From: Greg KH <gregkh@linuxfoundation.org>
To: Yuxiao Zhang <yuxiaozhang@google.com>
Cc: Kees Cook <keescook@chromium.org>,
Tony Luck <tony.luck@intel.com>,
"'Guilherme G . Piccoli'" <gpiccoli@igalia.com>,
linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org,
wak@google.com
Subject: Re: [PATCH] pstore: ramoops: support pmsg size larger than kmalloc limitation
Date: Wed, 28 Jun 2023 07:30:16 +0200 [thread overview]
Message-ID: <2023062832-barrier-strenuous-9499@gregkh> (raw)
In-Reply-To: <20230627202540.881909-2-yuxiaozhang@google.com>
On Tue, Jun 27, 2023 at 01:25:41PM -0700, Yuxiao Zhang wrote:
> Current pmsg implementation is using kmalloc for pmsg record buffer,
> which has max size limits based on page size.
What is that max size?
> Currently even we
> allocate enough space with pmsg-size, pmsg will still fail if the
> file size is larger than what kmalloc allowed.
>
> Since we don't need physical contiguous memory for pmsg buffer
> , we can use kvmalloc to avoid such limitation.
Odd placement of the ',' character :)
Anyway, thanks for getting this sent out.
But, what in-kernel user is hitting this in the pstore implementation?
How big of a buffer is it trying to create? Is this a bug in older
kernels with the in-kernel drivers as well? If so, should it go to
stable releases and how far back?
thanks,
greg k-h
next prev parent reply other threads:[~2023-06-28 8:07 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-27 20:25 [PATCH] pstore: ramoops: support pmsg size larger than kmalloc limitation Yuxiao Zhang
2023-06-28 5:30 ` Greg KH [this message]
2023-06-28 17:10 ` Yuxiao Zhang
2023-06-28 18:12 ` Guilherme G. Piccoli
2023-06-28 23:24 ` Kees Cook
2023-06-29 19:22 ` Guilherme G. Piccoli
2023-06-28 17:55 ` Kees Cook
2023-06-30 20:50 ` Yuxiao Zhang
2023-06-30 20:53 ` Yuxiao Zhang
2023-07-18 20:23 ` Yuxiao Zhang
2023-08-17 23:40 ` Kees Cook
-- strict thread matches above, loose matches on Subject: below --
2022-01-04 19:36 pstore/ramoops - why only collect a partial dmesg? Guilherme G. Piccoli
2023-06-28 18:48 ` [PATCH] pstore: ramoops: support pmsg size larger than kmalloc limitation Yuxiao Zhang
2023-06-28 19:05 ` Guilherme G. Piccoli
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