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From: Richard Biener <richard.guenther@gmail.com>
To: Costas Argyris <costas.argyris@gmail.com>
Cc: gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] libiberty: fix memory leak in pex-win32.c and refactor
Date: Thu, 2 Mar 2023 11:08:17 +0100	[thread overview]
Message-ID: <CAFiYyc0SJn-k55A1TSdXUtSbeSTheLsUnh9tjkQ1uZ++-e7Mzw@mail.gmail.com> (raw)
In-Reply-To: <CAHyHGC=un9tLm3WKtmQKb5adhOJGeknWqJV95uh=shnkBv5u-A@mail.gmail.com>

On Thu, Mar 2, 2023 at 10:21 AM Costas Argyris <costas.argyris@gmail.com> wrote:
>
> I forgot to mention that:
>
> 1) The CreateProcess documentation
>
> https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-createprocessa
>
> doesn't mention anything about taking ownership of this or any other buffer passed to it.

Thanks - thus the patch is OK.

Thanks,
Richard.

> 2) The cmdline buffer gets created by the argv_to_cmdline function
>
> https://github.com/gcc-mirror/gcc/blob/master/libiberty/pex-win32.c#L339
>
> which has this comment right above it:
>
> /* Return a Windows command-line from ARGV.  It is the caller's
>    responsibility to free the string returned.  */
>
> Thanks,
> Costas
>
> On Thu, 2 Mar 2023 at 07:32, Richard Biener <richard.guenther@gmail.com> wrote:
>>
>> On Wed, Mar 1, 2023 at 7:14 PM Costas Argyris via Gcc-patches
>> <gcc-patches@gcc.gnu.org> wrote:
>> >
>> > Hi
>> >
>> > It seems that the win32_spawn function in libiberty/pex-win32.c is leaking
>> > the cmdline buffer in 2/3 exit scenarios (it is only free'd in 1/3).    The
>> > problem here is that the cleanup code is written 3 times, one at each exit
>> > scenario.
>> >
>> > The proposed attached refactoring has the cleanup code appearing just once
>> > and is executed for all exit scenarios, reducing the likelihood of such
>> > leaks in the future.
>>
>> One could imagine that CreateProcess in case of success takes ownership of
>> the buffer pointed to by cmdline?  If you can confirm it is not then the patch
>> looks OK to me.
>>
>> Thanks,
>> Richard.
>>
>> > Thanks,
>> > Costas

  reply	other threads:[~2023-03-02 10:08 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-01 18:07 Costas Argyris
2023-03-02  7:32 ` Richard Biener
2023-03-02  9:21   ` Costas Argyris
2023-03-02 10:08     ` Richard Biener [this message]
2023-03-02 14:02       ` Costas Argyris
2023-03-03 11:25         ` Richard Biener

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