From: Mike Galbraith <efault@gmx.de>
To: Will Deacon <will@kernel.org>
Cc: lkml <linux-kernel@vger.kernel.org>, Mark Rutland <mark.rutland@arm.com>
Subject: Re: arm64: perf test 26 rpi4 oops
Date: Sun, 30 Jul 2023 18:09:15 +0200 [thread overview]
Message-ID: <8c56256399e2e6c41bc574749d6170d5529f24fc.camel@gmx.de> (raw)
In-Reply-To: <20230728141852.GA21718@willie-the-truck>
On Fri, 2023-07-28 at 15:18 +0100, Will Deacon wrote:
>
> Looking at this quickly with Mark, the most likely explanation is that
> a bogus kernel address is being passed as the source pointer to
> copy_to_user().
'start' in read_kcore_iter() is bogus a LOT when running perf test 26,
and that back to at least 5.15. Seems removal of bogon-proofing gave a
toothless old bug teeth, but seemingly only to perf test 26. Rummaging
around with crash vmlinux /proc/kcore seems to be bogon free anyway.
Someone should perhaps take a peek at perf. Bogons aside, it also
doesn't seem to care deeply about kernel response. Whether the kernel
oops or I bat 945 bogons aside, it says 'OK'. That seems a tad odd.
-Mike
next prev parent reply other threads:[~2023-07-30 16:13 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-28 4:06 Mike Galbraith
2023-07-28 14:18 ` Will Deacon
2023-07-28 15:12 ` Mike Galbraith
2023-07-28 15:23 ` Will Deacon
2023-07-28 16:35 ` Mike Galbraith
2023-07-29 16:30 ` Mike Galbraith
2023-07-30 5:54 ` Mike Galbraith
2023-07-30 11:01 ` Mike Galbraith
2023-07-30 16:09 ` Mike Galbraith [this message]
2023-07-31 10:43 ` Will Deacon
2023-07-31 11:37 ` Mike Galbraith
2023-07-31 11:52 ` Will Deacon
2023-07-31 16:07 ` Mike Galbraith
2023-07-31 21:08 ` Lorenzo Stoakes
2023-07-31 21:54 ` Lorenzo Stoakes
2023-07-31 23:27 ` Mike Galbraith
2023-07-31 23:48 ` Mike Galbraith
2023-08-01 0:33 ` Mike Galbraith
2023-08-01 4:34 ` Mike Galbraith
2023-08-01 7:27 ` Will Deacon
2023-08-01 8:39 ` Mike Galbraith
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=8c56256399e2e6c41bc574749d6170d5529f24fc.camel@gmx.de \
--to=efault@gmx.de \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=will@kernel.org \
/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
all inboxes | Powered by JetHome®