linux-kernel - [PATCH v0 04/12] x86/mce: Remove noinstr annotation from mce

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Date:   Thu,  4 Nov 2021 15:40:27 +0100
From:   Borislav Petkov <bp@...en8.de>
To:     Tony Luck <tony.luck@...el.com>
Cc:     X86 ML <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH v0 04/12] x86/mce: Remove noinstr annotation from mce_setup()

From: Borislav Petkov <bp@...e.de>

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@...e.de>
---
 arch/x86/kernel/cpu/mce/core.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index c660008ccd4a..c7181e8e2845 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -128,7 +128,7 @@ 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();
@@ -433,9 +433,11 @@ 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)
 {
+	instrumentation_begin();
 	mce_setup(m);
+	instrumentation_end();
 
 	m->mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS);
 	if (regs) {
-- 
2.29.2