From: "Martin Liška" <mliska@suse.cz>
To: Sergei Trofimovich <slyich@gmail.com>, gcc-patches@gcc.gnu.org
Cc: Sergei Trofimovich <siarheit@google.com>
Subject: Re: [PATCH] driver: fix environ corruption after putenv() [PR106624]
Date: Tue, 16 Aug 2022 13:59:27 +0200 [thread overview]
Message-ID: <6aa569c8-20c3-354a-34b7-8fcaf1d6c070@suse.cz> (raw)
In-Reply-To: <20220816114857.1632691-1-slyich@gmail.com>
On 8/16/22 13:48, Sergei Trofimovich wrote:
> From: Sergei Trofimovich <siarheit@google.com>
>
> The bug appeared afte r13-2010-g1270ccda70ca09 "Factor out
> jobserver_active_p" slightly changed `putenv()` use from allocating
> to non-allocating:
>
> -xputenv (concat ("MAKEFLAGS=", dup, NULL));
> +xputenv (jinfo.skipped_makeflags.c_str ());
>
> `xputenv()` (and `putenv()`) don't copy strings and only store the
> pointer in the `environ` global table. As a result `environ` got
> corrupted as soon as `jinfo.skipped_makeflags` store got deallocated.
>
> This started causing bootstrap crashes in `execv()` calls:
>
> xgcc: fatal error: cannot execute '/build/build/./prev-gcc/collect2': execv: Bad address
>
> The change restores memory allocation for `xputenv()` argument.
Thanks for the patch.
I think it's an obvious fix, please install it.
Martin
>
> gcc/
>
> PR driver/106624
> * gcc (driver::detect_jobserver): Allocate storage xputenv()
> argument using xstrdup().
> ---
> gcc/gcc.cc | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/gcc/gcc.cc b/gcc/gcc.cc
> index cac11c1a117..75ca0ece1a4 100644
> --- a/gcc/gcc.cc
> +++ b/gcc/gcc.cc
> @@ -9182,7 +9182,7 @@ driver::detect_jobserver () const
> {
> jobserver_info jinfo;
> if (!jinfo.is_active && !jinfo.skipped_makeflags.empty ())
> - xputenv (jinfo.skipped_makeflags.c_str ());
> + xputenv (xstrdup (jinfo.skipped_makeflags.c_str ()));
> }
>
> /* Determine what the exit code of the driver should be. */
prev parent reply other threads:[~2022-08-16 11:59 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-16 11:48 Sergei Trofimovich
2022-08-16 11:59 ` Martin Liška [this message]
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