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Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
-rw-r--r--arch/x86/kernel/cpu/common.c38
1 files changed, 23 insertions, 15 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 8feb8fd2957a..fb50c1dd53ef 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1233,6 +1233,8 @@ static const __initconst struct x86_cpu_id cpu_vuln_whitelist[] = {
#define ITS BIT(8)
/* CPU is affected by Indirect Target Selection, but guest-host isolation is not affected */
#define ITS_NATIVE_ONLY BIT(9)
+/* CPU is affected by Transient Scheduler Attacks */
+#define TSA BIT(10)
static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = {
VULNBL_INTEL_STEPS(INTEL_IVYBRIDGE, X86_STEP_MAX, SRBDS),
@@ -1280,7 +1282,7 @@ static const struct x86_cpu_id cpu_vuln_blacklist[] __initconst = {
VULNBL_AMD(0x16, RETBLEED),
VULNBL_AMD(0x17, RETBLEED | SMT_RSB | SRSO),
VULNBL_HYGON(0x18, RETBLEED | SMT_RSB | SRSO),
- VULNBL_AMD(0x19, SRSO),
+ VULNBL_AMD(0x19, SRSO | TSA),
VULNBL_AMD(0x1a, SRSO),
{}
};
@@ -1530,6 +1532,16 @@ static void __init cpu_set_bug_bits(struct cpuinfo_x86 *c)
setup_force_cpu_bug(X86_BUG_ITS_NATIVE_ONLY);
}
+ if (c->x86_vendor == X86_VENDOR_AMD) {
+ if (!cpu_has(c, X86_FEATURE_TSA_SQ_NO) ||
+ !cpu_has(c, X86_FEATURE_TSA_L1_NO)) {
+ if (cpu_matches(cpu_vuln_blacklist, TSA) ||
+ /* Enable bug on Zen guests to allow for live migration. */
+ (cpu_has(c, X86_FEATURE_HYPERVISOR) && cpu_has(c, X86_FEATURE_ZEN)))
+ setup_force_cpu_bug(X86_BUG_TSA);
+ }
+ }
+
if (cpu_matches(cpu_vuln_whitelist, NO_MELTDOWN))
return;
@@ -2243,20 +2255,16 @@ EXPORT_PER_CPU_SYMBOL(__stack_chk_guard);
#endif
#endif
-/*
- * Clear all 6 debug registers:
- */
-static void clear_all_debug_regs(void)
+static void initialize_debug_regs(void)
{
- int i;
-
- for (i = 0; i < 8; i++) {
- /* Ignore db4, db5 */
- if ((i == 4) || (i == 5))
- continue;
-
- set_debugreg(0, i);
- }
+ /* Control register first -- to make sure everything is disabled. */
+ set_debugreg(DR7_FIXED_1, 7);
+ set_debugreg(DR6_RESERVED, 6);
+ /* dr5 and dr4 don't exist */
+ set_debugreg(0, 3);
+ set_debugreg(0, 2);
+ set_debugreg(0, 1);
+ set_debugreg(0, 0);
}
#ifdef CONFIG_KGDB
@@ -2417,7 +2425,7 @@ void cpu_init(void)
load_mm_ldt(&init_mm);
- clear_all_debug_regs();
+ initialize_debug_regs();
dbg_restore_debug_regs();
doublefault_init_cpu_tss();