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, 368 insertions, 0 deletions

diff --git a/drivers/thunderbolt/acpi.c b/drivers/thunderbolt/acpi.c
new file mode 100644
index 000000000..53546bc47
--- /dev/null
+++ b/drivers/thunderbolt/acpi.c
@@ -0,0 +1,368 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ACPI support
+ *
+ * Copyright (C) 2020, Intel Corporation
+ * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
+ */
+
+#include <linux/acpi.h>
+#include <linux/pm_runtime.h>
+
+#include "tb.h"
+
+static acpi_status tb_acpi_add_link(acpi_handle handle, u32 level, void *data,
+				    void **ret)
+{
+	struct acpi_device *adev = acpi_fetch_acpi_dev(handle);
+	struct fwnode_handle *fwnode;
+	struct tb_nhi *nhi = data;
+	struct pci_dev *pdev;
+	struct device *dev;
+
+	if (!adev)
+		return AE_OK;
+
+	fwnode = fwnode_find_reference(acpi_fwnode_handle(adev), "usb4-host-interface", 0);
+	if (IS_ERR(fwnode))
+		return AE_OK;
+
+	/* It needs to reference this NHI */
+	if (dev_fwnode(nhi->dev) != fwnode)
+		goto out_put;
+
+	/*
+	 * Ignore USB3 ports here as USB core will set up device links between
+	 * tunneled USB3 devices and NHI host during USB device creation.
+	 * USB3 ports might not even have a physical device yet if xHCI driver
+	 * isn't bound yet.
+	 */
+	dev = acpi_get_first_physical_node(adev);
+	if (!dev || !dev_is_pci(dev))
+		goto out_put;
+
+	/* Check that this matches a PCIe root/downstream port. */
+	pdev = to_pci_dev(dev);
+	if (pci_is_pcie(pdev) &&
+	    (pci_pcie_type(pdev) == PCI_EXP_TYPE_ROOT_PORT ||
+	     pci_pcie_type(pdev) == PCI_EXP_TYPE_DOWNSTREAM)) {
+		const struct device_link *link;
+
+		/*
+		 * Make them both active first to make sure the NHI does
+		 * not runtime suspend before the consumer. The
+		 * pm_runtime_put() below then allows the consumer to
+		 * runtime suspend again (which then allows NHI runtime
+		 * suspend too now that the device link is established).
+		 */
+		pm_runtime_get_sync(&pdev->dev);
+
+		link = device_link_add(&pdev->dev, nhi->dev,
+				       DL_FLAG_AUTOREMOVE_SUPPLIER |
+				       DL_FLAG_RPM_ACTIVE |
+				       DL_FLAG_PM_RUNTIME);
+		if (link) {
+			dev_dbg(nhi->dev, "created link from %s\n",
+				dev_name(&pdev->dev));
+			*(bool *)ret = true;
+		} else {
+			dev_warn(nhi->dev, "device link creation from %s failed\n",
+				 dev_name(&pdev->dev));
+		}
+
+		pm_runtime_put(&pdev->dev);
+	}
+
+out_put:
+	fwnode_handle_put(fwnode);
+	return AE_OK;
+}
+
+/**
+ * tb_acpi_add_links() - Add device links based on ACPI description
+ * @nhi: Pointer to NHI
+ *
+ * Goes over ACPI namespace finding tunneled ports that reference to
+ * @nhi ACPI node. For each reference a device link is added. The link
+ * is automatically removed by the driver core.
+ *
+ * Returns %true if at least one link was created, %false otherwise.
+ */
+bool tb_acpi_add_links(struct tb_nhi *nhi)
+{
+	acpi_status status;
+	bool ret = false;
+
+	if (!has_acpi_companion(nhi->dev))
+		return false;
+
+	/*
+	 * Find all devices that have usb4-host-controller interface
+	 * property that references to this NHI.
+	 */
+	status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, 32,
+				     tb_acpi_add_link, NULL, nhi, (void **)&ret);
+	if (ACPI_FAILURE(status)) {
+		dev_warn(nhi->dev, "failed to enumerate tunneled ports\n");
+		return false;
+	}
+
+	return ret;
+}
+
+/**
+ * tb_acpi_is_native() - Did the platform grant native TBT/USB4 control
+ *
+ * Return: %true if the platform granted OS native control over
+ * TBT/USB4, %false otherwise.
+ *
+ * When returned %true, software based connection manager can be used,
+ * otherwise there is firmware based connection manager running.
+ */
+bool tb_acpi_is_native(void)
+{
+	return osc_sb_native_usb4_support_confirmed &&
+	       osc_sb_native_usb4_control;
+}
+
+/**
+ * tb_acpi_may_tunnel_usb3() - Is USB3 tunneling allowed by the platform
+ *
+ * Return: %true if software based connection manager is used and
+ * platform allows native USB 3.x tunneling, %false otherwise.
+ */
+bool tb_acpi_may_tunnel_usb3(void)
+{
+	if (tb_acpi_is_native())
+		return osc_sb_native_usb4_control & OSC_USB_USB3_TUNNELING;
+	return true;
+}
+
+/**
+ * tb_acpi_may_tunnel_dp() - Is DisplayPort tunneling allowed by the platform
+ *
+ * Return: %true if software based connection manager is used and
+ * platform allows native DP tunneling, %false otherwise.
+ */
+bool tb_acpi_may_tunnel_dp(void)
+{
+	if (tb_acpi_is_native())
+		return osc_sb_native_usb4_control & OSC_USB_DP_TUNNELING;
+	return true;
+}
+
+/**
+ * tb_acpi_may_tunnel_pcie() - Is PCIe tunneling allowed by the platform
+ *
+ * Return: %true if software based connection manager is used and
+ * platform allows native PCIe tunneling, %false otherwise.
+ */
+bool tb_acpi_may_tunnel_pcie(void)
+{
+	if (tb_acpi_is_native())
+		return osc_sb_native_usb4_control & OSC_USB_PCIE_TUNNELING;
+	return true;
+}
+
+/**
+ * tb_acpi_is_xdomain_allowed() - Are XDomain connections allowed
+ *
+ * Return: %true if software based connection manager is used and
+ * platform allows XDomain tunneling, %false otherwise.
+ */
+bool tb_acpi_is_xdomain_allowed(void)
+{
+	if (tb_acpi_is_native())
+		return osc_sb_native_usb4_control & OSC_USB_XDOMAIN;
+	return true;
+}
+
+/* UUID for retimer _DSM: e0053122-795b-4122-8a5e-57be1d26acb3 */
+static const guid_t retimer_dsm_guid =
+	GUID_INIT(0xe0053122, 0x795b, 0x4122,
+		  0x8a, 0x5e, 0x57, 0xbe, 0x1d, 0x26, 0xac, 0xb3);
+
+#define RETIMER_DSM_QUERY_ONLINE_STATE	1
+#define RETIMER_DSM_SET_ONLINE_STATE	2
+
+static int tb_acpi_retimer_set_power(struct tb_port *port, bool power)
+{
+	struct usb4_port *usb4 = port->usb4;
+	union acpi_object argv4[2];
+	struct acpi_device *adev;
+	union acpi_object *obj;
+	int ret;
+
+	if (!usb4->can_offline)
+		return 0;
+
+	adev = ACPI_COMPANION(&usb4->dev);
+	if (WARN_ON(!adev))
+		return 0;
+
+	/* Check if we are already powered on (and in correct mode) */
+	obj = acpi_evaluate_dsm_typed(adev->handle, &retimer_dsm_guid, 1,
+				      RETIMER_DSM_QUERY_ONLINE_STATE, NULL,
+				      ACPI_TYPE_INTEGER);
+	if (!obj) {
+		tb_port_warn(port, "ACPI: query online _DSM failed\n");
+		return -EIO;
+	}
+
+	ret = obj->integer.value;
+	ACPI_FREE(obj);
+
+	if (power == ret)
+		return 0;
+
+	tb_port_dbg(port, "ACPI: calling _DSM to power %s retimers\n",
+		    power ? "on" : "off");
+
+	argv4[0].type = ACPI_TYPE_PACKAGE;
+	argv4[0].package.count = 1;
+	argv4[0].package.elements = &argv4[1];
+	argv4[1].integer.type = ACPI_TYPE_INTEGER;
+	argv4[1].integer.value = power;
+
+	obj = acpi_evaluate_dsm_typed(adev->handle, &retimer_dsm_guid, 1,
+				      RETIMER_DSM_SET_ONLINE_STATE, argv4,
+				      ACPI_TYPE_INTEGER);
+	if (!obj) {
+		tb_port_warn(port,
+			     "ACPI: set online state _DSM evaluation failed\n");
+		return -EIO;
+	}
+
+	ret = obj->integer.value;
+	ACPI_FREE(obj);
+
+	if (ret >= 0) {
+		if (power)
+			return ret == 1 ? 0 : -EBUSY;
+		return 0;
+	}
+
+	tb_port_warn(port, "ACPI: set online state _DSM failed with error %d\n", ret);
+	return -EIO;
+}
+
+/**
+ * tb_acpi_power_on_retimers() - Call platform to power on retimers
+ * @port: USB4 port
+ *
+ * Calls platform to turn on power to all retimers behind this USB4
+ * port. After this function returns successfully the caller can
+ * continue with the normal retimer flows (as specified in the USB4
+ * spec). Note if this returns %-EBUSY it means the type-C port is in
+ * non-USB4/TBT mode (there is non-USB4/TBT device connected).
+ *
+ * This should only be called if the USB4/TBT link is not up.
+ *
+ * Return: %0 on success, negative errno otherwise.
+ */
+int tb_acpi_power_on_retimers(struct tb_port *port)
+{
+	return tb_acpi_retimer_set_power(port, true);
+}
+
+/**
+ * tb_acpi_power_off_retimers() - Call platform to power off retimers
+ * @port: USB4 port
+ *
+ * This is the opposite of tb_acpi_power_on_retimers(). After returning
+ * successfully the normal operations with the @port can continue.
+ *
+ * Return: %0 on success, negative errno otherwise.
+ */
+int tb_acpi_power_off_retimers(struct tb_port *port)
+{
+	return tb_acpi_retimer_set_power(port, false);
+}
+
+static bool tb_acpi_bus_match(struct device *dev)
+{
+	return tb_is_switch(dev) || tb_is_usb4_port_device(dev);
+}
+
+static struct acpi_device *tb_acpi_switch_find_companion(struct tb_switch *sw)
+{
+	struct tb_switch *parent_sw = tb_switch_parent(sw);
+	struct acpi_device *adev = NULL;
+
+	/*
+	 * Device routers exists under the downstream facing USB4 port
+	 * of the parent router. Their _ADR is always 0.
+	 */
+	if (parent_sw) {
+		struct tb_port *port = tb_switch_downstream_port(sw);
+		struct acpi_device *port_adev;
+
+		port_adev = acpi_find_child_by_adr(ACPI_COMPANION(&parent_sw->dev),
+						   port->port);
+		if (port_adev)
+			adev = acpi_find_child_device(port_adev, 0, false);
+	} else {
+		struct tb_nhi *nhi = sw->tb->nhi;
+		struct acpi_device *parent_adev;
+
+		parent_adev = ACPI_COMPANION(nhi->dev);
+		if (parent_adev)
+			adev = acpi_find_child_device(parent_adev, 0, false);
+	}
+
+	return adev;
+}
+
+static struct acpi_device *tb_acpi_find_companion(struct device *dev)
+{
+	/*
+	 * The Thunderbolt/USB4 hierarchy looks like following:
+	 *
+	 * Device (NHI)
+	 *   Device (HR)		// Host router _ADR == 0
+	 *      Device (DFP0)		// Downstream port _ADR == lane 0 adapter
+	 *        Device (DR)		// Device router _ADR == 0
+	 *          Device (UFP)	// Upstream port _ADR == lane 0 adapter
+	 *      Device (DFP1)		// Downstream port _ADR == lane 0 adapter number
+	 *
+	 * At the moment we bind the host router to the corresponding
+	 * Linux device.
+	 */
+	if (tb_is_switch(dev))
+		return tb_acpi_switch_find_companion(tb_to_switch(dev));
+	if (tb_is_usb4_port_device(dev))
+		return acpi_find_child_by_adr(ACPI_COMPANION(dev->parent),
+					      tb_to_usb4_port_device(dev)->port->port);
+	return NULL;
+}
+
+static void tb_acpi_setup(struct device *dev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+	struct usb4_port *usb4 = tb_to_usb4_port_device(dev);
+
+	if (!adev || !usb4)
+		return;
+
+	if (acpi_check_dsm(adev->handle, &retimer_dsm_guid, 1,
+			   BIT(RETIMER_DSM_QUERY_ONLINE_STATE) |
+			   BIT(RETIMER_DSM_SET_ONLINE_STATE)))
+		usb4->can_offline = true;
+}
+
+static struct acpi_bus_type tb_acpi_bus = {
+	.name = "thunderbolt",
+	.match = tb_acpi_bus_match,
+	.find_companion = tb_acpi_find_companion,
+	.setup = tb_acpi_setup,
+};
+
+int tb_acpi_init(void)
+{
+	return register_acpi_bus_type(&tb_acpi_bus);
+}
+
+void tb_acpi_exit(void)
+{
+	unregister_acpi_bus_type(&tb_acpi_bus);
+}