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From: Junio C Hamano <gitster@pobox.com>
To: Andrzej Hunt <andrzej@ahunt.org>
Cc: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>, git@vger.kernel.org
Subject: Re: [PATCH] leak tests: free() before die for two API functions
Date: Thu, 21 Oct 2021 11:51:32 -0700	[thread overview]
Message-ID: <xmqqcznyky8b.fsf@gitster.g> (raw)
In-Reply-To: <FD837FF9-E83F-42AA-AC13-EADD161D20BE@ahunt.org> (Andrzej Hunt's message of "Thu, 21 Oct 2021 17:33:41 +0200")

Andrzej Hunt <andrzej@ahunt.org> writes:

>> On 21 Oct 2021, at 13:42, Ævar Arnfjörð Bjarmason <avarab@gmail.com> wrote:
>> 
>> Call free() just before die() in two API functions whose tests are
>> asserted under SANITIZE=leak. Normally this would not be needed due to
>> how SANITIZE=leak works, but in these cases my GCC version (10.2.1-6)
>> will fail tests t0001 and t0017 under SANITIZE=leak depending on the
>> optimization level.
>
> I’m curious - to me this seems like a compiler/sanitiser bug, can
> it also be reproduced with clang, or even newer versions of gcc?
> Similarly, can it be reproduced with your gcc version, using
> ASAN+LSAN (as opposed to LSAN by itself)? I remember seeing some
> false positives in the past for some permutations of compilers and
> sanitisers, but I’ve lost track of the details.
>
> These kinds of fixes seem noisy if it’s just to work around what
> appears to be a bug (and to be philosophical: we wouldn’t want to
> do the same for all “leaks” up the call stack if a specific
> compiler complained about them after a die() - after all there
> will be many more allocations that didn’t get free’d floating
> around - so why is it OK for these “leaks”?)

Exactly my feeling.  I'll leave this patch hanging on the list
without picking it up until we know this is a reasonable "fix" on
our side and not adding noize only to work around the bug in the
tools.

Thanks.

  reply	other threads:[~2021-10-21 18:51 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-10-21 11:42 [PATCH] leak tests: free() before die for two API functions Ævar Arnfjörð Bjarmason
2021-10-21 15:33 ` Andrzej Hunt
2021-10-21 18:51   ` Junio C Hamano [this message]
2021-10-21 16:13 ` Martin Ågren
2021-10-21 19:54 ` [PATCH v2 0/3] refs.c + config.c: plug memory leaks Ævar Arnfjörð Bjarmason
2021-10-21 19:54   ` [PATCH v2 1/3] refs.c: make "repo_default_branch_name" static, remove xstrfmt() Ævar Arnfjörð Bjarmason
2021-10-21 23:26     ` Junio C Hamano
2021-10-21 19:54   ` [PATCH v2 2/3] config.c: don't leak memory in handle_path_include() Ævar Arnfjörð Bjarmason
2021-10-21 23:30     ` Junio C Hamano
2021-10-22 17:19       ` Ævar Arnfjörð Bjarmason
2021-10-22 21:21         ` Junio C Hamano
2021-10-22 22:30           ` Ævar Arnfjörð Bjarmason
2021-10-21 19:54   ` [PATCH v2 3/3] config.c: free(expanded) before die(), work around GCC oddity Ævar Arnfjörð Bjarmason
2021-10-21 23:32     ` Junio C Hamano
2021-10-22 18:19   ` [PATCH v3 0/6] usage.c: add die_message() & plug memory leaks in refs.c & config.c Ævar Arnfjörð Bjarmason
2021-10-22 18:19     ` [PATCH v3 1/6] usage.c: add a die_message() routine Ævar Arnfjörð Bjarmason
2021-10-24  5:49       ` Junio C Hamano
2021-10-22 18:19     ` [PATCH v3 2/6] usage.c API users: use die_message() where appropriate Ævar Arnfjörð Bjarmason
2021-10-22 18:19     ` [PATCH v3 3/6] usage.c + gc: add and use a die_message_errno() Ævar Arnfjörð Bjarmason
2021-10-24  5:52       ` Junio C Hamano
2021-10-22 18:19     ` [PATCH v3 4/6] config.c: don't leak memory in handle_path_include() Ævar Arnfjörð Bjarmason
2021-10-24  5:53       ` Junio C Hamano
2021-10-22 18:19     ` [PATCH v3 5/6] config.c: free(expanded) before die(), work around GCC oddity Ævar Arnfjörð Bjarmason
2021-10-26  8:53       ` Jeff King
2021-10-22 18:19     ` [PATCH v3 6/6] refs: plug memory leak in repo_default_branch_name() Ævar Arnfjörð Bjarmason
2021-10-27 21:50     ` [PATCH v3 0/6] usage.c: add die_message() & plug memory leaks in refs.c & config.c Jonathan Tan

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