[tip: ras/core] x86/mce: Mark mce_timed_out() noinstr

[tip-bot2 for Borislav Petkov]

The following commit has been merged into the ras/core branch of tip:

Commit-ID:     edb3d07e2403abd13fc664e8b6f23ea7efb52747
Gitweb:        https://git.kernel.org/tip/edb3d07e2403abd13fc664e8b6f23ea7efb52747
Author:        Borislav Petkov <bp@xxxxxxx>
AuthorDate:    Tue, 02 Nov 2021 22:25:12 +01:00
Committer:     Borislav Petkov <bp@xxxxxxx>
CommitterDate: Mon, 13 Dec 2021 14:13:54 +01:00

x86/mce: Mark mce_timed_out() noinstr

Fixes

  vmlinux.o: warning: objtool: do_machine_check()+0x482: call to mce_timed_out() leaves .noinstr.text section

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Link: https://lore.kernel.org/r/20211208111343.8130-12-bp@xxxxxxxxx
---
 arch/x86/kernel/cpu/mce/core.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 044c94b..7023d65 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -883,8 +883,13 @@ static cpumask_t mce_missing_cpus = CPU_MASK_ALL;
 /*
  * Check if a timeout waiting for other CPUs happened.
  */
-static int mce_timed_out(u64 *t, const char *msg)
+static noinstr int mce_timed_out(u64 *t, const char *msg)
 {
+	int ret = 0;
+
+	/* Enable instrumentation around calls to external facilities */
+	instrumentation_begin();
+
 	/*
 	 * The others already did panic for some reason.
 	 * Bail out like in a timeout.
@@ -903,12 +908,17 @@ static int mce_timed_out(u64 *t, const char *msg)
 					 cpumask_pr_args(&mce_missing_cpus));
 			mce_panic(msg, NULL, NULL);
 		}
-		return 1;
+		ret = 1;
+		goto out;
 	}
 	*t -= SPINUNIT;
+
 out:
 	touch_nmi_watchdog();
-	return 0;
+
+	instrumentation_end();
+
+	return ret;
 }
 
 /*