linux-kernel - [PATCH 3.13.y-ckt 090/122] Drivers: hv: vmbus: Add support for VMBus panic notifier handler

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]

Message-Id: <1434580149-3095-91-git-send-email-kamal@canonical.com>
Date:	Wed, 17 Jun 2015 15:28:37 -0700
From:	Kamal Mostafa <kamal@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	Nick Meier <nmeier@...rosoft.com>,
	"K. Y. Srinivasan" <kys@...rosoft.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Joseph Salisbury <joseph.salisbury@...onical.com>,
	Kamal Mostafa <kamal@...onical.com>
Subject: [PATCH 3.13.y-ckt 090/122] Drivers: hv: vmbus: Add support for VMBus panic notifier handler

3.13.11-ckt22 -stable review patch.  If anyone has any objections, please let me know.

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

From: Nick Meier <nmeier@...rosoft.com>

commit 96c1d0581d00f7abe033350edb021a9d947d8d81 upstream.

BugLink: http://bugs.launchpad.net/bugs/1463584

Hyper-V allows a guest to notify the Hyper-V host that a panic
condition occured.  This notification can include up to five 64
bit values.  These 64 bit values are written into crash MSRs.
Once the data has been written into the crash MSRs, the host is
then notified by writing into a Crash Control MSR.  On the Hyper-V
host, the panic notification data is captured in the Windows Event
log as a 18590 event.

Crash MSRs are defined in appendix H of the Hypervisor Top Level
Functional Specification.  At the time of this patch, v4.0 is the
current functional spec.  The URL for the v4.0 document is:

http://download.microsoft.com/download/A/B/4/AB43A34E-BDD0-4FA6-BDEF-79EEF16E880B/Hypervisor Top Level Functional Specification v4.0.docx

Signed-off-by: Nick Meier <nmeier@...rosoft.com>
Signed-off-by: K. Y. Srinivasan <kys@...rosoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
(backported from commit 96c1d0581d00f7abe033350edb021a9d947d8d81)
Signed-off-by: Joseph Salisbury <joseph.salisbury@...onical.com>
Signed-off-by: Kamal Mostafa <kamal@...onical.com>
---
 drivers/hv/hyperv_vmbus.h | 11 +++++++++++
 drivers/hv/vmbus_drv.c    | 40 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+)

diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 9fa0cab..7a68d28a 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -49,6 +49,17 @@ enum hv_cpuid_function {
 	HVCPUID_IMPLEMENTATION_LIMITS		= 0x40000005,
 };
 
+#define  HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE   0x400
+
+#define HV_X64_MSR_CRASH_P0   0x40000100
+#define HV_X64_MSR_CRASH_P1   0x40000101
+#define HV_X64_MSR_CRASH_P2   0x40000102
+#define HV_X64_MSR_CRASH_P3   0x40000103
+#define HV_X64_MSR_CRASH_P4   0x40000104
+#define HV_X64_MSR_CRASH_CTL  0x40000105
+
+#define HV_CRASH_CTL_CRASH_NOTIFY 0x8000000000000000
+
 /* Define version of the synthetic interrupt controller. */
 #define HV_SYNIC_VERSION		(1)
 
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
index 48aad4f..4b3d72a 100644
--- a/drivers/hv/vmbus_drv.c
+++ b/drivers/hv/vmbus_drv.c
@@ -37,6 +37,8 @@
 #include <asm/hyperv.h>
 #include <asm/hypervisor.h>
 #include <asm/mshyperv.h>
+#include <linux/notifier.h>
+#include <linux/ptrace.h>
 #include "hyperv_vmbus.h"
 
 
@@ -46,6 +48,36 @@ static struct tasklet_struct msg_dpc;
 static struct completion probe_event;
 static int irq;
 
+int hyperv_panic_event(struct notifier_block *nb,
+			unsigned long event, void *ptr)
+{
+	struct pt_regs *regs;
+
+	regs = current_pt_regs();
+
+	wrmsrl(HV_X64_MSR_CRASH_P0, regs->ip);
+	wrmsrl(HV_X64_MSR_CRASH_P1, regs->ax);
+	wrmsrl(HV_X64_MSR_CRASH_P2, regs->bx);
+	wrmsrl(HV_X64_MSR_CRASH_P3, regs->cx);
+	wrmsrl(HV_X64_MSR_CRASH_P4, regs->dx);
+
+	/*
+	 * Let Hyper-V know there is crash data available
+	 */
+	wrmsrl(HV_X64_MSR_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY);
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block hyperv_panic_block = {
+	.notifier_call = hyperv_panic_event,
+};
+
+struct resource hyperv_mmio = {
+	.name  = "hyperv mmio",
+	.flags = IORESOURCE_MEM,
+};
+EXPORT_SYMBOL_GPL(hyperv_mmio);
+
 static int vmbus_exists(void)
 {
 	if (hv_acpi_dev == NULL)
@@ -749,6 +781,14 @@ static int vmbus_bus_init(int irq)
 	if (ret)
 		goto err_alloc;
 
+	/*
+	 * Only register if the crash MSRs are available
+	 */
+	if (ms_hyperv.features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) {
+		atomic_notifier_chain_register(&panic_notifier_list,
+					       &hyperv_panic_block);
+	}
+
 	vmbus_request_offers();
 
 	return 0;
-- 
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/