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, 399 insertions, 0 deletions

diff --git a/lib/devres.c b/lib/devres.c
new file mode 100644
index 000000000..378b07730
--- /dev/null
+++ b/lib/devres.c
@@ -0,0 +1,399 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/bug.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/gfp_types.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/of_address.h>
+#include <linux/types.h>
+
+enum devm_ioremap_type {
+	DEVM_IOREMAP = 0,
+	DEVM_IOREMAP_UC,
+	DEVM_IOREMAP_WC,
+	DEVM_IOREMAP_NP,
+};
+
+void devm_ioremap_release(struct device *dev, void *res)
+{
+	iounmap(*(void __iomem **)res);
+}
+
+static int devm_ioremap_match(struct device *dev, void *res, void *match_data)
+{
+	return *(void **)res == match_data;
+}
+
+static void __iomem *__devm_ioremap(struct device *dev, resource_size_t offset,
+				    resource_size_t size,
+				    enum devm_ioremap_type type)
+{
+	void __iomem **ptr, *addr = NULL;
+
+	ptr = devres_alloc_node(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL,
+				dev_to_node(dev));
+	if (!ptr)
+		return NULL;
+
+	switch (type) {
+	case DEVM_IOREMAP:
+		addr = ioremap(offset, size);
+		break;
+	case DEVM_IOREMAP_UC:
+		addr = ioremap_uc(offset, size);
+		break;
+	case DEVM_IOREMAP_WC:
+		addr = ioremap_wc(offset, size);
+		break;
+	case DEVM_IOREMAP_NP:
+		addr = ioremap_np(offset, size);
+		break;
+	}
+
+	if (addr) {
+		*ptr = addr;
+		devres_add(dev, ptr);
+	} else
+		devres_free(ptr);
+
+	return addr;
+}
+
+/**
+ * devm_ioremap - Managed ioremap()
+ * @dev: Generic device to remap IO address for
+ * @offset: Resource address to map
+ * @size: Size of map
+ *
+ * Managed ioremap().  Map is automatically unmapped on driver detach.
+ */
+void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
+			   resource_size_t size)
+{
+	return __devm_ioremap(dev, offset, size, DEVM_IOREMAP);
+}
+EXPORT_SYMBOL(devm_ioremap);
+
+/**
+ * devm_ioremap_uc - Managed ioremap_uc()
+ * @dev: Generic device to remap IO address for
+ * @offset: Resource address to map
+ * @size: Size of map
+ *
+ * Managed ioremap_uc().  Map is automatically unmapped on driver detach.
+ */
+void __iomem *devm_ioremap_uc(struct device *dev, resource_size_t offset,
+			      resource_size_t size)
+{
+	return __devm_ioremap(dev, offset, size, DEVM_IOREMAP_UC);
+}
+EXPORT_SYMBOL_GPL(devm_ioremap_uc);
+
+/**
+ * devm_ioremap_wc - Managed ioremap_wc()
+ * @dev: Generic device to remap IO address for
+ * @offset: Resource address to map
+ * @size: Size of map
+ *
+ * Managed ioremap_wc().  Map is automatically unmapped on driver detach.
+ */
+void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset,
+			      resource_size_t size)
+{
+	return __devm_ioremap(dev, offset, size, DEVM_IOREMAP_WC);
+}
+EXPORT_SYMBOL(devm_ioremap_wc);
+
+/**
+ * devm_iounmap - Managed iounmap()
+ * @dev: Generic device to unmap for
+ * @addr: Address to unmap
+ *
+ * Managed iounmap().  @addr must have been mapped using devm_ioremap*().
+ */
+void devm_iounmap(struct device *dev, void __iomem *addr)
+{
+	WARN_ON(devres_release(dev, devm_ioremap_release, devm_ioremap_match,
+			       (__force void *)addr));
+}
+EXPORT_SYMBOL(devm_iounmap);
+
+static void __iomem *
+__devm_ioremap_resource(struct device *dev, const struct resource *res,
+			enum devm_ioremap_type type)
+{
+	resource_size_t size;
+	void __iomem *dest_ptr;
+	char *pretty_name;
+	int ret;
+
+	BUG_ON(!dev);
+
+	if (!res || resource_type(res) != IORESOURCE_MEM) {
+		ret = dev_err_probe(dev, -EINVAL, "invalid resource %pR\n", res);
+		return IOMEM_ERR_PTR(ret);
+	}
+
+	if (type == DEVM_IOREMAP && res->flags & IORESOURCE_MEM_NONPOSTED)
+		type = DEVM_IOREMAP_NP;
+
+	size = resource_size(res);
+
+	if (res->name)
+		pretty_name = devm_kasprintf(dev, GFP_KERNEL, "%s %s",
+					     dev_name(dev), res->name);
+	else
+		pretty_name = devm_kstrdup(dev, dev_name(dev), GFP_KERNEL);
+	if (!pretty_name) {
+		ret = dev_err_probe(dev, -ENOMEM, "can't generate pretty name for resource %pR\n", res);
+		return IOMEM_ERR_PTR(ret);
+	}
+
+	if (!devm_request_mem_region(dev, res->start, size, pretty_name)) {
+		ret = dev_err_probe(dev, -EBUSY, "can't request region for resource %pR\n", res);
+		return IOMEM_ERR_PTR(ret);
+	}
+
+	dest_ptr = __devm_ioremap(dev, res->start, size, type);
+	if (!dest_ptr) {
+		devm_release_mem_region(dev, res->start, size);
+		ret = dev_err_probe(dev, -ENOMEM, "ioremap failed for resource %pR\n", res);
+		return IOMEM_ERR_PTR(ret);
+	}
+
+	return dest_ptr;
+}
+
+/**
+ * devm_ioremap_resource() - check, request region, and ioremap resource
+ * @dev: generic device to handle the resource for
+ * @res: resource to be handled
+ *
+ * Checks that a resource is a valid memory region, requests the memory
+ * region and ioremaps it. All operations are managed and will be undone
+ * on driver detach.
+ *
+ * Usage example:
+ *
+ *	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ *	base = devm_ioremap_resource(&pdev->dev, res);
+ *	if (IS_ERR(base))
+ *		return PTR_ERR(base);
+ *
+ * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
+ * on failure.
+ */
+void __iomem *devm_ioremap_resource(struct device *dev,
+				    const struct resource *res)
+{
+	return __devm_ioremap_resource(dev, res, DEVM_IOREMAP);
+}
+EXPORT_SYMBOL(devm_ioremap_resource);
+
+/**
+ * devm_ioremap_resource_wc() - write-combined variant of
+ *				devm_ioremap_resource()
+ * @dev: generic device to handle the resource for
+ * @res: resource to be handled
+ *
+ * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
+ * on failure.
+ */
+void __iomem *devm_ioremap_resource_wc(struct device *dev,
+				       const struct resource *res)
+{
+	return __devm_ioremap_resource(dev, res, DEVM_IOREMAP_WC);
+}
+EXPORT_SYMBOL(devm_ioremap_resource_wc);
+
+/*
+ * devm_of_iomap - Requests a resource and maps the memory mapped IO
+ *		   for a given device_node managed by a given device
+ *
+ * Checks that a resource is a valid memory region, requests the memory
+ * region and ioremaps it. All operations are managed and will be undone
+ * on driver detach of the device.
+ *
+ * This is to be used when a device requests/maps resources described
+ * by other device tree nodes (children or otherwise).
+ *
+ * @dev:	The device "managing" the resource
+ * @node:       The device-tree node where the resource resides
+ * @index:	index of the MMIO range in the "reg" property
+ * @size:	Returns the size of the resource (pass NULL if not needed)
+ *
+ * Usage example:
+ *
+ *	base = devm_of_iomap(&pdev->dev, node, 0, NULL);
+ *	if (IS_ERR(base))
+ *		return PTR_ERR(base);
+ *
+ * Please Note: This is not a one-to-one replacement for of_iomap() because the
+ * of_iomap() function does not track whether the region is already mapped.  If
+ * two drivers try to map the same memory, the of_iomap() function will succeed
+ * but the devm_of_iomap() function will return -EBUSY.
+ *
+ * Return: a pointer to the requested and mapped memory or an ERR_PTR() encoded
+ * error code on failure.
+ */
+void __iomem *devm_of_iomap(struct device *dev, struct device_node *node, int index,
+			    resource_size_t *size)
+{
+	struct resource res;
+
+	if (of_address_to_resource(node, index, &res))
+		return IOMEM_ERR_PTR(-EINVAL);
+	if (size)
+		*size = resource_size(&res);
+	return devm_ioremap_resource(dev, &res);
+}
+EXPORT_SYMBOL(devm_of_iomap);
+
+#ifdef CONFIG_HAS_IOPORT_MAP
+/*
+ * Generic iomap devres
+ */
+static void devm_ioport_map_release(struct device *dev, void *res)
+{
+	ioport_unmap(*(void __iomem **)res);
+}
+
+static int devm_ioport_map_match(struct device *dev, void *res,
+				 void *match_data)
+{
+	return *(void **)res == match_data;
+}
+
+/**
+ * devm_ioport_map - Managed ioport_map()
+ * @dev: Generic device to map ioport for
+ * @port: Port to map
+ * @nr: Number of ports to map
+ *
+ * Managed ioport_map().  Map is automatically unmapped on driver
+ * detach.
+ *
+ * Return: a pointer to the remapped memory or NULL on failure.
+ */
+void __iomem *devm_ioport_map(struct device *dev, unsigned long port,
+			       unsigned int nr)
+{
+	void __iomem **ptr, *addr;
+
+	ptr = devres_alloc_node(devm_ioport_map_release, sizeof(*ptr), GFP_KERNEL,
+				dev_to_node(dev));
+	if (!ptr)
+		return NULL;
+
+	addr = ioport_map(port, nr);
+	if (addr) {
+		*ptr = addr;
+		devres_add(dev, ptr);
+	} else
+		devres_free(ptr);
+
+	return addr;
+}
+EXPORT_SYMBOL(devm_ioport_map);
+
+/**
+ * devm_ioport_unmap - Managed ioport_unmap()
+ * @dev: Generic device to unmap for
+ * @addr: Address to unmap
+ *
+ * Managed ioport_unmap().  @addr must have been mapped using
+ * devm_ioport_map().
+ */
+void devm_ioport_unmap(struct device *dev, void __iomem *addr)
+{
+	WARN_ON(devres_release(dev, devm_ioport_map_release,
+			       devm_ioport_map_match, (__force void *)addr));
+}
+EXPORT_SYMBOL(devm_ioport_unmap);
+#endif /* CONFIG_HAS_IOPORT_MAP */
+
+static void devm_arch_phys_ac_add_release(struct device *dev, void *res)
+{
+	arch_phys_wc_del(*((int *)res));
+}
+
+/**
+ * devm_arch_phys_wc_add - Managed arch_phys_wc_add()
+ * @dev: Managed device
+ * @base: Memory base address
+ * @size: Size of memory range
+ *
+ * Adds a WC MTRR using arch_phys_wc_add() and sets up a release callback.
+ * See arch_phys_wc_add() for more information.
+ */
+int devm_arch_phys_wc_add(struct device *dev, unsigned long base, unsigned long size)
+{
+	int *mtrr;
+	int ret;
+
+	mtrr = devres_alloc_node(devm_arch_phys_ac_add_release, sizeof(*mtrr), GFP_KERNEL,
+				 dev_to_node(dev));
+	if (!mtrr)
+		return -ENOMEM;
+
+	ret = arch_phys_wc_add(base, size);
+	if (ret < 0) {
+		devres_free(mtrr);
+		return ret;
+	}
+
+	*mtrr = ret;
+	devres_add(dev, mtrr);
+
+	return ret;
+}
+EXPORT_SYMBOL(devm_arch_phys_wc_add);
+
+struct arch_io_reserve_memtype_wc_devres {
+	resource_size_t start;
+	resource_size_t size;
+};
+
+static void devm_arch_io_free_memtype_wc_release(struct device *dev, void *res)
+{
+	const struct arch_io_reserve_memtype_wc_devres *this = res;
+
+	arch_io_free_memtype_wc(this->start, this->size);
+}
+
+/**
+ * devm_arch_io_reserve_memtype_wc - Managed arch_io_reserve_memtype_wc()
+ * @dev: Managed device
+ * @start: Memory base address
+ * @size: Size of memory range
+ *
+ * Reserves a memory range with WC caching using arch_io_reserve_memtype_wc()
+ * and sets up a release callback See arch_io_reserve_memtype_wc() for more
+ * information.
+ */
+int devm_arch_io_reserve_memtype_wc(struct device *dev, resource_size_t start,
+				    resource_size_t size)
+{
+	struct arch_io_reserve_memtype_wc_devres *dr;
+	int ret;
+
+	dr = devres_alloc_node(devm_arch_io_free_memtype_wc_release, sizeof(*dr), GFP_KERNEL,
+			       dev_to_node(dev));
+	if (!dr)
+		return -ENOMEM;
+
+	ret = arch_io_reserve_memtype_wc(start, size);
+	if (ret < 0) {
+		devres_free(dr);
+		return ret;
+	}
+
+	dr->start = start;
+	dr->size = size;
+	devres_add(dev, dr);
+
+	return ret;
+}
+EXPORT_SYMBOL(devm_arch_io_reserve_memtype_wc);