linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Namhyung Kim <namhyung@gmail.com>
To: Kees Cook <keescook@chromium.org>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Nobuhiro Iwamatsu <nobuhiro.iwamatsu.kw@hitachi.com>,
	Qiuxu Zhuo <qiuxu.zhuo@intel.com>,
	Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	Anton Vorontsov <anton@enomsg.org>,
	Colin Cross <ccross@android.com>, Tony Luck <tony.luck@intel.com>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	"Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Len Brown <lenb@kernel.org>,
	Matt Fleming <matt@codeblueprint.co.uk>,
	Nathan Fontenot <nfont@linux.vnet.ibm.com>,
	Pan Xinhui <xinhui.pan@linux.vnet.ibm.com>,
	Daniel Axtens <dja@axtens.net>,
	Paul Gortmaker <paul.gortmaker@windriver.com>,
	Geliang Tang <geliangtang@163.com>,
	linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org,
	linux-efi@vger.kernel.org, linux-doc@vger.kernel.org
Subject: Re: [PATCH 03/18] pstore: Avoid race in module unloading
Date: Wed, 8 Mar 2017 01:16:43 +0900	[thread overview]
Message-ID: <CADWwUUZAxwUqHU9eRrtP5Hk7KO9KkyvdBy7Z5Xehwhv43fvZVQ@mail.gmail.com> (raw)
In-Reply-To: <1488837332-71582-4-git-send-email-keescook@chromium.org>

Hi Kees,

On Tue, Mar 7, 2017 at 6:55 AM, Kees Cook <keescook@chromium.org> wrote:
> Technically, it might be possible for struct pstore_info to go out of
> scope after the module_put(), so report the backend name first.

But in that case, using pstore will crash the kernel anyway, right?
If so, why pstore doesn't keep a reference until unregister?
Do I miss something?

Thanks,
Namhyung


>
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  fs/pstore/platform.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
> index 074fe85a2078..d69ef8a840b9 100644
> --- a/fs/pstore/platform.c
> +++ b/fs/pstore/platform.c
> @@ -722,10 +722,10 @@ int pstore_register(struct pstore_info *psi)
>          */
>         backend = psi->name;
>
> -       module_put(owner);
> -
>         pr_info("Registered %s as persistent store backend\n", psi->name);
>
> +       module_put(owner);
> +
>         return 0;
>  }
>  EXPORT_SYMBOL_GPL(pstore_register);
> --
> 2.7.4
>

  reply	other threads:[~2017-03-07 16:16 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-03-06 21:55 [PATCH 00/18] pstore: refactor internal APIs Kees Cook
2017-03-06 21:55 ` [PATCH 01/18] pstore: Use dynamic spinlock initializer Kees Cook
2017-03-06 21:55 ` [PATCH 02/18] pstore: Shut down worker when unregistering Kees Cook
2017-03-06 21:55 ` [PATCH 03/18] pstore: Avoid race in module unloading Kees Cook
2017-03-07 16:16   ` Namhyung Kim [this message]
2017-03-07 16:18     ` Kees Cook
2017-03-06 21:55 ` [PATCH 04/18] pstore: Improve register_pstore() error reporting Kees Cook
2017-03-06 21:55 ` [PATCH 05/18] pstore: Add kernel-doc for struct pstore_info Kees Cook
2017-03-06 21:55 ` [PATCH 06/18] pstore: Extract common arguments into structure Kees Cook
2017-03-07 16:22   ` Namhyung Kim
2017-03-07 19:31     ` Kees Cook
2017-03-06 21:55 ` [PATCH 07/18] pstore: Move record decompression to function Kees Cook
2017-03-06 21:55 ` [PATCH 08/18] pstore: Switch pstore_mkfile to pass record Kees Cook
2017-03-06 21:55 ` [PATCH 09/18] pstore: Replace arguments for read() API Kees Cook
2017-03-06 21:55 ` [PATCH 10/18] pstore: Replace arguments for write() API Kees Cook
2017-03-06 21:55 ` [PATCH 11/18] pstore: Always allocate buffer for decompression Kees Cook
2017-03-06 21:55 ` [PATCH 12/18] pstore: Pass record contents instead of copying Kees Cook
2017-03-06 21:55 ` [PATCH 13/18] pstore: Allocate records on heap instead of stack Kees Cook
2017-03-06 21:55 ` [PATCH 14/18] pstore: Do not duplicate record metadata Kees Cook
2017-03-06 21:55 ` [PATCH 15/18] pstore: Replace arguments for erase() API Kees Cook
2017-03-06 21:55 ` [PATCH 16/18] pstore: Replace arguments for write_buf() API Kees Cook
2017-03-06 21:55 ` [PATCH 17/18] pstore: Replace arguments for write_buf_user() API Kees Cook
2017-03-06 21:55 ` [PATCH 18/18] pstore: Remove write_buf() callback Kees Cook

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CADWwUUZAxwUqHU9eRrtP5Hk7KO9KkyvdBy7Z5Xehwhv43fvZVQ@mail.gmail.com \
    --to=namhyung@gmail.com \
    --cc=anton@enomsg.org \
    --cc=ard.biesheuvel@linaro.org \
    --cc=benh@kernel.crashing.org \
    --cc=ccross@android.com \
    --cc=dja@axtens.net \
    --cc=geliangtang@163.com \
    --cc=keescook@chromium.org \
    --cc=lenb@kernel.org \
    --cc=linux-acpi@vger.kernel.org \
    --cc=linux-doc@vger.kernel.org \
    --cc=linux-efi@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=matt@codeblueprint.co.uk \
    --cc=mpe@ellerman.id.au \
    --cc=nfont@linux.vnet.ibm.com \
    --cc=nobuhiro.iwamatsu.kw@hitachi.com \
    --cc=paul.gortmaker@windriver.com \
    --cc=paulus@samba.org \
    --cc=qiuxu.zhuo@intel.com \
    --cc=rjw@rjwysocki.net \
    --cc=tony.luck@intel.com \
    --cc=xinhui.pan@linux.vnet.ibm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).