lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Tue,  7 Jul 2015 11:23:25 -0700
From:	Kamal Mostafa <kamal@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	Radim Krčmář <rkrcmar@...hat.com>,
	Marcelo Tosatti <mtosatti@...hat.com>,
	Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 3.19.y-ckt 095/102] KVM: x86: fix lapic.timer_mode on restore

3.19.8-ckt3 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= <rkrcmar@...hat.com>

commit b6ac069532218027f2991cba01d7a72a200688b0 upstream.

lapic.timer_mode was not properly initialized after migration, which
broke few useful things, like login, by making every sleep eternal.

Fix this by calling apic_update_lvtt in kvm_apic_post_state_restore.

There are other slowpaths that update lvtt, so this patch makes sure
something similar doesn't happen again by calling apic_update_lvtt
after every modification.

Fixes: f30ebc312ca9 ("KVM: x86: optimize some accesses to LVTT and SPIV")
Signed-off-by: Radim Krčmář <rkrcmar@...hat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@...hat.com>
Signed-off-by: Kamal Mostafa <kamal@...onical.com>
---
 arch/x86/kvm/lapic.c | 26 ++++++++++++++++----------
 1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index d52dcf0..5ee4e1f 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -1072,6 +1072,17 @@ static void update_divide_count(struct kvm_lapic *apic)
 				   apic->divide_count);
 }
 
+static void apic_update_lvtt(struct kvm_lapic *apic)
+{
+	u32 timer_mode = kvm_apic_get_reg(apic, APIC_LVTT) &
+			apic->lapic_timer.timer_mode_mask;
+
+	if (apic->lapic_timer.timer_mode != timer_mode) {
+		apic->lapic_timer.timer_mode = timer_mode;
+		hrtimer_cancel(&apic->lapic_timer.timer);
+	}
+}
+
 static void apic_timer_expired(struct kvm_lapic *apic)
 {
 	struct kvm_vcpu *vcpu = apic->vcpu;
@@ -1230,6 +1241,7 @@ static int apic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val)
 				apic_set_reg(apic, APIC_LVTT + 0x10 * i,
 					     lvt_val | APIC_LVT_MASKED);
 			}
+			apic_update_lvtt(apic);
 			atomic_set(&apic->lapic_timer.pending, 0);
 
 		}
@@ -1262,20 +1274,13 @@ static int apic_reg_write(struct kvm_lapic *apic, u32 reg, u32 val)
 
 		break;
 
-	case APIC_LVTT: {
-		u32 timer_mode = val & apic->lapic_timer.timer_mode_mask;
-
-		if (apic->lapic_timer.timer_mode != timer_mode) {
-			apic->lapic_timer.timer_mode = timer_mode;
-			hrtimer_cancel(&apic->lapic_timer.timer);
-		}
-
+	case APIC_LVTT:
 		if (!kvm_apic_sw_enabled(apic))
 			val |= APIC_LVT_MASKED;
 		val &= (apic_lvt_mask[0] | apic->lapic_timer.timer_mode_mask);
 		apic_set_reg(apic, APIC_LVTT, val);
+		apic_update_lvtt(apic);
 		break;
-	}
 
 	case APIC_TMICT:
 		if (apic_lvtt_tscdeadline(apic))
@@ -1510,7 +1515,7 @@ void kvm_lapic_reset(struct kvm_vcpu *vcpu)
 
 	for (i = 0; i < APIC_LVT_NUM; i++)
 		apic_set_reg(apic, APIC_LVTT + 0x10 * i, APIC_LVT_MASKED);
-	apic->lapic_timer.timer_mode = 0;
+	apic_update_lvtt(apic);
 	apic_set_reg(apic, APIC_LVT0,
 		     SET_APIC_DELIVERY_MODE(0, APIC_MODE_EXTINT));
 
@@ -1736,6 +1741,7 @@ void kvm_apic_post_state_restore(struct kvm_vcpu *vcpu,
 
 	apic_update_ppr(apic);
 	hrtimer_cancel(&apic->lapic_timer.timer);
+	apic_update_lvtt(apic);
 	update_divide_count(apic);
 	start_apic_timer(apic);
 	apic->irr_pending = true;
-- 
1.9.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists