path: root/builtin/fsck.c
diff options
authorJeff King <>2013-06-05 22:37:39 (GMT)
committerJunio C Hamano <>2013-06-06 17:29:12 (GMT)
commit6e454b9a31840102807f1eee527ee717bf134102 (patch)
tree44920f41fae44ba48c914b5bc13f372c539e5469 /builtin/fsck.c
parentedca4152560522a431a51fc0a06147fc680b5b18 (diff)
clear parsed flag when we free tree buffers
Many code paths will free a tree object's buffer and set it to NULL after finishing with it in order to keep memory usage down during a traversal. However, out of 8 sites that do this, only one actually unsets the "parsed" flag back. Those sites that don't are setting a trap for later users of the tree object; even after calling parse_tree, the buffer will remain NULL, causing potential segfaults. It is not known whether this is triggerable in the current code. Most commands do not do an in-memory traversal followed by actually using the objects again. However, it does not hurt to be safe for future callers. In most cases, we can abstract this out to a "free_tree_buffer" helper. However, there are two exceptions: 1. The fsck code relies on the parsed flag to know that we were able to parse the object at one point. We can switch this to using a flag in the "flags" field. 2. The index-pack code sets the buffer to NULL but does not free it (it is freed by a caller). We should still unset the parsed flag here, but we cannot use our helper, as we do not want to free the buffer. Signed-off-by: Jeff King <> Signed-off-by: Junio C Hamano <>
Diffstat (limited to 'builtin/fsck.c')
1 files changed, 8 insertions, 9 deletions
diff --git a/builtin/fsck.c b/builtin/fsck.c
index bb9a2cd..579fdcc 100644
--- a/builtin/fsck.c
+++ b/builtin/fsck.c
@@ -16,6 +16,7 @@
#define REACHABLE 0x0001
#define SEEN 0x0002
+#define HAS_OBJ 0x0004
static int show_root;
static int show_tags;
@@ -101,7 +102,7 @@ static int mark_object(struct object *obj, int type, void *data)
if (obj->flags & REACHABLE)
return 0;
obj->flags |= REACHABLE;
- if (!obj->parsed) {
+ if (!(obj->flags & HAS_OBJ)) {
if (parent && !has_sha1_file(obj->sha1)) {
printf("broken link from %7s %s\n",
typename(parent->type), sha1_to_hex(parent->sha1));
@@ -127,16 +128,13 @@ static int traverse_one_object(struct object *obj)
struct tree *tree = NULL;
if (obj->type == OBJ_TREE) {
- obj->parsed = 0;
tree = (struct tree *)obj;
if (parse_tree(tree) < 0)
return 1; /* error already displayed */
result = fsck_walk(obj, mark_object, obj);
- if (tree) {
- free(tree->buffer);
- tree->buffer = NULL;
- }
+ if (tree)
+ free_tree_buffer(tree);
return result;
@@ -178,7 +176,7 @@ static void check_reachable_object(struct object *obj)
* except if it was in a pack-file and we didn't
* do a full fsck
- if (!obj->parsed) {
+ if (!(obj->flags & HAS_OBJ)) {
if (has_sha1_pack(obj->sha1))
return; /* it is in pack - forget about it */
printf("missing %s %s\n", typename(obj->type), sha1_to_hex(obj->sha1));
@@ -306,8 +304,7 @@ static int fsck_obj(struct object *obj)
if (obj->type == OBJ_TREE) {
struct tree *item = (struct tree *) obj;
- free(item->buffer);
- item->buffer = NULL;
+ free_tree_buffer(item);
if (obj->type == OBJ_COMMIT) {
@@ -340,6 +337,7 @@ static int fsck_sha1(const unsigned char *sha1)
return error("%s: object corrupt or missing",
+ obj->flags |= HAS_OBJ;
return fsck_obj(obj);
@@ -352,6 +350,7 @@ static int fsck_obj_buffer(const unsigned char *sha1, enum object_type type,
errors_found |= ERROR_OBJECT;
return error("%s: object corrupt or missing", sha1_to_hex(sha1));
+ obj->flags = HAS_OBJ;
return fsck_obj(obj);