From: Ingo Molnar <mingo@elte.hu>
Date: Wed, 15 Apr 2009 21:15:14 +0000 (+0200)
Subject: x86: disable X86_PTRACE_BTS for now
X-Git-Tag: v2.6.29.2~24
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0857bb06065b5c5a51d205c4c04ec1202e27d399;p=thirdparty%2Fkernel%2Fstable.git

x86: disable X86_PTRACE_BTS for now

upstream commit: d45b41ae8da0f54aec0eebcc6f893ba5f22a1e8e

Oleg Nesterov found a couple of races in the ptrace-bts code
and fixes are queued up for it but they did not get ready in time
for the merge window. We'll merge them in v2.6.31 - until then
mark the feature as CONFIG_BROKEN. There's no user-space yet
making use of this so it's not a big issue.

Cc: <stable@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
[chrisw: trivial 2.6.29 backport]
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
---

diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index c98d52e82966f..6ed3aca7dd414 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -523,6 +523,7 @@ config X86_PTRACE_BTS
 	bool "Branch Trace Store"
 	default y
 	depends on X86_DEBUGCTLMSR
+	depends on BROKEN
 	help
 	  This adds a ptrace interface to the hardware's branch trace store.