[PATCH v1 04/12] x86/mce: Remove noinstr annotation from mce_setup()

From: Borislav Petkov
Date: Wed Dec 08 2021 - 06:13:55 EST


From: Borislav Petkov <bp@xxxxxxx>

Instead, sandwitch around the call which is done in noinstr context and
mark the caller - mce_gather_info() - as noinstr.

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
---
arch/x86/kernel/cpu/mce/core.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 87a277fc80b4..f61f14faa532 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -127,7 +127,7 @@ static struct irq_work mce_irq_work;
BLOCKING_NOTIFIER_HEAD(x86_mce_decoder_chain);

/* Do initial initialization of a struct mce */
-noinstr void mce_setup(struct mce *m)
+void mce_setup(struct mce *m)
{
memset(m, 0, sizeof(struct mce));
m->cpu = m->extcpu = smp_processor_id();
@@ -430,9 +430,15 @@ static noinstr void mce_wrmsrl(u32 msr, u64 v)
* check into our "mce" struct so that we can use it later to assess
* the severity of the problem as we read per-bank specific details.
*/
-static inline void mce_gather_info(struct mce *m, struct pt_regs *regs)
+static noinstr void mce_gather_info(struct mce *m, struct pt_regs *regs)
{
+ /*
+ * Enable instrumentation around mce_setup() which calls external
+ * facilities.
+ */
+ instrumentation_begin();
mce_setup(m);
+ instrumentation_end();

m->mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS);
if (regs) {
--
2.29.2