From 4fbce464db81a42f9a57ee242d6150ec7f996415 Mon Sep 17 00:00:00 2001
From: Borislav Petkov <bp@suse.de>
Date: Wed, 13 Oct 2021 09:07:19 +0200
Subject: [PATCH] x86/mce: Allow instrumentation during task work queueing
Fixes
vmlinux.o: warning: objtool: do_machine_check()+0xdb1: call to queue_task_work() leaves .noinstr.text section
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20211208111343.8130-6-bp@alien8.de
---
arch/x86/kernel/cpu/mce/core.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index c11fc8d6a4c55..d788ccc5a35f9 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1459,6 +1459,14 @@ noinstr void do_machine_check(struct pt_regs *regs)
if (worst != MCE_AR_SEVERITY && !kill_current_task)
goto out;
+ /*
+ * Enable instrumentation around the external facilities like
+ * task_work_add() (via queue_task_work()), fixup_exception() etc.
+ * For now, that is. Fixing this properly would need a lot more involved
+ * reorganization.
+ */
+ instrumentation_begin();
+
/* Fault was in user mode and we need to take some action */
if ((m.cs & 3) == 3) {
/* If this triggers there is no way to recover. Die hard. */
@@ -1487,6 +1495,9 @@ noinstr void do_machine_check(struct pt_regs *regs)
if (m.kflags & MCE_IN_KERNEL_COPYIN)
queue_task_work(&m, msg, kill_me_never);
}
+
+ instrumentation_end();
+
out:
mce_wrmsrl(MSR_IA32_MCG_STATUS, 0);
}
--
2.30.2