From: Jeff King <peff@peff.net>
To: Junio C Hamano <gitster@pobox.com>
Cc: git@vger.kernel.org
Subject: Re: [PATCH] for-each-ref: delay parsing of --sort=<atom> options
Date: Tue, 19 Oct 2021 22:20:40 -0400 [thread overview]
Message-ID: <YW98+Lj9xVsR9u9Q@coredump.intra.peff.net> (raw)
In-Reply-To: <YW9EP5UNX0f+eOke@coredump.intra.peff.net>
On Tue, Oct 19, 2021 at 06:18:40PM -0400, Jeff King wrote:
> > @@ -86,8 +86,6 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
> >
> > packet_trace_identity("ls-remote");
> >
> > - UNLEAK(sorting);
> > -
> > if (argc > 1) {
> > int i;
> > CALLOC_ARRAY(pattern, argc);
> > @@ -139,8 +137,13 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
> > item->symref = xstrdup_or_null(ref->symref);
> > }
> >
> > - if (sorting)
> > + if (sorting_options.nr) {
> > + struct ref_sorting *sorting;
> > + UNLEAK(sorting);
> > +
> > + sorting = ref_sorting_options(&sorting_options);
> > ref_array_sort(sorting, &ref_array);
> > + }
>
> I wondered at first about pulling this UNLEAK() down, but it's because
> you move the "sorting" variable itself into the smaller scope. So this
> makes sense (and calling UNLEAK() before the pointer is set is perfectly
> fine, since it takes the address of the auto variable). It is a shame
> you can't just ref_sorting_free() afterwards, but we don't have that
> function yet. And adding it is way out of scope here. :)
Actually, I think I was wrong here. UNLEAK() will look at &sorting, but
it will snapshot its data at the time of the call. So it won't do
anything when the variable doesn't yet have a value.
You can demonstrate with:
$ make SANITIZE=leak
$ ./git ls-remote --sort=refname .
which will complain. Bumping it down like this:
diff --git a/builtin/ls-remote.c b/builtin/ls-remote.c
index 1e6017cdaa..a94a220256 100644
--- a/builtin/ls-remote.c
+++ b/builtin/ls-remote.c
@@ -139,10 +139,10 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
if (sorting_options.nr) {
struct ref_sorting *sorting;
- UNLEAK(sorting);
sorting = ref_sorting_options(&sorting_options);
ref_array_sort(sorting, &ref_array);
+ UNLEAK(sorting);
}
for (i = 0; i < ref_array.nr; i++) {
clears it up. Note that there are other similar "leaks" (e.g., if you
give a pattern in argv[1]) which should be punted to another topic, but
I think you'd want to deal with this one since you're moving the
UNLEAK() around.
-Peff
next prev parent reply other threads:[~2021-10-20 2:20 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-18 18:32 [PATCH] for-each-ref: delay parsing of --sort=<atom> options Junio C Hamano
2021-10-19 22:18 ` Jeff King
2021-10-20 2:20 ` Jeff King [this message]
2021-10-20 12:30 ` Ævar Arnfjörð Bjarmason
2021-10-20 13:24 ` [RFC PATCH v2 0/4] for-each-ref: delay parsing of --sort=<atom> options + linux-leaks fixes Ævar Arnfjörð Bjarmason
2021-10-20 13:24 ` [RFC PATCH v2 1/4] tag: use a "goto cleanup" pattern, leak less memory Ævar Arnfjörð Bjarmason
2021-10-20 14:37 ` Junio C Hamano
2021-10-20 13:24 ` [RFC PATCH v2 2/4] ref-filter API user: add and use a ref_sorting_release() Ævar Arnfjörð Bjarmason
2021-10-20 14:39 ` Junio C Hamano
2021-10-20 13:24 ` [RFC PATCH v2 3/4] for-each-ref: delay parsing of --sort=<atom> options Ævar Arnfjörð Bjarmason
2021-10-20 13:24 ` [RFC PATCH v2 4/4] branch: use ref_sorting_release() Ævar Arnfjörð Bjarmason
2021-10-20 14:43 ` [RFC PATCH v2 0/4] for-each-ref: delay parsing of --sort=<atom> options + linux-leaks fixes Junio C Hamano
2021-10-20 18:27 ` [PATCH 0/3] ref-filter: add a ref_sorting_release() Ævar Arnfjörð Bjarmason
2021-10-20 18:27 ` [PATCH 1/3] tag: use a "goto cleanup" pattern, leak less memory Ævar Arnfjörð Bjarmason
2021-10-20 18:27 ` [PATCH 2/3] ref-filter API user: add and use a ref_sorting_release() Ævar Arnfjörð Bjarmason
2021-10-20 18:27 ` [PATCH 3/3] branch: use ref_sorting_release() Ævar Arnfjörð Bjarmason
2021-10-20 13:58 ` [PATCH] for-each-ref: delay parsing of --sort=<atom> options Junio C Hamano
2021-10-20 20:48 ` Jeff King
2021-10-20 21:32 ` Junio C Hamano
2021-10-21 14:54 ` Jeff King
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