From: Taylor Blau <me@ttaylorr.com>
To: Junio C Hamano <gitster@pobox.com>
Cc: git@vger.kernel.org, avarab@gmail.com, dstolee@microsoft.com,
peff@peff.net
Subject: Re: [PATCH 05/11] builtin/repack.c: avoid leaking child arguments
Date: Thu, 21 Oct 2021 23:21:53 -0400 [thread overview]
Message-ID: <YXIuURFP/FOpae7U@nand.local> (raw)
In-Reply-To: <xmqqmtn2mj0s.fsf@gitster.g>
On Thu, Oct 21, 2021 at 09:37:07AM -0700, Junio C Hamano wrote:
> Taylor Blau <me@ttaylorr.com> writes:
>
> > `git repack` invokes a handful of child processes: one to write the
> > actual pack, and optionally ones to repack promisor objects and update
> > the MIDX.
> >
> > In none of these cases do we bother to call child_process_clear(), which
> > frees the memory associated with each child's arguments and environment.
> >
> > In order to do so, tweak each function that spawns a child process to
> > have a `cleanup` label that we always visit before returning from each
> > function. Then, make sure that we call child_process_clear() as a part
> > of that label.
>
> I have a slight aversion against the fact that this patch makes us
> call child_process_clear(), when we know we may have called
> finish_command(). Callers of finish_command() in other codepaths
> rely on the fact that finish_command() calls child_process_clear(),
> which means that because of this change, we are now constrained to
> keep child_process_clear() idempotent?
Good point. In functions besides cmd_repack(), it's easy enough to just
call child_process_clear() once before returning instead of using a
label. That has the added benefit of side-stepping the variable name
question that you and Stolee raised (but I think whether we call it
"result", "res", or "ret" is besides the point).
In cmd_repack(), I'd like to wrap the other cleanup-related calls
underneath a 'cleanup' label. So there we want to track whether or not
we have called finish_command(), so that we only call
child_process_clear() when we *haven't* already called it via
finish_command().
Thanks,
Taylor
next prev parent reply other threads:[~2021-10-22 3:32 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-21 3:39 [PATCH 00/11] midx: clean up t5319 under 'SANITIZE=leak' Taylor Blau
2021-10-21 3:39 ` [PATCH 01/11] midx.c: clean up chunkfile after reading the MIDX Taylor Blau
2021-10-21 5:50 ` Junio C Hamano
2021-10-21 11:34 ` Ævar Arnfjörð Bjarmason
2021-10-21 16:16 ` Junio C Hamano
2021-10-22 3:04 ` Taylor Blau
2021-10-21 3:39 ` [PATCH 02/11] midx.c: don't leak MIDX from verify_midx_file Taylor Blau
2021-10-21 5:00 ` Eric Sunshine
2021-10-21 5:54 ` Junio C Hamano
2021-10-21 16:27 ` Junio C Hamano
2021-10-21 3:39 ` [PATCH 03/11] t/helper/test-read-midx.c: free MIDX within read_midx_file() Taylor Blau
2021-10-21 3:39 ` [PATCH 04/11] builtin/pack-objects.c: don't leak memory via arguments Taylor Blau
2021-10-21 3:39 ` [PATCH 05/11] builtin/repack.c: avoid leaking child arguments Taylor Blau
2021-10-21 13:32 ` Derrick Stolee
2021-10-21 18:47 ` Junio C Hamano
2021-10-21 16:37 ` Junio C Hamano
2021-10-22 3:21 ` Taylor Blau [this message]
2021-10-21 3:40 ` [PATCH 06/11] builtin/multi-pack-index.c: don't leak concatenated options Taylor Blau
2021-10-21 3:40 ` [PATCH 07/11] pack-bitmap.c: avoid leaking via midx_bitmap_filename() Taylor Blau
2021-10-21 16:54 ` Junio C Hamano
2021-10-22 4:27 ` Taylor Blau
2021-10-21 3:40 ` [PATCH 08/11] pack-bitmap.c: don't leak type-level bitmaps Taylor Blau
2021-10-21 16:59 ` Junio C Hamano
2021-10-21 3:40 ` [PATCH 09/11] pack-bitmap.c: more aggressively free in free_bitmap_index() Taylor Blau
2021-10-21 5:10 ` Eric Sunshine
2021-10-21 18:32 ` Junio C Hamano
2021-10-22 4:29 ` Taylor Blau
2021-10-21 18:43 ` Junio C Hamano
2021-10-21 3:40 ` [PATCH 10/11] pack-bitmap-write.c: don't return without stop_progress() Taylor Blau
2021-10-21 5:12 ` Eric Sunshine
2021-10-21 11:31 ` Ævar Arnfjörð Bjarmason
2021-10-21 18:39 ` Junio C Hamano
2021-10-22 4:32 ` Taylor Blau
2021-10-23 20:28 ` Junio C Hamano
2021-10-23 20:32 ` SubmittingPatchs: clarify choice of base and testing Junio C Hamano
2021-10-23 20:59 ` Ævar Arnfjörð Bjarmason
2021-10-23 21:31 ` Junio C Hamano
2021-10-23 21:40 ` Junio C Hamano
2021-10-25 8:59 ` Fabian Stelzer
2021-10-25 16:48 ` Junio C Hamano
2021-10-25 16:56 ` Junio C Hamano
2021-10-25 17:00 ` Junio C Hamano
2021-12-23 23:12 ` [PATCH v2] " Junio C Hamano
2021-12-28 17:47 ` Elijah Newren
2021-12-30 10:20 ` Fabian Stelzer
2021-12-30 20:18 ` Re* " Junio C Hamano
2021-10-21 3:40 ` [PATCH 11/11] t5319: UNLEAK() the remaining leaks Taylor Blau
2021-10-21 11:50 ` [PATCH 00/11] midx: clean up t5319 under 'SANITIZE=leak' Ævar Arnfjörð Bjarmason
2021-10-22 4:39 ` Taylor Blau
2021-10-22 8:23 ` Ævar Arnfjörð Bjarmason
2021-10-22 10:32 ` [PATCH] leak tests: add an interface to the LSAN_OPTIONS "suppressions" Ævar Arnfjörð Bjarmason
2021-10-26 20:23 ` Taylor Blau
2021-10-26 21:11 ` Jeff King
2021-10-26 21:30 ` Taylor Blau
2021-10-26 21:48 ` Jeff King
2021-10-27 8:04 ` Ævar Arnfjörð Bjarmason
2021-10-27 9:06 ` Jeff King
2021-10-27 20:21 ` Junio C Hamano
2021-10-27 20:57 ` Ævar Arnfjörð Bjarmason
2021-10-29 20:56 ` Jeff King
2021-10-29 21:05 ` Jeff King
2021-10-27 7:51 ` Ævar Arnfjörð Bjarmason
2021-10-21 13:37 ` [PATCH 00/11] midx: clean up t5319 under 'SANITIZE=leak' Derrick Stolee
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