From: ebiederm@xmission.com (Eric W. Biederman)
To: Jean Delvare <jdelvare@suse.de>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Dave Young <dyoung@redhat.com>,
linux-efi <linux-efi@vger.kernel.org>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Matt Fleming <matt@codeblueprint.co.uk>,
kexec@lists.infradead.org,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Mika Westerberg <mika.westerberg@linux.intel.com>
Subject: Re: [PATCH v1 2/2] firmware: dmi_scan: Pass dmi_entry_point to kexec'ed kernel
Date: Tue, 21 Jan 2020 10:29:35 -0600 [thread overview]
Message-ID: <87zheg93io.fsf@x220.int.ebiederm.org> (raw)
In-Reply-To: <20200121100359.6125498c@endymion> (Jean Delvare's message of "Tue, 21 Jan 2020 10:03:59 +0100")
Jean Delvare <jdelvare@suse.de> writes:
> On Mon, 20 Jan 2020 23:55:43 +0200, Andy Shevchenko wrote:
>> On Mon, Jan 20, 2020 at 11:44 PM Jean Delvare <jdelvare@suse.de> wrote:
>> >
>> > On Mon, 20 Jan 2020 10:04:04 -0600, Eric W. Biederman wrote:
>> > > Second. I looked at your test results and they don't directly make
>> > > sense. dmidecode bypasses the kernel completely or it did last time
>> > > I looked so I don't know why you would be using that to test if
>> > > something in the kernel is working.
>> >
>> > That must have been long ago. A recent version of dmidecode (>= 3.0)
>> > running on a recent kernel
>> > (>= d7f96f97c4031fa4ffdb7801f9aae23e96170a6f, v4.2) will read the DMI
>> > data from /sys/firmware/dmi/tables, so it is very much relying on the
>> > kernel doing the right thing. If not, it will still try to fallback to
>> > reading from /dev/mem directly on certain architectures. You can force
>> > that old method with --no-sysfs.
>> >
>> > Hope that helps,
>>
>> I don't understand how it possible can help for in-kernel code, like
>> DMI quirks in a drivers.
>
> OK, just ignore me then, probably I misunderstood the point made by
> Eric.
No. I just haven't dived into this area of code in a long time.
It seems a little indirect to use dmidecode as the test to see if the
kernel has the pointer to the dmitables, but with the knowledge you
provided it seems like a perfectly valid test.
Eric
next prev parent reply other threads:[~2020-01-21 16:31 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-02 19:54 [PATCH v1 0/2] firmware: dmi_scan: Make it work in kexec'ed kernel Andy Shevchenko
2016-12-02 19:54 ` [PATCH v1 1/2] firmware: dmi_scan: Split out dmi_get_entry_point() helper Andy Shevchenko
2016-12-15 11:13 ` Jean Delvare
2016-12-02 19:54 ` [PATCH v1 2/2] firmware: dmi_scan: Pass dmi_entry_point to kexec'ed kernel Andy Shevchenko
2016-12-15 11:28 ` Jean Delvare
2016-12-16 2:32 ` Dave Young
2016-12-16 12:18 ` Andy Shevchenko
2016-12-16 13:33 ` Jean Delvare
2016-12-17 10:57 ` Dave Young
2019-09-06 19:00 ` Andy Shevchenko
2020-01-20 12:19 ` Andy Shevchenko
2020-01-20 16:04 ` Eric W. Biederman
2020-01-20 21:42 ` Jean Delvare
2020-01-20 21:55 ` Andy Shevchenko
2020-01-21 9:03 ` Jean Delvare
2020-01-21 16:29 ` Eric W. Biederman [this message]
2020-01-21 17:24 ` Andy Shevchenko
2020-01-20 22:31 ` Andy Shevchenko
2020-01-20 23:18 ` Ard Biesheuvel
2020-01-21 15:37 ` Andy Shevchenko
2020-01-21 17:17 ` Eric W. Biederman
2020-05-21 17:39 ` Andy Shevchenko
2021-06-02 8:37 ` Andy Shevchenko
2021-06-02 8:53 ` Andy Shevchenko
2016-12-17 10:50 ` Dave Young
2020-01-20 12:16 ` [PATCH v1 0/2] firmware: dmi_scan: Make it work in " Andy Shevchenko
2020-05-21 15:53 ` Andy Shevchenko
2020-05-21 15:59 ` Andy Shevchenko
2021-06-02 8:42 ` Andy Shevchenko
2021-06-02 8:53 ` Andy Shevchenko
2021-06-05 7:51 ` Dave Young
2021-06-07 16:22 ` Andy Shevchenko
2021-06-07 17:18 ` Andy Shevchenko
2021-06-08 12:25 ` Dave Young
2021-06-08 12:38 ` Andy Shevchenko
2021-06-09 11:55 ` Dave Young
2021-06-12 4:40 ` Dave Young
2021-06-14 15:38 ` Andy Shevchenko
2021-06-14 17:07 ` Andy Shevchenko
2021-06-14 17:27 ` Andy Shevchenko
2021-07-19 7:53 ` Ard Biesheuvel
2021-07-19 8:25 ` Andy Shevchenko
2021-10-06 16:28 ` Andy Shevchenko
2021-10-07 7:20 ` Ard Biesheuvel
2021-10-07 7:23 ` Andy Shevchenko
2021-10-17 13:31 ` Ard Biesheuvel
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=87zheg93io.fsf@x220.int.ebiederm.org \
--to=ebiederm@xmission.com \
--cc=andriy.shevchenko@linux.intel.com \
--cc=andy.shevchenko@gmail.com \
--cc=ard.biesheuvel@linaro.org \
--cc=dyoung@redhat.com \
--cc=jdelvare@suse.de \
--cc=kexec@lists.infradead.org \
--cc=linux-efi@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=matt@codeblueprint.co.uk \
--cc=mika.westerberg@linux.intel.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).