[PATCH 1/4] objtool: KVM: x86: Check kvm_rebooting in kvm_spurious_fault()

From: Sean Christopherson <sean.j.christopherson@intel.com>
To: "Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	"Josh Poimboeuf" <jpoimboe@redhat.com>,
	"Peter Zijlstra" <peterz@infradead.org>
Cc: kvm@vger.kernel.org
Subject: [PATCH 1/4] objtool: KVM: x86: Check kvm_rebooting in kvm_spurious_fault()
Date: Fri, 19 Jul 2019 10:25:37 -0700	[thread overview]
Message-ID: <20190719172540.7697-2-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20190719172540.7697-1-sean.j.christopherson@intel.com>

Explicitly check kvm_reboot in kvm_spurious_fault() prior to invoking
BUG(), as opposed to assuming the caller has already done so.  Letting
kvm_spurious_fault() be called "directly" will allow VMX to better
optimize its low level assembly flows.

As a happy side effect, kvm_spurious_fault() no longer needs to be
marked as a dead end since it doesn't unconditionally BUG().

Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/x86.c    | 3 ++-
 tools/objtool/check.c | 1 -
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9d7b9e6a0939..7bbfed3877bd 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -356,7 +356,8 @@ EXPORT_SYMBOL_GPL(kvm_set_apic_base);
 asmlinkage __visible void kvm_spurious_fault(void)
 {
 	/* Fault while not rebooting.  We want the trace. */
-	BUG();
+	if (!kvm_rebooting)
+		BUG();
 }
 EXPORT_SYMBOL_GPL(kvm_spurious_fault);
 
diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 172f99195726..bc3b405acce9 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -127,7 +127,6 @@ static int __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"do_task_dead",
 		"__module_put_and_exit",
 		"complete_and_exit",
-		"kvm_spurious_fault",
 		"__reiserfs_panic",
 		"lbug_with_loc",
 		"fortify_panic",
-- 
2.22.0

