From: Jim Meyering <jim@meyering•net>
To: Junio C Hamano <gitster@pobox•com>
Cc: git list <git@vger•kernel.org>,
Daniel Barkalow <barkalow@iabervon•org>,
Johannes Sixt <j6t@kdbg•org>
Subject: Re: [PATCH] transport-helper.c: don't leak fdopen'd stream buffers
Date: Sun, 13 Sep 2009 09:45:10 +0200 [thread overview]
Message-ID: <878wgjz3sp.fsf@meyering.net> (raw)
In-Reply-To: <7vtyz760lm.fsf@alter.siamese.dyndns.org> (Junio C. Hamano's message of "Sat, 12 Sep 2009 19:27:01 -0700")
Junio C Hamano wrote:
> Jim Meyering <jim@meyering•net> writes:
>
>> diff --git a/transport-helper.c b/transport-helper.c
>> index f57e84c..0bbd014 100644
>> --- a/transport-helper.c
>> +++ b/transport-helper.c
>> @@ -49,6 +49,7 @@ static struct child_process *get_helper(struct transport *transport)
>> if (!strcmp(buf.buf, "fetch"))
>> data->fetch = 1;
>> }
>> + fclose (file);
>> return data->helper;
>> }
>>
>> @@ -88,6 +89,7 @@ static int fetch_with_fetch(struct transport *transport,
>> if (strbuf_getline(&buf, file, '\n') == EOF)
>> exit(128); /* child died, message supplied already */
>> }
>> + fclose (file);
>> return 0;
>> }
>
> The callchain of fetch_with_fetch() looks like:
>
> fetch_with_fetch()
> helper = get_helper();
> --> get_helper()
> - start helper with start_command();
> - read from helper->out until it sees an empty line;
> - break out of the loop;
> <-- return helper
> - file = xfdopen(helper->out) to get another FILE on the fd
> - read the rest of the output from helper->out via file
>
> It seems to me that the fclose() in get_helper() will close the underlying
> fd and would break the caller, no?
I confess that my sole test was to run "make test", which passed.
If the fd must live on, a slightly less invasive change would be to
xdup each descriptor just before each of the three xfdopen calls, e.g.,
- file = xfdopen(helper->out, "r");
+ file = xfdopen(xdup(helper->out), "r");
> I think "struct helper_data" should get a new FILE* field and once
> somebody creates a FILE* out of its helper->out, that FILE* can be passed
> around without a new xfdopen().
>
> Or something like that.
That's probably best.
> Who is responsible for closing the underlying helper->out fd in the
> start_command() API, by the way?
next prev parent reply other threads:[~2009-09-13 7:45 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-12 9:38 [PATCH] transport-helper.c: don't leak fdopen'd stream buffers Jim Meyering
2009-09-13 2:27 ` Junio C Hamano
2009-09-13 7:45 ` Jim Meyering [this message]
2009-09-13 15:20 ` Johannes Sixt
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