x86, cpu, amd: Add workaround for family 16h, erratum 793

[pandora-kernel.git] / arch / x86 / kernel / cpu / amd.c

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index bca023b..59bfebc 100644 (file)
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -508,6 +508,16 @@ 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[];