Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 438 insertions, 0 deletions

diff --git a/drivers/input/serio/hyperv-keyboard.c b/drivers/input/serio/hyperv-keyboard.c
new file mode 100644
index 000000000..13434b933
--- /dev/null
+++ b/drivers/input/serio/hyperv-keyboard.c
@@ -0,0 +1,438 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  Copyright (c) 2013, Microsoft Corporation.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/completion.h>
+#include <linux/hyperv.h>
+#include <linux/serio.h>
+#include <linux/slab.h>
+
+/*
+ * Current version 1.0
+ *
+ */
+#define SYNTH_KBD_VERSION_MAJOR 1
+#define SYNTH_KBD_VERSION_MINOR	0
+#define SYNTH_KBD_VERSION		(SYNTH_KBD_VERSION_MINOR | \
+					 (SYNTH_KBD_VERSION_MAJOR << 16))
+
+
+/*
+ * Message types in the synthetic input protocol
+ */
+enum synth_kbd_msg_type {
+	SYNTH_KBD_PROTOCOL_REQUEST = 1,
+	SYNTH_KBD_PROTOCOL_RESPONSE = 2,
+	SYNTH_KBD_EVENT = 3,
+	SYNTH_KBD_LED_INDICATORS = 4,
+};
+
+/*
+ * Basic message structures.
+ */
+struct synth_kbd_msg_hdr {
+	__le32 type;
+};
+
+struct synth_kbd_msg {
+	struct synth_kbd_msg_hdr header;
+	char data[]; /* Enclosed message */
+};
+
+union synth_kbd_version {
+	__le32 version;
+};
+
+/*
+ * Protocol messages
+ */
+struct synth_kbd_protocol_request {
+	struct synth_kbd_msg_hdr header;
+	union synth_kbd_version version_requested;
+};
+
+#define PROTOCOL_ACCEPTED	BIT(0)
+struct synth_kbd_protocol_response {
+	struct synth_kbd_msg_hdr header;
+	__le32 proto_status;
+};
+
+#define IS_UNICODE	BIT(0)
+#define IS_BREAK	BIT(1)
+#define IS_E0		BIT(2)
+#define IS_E1		BIT(3)
+struct synth_kbd_keystroke {
+	struct synth_kbd_msg_hdr header;
+	__le16 make_code;
+	__le16 reserved0;
+	__le32 info; /* Additional information */
+};
+
+
+#define HK_MAXIMUM_MESSAGE_SIZE 256
+
+#define KBD_VSC_SEND_RING_BUFFER_SIZE	VMBUS_RING_SIZE(36 * 1024)
+#define KBD_VSC_RECV_RING_BUFFER_SIZE	VMBUS_RING_SIZE(36 * 1024)
+
+#define XTKBD_EMUL0     0xe0
+#define XTKBD_EMUL1     0xe1
+#define XTKBD_RELEASE   0x80
+
+
+/*
+ * Represents a keyboard device
+ */
+struct hv_kbd_dev {
+	struct hv_device *hv_dev;
+	struct serio *hv_serio;
+	struct synth_kbd_protocol_request protocol_req;
+	struct synth_kbd_protocol_response protocol_resp;
+	/* Synchronize the request/response if needed */
+	struct completion wait_event;
+	spinlock_t lock; /* protects 'started' field */
+	bool started;
+};
+
+static void hv_kbd_on_receive(struct hv_device *hv_dev,
+			      struct synth_kbd_msg *msg, u32 msg_length)
+{
+	struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev);
+	struct synth_kbd_keystroke *ks_msg;
+	u32 msg_type = __le32_to_cpu(msg->header.type);
+	u32 info;
+	u16 scan_code;
+
+	switch (msg_type) {
+	case SYNTH_KBD_PROTOCOL_RESPONSE:
+		/*
+		 * Validate the information provided by the host.
+		 * If the host is giving us a bogus packet,
+		 * drop the packet (hoping the problem
+		 * goes away).
+		 */
+		if (msg_length < sizeof(struct synth_kbd_protocol_response)) {
+			dev_err(&hv_dev->device,
+				"Illegal protocol response packet (len: %d)\n",
+				msg_length);
+			break;
+		}
+
+		memcpy(&kbd_dev->protocol_resp, msg,
+			sizeof(struct synth_kbd_protocol_response));
+		complete(&kbd_dev->wait_event);
+		break;
+
+	case SYNTH_KBD_EVENT:
+		/*
+		 * Validate the information provided by the host.
+		 * If the host is giving us a bogus packet,
+		 * drop the packet (hoping the problem
+		 * goes away).
+		 */
+		if (msg_length < sizeof(struct  synth_kbd_keystroke)) {
+			dev_err(&hv_dev->device,
+				"Illegal keyboard event packet (len: %d)\n",
+				msg_length);
+			break;
+		}
+
+		ks_msg = (struct synth_kbd_keystroke *)msg;
+		info = __le32_to_cpu(ks_msg->info);
+
+		/*
+		 * Inject the information through the serio interrupt.
+		 */
+		scoped_guard(spinlock_irqsave, &kbd_dev->lock) {
+			if (kbd_dev->started) {
+				if (info & IS_E0)
+					serio_interrupt(kbd_dev->hv_serio,
+							XTKBD_EMUL0, 0);
+				if (info & IS_E1)
+					serio_interrupt(kbd_dev->hv_serio,
+							XTKBD_EMUL1, 0);
+				scan_code = __le16_to_cpu(ks_msg->make_code);
+				if (info & IS_BREAK)
+					scan_code |= XTKBD_RELEASE;
+
+				serio_interrupt(kbd_dev->hv_serio,
+						scan_code, 0);
+			}
+		}
+
+		/*
+		 * Only trigger a wakeup on key down, otherwise
+		 * "echo freeze > /sys/power/state" can't really enter the
+		 * state because the Enter-UP can trigger a wakeup at once.
+		 */
+		if (!(info & IS_BREAK))
+			pm_wakeup_hard_event(&hv_dev->device);
+
+		break;
+
+	default:
+		dev_err(&hv_dev->device,
+			"unhandled message type %d\n", msg_type);
+	}
+}
+
+static void hv_kbd_handle_received_packet(struct hv_device *hv_dev,
+					  struct vmpacket_descriptor *desc,
+					  u32 bytes_recvd,
+					  u64 req_id)
+{
+	struct synth_kbd_msg *msg;
+	u32 msg_sz;
+
+	switch (desc->type) {
+	case VM_PKT_COMP:
+		break;
+
+	case VM_PKT_DATA_INBAND:
+		/*
+		 * We have a packet that has "inband" data. The API used
+		 * for retrieving the packet guarantees that the complete
+		 * packet is read. So, minimally, we should be able to
+		 * parse the payload header safely (assuming that the host
+		 * can be trusted.  Trusting the host seems to be a
+		 * reasonable assumption because in a virtualized
+		 * environment there is not whole lot you can do if you
+		 * don't trust the host.
+		 *
+		 * Nonetheless, let us validate if the host can be trusted
+		 * (in a trivial way).  The interesting aspect of this
+		 * validation is how do you recover if we discover that the
+		 * host is not to be trusted? Simply dropping the packet, I
+		 * don't think is an appropriate recovery.  In the interest
+		 * of failing fast, it may be better to crash the guest.
+		 * For now, I will just drop the packet!
+		 */
+
+		msg_sz = bytes_recvd - (desc->offset8 << 3);
+		if (msg_sz <= sizeof(struct synth_kbd_msg_hdr)) {
+			/*
+			 * Drop the packet and hope
+			 * the problem magically goes away.
+			 */
+			dev_err(&hv_dev->device,
+				"Illegal packet (type: %d, tid: %llx, size: %d)\n",
+				desc->type, req_id, msg_sz);
+			break;
+		}
+
+		msg = (void *)desc + (desc->offset8 << 3);
+		hv_kbd_on_receive(hv_dev, msg, msg_sz);
+		break;
+
+	default:
+		dev_err(&hv_dev->device,
+			"unhandled packet type %d, tid %llx len %d\n",
+			desc->type, req_id, bytes_recvd);
+		break;
+	}
+}
+
+static void hv_kbd_on_channel_callback(void *context)
+{
+	struct vmpacket_descriptor *desc;
+	struct hv_device *hv_dev = context;
+	u32 bytes_recvd;
+	u64 req_id;
+
+	foreach_vmbus_pkt(desc, hv_dev->channel) {
+		bytes_recvd = desc->len8 * 8;
+		req_id = desc->trans_id;
+
+		hv_kbd_handle_received_packet(hv_dev, desc, bytes_recvd,
+					      req_id);
+	}
+}
+
+static int hv_kbd_connect_to_vsp(struct hv_device *hv_dev)
+{
+	struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev);
+	struct synth_kbd_protocol_request *request;
+	struct synth_kbd_protocol_response *response;
+	u32 proto_status;
+	int error;
+
+	reinit_completion(&kbd_dev->wait_event);
+
+	request = &kbd_dev->protocol_req;
+	memset(request, 0, sizeof(struct synth_kbd_protocol_request));
+	request->header.type = __cpu_to_le32(SYNTH_KBD_PROTOCOL_REQUEST);
+	request->version_requested.version = __cpu_to_le32(SYNTH_KBD_VERSION);
+
+	error = vmbus_sendpacket(hv_dev->channel, request,
+				 sizeof(struct synth_kbd_protocol_request),
+				 (unsigned long)request,
+				 VM_PKT_DATA_INBAND,
+				 VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED);
+	if (error)
+		return error;
+
+	if (!wait_for_completion_timeout(&kbd_dev->wait_event, 10 * HZ))
+		return -ETIMEDOUT;
+
+	response = &kbd_dev->protocol_resp;
+	proto_status = __le32_to_cpu(response->proto_status);
+	if (!(proto_status & PROTOCOL_ACCEPTED)) {
+		dev_err(&hv_dev->device,
+			"synth_kbd protocol request failed (version %d)\n",
+		        SYNTH_KBD_VERSION);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int hv_kbd_start(struct serio *serio)
+{
+	struct hv_kbd_dev *kbd_dev = serio->port_data;
+
+	guard(spinlock_irqsave)(&kbd_dev->lock);
+
+	kbd_dev->started = true;
+
+	return 0;
+}
+
+static void hv_kbd_stop(struct serio *serio)
+{
+	struct hv_kbd_dev *kbd_dev = serio->port_data;
+
+	guard(spinlock_irqsave)(&kbd_dev->lock);
+
+	kbd_dev->started = false;
+}
+
+static int hv_kbd_probe(struct hv_device *hv_dev,
+			const struct hv_vmbus_device_id *dev_id)
+{
+	struct hv_kbd_dev *kbd_dev;
+	struct serio *hv_serio;
+	int error;
+
+	kbd_dev = kzalloc_obj(*kbd_dev);
+	hv_serio = kzalloc_obj(*hv_serio);
+	if (!kbd_dev || !hv_serio) {
+		error = -ENOMEM;
+		goto err_free_mem;
+	}
+
+	kbd_dev->hv_dev = hv_dev;
+	kbd_dev->hv_serio = hv_serio;
+	spin_lock_init(&kbd_dev->lock);
+	init_completion(&kbd_dev->wait_event);
+	hv_set_drvdata(hv_dev, kbd_dev);
+
+	hv_serio->dev.parent  = &hv_dev->device;
+	hv_serio->id.type = SERIO_8042_XL;
+	hv_serio->port_data = kbd_dev;
+	strscpy(hv_serio->name, dev_name(&hv_dev->device),
+		sizeof(hv_serio->name));
+	strscpy(hv_serio->phys, dev_name(&hv_dev->device),
+		sizeof(hv_serio->phys));
+
+	hv_serio->start = hv_kbd_start;
+	hv_serio->stop = hv_kbd_stop;
+
+	error = vmbus_open(hv_dev->channel,
+			   KBD_VSC_SEND_RING_BUFFER_SIZE,
+			   KBD_VSC_RECV_RING_BUFFER_SIZE,
+			   NULL, 0,
+			   hv_kbd_on_channel_callback,
+			   hv_dev);
+	if (error)
+		goto err_free_mem;
+
+	error = hv_kbd_connect_to_vsp(hv_dev);
+	if (error)
+		goto err_close_vmbus;
+
+	serio_register_port(kbd_dev->hv_serio);
+
+	device_init_wakeup(&hv_dev->device, true);
+
+	return 0;
+
+err_close_vmbus:
+	vmbus_close(hv_dev->channel);
+err_free_mem:
+	kfree(hv_serio);
+	kfree(kbd_dev);
+	return error;
+}
+
+static void hv_kbd_remove(struct hv_device *hv_dev)
+{
+	struct hv_kbd_dev *kbd_dev = hv_get_drvdata(hv_dev);
+
+	serio_unregister_port(kbd_dev->hv_serio);
+	vmbus_close(hv_dev->channel);
+	kfree(kbd_dev);
+
+	hv_set_drvdata(hv_dev, NULL);
+}
+
+static int hv_kbd_suspend(struct hv_device *hv_dev)
+{
+	vmbus_close(hv_dev->channel);
+
+	return 0;
+}
+
+static int hv_kbd_resume(struct hv_device *hv_dev)
+{
+	int ret;
+
+	ret = vmbus_open(hv_dev->channel,
+			 KBD_VSC_SEND_RING_BUFFER_SIZE,
+			 KBD_VSC_RECV_RING_BUFFER_SIZE,
+			 NULL, 0,
+			 hv_kbd_on_channel_callback,
+			 hv_dev);
+	if (ret == 0)
+		ret = hv_kbd_connect_to_vsp(hv_dev);
+
+	return ret;
+}
+
+static const struct hv_vmbus_device_id id_table[] = {
+	/* Keyboard guid */
+	{ HV_KBD_GUID, },
+	{ },
+};
+
+MODULE_DEVICE_TABLE(vmbus, id_table);
+
+static struct  hv_driver hv_kbd_drv = {
+	.name = KBUILD_MODNAME,
+	.id_table = id_table,
+	.probe = hv_kbd_probe,
+	.remove = hv_kbd_remove,
+	.suspend = hv_kbd_suspend,
+	.resume = hv_kbd_resume,
+	.driver = {
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+	},
+};
+
+static int __init hv_kbd_init(void)
+{
+	return vmbus_driver_register(&hv_kbd_drv);
+}
+
+static void __exit hv_kbd_exit(void)
+{
+	vmbus_driver_unregister(&hv_kbd_drv);
+}
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Microsoft Hyper-V Synthetic Keyboard Driver");
+
+module_init(hv_kbd_init);
+module_exit(hv_kbd_exit);