From: Junio C Hamano <gitster@pobox•com>
To: Jeff King <peff@peff•net>
Cc: git@vger•kernel.org, Christian Couder <chriscool@tuxfamily•org>,
Jakub Narebski <jnareb@gmail•com>,
Eric Sunshine <sunshine@sunshineco•com>
Subject: Re: [PATCH 03/15] do not create "struct commit" with xcalloc
Date: Tue, 10 Jun 2014 14:35:48 -0700 [thread overview]
Message-ID: <xmqqbnu08n2j.fsf@gitster.dls.corp.google.com> (raw)
In-Reply-To: <20140609181008.GC20315@sigill.intra.peff.net> (Jeff King's message of "Mon, 9 Jun 2014 14:10:08 -0400")
Jeff King <peff@peff•net> writes:
> In both blame and merge-recursive, we sometimes create a
> "fake" commit struct for convenience (e.g., to represent the
> HEAD state as if we would commit it). By allocating
> ourselves rather than using alloc_commit_node, we do not
> properly set the "index" field of the commit. This can
> produce subtle bugs if we then use commit-slab on the
> resulting commit, as we will share the "0" index with
> another commit.
The change I see here is all good, but I wonder if it is too late to
start the real index from 1 and catch anything that has 0 index with
a BUG("do not hand-allocate a commit").
> We can fix this by using alloc_commit_node() to allocate.
> Note that we cannot free the result, as it is part of our
> commit allocator. However, both cases were already leaking
> the allocated commit anyway, so there's nothing to fix up.
>
> Signed-off-by: Jeff King <peff@peff•net>
> ---
> builtin/blame.c | 2 +-
> merge-recursive.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/builtin/blame.c b/builtin/blame.c
> index a52a279..d6056a5 100644
> --- a/builtin/blame.c
> +++ b/builtin/blame.c
> @@ -2286,7 +2286,7 @@ static struct commit *fake_working_tree_commit(struct diff_options *opt,
> struct strbuf msg = STRBUF_INIT;
>
> time(&now);
> - commit = xcalloc(1, sizeof(*commit));
> + commit = alloc_commit_node();
> commit->object.parsed = 1;
> commit->date = now;
> commit->object.type = OBJ_COMMIT;
> diff --git a/merge-recursive.c b/merge-recursive.c
> index cab16fa..2b37d42 100644
> --- a/merge-recursive.c
> +++ b/merge-recursive.c
> @@ -40,7 +40,7 @@ static struct tree *shift_tree_object(struct tree *one, struct tree *two,
>
> static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
> {
> - struct commit *commit = xcalloc(1, sizeof(struct commit));
> + struct commit *commit = alloc_commit_node();
> struct merge_remote_desc *desc = xmalloc(sizeof(*desc));
>
> desc->name = comment;
next prev parent reply other threads:[~2014-06-10 21:36 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-09 18:02 [PATCH 0/15] store length of commit->buffer Jeff King
2014-06-09 18:09 ` [PATCH 01/15] alloc: include any-object allocations in alloc_report Jeff King
2014-06-09 18:09 ` [PATCH 02/15] commit: push commit_index update into alloc_commit_node Jeff King
2014-06-10 21:31 ` Junio C Hamano
2014-06-09 18:10 ` [PATCH 03/15] do not create "struct commit" with xcalloc Jeff King
2014-06-10 21:35 ` Junio C Hamano [this message]
2014-06-10 21:49 ` Jeff King
2014-06-09 18:10 ` [PATCH 04/15] logmsg_reencode: return const buffer Jeff King
2014-06-10 1:36 ` Eric Sunshine
2014-06-09 18:10 ` [PATCH 05/15] sequencer: use logmsg_reencode in get_message Jeff King
2014-06-10 21:40 ` Junio C Hamano
2014-06-10 21:50 ` Jeff King
2014-06-09 18:11 ` [PATCH 06/15] provide a helper to free commit buffer Jeff King
2014-06-09 18:11 ` [PATCH 07/15] provide a helper to set the " Jeff King
2014-06-09 18:11 ` [PATCH 08/15] provide helpers to access " Jeff King
2014-06-10 8:00 ` Eric Sunshine
2014-06-09 18:12 ` [PATCH 09/15] use get_cached_commit_buffer where appropriate Jeff King
2014-06-09 18:12 ` [PATCH 10/15] use get_commit_buffer to avoid duplicate code Jeff King
2014-06-10 8:01 ` Eric Sunshine
2014-06-10 20:34 ` Jeff King
2014-06-09 18:13 ` [PATCH 11/15] convert logmsg_reencode to get_commit_buffer Jeff King
2014-06-09 18:13 ` [PATCH 12/15] use get_commit_buffer everywhere Jeff King
2014-06-09 22:40 ` Junio C Hamano
2014-06-10 0:02 ` Jeff King
2014-06-10 0:22 ` Jeff King
2014-06-10 16:06 ` Junio C Hamano
2014-06-10 21:27 ` Jeff King
2014-06-09 18:15 ` [PATCH 13/15] commit-slab: provide a static initializer Jeff King
2014-06-09 18:15 ` [PATCH 14/15] commit: convert commit->buffer to a slab Jeff King
2014-06-09 18:15 ` [PATCH 15/15] commit: record buffer length in cache Jeff King
2014-06-10 5:12 ` Christian Couder
2014-06-10 5:27 ` Jeff King
2014-06-10 20:33 ` Jeff King
2014-06-10 21:30 ` Christian Couder
2014-06-10 21:35 ` [PATCH v2 0/17] store length of commit->buffer Jeff King
2014-06-10 21:36 ` [PATCH 01/17] commit_tree: take a pointer/len pair rather than a const strbuf Jeff King
2014-06-10 21:38 ` [PATCH 02/17] replace dangerous uses of strbuf_attach Jeff King
2014-06-10 21:38 ` [PATCH 03/17] alloc: include any-object allocations in alloc_report Jeff King
2014-06-10 21:39 ` [PATCH 04/17] commit: push commit_index update into alloc_commit_node Jeff King
2014-06-10 21:39 ` [PATCH 05/17] do not create "struct commit" with xcalloc Jeff King
2014-06-10 21:39 ` [PATCH 06/17] logmsg_reencode: return const buffer Jeff King
2014-06-10 21:39 ` [PATCH 07/17] sequencer: use logmsg_reencode in get_message Jeff King
2014-06-10 21:40 ` [PATCH 08/17] provide a helper to free commit buffer Jeff King
2014-06-12 18:22 ` Junio C Hamano
2014-06-12 20:08 ` Jeff King
2014-06-12 22:05 ` Jeff King
2014-06-10 21:40 ` [PATCH 09/17] provide a helper to set the " Jeff King
2014-06-10 21:40 ` [PATCH 10/17] provide helpers to access " Jeff King
2014-06-10 21:40 ` [PATCH 11/17] use get_cached_commit_buffer where appropriate Jeff King
2014-06-10 21:41 ` [PATCH 12/17] use get_commit_buffer to avoid duplicate code Jeff King
2014-06-10 21:41 ` [PATCH 13/17] convert logmsg_reencode to get_commit_buffer Jeff King
2014-06-10 21:41 ` [PATCH 14/17] use get_commit_buffer everywhere Jeff King
2014-06-10 21:42 ` [PATCH 15/17] commit-slab: provide a static initializer Jeff King
2014-06-12 18:15 ` Junio C Hamano
2014-06-12 19:51 ` Jeff King
2014-06-10 21:43 ` [PATCH 16/17] commit: convert commit->buffer to a slab Jeff King
2014-06-10 21:44 ` [PATCH 17/17] commit: record buffer length in cache Jeff King
2014-06-10 21:46 ` [PATCH v2 0/17] store length of commit->buffer Jeff King
2014-06-12 17:22 ` Junio C Hamano
2014-06-13 6:32 ` [PATCH v2] reuse cached commit buffer when parsing signatures Jeff King
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