 	void *oldparent = NULL;
@@ -508,7 +508,7 @@ static inline int _talloc_free(void *ptr)
 			return -1;
 		}
 		tc->destructor = (talloc_destructor_t)-1;
-		if (d(ptr) == -1) {
+		if (d(discard_const_p(void, ptr)) == -1) {
 			tc->destructor = d;
 			return -1;
 		}
@@ -789,6 +789,35 @@ void *_talloc(const void *context, size_t size)
 	return __talloc(context, size);
 }
 
+static int talloc_destroy_pointer(void ***pptr)
+{
+	if ((uintptr_t)**pptr < getpagesize())
+		TALLOC_ABORT("Double free or invalid talloc_set?");
+	/* Invalidate pointer so it can't be used again. */
+	**pptr = (void *)1;
+	return 0;
+}
+
+void _talloc_set(void *ptr, const void *ctx, size_t size, const char *name)
+{
+	void ***child;
+	void **pptr = ptr;
+
+	*pptr = talloc_named_const(ctx, size, name);
+	if (unlikely(!*pptr))
+		return;
+
+	child = talloc(*pptr, void **);
+	if (unlikely(!child)) {
+		talloc_free(*pptr);
+		*pptr = NULL;
+		return;
+	}
+	*child = pptr;
+	talloc_set_name_const(child, "talloc_set destructor");
+	talloc_set_destructor(child, talloc_destroy_pointer);
+}
+
 /*
   externally callable talloc_set_name_const()
 */
@@ -819,12 +848,12 @@ void *talloc_named_const(const void *context, size_t size, const char *name)
    will not be freed if the ref_count is > 1 or the destructor (if
    any) returns non-zero
 */
-int talloc_free(void *ptr)
+int talloc_free(const void *ptr)
 {
 	int saved_errno = errno, ret;
 
 	lock(ptr);
-	ret = _talloc_free(ptr);
+	ret = _talloc_free(discard_const_p(void, ptr));
 	unlock();
 	if (ret == 0)
 		errno = saved_errno;