From: Ingo Molnar <mingo@kernel.org>
To: Baoquan He <bhe@redhat.com>
Cc: linux-kernel@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>
Subject: Re: [PATCH] x86/boot/KASLR: Skip relocation handling in no kaslr case
Date: Mon, 26 Jun 2017 11:47:38 +0200 [thread overview]
Message-ID: <20170626094737.d2pzetkhe2sorn6m@gmail.com> (raw)
In-Reply-To: <1498314309-18502-1-git-send-email-bhe@redhat.com>
* Baoquan He <bhe@redhat.com> wrote:
> Kdump kernel will reset to firmware after crash is trigered when
> crashkernel=xxM,high is added to kernel command line. Kexec has the
> same phenomenon. This only happened on system with kaslr code
> compiled in and kernel option 'nokaslr'is added. Both of them works
> well when kaslr is enabled.
>
> When crashkernel high is set or kexec case, kexec/kdump kernel will be
> put above 4G. Since we assign the original loading address of kernel to
> virt_addr as initial value, the virt_addr will be larger than 1G if kaslr
> is disabled, it exceeds the kernel mapping size which is only 1G. Then
> it will cause relocation handling error in handle_relocations().
So instead of whacking yet another kexec mole, how could we turn this into a more
debuggable warning (either during build or during the failed bootup) instead of a
crash and reset (triple fault?) back to the BIOS screen?
If kexec/kdump wants to do crazy things they should at least be _debuggable_ in a
straightforward manner.
Thanks,
Ingo
next parent reply other threads:[~2017-06-26 9:47 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1498314309-18502-1-git-send-email-bhe@redhat.com>
2017-06-26 9:47 ` Ingo Molnar [this message]
2017-06-26 10:43 ` Baoquan He
2017-06-27 8:34 ` Ingo Molnar
2017-06-27 8:55 ` Baoquan He
2017-06-27 22:42 ` Kees Cook
2017-06-27 23:24 ` Baoquan He
2017-06-27 23:33 ` Baoquan He
2017-07-05 19:06 ` Kees Cook
2017-07-06 13:28 ` Baoquan He
2017-07-06 13:54 ` Baoquan He
2017-06-24 14:16 Baoquan He
2017-06-24 14:23 ` Baoquan He
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=20170626094737.d2pzetkhe2sorn6m@gmail.com \
--to=mingo@kernel.org \
--cc=bhe@redhat.com \
--cc=hpa@zytor.com \
--cc=linux-kernel@vger.kernel.org \
--cc=tglx@linutronix.de \
/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®