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, 367 insertions, 0 deletions

diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
new file mode 100644
index 000000000..1d7dfe4ee
--- /dev/null
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -0,0 +1,367 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2004, 2013 Intel Corporation
+ * Author: Naveen B S <naveen.b.s@intel.com>
+ * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
+ *
+ * All rights reserved.
+ *
+ * ACPI based HotPlug driver that supports Memory Hotplug
+ * This driver fields notifications from firmware for memory add
+ * and remove operations and alerts the VM of the affected memory
+ * ranges.
+ */
+
+#include <linux/acpi.h>
+#include <linux/memory.h>
+#include <linux/memory_hotplug.h>
+
+#include "internal.h"
+
+#define ACPI_MEMORY_DEVICE_HID			"PNP0C80"
+
+static const struct acpi_device_id memory_device_ids[] = {
+	{ACPI_MEMORY_DEVICE_HID, 0},
+	{"", 0},
+};
+
+#ifdef CONFIG_ACPI_HOTPLUG_MEMORY
+
+static int acpi_memory_device_add(struct acpi_device *device,
+				  const struct acpi_device_id *not_used);
+static void acpi_memory_device_remove(struct acpi_device *device);
+
+static struct acpi_scan_handler memory_device_handler = {
+	.ids = memory_device_ids,
+	.attach = acpi_memory_device_add,
+	.detach = acpi_memory_device_remove,
+	.hotplug = {
+		.enabled = true,
+	},
+};
+
+struct acpi_memory_info {
+	struct list_head list;
+	u64 start_addr;		/* Memory Range start physical addr */
+	u64 length;		/* Memory Range length */
+	unsigned short caching;	/* memory cache attribute */
+	unsigned short write_protect;	/* memory read/write attribute */
+	unsigned int enabled:1;
+};
+
+struct acpi_memory_device {
+	struct acpi_device *device;
+	struct list_head res_list;
+	int mgid;
+};
+
+static acpi_status
+acpi_memory_get_resource(struct acpi_resource *resource, void *context)
+{
+	struct acpi_memory_device *mem_device = context;
+	struct acpi_resource_address64 address64;
+	struct acpi_memory_info *info, *new;
+	acpi_status status;
+
+	status = acpi_resource_to_address64(resource, &address64);
+	if (ACPI_FAILURE(status) ||
+	    (address64.resource_type != ACPI_MEMORY_RANGE))
+		return AE_OK;
+
+	list_for_each_entry(info, &mem_device->res_list, list) {
+		/* Can we combine the resource range information? */
+		if ((info->caching == address64.info.mem.caching) &&
+		    (info->write_protect == address64.info.mem.write_protect) &&
+		    (info->start_addr + info->length == address64.address.minimum)) {
+			info->length += address64.address.address_length;
+			return AE_OK;
+		}
+	}
+
+	new = kzalloc_obj(struct acpi_memory_info);
+	if (!new)
+		return AE_ERROR;
+
+	INIT_LIST_HEAD(&new->list);
+	new->caching = address64.info.mem.caching;
+	new->write_protect = address64.info.mem.write_protect;
+	new->start_addr = address64.address.minimum;
+	new->length = address64.address.address_length;
+	list_add_tail(&new->list, &mem_device->res_list);
+
+	return AE_OK;
+}
+
+static void
+acpi_memory_free_device_resources(struct acpi_memory_device *mem_device)
+{
+	struct acpi_memory_info *info, *n;
+
+	list_for_each_entry_safe(info, n, &mem_device->res_list, list)
+		kfree(info);
+	INIT_LIST_HEAD(&mem_device->res_list);
+}
+
+static int
+acpi_memory_get_device_resources(struct acpi_memory_device *mem_device)
+{
+	acpi_status status;
+
+	if (!list_empty(&mem_device->res_list))
+		return 0;
+
+	status = acpi_walk_resources(mem_device->device->handle, METHOD_NAME__CRS,
+				     acpi_memory_get_resource, mem_device);
+	if (ACPI_FAILURE(status)) {
+		acpi_memory_free_device_resources(mem_device);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int acpi_memory_check_device(struct acpi_memory_device *mem_device)
+{
+	unsigned long long current_status;
+
+	/* Get device present/absent information from the _STA */
+	if (ACPI_FAILURE(acpi_evaluate_integer(mem_device->device->handle,
+					       METHOD_NAME__STA, NULL,
+					       &current_status)))
+		return -ENODEV;
+	/*
+	 * Check for device status. Device should be
+	 * present/enabled/functioning.
+	 */
+	if (!((current_status & ACPI_STA_DEVICE_PRESENT)
+	      && (current_status & ACPI_STA_DEVICE_ENABLED)
+	      && (current_status & ACPI_STA_DEVICE_FUNCTIONING)))
+		return -ENODEV;
+
+	return 0;
+}
+
+static int acpi_bind_memblk(struct memory_block *mem, void *arg)
+{
+	return acpi_bind_one(&mem->dev, arg);
+}
+
+static int acpi_bind_memory_blocks(struct acpi_memory_info *info,
+				   struct acpi_device *adev)
+{
+	return walk_memory_blocks(info->start_addr, info->length, adev,
+				  acpi_bind_memblk);
+}
+
+static int acpi_unbind_memblk(struct memory_block *mem, void *arg)
+{
+	acpi_unbind_one(&mem->dev);
+	return 0;
+}
+
+static void acpi_unbind_memory_blocks(struct acpi_memory_info *info)
+{
+	walk_memory_blocks(info->start_addr, info->length, NULL,
+			   acpi_unbind_memblk);
+}
+
+static int acpi_memory_enable_device(struct acpi_memory_device *mem_device)
+{
+	acpi_handle handle = mem_device->device->handle;
+	mhp_t mhp_flags = MHP_NID_IS_MGID;
+	int result, num_enabled = 0;
+	struct acpi_memory_info *info;
+	u64 total_length = 0;
+	int node, mgid;
+
+	node = acpi_get_node(handle);
+
+	list_for_each_entry(info, &mem_device->res_list, list) {
+		if (!info->length)
+			continue;
+		/* We want a single node for the whole memory group */
+		if (node < 0)
+			node = memory_add_physaddr_to_nid(info->start_addr);
+		total_length += info->length;
+	}
+
+	if (!total_length) {
+		dev_err(&mem_device->device->dev, "device is empty\n");
+		return -EINVAL;
+	}
+
+	mgid = memory_group_register_static(node, PFN_UP(total_length));
+	if (mgid < 0)
+		return mgid;
+	mem_device->mgid = mgid;
+
+	/*
+	 * Tell the VM there is more memory here...
+	 * Note: Assume that this function returns zero on success
+	 * We don't have memory-hot-add rollback function,now.
+	 * (i.e. memory-hot-remove function)
+	 */
+	list_for_each_entry(info, &mem_device->res_list, list) {
+		/*
+		 * If the memory block size is zero, please ignore it.
+		 * Don't try to do the following memory hotplug flowchart.
+		 */
+		if (!info->length)
+			continue;
+
+		mhp_flags |= MHP_MEMMAP_ON_MEMORY;
+		result = __add_memory(mgid, info->start_addr, info->length,
+				      mhp_flags);
+
+		/*
+		 * If the memory block has been used by the kernel, add_memory()
+		 * returns -EEXIST. If add_memory() returns the other error, it
+		 * means that this memory block is not used by the kernel.
+		 */
+		if (result && result != -EEXIST)
+			continue;
+
+		result = acpi_bind_memory_blocks(info, mem_device->device);
+		if (result) {
+			acpi_unbind_memory_blocks(info);
+			return -ENODEV;
+		}
+
+		info->enabled = 1;
+
+		/*
+		 * Add num_enable even if add_memory() returns -EEXIST, so the
+		 * device is bound to this driver.
+		 */
+		num_enabled++;
+	}
+	if (!num_enabled) {
+		dev_err(&mem_device->device->dev, "add_memory failed\n");
+		return -EINVAL;
+	}
+	/*
+	 * Sometimes the memory device will contain several memory blocks.
+	 * When one memory block is hot-added to the system memory, it will
+	 * be regarded as a success.
+	 * Otherwise if the last memory block can't be hot-added to the system
+	 * memory, it will be failure and the memory device can't be bound with
+	 * driver.
+	 */
+	return 0;
+}
+
+static void acpi_memory_remove_memory(struct acpi_memory_device *mem_device)
+{
+	struct acpi_memory_info *info, *n;
+
+	list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
+		if (!info->enabled)
+			continue;
+
+		acpi_unbind_memory_blocks(info);
+		__remove_memory(info->start_addr, info->length);
+		list_del(&info->list);
+		kfree(info);
+	}
+}
+
+static void acpi_memory_device_free(struct acpi_memory_device *mem_device)
+{
+	if (!mem_device)
+		return;
+
+	/* In case we succeeded adding *some* memory, unregistering fails. */
+	if (mem_device->mgid >= 0)
+		memory_group_unregister(mem_device->mgid);
+
+	acpi_memory_free_device_resources(mem_device);
+	mem_device->device->driver_data = NULL;
+	kfree(mem_device);
+}
+
+static int acpi_memory_device_add(struct acpi_device *device,
+				  const struct acpi_device_id *not_used)
+{
+	struct acpi_memory_device *mem_device;
+	int result;
+
+	if (!device)
+		return -EINVAL;
+
+	mem_device = kzalloc_obj(struct acpi_memory_device);
+	if (!mem_device)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&mem_device->res_list);
+	mem_device->device = device;
+	mem_device->mgid = -1;
+	device->driver_data = mem_device;
+
+	/* Get the range from the _CRS */
+	result = acpi_memory_get_device_resources(mem_device);
+	if (result) {
+		device->driver_data = NULL;
+		kfree(mem_device);
+		return result;
+	}
+
+	result = acpi_memory_check_device(mem_device);
+	if (result) {
+		acpi_memory_device_free(mem_device);
+		return 0;
+	}
+
+	result = acpi_memory_enable_device(mem_device);
+	if (result) {
+		dev_err(&device->dev, "acpi_memory_enable_device() error\n");
+		acpi_memory_device_free(mem_device);
+		return result;
+	}
+
+	dev_dbg(&device->dev, "Memory device configured by ACPI\n");
+	return 1;
+}
+
+static void acpi_memory_device_remove(struct acpi_device *device)
+{
+	struct acpi_memory_device *mem_device;
+
+	if (!device || !acpi_driver_data(device))
+		return;
+
+	mem_device = acpi_driver_data(device);
+	acpi_memory_remove_memory(mem_device);
+	acpi_memory_device_free(mem_device);
+}
+
+static bool __initdata acpi_no_memhotplug;
+
+void __init acpi_memory_hotplug_init(void)
+{
+	if (acpi_no_memhotplug) {
+		memory_device_handler.attach = NULL;
+		acpi_scan_add_handler(&memory_device_handler);
+		return;
+	}
+	acpi_scan_add_handler_with_hotplug(&memory_device_handler, "memory");
+}
+
+static int __init disable_acpi_memory_hotplug(char *str)
+{
+	acpi_no_memhotplug = true;
+	return 1;
+}
+__setup("acpi_no_memhotplug", disable_acpi_memory_hotplug);
+
+#else
+
+static struct acpi_scan_handler memory_device_handler = {
+	.ids = memory_device_ids,
+};
+
+void __init acpi_memory_hotplug_init(void)
+{
+	acpi_scan_add_handler(&memory_device_handler);
+}
+
+#endif /* CONFIG_ACPI_HOTPLUG_MEMORY */