From: walter harms <wharms@bfs.de>
To: Andi Kleen <ak@linux.intel.com>
Cc: Vasiliy Kulikov <segooon@gmail.com>,
kernel-janitors@vger.kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>,
Borislav Petkov <borislav.petkov@amd.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 04/10] x86: mce: fix error handling
Date: Thu, 29 Jul 2010 10:10:20 +0000 [thread overview]
Message-ID: <4C51538C.1090803@bfs.de> (raw)
In-Reply-To: <4C514F04.80603@linux.intel.com>
Andi Kleen schrieb:
>
>> IMO memmory allocation fails are dangerous in kernel mode. As it is
>> probably not exploitable because of boot time, it can destroy some
>> sensitive data like dirty disk caches those are going to be written on
>> disk.
>
> It's true for runtime, but not for normal boot time.
>
> Anyways if it happens on boot time the only thing you can do is panic,
> but someone else
> will likely panic anyways for you. Just ignoring it like your patch
> effectively does
> (because nothing will ever look at the ENOMEMs for an initcall) is wrong
> though
> In this case it's actually better to oops like the original code does.
>
> BTW even with your patch likely later code will crash anyways because it
> doesn't
> expect init code to fail.
>
NTL it is nice to have a error message. for users it is worse if you crash suddenly
with out warning than having a crash with "OOM" before because it gives you a clue
what is going on.
short:
please think of users that are not kernel developers give them a hint what went wrong.
to make thinks more easy on boot we could replace kalloc() with kmalloc_or_die().
When anyone runs out of mem on boottime you can panic() instantly.
just my to cents,
wh
next prev parent reply other threads:[~2010-07-29 10:10 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-28 16:39 [PATCH 04/10] x86: mce: fix error handling Kulikov Vasiliy
2010-07-28 16:48 ` Borislav Petkov
2010-07-28 17:07 ` Andi Kleen
2010-07-28 17:13 ` Vasiliy Kulikov
2010-07-28 17:20 ` Andi Kleen
2010-07-29 9:35 ` Vasiliy Kulikov
2010-07-29 9:51 ` Andi Kleen
2010-07-29 10:10 ` walter harms [this message]
2010-07-31 18:18 ` Vasiliy Kulikov
2010-07-31 19:07 ` Vasiliy Kulikov
2010-07-29 10:16 ` Borislav Petkov
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=4C51538C.1090803@bfs.de \
--to=wharms@bfs.de \
--cc=ak@linux.intel.com \
--cc=borislav.petkov@amd.com \
--cc=hpa@zytor.com \
--cc=kernel-janitors@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=segooon@gmail.com \
--cc=seto.hidetoshi@jp.fujitsu.com \
--cc=tglx@linutronix.de \
--cc=x86@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;
as well as URLs for NNTP newsgroup(s).