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-rw-r--r--arch/x86/coco/sev/svsm.c10
-rw-r--r--arch/x86/kernel/cpu/mce/core.c27
2 files changed, 18 insertions, 19 deletions
diff --git a/arch/x86/coco/sev/svsm.c b/arch/x86/coco/sev/svsm.c
index 916d62cd1..2d493d55f 100644
--- a/arch/x86/coco/sev/svsm.c
+++ b/arch/x86/coco/sev/svsm.c
@@ -74,6 +74,14 @@ int svsm_perform_call_protocol(struct svsm_call *call)
flags = native_local_irq_save();
+ /*
+ * 'caa' is a per-CPU variable. To avoid using a stale or incorrect
+ * 'caa' if the task is preempted or migrated to another CPU after it
+ * is fetched, always fetch 'caa' and then issue the SVSM call with
+ * interrupts disabled. This ensures the correct 'caa' is used.
+ */
+ call->caa = svsm_get_caa();
+
ghcb = __sev_get_ghcb(&state);
do {
@@ -321,7 +329,6 @@ int snp_svsm_vtpm_send_command(u8 *buffer)
{
struct svsm_call call = {};
- call.caa = svsm_get_caa();
call.rax = SVSM_VTPM_CALL(SVSM_VTPM_CMD);
call.rcx = __pa(buffer);
@@ -345,7 +352,6 @@ bool snp_svsm_vtpm_probe(void)
if (!snp_vmpl)
return false;
- call.caa = svsm_get_caa();
call.rax = SVSM_VTPM_CALL(SVSM_VTPM_QUERY);
if (svsm_perform_call_protocol(&call))
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index ab469605f..39f238952 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -2108,6 +2108,9 @@ bool filter_mce(struct mce *m)
static __always_inline void exc_machine_check_kernel(struct pt_regs *regs)
{
irqentry_state_t irq_state;
+ unsigned long dr7;
+
+ dr7 = local_db_save();
WARN_ON_ONCE(user_mode(regs));
@@ -2116,20 +2119,26 @@ static __always_inline void exc_machine_check_kernel(struct pt_regs *regs)
* mce_check_crashing_cpu() for details.
*/
if (mca_cfg.initialized && mce_check_crashing_cpu())
- return;
+ goto out;
irq_state = irqentry_nmi_enter(regs);
do_machine_check(regs);
irqentry_nmi_exit(regs, irq_state);
+out:
+ local_db_restore(dr7);
}
static __always_inline void exc_machine_check_user(struct pt_regs *regs)
{
+ unsigned long dr7;
+
irqentry_enter_from_user_mode(regs);
+ dr7 = local_db_save();
do_machine_check(regs);
+ local_db_restore(dr7);
irqentry_exit_to_user_mode(regs);
}
@@ -2138,21 +2147,13 @@ static __always_inline void exc_machine_check_user(struct pt_regs *regs)
/* MCE hit kernel mode */
DEFINE_IDTENTRY_MCE(exc_machine_check)
{
- unsigned long dr7;
-
- dr7 = local_db_save();
exc_machine_check_kernel(regs);
- local_db_restore(dr7);
}
/* The user mode variant. */
DEFINE_IDTENTRY_MCE_USER(exc_machine_check)
{
- unsigned long dr7;
-
- dr7 = local_db_save();
exc_machine_check_user(regs);
- local_db_restore(dr7);
}
#ifdef CONFIG_X86_FRED
@@ -2169,28 +2170,20 @@ DEFINE_IDTENTRY_MCE_USER(exc_machine_check)
*/
DEFINE_FREDENTRY_MCE(exc_machine_check)
{
- unsigned long dr7;
-
- dr7 = local_db_save();
if (user_mode(regs))
exc_machine_check_user(regs);
else
exc_machine_check_kernel(regs);
- local_db_restore(dr7);
}
#endif
#else
/* 32bit unified entry point */
DEFINE_IDTENTRY_RAW(exc_machine_check)
{
- unsigned long dr7;
-
- dr7 = local_db_save();
if (user_mode(regs))
exc_machine_check_user(regs);
else
exc_machine_check_kernel(regs);
- local_db_restore(dr7);
}
#endif