[kernel] r22253 - dists/wheezy-security/linux/debian/patches/bugfix/x86

[Ben Hutchings]

Author: benh
Date: Mon Jan 12 05:49:17 2015
New Revision: 22253

Log:
Change CVE-2013-6885 fix to (probably) work in KVM, thanks to Venkatesh Srinivas

Modified:
   dists/wheezy-security/linux/debian/patches/bugfix/x86/x86-cpu-amd-add-workaround-for-family-16h-erratum-79.patch

Modified: dists/wheezy-security/linux/debian/patches/bugfix/x86/x86-cpu-amd-add-workaround-for-family-16h-erratum-79.patch
==============================================================================
--- dists/wheezy-security/linux/debian/patches/bugfix/x86/x86-cpu-amd-add-workaround-for-family-16h-erratum-79.patch	Mon Jan 12 05:35:21 2015	(r22252)
+++ dists/wheezy-security/linux/debian/patches/bugfix/x86/x86-cpu-amd-add-workaround-for-family-16h-erratum-79.patch	Mon Jan 12 05:49:17 2015	(r22253)
@@ -40,7 +40,12 @@
 Link: http://lkml.kernel.org/r/20140114230711.GS29865@pd.tnic
 Tested-by: Aravind Gopalakrishnan <aravind.gopalakrishnan at amd.com>
 Signed-off-by: H. Peter Anvin <hpa at linux.intel.com>
-[bwh: Backported to 3.2: adjust filename]
+[bwh: Backported to 3.2:
+ - Adjust filename
+ - Venkatesh Srinivas pointed out we should use {rd,wr}msrl_safe() to
+   avoid crashing on KVM.  This was fixed upstream by commit 8f86a7373a1c
+   ("x86, AMD: Convert to the new bit access MSR accessors") but that's too
+   much trouble to backport.]
 ---
  arch/x86/include/asm/msr-index.h |  1 +
  arch/x86/kernel/cpu/amd.c             | 10 ++++++++++
@@ -67,9 +72,9 @@
 +	if (c->x86 == 0x16 && c->x86_model <= 0xf) {
 +		u64 val;
 +
-+		rdmsrl(MSR_AMD64_LS_CFG, val);
-+		if (!(val & BIT(15)))
-+			wrmsrl(MSR_AMD64_LS_CFG, val | BIT(15));
++		if (!rdmsrl_safe(MSR_AMD64_LS_CFG, &val) &&
++		    !(val & BIT(15)))
++			wrmsrl_safe(MSR_AMD64_LS_CFG, val | BIT(15));
 +	}
 +
  }