From: "H. Peter Anvin" <hpa@zytor.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@elte.hu>,
linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Jason Baron <jbaron@redhat.com>,
Frederic Weisbecker <fweisbec@gmail.com>
Subject: Re: [PATCH 0/5 v2] [GIT PULL] x86/jump label: Paranoid checks and 2 or 5 byte nops
Date: Thu, 02 Feb 2012 14:07:11 -0800 [thread overview]
Message-ID: <4F2B090F.5020609@zytor.com> (raw)
In-Reply-To: <1328220280.5882.122.camel@gandalf.stny.rr.com>
On 02/02/2012 02:04 PM, Steven Rostedt wrote:
> commit 7bbd9688727dd30cd44b90b3c9c35f0f66af77ff
> Author: Steven Rostedt<srostedt@redhat.com>
> Date: Thu Feb 2 16:55:43 2012 -0500
>
> x86/jump labels: Handle initialization of enabled nops
>
> When jump labels are initialized at boot up, they are compared
> to the default_nop before switching to the ideal nop.
>
> But if a jump label is enabled by default on start up, the
> enabled code does not test against the default nop, only the
> ideal nop. But as this jump label has not been converted to the
> ideal nop, it fails the check, and will crash the box.
>
> The enabled path needs to be aware of initialization too.
>
> Reported-by: Ingo Molnar<mingo@elte.hu>
> Signed-off-by: Steven Rostedt<rostedt@goodmis.org>
>
Would it make more sense to keep track of three states:
"Default"
"Enabled"
"Disabled"
-?
next prev parent reply other threads:[~2012-02-02 22:07 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-28 16:09 [PATCH 0/5 v2] [GIT PULL] x86/jump label: Paranoid checks and 2 or 5 byte nops Steven Rostedt
2012-01-28 16:09 ` [PATCH 1/5 v2] x86/jump-label: Use best default nops for inital jump label calls Steven Rostedt
2012-01-28 16:09 ` [PATCH 2/5 v2] x86/jump-label: Do not bother updating nops if they are correct Steven Rostedt
2012-01-28 16:09 ` [PATCH 3/5 v2] x86/jump-label: Add safety checks to jump label conversions Steven Rostedt
2012-01-28 16:09 ` [PATCH 4/5 v2] jump labels: Add infrastructure to update jump labels at compile time Steven Rostedt
2012-01-28 16:09 ` [PATCH 5/5 v2] x86/jump labels: Use etiher 5 byte or 2 byte jumps Steven Rostedt
2012-01-30 14:48 ` [PATCH 0/5 v2] [GIT PULL] x86/jump label: Paranoid checks and 2 or 5 byte nops Ingo Molnar
2012-01-30 15:07 ` Steven Rostedt
2012-01-31 19:48 ` Ingo Molnar
2012-02-01 5:08 ` Steven Rostedt
2012-02-01 8:05 ` Ingo Molnar
2012-02-01 13:20 ` Steven Rostedt
2012-02-01 15:21 ` Steven Rostedt
2012-02-02 13:51 ` Ingo Molnar
2012-02-02 14:10 ` H. Peter Anvin
2012-02-02 14:31 ` Steven Rostedt
2012-02-02 22:04 ` Steven Rostedt
2012-02-02 22:07 ` H. Peter Anvin [this message]
2012-02-02 22:53 ` Steven Rostedt
2012-02-03 7:36 ` Ingo Molnar
2012-02-03 13:31 ` Steven Rostedt
2012-02-05 11:47 ` Ingo Molnar
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