On Tue, Jan 14, 2014 at 04:38:27PM -0800, H. Peter Anvin wrote:
> In file included from
> /home/hpa/kernel/distwork/arch/x86/include/asm/processor.h:20:0,
Finnish!
Well, Boris the dumbass forgot to amend, changes were still in the index
but not committed. This is what I get when I do a couple of things at
the same time. :(
---
From: Borislav Petkov <b...@suse.de>
This adds the workaround for erratum 793 as a precaution in case not
every BIOS implements it. This addresses CVE-2013-6885.
Signed-off-by: Borislav Petkov <b...@suse.de>
Tested-by: Aravind Gopalakrishnan <aravind.gopalakrish...@amd.com>
---
arch/x86/include/uapi/asm/msr-index.h | 1 +
arch/x86/kernel/cpu/amd.c | 10 ++++++++++
2 files changed, 11 insertions(+)
diff --git a/arch/x86/include/uapi/asm/msr-index.h
b/arch/x86/include/uapi/asm/msr-index.h
index 37813b5ddc37..59cea185ad1d 100644
--- a/arch/x86/include/uapi/asm/msr-index.h
+++ b/arch/x86/include/uapi/asm/msr-index.h
@@ -184,6 +184,7 @@
#define MSR_AMD64_PATCH_LOADER 0xc0010020
#define MSR_AMD64_OSVW_ID_LENGTH 0xc0010140
#define MSR_AMD64_OSVW_STATUS 0xc0010141
+#define MSR_AMD64_LS_CFG 0xc0011020
#define MSR_AMD64_DC_CFG 0xc0011022
#define MSR_AMD64_BU_CFG2 0xc001102a
#define MSR_AMD64_IBSFETCHCTL 0xc0011030
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 4a48e8bbd857..6ac3a67ad471 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -507,6 +507,16 @@ static void early_init_amd(struct cpuinfo_x86 *c)
set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
}
#endif
+
+ /* F16h erratum 793, CVE-2013-6885 */
+ 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));
+ }
+
}
static const int amd_erratum_383[];
--
1.8.5.2.192.g7794a68
--
Regards/Gruss,
Boris.
Sent from a fat crate under my desk. Formatting is fine.
--
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