LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Roland McGrath <roland@redhat.com>
To: "Jan Beulich" <jbeulich@novell.com>
Cc: "Ingo Molnar" <mingo@elte.hu>, <markus.t.metzger@intel.com>,
	<tglx@linutronix.de>, <linux-kernel@vger.kernel.org>,
	<hpa@zytor.com>
Subject: Re: [PATCH] x86: fix typo(?) in step.c
Date: Mon, 10 Mar 2008 20:44:08 -0700 (PDT)	[thread overview]
Message-ID: <20080311034408.4F1A226F991@magilla.localdomain> (raw)
In-Reply-To: Jan Beulich's message of  Monday, 10 March 2008 11:53:19 +0000 <47D52F3F.76E4.0078.0@novell.com>

> So, is this going to be fully reverted, or is it worth pointing out/fixing
> other issues? The thing I'm recognizing right now is that
> eee3af4a2c83a97fff107ddc445d9df6fded9ce4 made the writes to
> DebugCtlMSR unconditional, which means any attempt to do
> debugging on i[345]86 will ultimately cause the kernel to oops. All of
> that stuff should really depend on CONFIG_X86_DEBUGCTLMSR...

I think it would be wise to excise all the BTS-related additions until
after 2.6.25.  But I am too swamped already and not planning to do
anything about this myself.  But, that said, FWIW it does not look to
me like debugctlmsr will ever be written on hardware that doesn't
support it.  The stores are all only enabled if TIF_DEBUGCTLMSR gets
set and thread.debugctlmsr is nonzero.  That can't be set by ptrace
unless arch_has_block_step() returns true.


Thanks,
Roland

  reply	other threads:[~2008-03-11  3:44 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-03-05  8:36 Jan Beulich
2008-03-05 13:41 ` Ingo Molnar
2008-03-06  7:52   ` Roland McGrath
2008-03-06 11:28     ` Ingo Molnar
2008-03-06 12:03       ` Roland McGrath
2008-03-06 13:11         ` Ingo Molnar
2008-03-10 11:53           ` Jan Beulich
2008-03-11  3:44             ` Roland McGrath [this message]
2008-03-06 11:34     ` Ingo Molnar
2008-03-06 12:16       ` Roland McGrath
2008-03-06 13:13         ` Ingo Molnar

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=20080311034408.4F1A226F991@magilla.localdomain \
    --to=roland@redhat.com \
    --cc=hpa@zytor.com \
    --cc=jbeulich@novell.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=markus.t.metzger@intel.com \
    --cc=mingo@elte.hu \
    --cc=tglx@linutronix.de \
    --subject='Re: [PATCH] x86: fix typo(?) in step.c' \
    /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

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).