[SCM] Samba Shared Repository - branch master updated - release-4-0-0alpha8-172-gacfb01a

[Stefan (metze) Metzmacher]

Hi Tridge,

>     change talloc to 2.0.0
>     
>     This is needed to prevent samba3 and samba4 from using an ABI
>     incompatible system version of talloc
>     
>     See ongoing discussion on the samba-technical mailing list

I think we should also change TALLOC_MAGIC to make 100% sure we abort,
when libtalloc.so.1 and libtalloc.so.2 are loaded into the same process.

Like this:
http://gitweb.samba.org/?p=metze/samba/wip.git;a=commitdiff;h=c534a8af46e1efbfad8cd953dadb3a68b29b9919

--- a/lib/talloc/talloc.c
+++ b/lib/talloc/talloc.c
@@ -57,7 +57,9 @@


 #define MAX_TALLOC_SIZE 0x10000000
-#define TALLOC_MAGIC 0xe814ec70
+#define TALLOC_MAGIC_V1 0xe814ec70
+#define TALLOC_MAGIC_V2 0xe814ec80
+#define TALLOC_MAGIC    TALLOC_MAGIC_V2
 #define TALLOC_FLAG_FREE 0x01
 #define TALLOC_FLAG_LOOP 0x02
 #define TALLOC_FLAG_POOL 0x04		/* This is a talloc pool */
@@ -154,6 +156,11 @@ static void talloc_abort(const char *reason)
 	talloc_abort_fn(reason);
 }

+static void talloc_abort_magic_v1(void)
+{
+	talloc_abort("Bad talloc magic value - old magic v1 used");
+}
+
 static void talloc_abort_double_free(void)
 {
 	talloc_abort("Bad talloc magic value - double free");
@@ -170,6 +177,10 @@ static inline struct talloc_chunk
*talloc_chunk_from_ptr(const void *ptr)
 	const char *pp = (const char *)ptr;
 	struct talloc_chunk *tc = discard_const_p(struct talloc_chunk, pp -
TC_HDR_SIZE);
 	if (unlikely((tc->flags & (TALLOC_FLAG_FREE | ~0xF)) != TALLOC_MAGIC)) {
+		if ((tc->flags & (~0xF)) == TALLOC_MAGIC_V1)) {
+			talloc_abort_magic_v1();
+		}
+
 		if (tc->flags & TALLOC_FLAG_FREE) {
 			talloc_abort_double_free();
 		} else {

metze

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