talloc: add TC_INVALIDATE_SHRINK_CHUNK() marco

This invalidates the unused bytes if we shrink memory.

metze

Signed-off-By: Andrew Tridgell <tridge@samba.org>

diff --git a/lib/talloc/talloc.c b/lib/talloc/talloc.c
index 522d60ff8f4e2171702875ab64295132c75e82d6..3ec5d85eee177c20e9b6371c77ba1bd1c890e8f2 100644 (file)
--- a/lib/talloc/talloc.c
+++ b/lib/talloc/talloc.c
@@ -143,6 +143,32 @@ static struct {
        TC_INVALIDATE_FULL_VALGRIND_CHUNK(_tc); \
 } while (0)
 
+#define TC_INVALIDATE_SHRINK_FILL_CHUNK(_tc, _new_size) do { \
+       if (unlikely(talloc_fill.enabled)) { \
+               size_t _flen = (_tc)->size - (_new_size); \
+               char *_fptr = TC_PTR_FROM_CHUNK(_tc); \
+               _fptr += (_new_size); \
+               memset(_fptr, talloc_fill.fill_value, _flen); \
+       } \
+} while (0)
+
+#if defined(DEVELOPER) && defined(VALGRIND_MAKE_MEM_NOACCESS)
+/* Mark the unused bytes not accessable */
+#define TC_INVALIDATE_SHRINK_VALGRIND_CHUNK(_tc, _new_size) do { \
+       size_t _flen = (_tc)->size - (_new_size); \
+       char *_fptr = TC_PTR_FROM_CHUNK(_tc); \
+       _fptr += (_new_size); \
+       VALGRIND_MAKE_MEM_NOACCESS(_fptr, _flen); \
+} while (0)
+#else
+#define TC_INVALIDATE_SHRINK_VALGRIND_CHUNK(_tc, _new_size) do { } while (0)
+#endif
+
+#define TC_INVALIDATE_SHRINK_CHUNK(_tc, _new_size) do { \
+       TC_INVALIDATE_SHRINK_FILL_CHUNK(_tc, _new_size); \
+       TC_INVALIDATE_SHRINK_VALGRIND_CHUNK(_tc, _new_size); \
+} while (0)
+
 struct talloc_reference_handle {
        struct talloc_reference_handle *next, *prev;
        void *ptr;
@@ -1282,12 +1308,14 @@ _PUBLIC_ void *_talloc_realloc(const void *context, void *ptr, size_t size, cons
        if (size < tc->size) {
                if (pool_tc) {
                        void *next_tc = TC_POOLMEM_NEXT_CHUNK(tc);
+                       TC_INVALIDATE_SHRINK_CHUNK(tc, size);
                        tc->size = size;
                        if (next_tc == pool_tc->pool) {
                                pool_tc->pool = TC_POOLMEM_NEXT_CHUNK(tc);
                        }
                        return ptr;
                } else if ((tc->size - size) < 1024) {
+                       TC_INVALIDATE_SHRINK_CHUNK(tc, size);
                        /* do not shrink if we have less than 1k to gain */
                        tc->size = size;
                        return ptr;