r2649: - used some cpp tricks to make users of talloc() and talloc_realloc()

to get auto-naming of pointers very cheaply.

- fixed a couple of memory leaks found with the new tricks

A typical exit report for smbd is now:

talloc report on 'null_context' (total 811 bytes in 54 blocks)
        auth/auth_sam.c:334            contains     20 bytes in   1 blocks
        struct auth_serversupplied_info contains    498 bytes in  33 blocks
        UNNAMED                        contains      8 bytes in   1 blocks
        lib/data_blob.c:40             contains     16 bytes in   1 blocks
        iconv(CP850,UTF8)              contains     61 bytes in   4 blocks
        iconv(UTF8,CP850)              contains     61 bytes in   4 blocks
        iconv(UTF8,UTF-16LE)           contains     67 bytes in   4 blocks
        iconv(UTF-16LE,UTF8)           contains     67 bytes in   4 blocks
        UNNAMED                        contains     13 bytes in   1 blocks

which is much better than before
(This used to be commit 6e721393d03afd3c2f8ced8422533547a9e33342)

source4/include/talloc.h

@@ -24,10 +24,20 @@
 /* this is only needed for compatibility with the old talloc */
 typedef void TALLOC_CTX;
 
+/*
+  this uses a little trick to allow __LINE__ to be stringified
+*/
+#define _STRING_LINE_(s)    #s
+#define _STRING_LINE2_(s)   _STRING_LINE_(s)
+#define __LINESTR__       _STRING_LINE2_(__LINE__)
+#define __location__ __FILE__ ":" __LINESTR__
+
 /* useful macros for creating type checked pointers */
+#define talloc(ctx, size) talloc_named_const(ctx, size, __location__)
+#define talloc_realloc(ptr, size) _talloc_realloc(ptr, size, __location__)
 #define talloc_p(ctx, type) (type *)talloc_named_const(ctx, sizeof(type), #type)
-#define talloc_array_p(ctx, type, count) (type *)talloc_array(ctx, sizeof(type), count)
-#define talloc_realloc_p(p, type, count) (type *)talloc_realloc_array(p, sizeof(type), count)
+#define talloc_array_p(ctx, type, count) (type *)talloc_array(ctx, sizeof(type), count, __location__)
+#define talloc_realloc_p(p, type, count) (type *)talloc_realloc_array(p, sizeof(type), count, __location__)
 
 #define talloc_destroy(ctx) talloc_free(ctx)
 

source4/lib/data_blob.c

@@ -56,6 +56,11 @@ DATA_BLOB data_blob_talloc(TALLOC_CTX *mem_ctx, const void *p, size_t length)
 
 	if (ret.data) {
 		ret.data = talloc_steal(mem_ctx, ret.data);
+	} else {
+		/* this ensures the blob has the context attached, so a zero length call
+		   to data_blob_talloc followed by a realloc doesn't cause the memory to come
+		   from the NULL context */
+		ret.data = talloc(mem_ctx, 0);
 	}
 	return ret;
 }

source4/lib/talloc.c

@@ -26,6 +26,9 @@
 
 #include "includes.h"
 
+#undef talloc
+#define talloc(ctx, size) _talloc(ctx, size)
+
 #define MAX_TALLOC_SIZE 0x10000000
 #define TALLOC_MAGIC 0xe814ec4f
 #define TALLOC_MAGIC_FREE 0x7faebef3
@@ -59,7 +62,7 @@ static struct talloc_chunk *talloc_chunk_from_ptr(void *ptr)
 /* 
    Allocate a bit of memory as a child of an existing pointer
 */
-void *talloc(void *context, size_t size)
+void *_talloc(void *context, size_t size)
 {
 	struct talloc_chunk *tc;
 
@@ -289,7 +292,7 @@ int talloc_free(void *ptr)
 /*
   A talloc version of realloc 
 */
-void *talloc_realloc(void *ptr, size_t size)
+void *_talloc_realloc(void *ptr, size_t size, const char *name)
 {
 	struct talloc_chunk *tc;
 	void *new_ptr;
@@ -302,7 +305,7 @@ void *talloc_realloc(void *ptr, size_t size)
 
 	/* realloc(NULL) is equavalent to malloc() */
 	if (ptr == NULL) {
-		return talloc(NULL, size);
+		return talloc_named_const(NULL, size, name);
 	}
 
 	tc = talloc_chunk_from_ptr(ptr);
@@ -330,6 +333,7 @@ void *talloc_realloc(void *ptr, size_t size)
 	}
 
 	tc->size = size;
+	talloc_set_name_const(tc+1, name);
 
 	return (void *)(tc+1);
 }
@@ -582,26 +586,30 @@ char *talloc_asprintf_append(char *s,
 /*
   alloc an array, checking for integer overflow in the array size
 */
-void *talloc_array(void *ctx, size_t el_size, uint_t count)
+void *talloc_array(void *ctx, size_t el_size, uint_t count, const char *name)
 {
 	if (count == 0 ||
 	    count >= MAX_TALLOC_SIZE/el_size) {
 		return NULL;
 	}
-	return talloc(ctx, el_size * count);
+	return talloc_named_const(ctx, el_size * count, name);
 }
 
 
 /*
   realloc an array, checking for integer overflow in the array size
 */
-void *talloc_realloc_array(void *ptr, size_t el_size, uint_t count)
+void *talloc_realloc_array(void *ptr, size_t el_size, uint_t count, const char *name)
 {
 	if (count == 0 ||
 	    count >= MAX_TALLOC_SIZE/el_size) {
 		return NULL;
 	}
-	return talloc_realloc(ptr, el_size * count);
+	ptr = talloc_realloc(ptr, el_size * count);
+	if (ptr) {
+		talloc_set_name_const(ptr, name);
+	}
+	return ptr;
 }
 
 /*

source4/libcli/raw/rawtrans.c

@@ -84,7 +84,7 @@ NTSTATUS smb_raw_trans2_recv(struct smbcli_request *req,
 
 	/* allocate it */
 	if (total_data != 0) {
-		tdata = talloc_realloc(parms->out.data.data,total_data);
+		tdata = talloc(mem_ctx, total_data);
 		if (!tdata) {
 			DEBUG(0,("smb_raw_receive_trans: failed to enlarge data buffer to %d bytes\n", total_data));
 			req->status = NT_STATUS_NO_MEMORY;
@@ -94,7 +94,7 @@ NTSTATUS smb_raw_trans2_recv(struct smbcli_request *req,
 	}
 
 	if (total_param != 0) {
-		tparam = talloc_realloc(parms->out.params.data,total_param);
+		tparam = talloc(mem_ctx, total_param);
 		if (!tparam) {
 			DEBUG(0,("smb_raw_receive_trans: failed to enlarge param buffer to %d bytes\n", total_param));
 			req->status = NT_STATUS_NO_MEMORY;

source4/torture/raw/search.c

@@ -681,6 +681,7 @@ static BOOL test_many_files(struct smbcli_state *cli, TALLOC_CTX *mem_ctx)
 			}
 			free(fname);
 		}
+		talloc_free(result.list);
 	}
 
 done:
@@ -898,6 +899,8 @@ static BOOL test_sorted(struct smbcli_state *cli, TALLOC_CTX *mem_ctx)
 		}
 	}
 
+	talloc_free(result.list);
+
 done:
 	smb_raw_exit(cli->session);
 	smbcli_deltree(cli->tree, BASEDIR);