1 files changed, 100 insertions, 57 deletions

diff --git a/commit-graph.c b/commit-graph.c
index 017225ccea..47e9be0a3a 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -23,18 +23,12 @@
 #define GRAPH_CHUNKID_DATA 0x43444154 /* "CDAT" */
 #define GRAPH_CHUNKID_EXTRAEDGES 0x45444745 /* "EDGE" */
 
-#define GRAPH_DATA_WIDTH 36
+#define GRAPH_DATA_WIDTH (the_hash_algo->rawsz + 16)
 
 #define GRAPH_VERSION_1 0x1
 #define GRAPH_VERSION GRAPH_VERSION_1
 
-#define GRAPH_OID_VERSION_SHA1 1
-#define GRAPH_OID_LEN_SHA1 GIT_SHA1_RAWSZ
-#define GRAPH_OID_VERSION GRAPH_OID_VERSION_SHA1
-#define GRAPH_OID_LEN GRAPH_OID_LEN_SHA1
-
 #define GRAPH_EXTRA_EDGES_NEEDED 0x80000000
-#define GRAPH_PARENT_MISSING 0x7fffffff
 #define GRAPH_EDGE_LAST_MASK 0x7fffffff
 #define GRAPH_PARENT_NONE 0x70000000
 
@@ -44,13 +38,18 @@
 #define GRAPH_FANOUT_SIZE (4 * 256)
 #define GRAPH_CHUNKLOOKUP_WIDTH 12
 #define GRAPH_MIN_SIZE (GRAPH_HEADER_SIZE + 4 * GRAPH_CHUNKLOOKUP_WIDTH \
-			+ GRAPH_FANOUT_SIZE + GRAPH_OID_LEN)
+			+ GRAPH_FANOUT_SIZE + the_hash_algo->rawsz)
 
 char *get_commit_graph_filename(const char *obj_dir)
 {
 	return xstrfmt("%s/info/commit-graph", obj_dir);
 }
 
+static uint8_t oid_version(void)
+{
+	return 1;
+}
+
 static struct commit_graph *alloc_commit_graph(void)
 {
 	struct commit_graph *g = xcalloc(1, sizeof(*g));
@@ -84,16 +83,10 @@ static int commit_graph_compatible(struct repository *r)
 struct commit_graph *load_commit_graph_one(const char *graph_file)
 {
 	void *graph_map;
-	const unsigned char *data, *chunk_lookup;
 	size_t graph_size;
 	struct stat st;
-	uint32_t i;
-	struct commit_graph *graph;
+	struct commit_graph *ret;
 	int fd = git_open(graph_file);
-	uint64_t last_chunk_offset;
-	uint32_t last_chunk_id;
-	uint32_t graph_signature;
-	unsigned char graph_version, hash_version;
 
 	if (fd < 0)
 		return NULL;
@@ -108,32 +101,60 @@ struct commit_graph *load_commit_graph_one(const char *graph_file)
 		die(_("graph file %s is too small"), graph_file);
 	}
 	graph_map = xmmap(NULL, graph_size, PROT_READ, MAP_PRIVATE, fd, 0);
+	ret = parse_commit_graph(graph_map, fd, graph_size);
+
+	if (!ret) {
+		munmap(graph_map, graph_size);
+		close(fd);
+		exit(1);
+	}
+
+	return ret;
+}
+
+struct commit_graph *parse_commit_graph(void *graph_map, int fd,
+					size_t graph_size)
+{
+	const unsigned char *data, *chunk_lookup;
+	uint32_t i;
+	struct commit_graph *graph;
+	uint64_t last_chunk_offset;
+	uint32_t last_chunk_id;
+	uint32_t graph_signature;
+	unsigned char graph_version, hash_version;
+
+	if (!graph_map)
+		return NULL;
+
+	if (graph_size < GRAPH_MIN_SIZE)
+		return NULL;
+
 	data = (const unsigned char *)graph_map;
 
 	graph_signature = get_be32(data);
 	if (graph_signature != GRAPH_SIGNATURE) {
 		error(_("graph signature %X does not match signature %X"),
 		      graph_signature, GRAPH_SIGNATURE);
-		goto cleanup_fail;
+		return NULL;
 	}
 
 	graph_version = *(unsigned char*)(data + 4);
 	if (graph_version != GRAPH_VERSION) {
 		error(_("graph version %X does not match version %X"),
 		      graph_version, GRAPH_VERSION);
-		goto cleanup_fail;
+		return NULL;
 	}
 
 	hash_version = *(unsigned char*)(data + 5);
-	if (hash_version != GRAPH_OID_VERSION) {
+	if (hash_version != oid_version()) {
 		error(_("hash version %X does not match version %X"),
-		      hash_version, GRAPH_OID_VERSION);
-		goto cleanup_fail;
+		      hash_version, oid_version());
+		return NULL;
 	}
 
 	graph = alloc_commit_graph();
 
-	graph->hash_len = GRAPH_OID_LEN;
+	graph->hash_len = the_hash_algo->rawsz;
 	graph->num_chunks = *(unsigned char*)(data + 6);
 	graph->graph_fd = fd;
 	graph->data = graph_map;
@@ -143,16 +164,27 @@ struct commit_graph *load_commit_graph_one(const char *graph_file)
 	last_chunk_offset = 8;
 	chunk_lookup = data + 8;
 	for (i = 0; i < graph->num_chunks; i++) {
-		uint32_t chunk_id = get_be32(chunk_lookup + 0);
-		uint64_t chunk_offset = get_be64(chunk_lookup + 4);
+		uint32_t chunk_id;
+		uint64_t chunk_offset;
 		int chunk_repeated = 0;
 
+		if (data + graph_size - chunk_lookup <
+		    GRAPH_CHUNKLOOKUP_WIDTH) {
+			error(_("chunk lookup table entry missing; graph file may be incomplete"));
+			free(graph);
+			return NULL;
+		}
+
+		chunk_id = get_be32(chunk_lookup + 0);
+		chunk_offset = get_be64(chunk_lookup + 4);
+
 		chunk_lookup += GRAPH_CHUNKLOOKUP_WIDTH;
 
-		if (chunk_offset > graph_size - GIT_MAX_RAWSZ) {
+		if (chunk_offset > graph_size - the_hash_algo->rawsz) {
 			error(_("improper chunk offset %08x%08x"), (uint32_t)(chunk_offset >> 32),
 			      (uint32_t)chunk_offset);
-			goto cleanup_fail;
+			free(graph);
+			return NULL;
 		}
 
 		switch (chunk_id) {
@@ -187,7 +219,8 @@ struct commit_graph *load_commit_graph_one(const char *graph_file)
 
 		if (chunk_repeated) {
 			error(_("chunk id %08x appears multiple times"), chunk_id);
-			goto cleanup_fail;
+			free(graph);
+			return NULL;
 		}
 
 		if (last_chunk_id == GRAPH_CHUNKID_OIDLOOKUP)
@@ -201,11 +234,6 @@ struct commit_graph *load_commit_graph_one(const char *graph_file)
 	}
 
 	return graph;
-
-cleanup_fail:
-	munmap(graph_map, graph_size);
-	close(fd);
-	exit(1);
 }
 
 static void prepare_commit_graph_one(struct repository *r, const char *obj_dir)
@@ -289,7 +317,8 @@ static int bsearch_graph(struct commit_graph *g, struct object_id *oid, uint32_t
 			    g->chunk_oid_lookup, g->hash_len, pos);
 }
 
-static struct commit_list **insert_parent_or_die(struct commit_graph *g,
+static struct commit_list **insert_parent_or_die(struct repository *r,
+						 struct commit_graph *g,
 						 uint64_t pos,
 						 struct commit_list **pptr)
 {
@@ -300,7 +329,7 @@ static struct commit_list **insert_parent_or_die(struct commit_graph *g,
 		die("invalid parent position %"PRIu64, pos);
 
 	hashcpy(oid.hash, g->chunk_oid_lookup + g->hash_len * pos);
-	c = lookup_commit(the_repository, &oid);
+	c = lookup_commit(r, &oid);
 	if (!c)
 		die(_("could not find commit %s"), oid_to_hex(&oid));
 	c->graph_pos = pos;
@@ -314,7 +343,9 @@ static void fill_commit_graph_info(struct commit *item, struct commit_graph *g,
 	item->generation = get_be32(commit_data + g->hash_len + 8) >> 2;
 }
 
-static int fill_commit_in_graph(struct commit *item, struct commit_graph *g, uint32_t pos)
+static int fill_commit_in_graph(struct repository *r,
+				struct commit *item,
+				struct commit_graph *g, uint32_t pos)
 {
 	uint32_t edge_value;
 	uint32_t *parent_data_ptr;
@@ -338,13 +369,13 @@ static int fill_commit_in_graph(struct commit *item, struct commit_graph *g, uin
 	edge_value = get_be32(commit_data + g->hash_len);
 	if (edge_value == GRAPH_PARENT_NONE)
 		return 1;
-	pptr = insert_parent_or_die(g, edge_value, pptr);
+	pptr = insert_parent_or_die(r, g, edge_value, pptr);
 
 	edge_value = get_be32(commit_data + g->hash_len + 4);
 	if (edge_value == GRAPH_PARENT_NONE)
 		return 1;
 	if (!(edge_value & GRAPH_EXTRA_EDGES_NEEDED)) {
-		pptr = insert_parent_or_die(g, edge_value, pptr);
+		pptr = insert_parent_or_die(r, g, edge_value, pptr);
 		return 1;
 	}
 
@@ -352,7 +383,7 @@ static int fill_commit_in_graph(struct commit *item, struct commit_graph *g, uin
 			  4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
 	do {
 		edge_value = get_be32(parent_data_ptr);
-		pptr = insert_parent_or_die(g,
+		pptr = insert_parent_or_die(r, g,
 					    edge_value & GRAPH_EDGE_LAST_MASK,
 					    pptr);
 		parent_data_ptr++;
@@ -371,7 +402,9 @@ static int find_commit_in_graph(struct commit *item, struct commit_graph *g, uin
 	}
 }
 
-static int parse_commit_in_graph_one(struct commit_graph *g, struct commit *item)
+static int parse_commit_in_graph_one(struct repository *r,
+				     struct commit_graph *g,
+				     struct commit *item)
 {
 	uint32_t pos;
 
@@ -379,7 +412,7 @@ static int parse_commit_in_graph_one(struct commit_graph *g, struct commit *item
 		return 1;
 
 	if (find_commit_in_graph(item, g, &pos))
-		return fill_commit_in_graph(item, g, pos);
+		return fill_commit_in_graph(r, item, g, pos);
 
 	return 0;
 }
@@ -388,7 +421,7 @@ int parse_commit_in_graph(struct repository *r, struct commit *item)
 {
 	if (!prepare_commit_graph(r))
 		return 0;
-	return parse_commit_in_graph_one(r->objects->commit_graph, item);
+	return parse_commit_in_graph_one(r, r->objects->commit_graph, item);
 }
 
 void load_commit_graph_info(struct repository *r, struct commit *item)
@@ -400,19 +433,22 @@ void load_commit_graph_info(struct repository *r, struct commit *item)
 		fill_commit_graph_info(item, r->objects->commit_graph, pos);
 }
 
-static struct tree *load_tree_for_commit(struct commit_graph *g, struct commit *c)
+static struct tree *load_tree_for_commit(struct repository *r,
+					 struct commit_graph *g,
+					 struct commit *c)
 {
 	struct object_id oid;
 	const unsigned char *commit_data = g->chunk_commit_data +
 					   GRAPH_DATA_WIDTH * (c->graph_pos);
 
 	hashcpy(oid.hash, commit_data);
-	c->maybe_tree = lookup_tree(the_repository, &oid);
+	c->maybe_tree = lookup_tree(r, &oid);
 
 	return c->maybe_tree;
 }
 
-static struct tree *get_commit_tree_in_graph_one(struct commit_graph *g,
+static struct tree *get_commit_tree_in_graph_one(struct repository *r,
+						 struct commit_graph *g,
 						 const struct commit *c)
 {
 	if (c->maybe_tree)
@@ -420,12 +456,12 @@ static struct tree *get_commit_tree_in_graph_one(struct commit_graph *g,
 	if (c->graph_pos == COMMIT_NOT_FROM_GRAPH)
 		BUG("get_commit_tree_in_graph_one called from non-commit-graph commit");
 
-	return load_tree_for_commit(g, (struct commit *)c);
+	return load_tree_for_commit(r, g, (struct commit *)c);
 }
 
 struct tree *get_commit_tree_in_graph(struct repository *r, const struct commit *c)
 {
-	return get_commit_tree_in_graph_one(r->objects->commit_graph, c);
+	return get_commit_tree_in_graph_one(r, r->objects->commit_graph, c);
 }
 
 static void write_graph_chunk_fanout(struct hashfile *f,
@@ -503,7 +539,9 @@ static void write_graph_chunk_data(struct hashfile *f, int hash_len,
 					      commit_to_sha1);
 
 			if (edge_value < 0)
-				edge_value = GRAPH_PARENT_MISSING;
+				BUG("missing parent %s for commit %s",
+				    oid_to_hex(&parent->item->object.oid),
+				    oid_to_hex(&(*list)->object.oid));
 		}
 
 		hashwrite_be32(f, edge_value);
@@ -521,7 +559,9 @@ static void write_graph_chunk_data(struct hashfile *f, int hash_len,
 					      nr_commits,
 					      commit_to_sha1);
 			if (edge_value < 0)
-				edge_value = GRAPH_PARENT_MISSING;
+				BUG("missing parent %s for commit %s",
+				    oid_to_hex(&parent->item->object.oid),
+				    oid_to_hex(&(*list)->object.oid));
 		}
 
 		hashwrite_be32(f, edge_value);
@@ -579,7 +619,9 @@ static void write_graph_chunk_extra_edges(struct hashfile *f,
 						  commit_to_sha1);
 
 			if (edge_value < 0)
-				edge_value = GRAPH_PARENT_MISSING;
+				BUG("missing parent %s for commit %s",
+				    oid_to_hex(&parent->item->object.oid),
+				    oid_to_hex(&(*list)->object.oid));
 			else if (!parent->next)
 				edge_value |= GRAPH_LAST_EDGE;
 
@@ -783,6 +825,7 @@ void write_commit_graph(const char *obj_dir,
 	int num_extra_edges;
 	struct commit_list *parent;
 	struct progress *progress = NULL;
+	const unsigned hashsz = the_hash_algo->rawsz;
 	uint64_t progress_cnt = 0;
 	struct strbuf progress_title = STRBUF_INIT;
 	unsigned long approx_nr_objects;
@@ -909,7 +952,7 @@ void write_commit_graph(const char *obj_dir,
 	}
 	stop_progress(&progress);
 
-	if (count_distinct >= GRAPH_PARENT_MISSING)
+	if (count_distinct >= GRAPH_EDGE_LAST_MASK)
 		die(_("the commit graph format cannot write %d commits"), count_distinct);
 
 	commits.nr = 0;
@@ -942,7 +985,7 @@ void write_commit_graph(const char *obj_dir,
 	num_chunks = num_extra_edges ? 4 : 3;
 	stop_progress(&progress);
 
-	if (commits.nr >= GRAPH_PARENT_MISSING)
+	if (commits.nr >= GRAPH_EDGE_LAST_MASK)
 		die(_("too many commits to write graph"));
 
 	compute_generation_numbers(&commits, report_progress);
@@ -960,7 +1003,7 @@ void write_commit_graph(const char *obj_dir,
 	hashwrite_be32(f, GRAPH_SIGNATURE);
 
 	hashwrite_u8(f, GRAPH_VERSION);
-	hashwrite_u8(f, GRAPH_OID_VERSION);
+	hashwrite_u8(f, oid_version());
 	hashwrite_u8(f, num_chunks);
 	hashwrite_u8(f, 0); /* unused padding byte */
 
@@ -975,8 +1018,8 @@ void write_commit_graph(const char *obj_dir,
 
 	chunk_offsets[0] = 8 + (num_chunks + 1) * GRAPH_CHUNKLOOKUP_WIDTH;
 	chunk_offsets[1] = chunk_offsets[0] + GRAPH_FANOUT_SIZE;
-	chunk_offsets[2] = chunk_offsets[1] + GRAPH_OID_LEN * commits.nr;
-	chunk_offsets[3] = chunk_offsets[2] + (GRAPH_OID_LEN + 16) * commits.nr;
+	chunk_offsets[2] = chunk_offsets[1] + hashsz * commits.nr;
+	chunk_offsets[3] = chunk_offsets[2] + (hashsz + 16) * commits.nr;
 	chunk_offsets[4] = chunk_offsets[3] + 4 * num_extra_edges;
 
 	for (i = 0; i <= num_chunks; i++) {
@@ -999,8 +1042,8 @@ void write_commit_graph(const char *obj_dir,
 			num_chunks * commits.nr);
 	}
 	write_graph_chunk_fanout(f, commits.list, commits.nr, progress, &progress_cnt);
-	write_graph_chunk_oids(f, GRAPH_OID_LEN, commits.list, commits.nr, progress, &progress_cnt);
-	write_graph_chunk_data(f, GRAPH_OID_LEN, commits.list, commits.nr, progress, &progress_cnt);
+	write_graph_chunk_oids(f, hashsz, commits.list, commits.nr, progress, &progress_cnt);
+	write_graph_chunk_data(f, hashsz, commits.list, commits.nr, progress, &progress_cnt);
 	if (num_extra_edges)
 		write_graph_chunk_extra_edges(f, commits.list, commits.nr, progress, &progress_cnt);
 	stop_progress(&progress);
@@ -1089,7 +1132,7 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
 		}
 
 		graph_commit = lookup_commit(r, &cur_oid);
-		if (!parse_commit_in_graph_one(g, graph_commit))
+		if (!parse_commit_in_graph_one(r, g, graph_commit))
 			graph_report("failed to parse %s from commit-graph",
 				     oid_to_hex(&cur_oid));
 	}
@@ -1125,7 +1168,7 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
 			continue;
 		}
 
-		if (!oideq(&get_commit_tree_in_graph_one(g, graph_commit)->object.oid,
+		if (!oideq(&get_commit_tree_in_graph_one(r, g, graph_commit)->object.oid,
 			   get_commit_tree_oid(odb_commit)))
 			graph_report("root tree OID for commit %s in commit-graph is %s != %s",
 				     oid_to_hex(&cur_oid),