From: Jeff King <peff@peff.net>
To: Jonathan Tan <jonathantanmy@google.com>
Cc: git@vger.kernel.org, stolee@gmail.com, gitster@pobox.com,
jeffhost@microsoft.com
Subject: Re: [PATCH v2] usage: trace2 BUG() invocations
Date: Tue, 9 Feb 2021 07:03:27 -0500 [thread overview]
Message-ID: <YCJ6D1wGgmo1a+KT@coredump.intra.peff.net> (raw)
In-Reply-To: <20210205200908.805639-1-jonathantanmy@google.com>
On Fri, Feb 05, 2021 at 12:09:08PM -0800, Jonathan Tan wrote:
> die() messages are traced in trace2, but BUG() messages are not. Anyone
> tracking die() messages would have even more reason to track BUG().
> Therefore, write to trace2 when BUG() is invoked.
>
> Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
> ---
> Thanks everyone for your suggestions. I've used an in_bug static
> variable (which does prevent the infinite loop - I injected the bug that
> Peff described and verified that it indeed loops without the mitigation
> and doesn't loop with the mitigation) and moved the trace2 to be below
> the vreportf (necessitating a va_copy).
Thanks. I think the single static in_bug is sufficient. We can always
extend it later if that turns out not to be the case.
> diff --git a/t/t0210-trace2-normal.sh b/t/t0210-trace2-normal.sh
> index ce7574edb1..81af180c4c 100755
> --- a/t/t0210-trace2-normal.sh
> +++ b/t/t0210-trace2-normal.sh
> @@ -147,6 +147,25 @@ test_expect_success 'normal stream, error event' '
> test_cmp expect actual
> '
>
> +# Verb 007bug
> +#
> +# Check that BUG writes to trace2
> +
> +test_expect_success 'normal stream, exit code 1' '
Is this description accurate? It doesn't really seem like "exit code 1".
Maybe "99", though BUG is probably more accurate.
> + test_when_finished "rm trace.normal actual expect" &&
> + test_must_fail env GIT_TRACE2="$(pwd)/trace.normal" test-tool trace2 007bug &&
> + perl "$TEST_DIRECTORY/t0210/scrub_normal.perl" <trace.normal >actual &&
> + cat >expect <<-EOF &&
> + version $V
> + start _EXE_ trace2 007bug
> + cmd_name trace2 (trace2)
> + error the bug message
> + exit elapsed:_TIME_ code:99
> + atexit elapsed:_TIME_ code:99
> + EOF
> + test_cmp expect actual
I wondered how we triggered the BUG_exit_code magic, since I didn't see
any environment set up. It turns out that it's hard-coded into
test-tool, so we don't need to do anything special here in the test.
-Peff
next prev parent reply other threads:[~2021-02-09 12:05 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-05 5:49 [PATCH] usage: trace2 BUG() invocations Jonathan Tan
2021-02-05 6:17 ` Junio C Hamano
2021-02-05 9:01 ` Jeff King
2021-02-05 12:51 ` Derrick Stolee
2021-02-05 13:44 ` Jeff King
2021-02-05 16:34 ` Jeff Hostetler
2021-02-05 20:09 ` [PATCH v2] " Jonathan Tan
2021-02-09 12:03 ` Jeff King [this message]
2021-02-09 19:34 ` Jonathan Tan
2021-02-09 21:18 ` Junio C Hamano
2021-02-09 22:15 ` Junio C Hamano
2021-03-27 17:56 ` Ævar Arnfjörð Bjarmason
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