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[PATCH v2 1/3] commit-graph: clean up leaked memory during write

From
Derrick Stolee via GitGitGadget <gitgitgadget@gmail.com>
Date
Oct 3, 2018, 17:12 UTC
Message-ID
<ba65680b3d0e50ad8be415e10c1e6b63c58d8b13.1538586732.git.gitgitgadget@gmail.com>
In-Reply-To
<pull.42.v2.git.gitgitgadget@gmail.com>
From: Derrick Stolee <dstolee@microsoft.com>

The write_commit_graph() method in commit-graph.c leaks some lits and strings during execution. In addition, a list of strings is leaked in write_commit_graph_reachable(). Clean these up so our memory checking is cleaner.

Further, if we use a list of pack-files to find the commits, we can leak the packed_git structs after scanning them for commits.

Running the following commands demonstrates the leak before and the fix after:

* valgrind --leak-check=full ./git commit-graph write --reachable
* valgrind --leak-check=full ./git commit-graph write --stdin-packs
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
---
 commit-graph.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)
diff --git a/commit-graph.c b/commit-graph.c
index 2a24eb8b5a..ceca6026b0 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -693,11 +693,12 @@ static int add_ref_to_list(const char *refname,
 void write_commit_graph_reachable(const char *obj_dir, int append,
 				  int report_progress)
 {
-	struct string_list list;
+	struct string_list list = STRING_LIST_INIT_DUP;
 
-	string_list_init(&list, 1);
 	for_each_ref(add_ref_to_list, &list);
 	write_commit_graph(obj_dir, NULL, &list, append, report_progress);
+
+	string_list_clear(&list, 0);
 }
 
 void write_commit_graph(const char *obj_dir,
@@ -764,6 +765,7 @@ void write_commit_graph(const char *obj_dir,
 				die(_("error opening index for %s"), packname.buf);
 			for_each_object_in_pack(p, add_packed_commits, &oids, 0);
 			close_pack(p);
+			free(p);
 		}
 		stop_progress(&oids.progress);
 		strbuf_release(&packname);
@@ -846,9 +848,11 @@ void write_commit_graph(const char *obj_dir,
 	compute_generation_numbers(&commits, report_progress);
 
 	graph_name = get_commit_graph_filename(obj_dir);
-	if (safe_create_leading_directories(graph_name))
+	if (safe_create_leading_directories(graph_name)) {
+		UNLEAK(graph_name);
 		die_errno(_("unable to create leading directories of %s"),
 			  graph_name);
+	}
 
 	hold_lock_file_for_update(&lk, graph_name, LOCK_DIE_ON_ERROR);
 	f = hashfd(lk.tempfile->fd, lk.tempfile->filename.buf);
@@ -893,9 +897,9 @@ void write_commit_graph(const char *obj_dir,
 	finalize_hashfile(f, NULL, CSUM_HASH_IN_STREAM | CSUM_FSYNC);
 	commit_lock_file(&lk);
 
+	free(graph_name);
+	free(commits.list);
 	free(oids.list);
-	oids.alloc = 0;
-	oids.nr = 0;
 }
 
 #define VERIFY_COMMIT_GRAPH_ERROR_HASH 2
-- 
gitgitgadget
Previous: Derrick Stolee via GitGitGadgetNext: Martin Ågren via GitGitGadget
Message 18 of 20 in “Clean up leaks in commit-graph.c”
  1. 0/2 Clean up leaks in commit-graph.cDerrick Stolee via GitGitGadget, Oct 2, 2018
  2. 1/2 commit-graph: clean up leaked memory during writeDerrick Stolee via GitGitGadget, Oct 2, 2018
  3. Martin ÅgrenOct 2, 2018
  4. Stefan BellerOct 2, 2018
  5. Martin ÅgrenOct 2, 2018
  6. Stefan BellerOct 2, 2018
  7. Jeff KingOct 2, 2018
  8. Stefan BellerOct 2, 2018
  9. Derrick StoleeOct 3, 2018
  10. 0/2 commit-graph: more leak fixesMartin Ågren, Oct 3, 2018
  11. 1/2 commit-graph: free `struct packed_git` after closing itMartin Ågren, Oct 3, 2018
  12. 2/2 builtin/commit-graph.c: UNLEAK variablesMartin Ågren, Oct 3, 2018
  13. Derrick StoleeOct 3, 2018
  14. Martin ÅgrenOct 3, 2018
  15. Jeff KingOct 2, 2018
  16. 2/2 commit-graph: reduce initial oid allocationDerrick Stolee via GitGitGadget, Oct 2, 2018
  17. 0/3 Clean up leaks in commit-graph.cDerrick Stolee via GitGitGadget, Oct 3, 2018
  18. 1/3 commit-graph: clean up leaked memory during writeDerrick Stolee via GitGitGadget, Oct 3, 2018
  19. 2/3 builtin/commit-graph.c: UNLEAK variablesMartin Ågren via GitGitGadget, Oct 3, 2018
  20. 3/3 commit-graph: reduce initial oid allocationDerrick Stolee via GitGitGadget, Oct 3, 2018

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