From: Junio C Hamano <gitster@pobox•com>
To: Patrick Steinhardt <ps@pks•im>
Cc: git@vger•kernel.org
Subject: Re: [PATCH 22/23] revision: fix leaking parents when simplifying commits
Date: Thu, 19 Sep 2024 10:17:46 -0700 [thread overview]
Message-ID: <xmqq34lv8sw5.fsf@gitster.g> (raw)
In-Reply-To: <2a23df9a6869f58a231cfe4947b322690d48cb1a.1726484308.git.ps@pks.im> (Patrick Steinhardt's message of "Mon, 16 Sep 2024 13:46:28 +0200")
Patrick Steinhardt <ps@pks•im> writes:
> When simplifying commits, e.g. because they are treesame with their
> parents, we unset the commit's parent pointers but never free them. Plug
> the resulting memory leaks.
>
> Signed-off-by: Patrick Steinhardt <ps@pks•im>
> ---
> revision.c | 5 +++++
> t/t1414-reflog-walk.sh | 1 +
> t/t5310-pack-bitmaps.sh | 1 +
> t/t5326-multi-pack-bitmaps.sh | 2 ++
> t/t6004-rev-list-path-optim.sh | 1 +
> t/t6019-rev-list-ancestry-path.sh | 1 +
> t/t6111-rev-list-treesame.sh | 1 +
> 7 files changed, 12 insertions(+)
>
> diff --git a/revision.c b/revision.c
> index 2d7ad2bddff..e79f39e5555 100644
> --- a/revision.c
> +++ b/revision.c
> @@ -1071,7 +1071,11 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
> ts->treesame[nth_parent] = 1;
> continue;
> }
> +
> + free_commit_list(parent->next);
> parent->next = NULL;
We have been walking commit->parents linked list, "parent" is the
current parent we are looking at. We are simplifying the history
and decided that later parents are not needed, hence we discard the
remaining commit_list entries starting from parents->next. But we
didn't discard; we just updated parent->next pointer and made the
pointed data unreachable, leaking. So we free_commit_list().
> + while (commit->parents != parent)
> + pop_commit(&commit->parents);
> commit->parents = parent;
And this is the other direction, discarding the parents before the
current one we are looking at.
Of course it makes me wonder if we can just free_commit_list() the
whole thing and then add the current parent commit (in "p", which
was taken with "p = parent->item" before) as the sole parent, with
something like
free_commit_list(commit->parents);
commit->parents = NULL;
/* parent = */ commit_list_insert(p, &commit->parents);
to replace the 5-line (2 to discard later parents, 3 to discard
earlier ones) code, but I do not think it becomes particularly
easier to read, so let's drop that.
> @@ -1103,6 +1107,7 @@ static void try_to_simplify_commit(struct rev_info *revs, struct commit *commit)
> die("cannot simplify commit %s (invalid %s)",
> oid_to_hex(&commit->object.oid),
> oid_to_hex(&p->object.oid));
> + free_commit_list(p->parents);
> p->parents = NULL;
> }
> /* fallthrough */
Looking good.
Thanks.
next prev parent reply other threads:[~2024-09-19 17:17 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-16 11:45 [PATCH 00/23] Memory leak fixes (pt.7) Patrick Steinhardt
2024-09-16 11:45 ` [PATCH 01/23] builtin/help: fix dangling reference to `html_path` Patrick Steinhardt
2024-09-16 16:24 ` Justin Tobler
2024-09-16 11:45 ` [PATCH 02/23] builtin/help: fix leaking `html_path` when reading config multiple times Patrick Steinhardt
2024-09-16 11:45 ` [PATCH 03/23] git: fix leaking argv when handling builtins Patrick Steinhardt
2024-09-16 11:45 ` [PATCH 04/23] submodule: fix leaking update strategy Patrick Steinhardt
2024-09-16 11:45 ` [PATCH 05/23] builtin/submodule--helper: clear child process when not running it Patrick Steinhardt
2024-09-16 11:45 ` [PATCH 06/23] builtin/submodule--helper: fix leaking error buffer Patrick Steinhardt
2024-09-16 11:45 ` [PATCH 07/23] t/helper: fix leaking subrepo in nested submodule config helper Patrick Steinhardt
2024-09-16 11:45 ` [PATCH 08/23] builtin/submodule--helper: fix leaking remote ref on errors Patrick Steinhardt
2024-09-16 18:51 ` Justin Tobler
2024-09-17 10:19 ` Patrick Steinhardt
2024-09-25 20:26 ` Junio C Hamano
2024-09-26 11:58 ` Patrick Steinhardt
2024-09-16 11:45 ` [PATCH 09/23] dir: fix off by one errors for ignored and untracked entries Patrick Steinhardt
2024-09-20 16:43 ` Junio C Hamano
2024-09-16 11:45 ` [PATCH 10/23] builtin/pull: fix leaking "ff" option Patrick Steinhardt
2024-09-20 17:00 ` Junio C Hamano
2024-09-24 7:20 ` Patrick Steinhardt
2024-09-16 11:45 ` [PATCH 11/23] diff: fix leaking orderfile option Patrick Steinhardt
2024-09-16 11:45 ` [PATCH 12/23] parse-options: free previous value of `OPTION_FILENAME` Patrick Steinhardt
2024-09-20 17:21 ` Junio C Hamano
2024-09-16 11:46 ` [PATCH 13/23] diffcore-order: fix leaking buffer when parsing orderfiles Patrick Steinhardt
2024-09-16 11:46 ` [PATCH 14/23] builtin/repack: fix leaking configuration Patrick Steinhardt
2024-09-20 17:28 ` Junio C Hamano
2024-09-16 11:46 ` [PATCH 15/23] builtin/difftool: plug several trivial memory leaks Patrick Steinhardt
2024-09-16 11:46 ` [PATCH 16/23] trace2: destroy context stored in thread-local storage Patrick Steinhardt
2024-09-16 11:46 ` [PATCH 17/23] submodule: fix leaking submodule ODB paths Patrick Steinhardt
2024-09-16 11:46 ` [PATCH 18/23] grep: fix leaking grep pattern Patrick Steinhardt
2024-09-16 11:46 ` [PATCH 19/23] promisor-remote: fix leaking partial clone filter Patrick Steinhardt
2024-09-16 11:46 ` [PATCH 20/23] builtin/maintenance: fix leaking config string Patrick Steinhardt
2024-09-20 17:59 ` Junio C Hamano
2024-09-16 11:46 ` [PATCH 21/23] builtin/maintenance: fix leak in `get_schedule_cmd()` Patrick Steinhardt
2024-09-16 11:46 ` [PATCH 22/23] revision: fix leaking parents when simplifying commits Patrick Steinhardt
2024-09-19 17:17 ` Junio C Hamano [this message]
2024-09-16 11:46 ` [PATCH 23/23] diffcore-break: fix leaking filespecs when merging broken pairs Patrick Steinhardt
2024-09-19 18:54 ` [PATCH 00/23] Memory leak fixes (pt.7) Junio C Hamano
2024-09-24 7:20 ` Patrick Steinhardt
2024-09-26 11:45 ` [PATCH v2 " Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 01/23] builtin/help: fix dangling reference to `html_path` Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 02/23] builtin/help: fix leaking `html_path` when reading config multiple times Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 03/23] git: fix leaking argv when handling builtins Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 04/23] submodule: fix leaking update strategy Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 05/23] builtin/submodule--helper: clear child process when not running it Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 06/23] builtin/submodule--helper: fix leaking error buffer Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 07/23] t/helper: fix leaking subrepo in nested submodule config helper Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 08/23] builtin/submodule--helper: fix leaking remote ref on errors Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 09/23] dir: fix off by one errors for ignored and untracked entries Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 10/23] builtin/pull: fix leaking "ff" option Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 11/23] diff: fix leaking orderfile option Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 12/23] parse-options: free previous value of `OPTION_FILENAME` Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 13/23] diffcore-order: fix leaking buffer when parsing orderfiles Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 14/23] builtin/repack: fix leaking configuration Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 15/23] builtin/difftool: plug several trivial memory leaks Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 16/23] trace2: destroy context stored in thread-local storage Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 17/23] submodule: fix leaking submodule ODB paths Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 18/23] grep: fix leaking grep pattern Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 19/23] promisor-remote: fix leaking partial clone filter Patrick Steinhardt
2024-09-26 11:46 ` [PATCH v2 20/23] builtin/maintenance: fix leaking config string Patrick Steinhardt
2024-09-26 11:47 ` [PATCH v2 21/23] builtin/maintenance: fix leak in `get_schedule_cmd()` Patrick Steinhardt
2024-09-26 11:47 ` [PATCH v2 22/23] revision: fix leaking parents when simplifying commits Patrick Steinhardt
2024-09-26 11:47 ` [PATCH v2 23/23] diffcore-break: fix leaking filespecs when merging broken pairs Patrick Steinhardt
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