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, 462 insertions, 0 deletions

diff --git a/drivers/dma/acpi-dma.c b/drivers/dma/acpi-dma.c
new file mode 100644
index 000000000..be73021ec
--- /dev/null
+++ b/drivers/dma/acpi-dma.c
@@ -0,0 +1,462 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ACPI helpers for DMA request / controller
+ *
+ * Based on of-dma.c
+ *
+ * Copyright (C) 2013, Intel Corporation
+ * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+ *	    Mika Westerberg <mika.westerberg@linux.intel.com>
+ */
+
+#include <linux/acpi.h>
+#include <linux/acpi_dma.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/mutex.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+static LIST_HEAD(acpi_dma_list);
+static DEFINE_MUTEX(acpi_dma_lock);
+
+/**
+ * acpi_dma_parse_resource_group - match device and parse resource group
+ * @grp:	CSRT resource group
+ * @adev:	ACPI device to match with
+ * @adma:	struct acpi_dma of the given DMA controller
+ *
+ * In order to match a device from DSDT table to the corresponding CSRT device
+ * we use MMIO address and IRQ.
+ *
+ * Return:
+ * 1 on success, 0 when no information is available, or appropriate errno value
+ * on error.
+ */
+static int acpi_dma_parse_resource_group(const struct acpi_csrt_group *grp,
+		struct acpi_device *adev, struct acpi_dma *adma)
+{
+	const struct acpi_csrt_shared_info *si;
+	struct list_head resource_list;
+	struct resource_entry *rentry;
+	resource_size_t mem = 0, irq = 0;
+	int ret;
+
+	if (grp->shared_info_length != sizeof(struct acpi_csrt_shared_info))
+		return -ENODEV;
+
+	INIT_LIST_HEAD(&resource_list);
+	ret = acpi_dev_get_resources(adev, &resource_list, NULL, NULL);
+	if (ret <= 0)
+		return 0;
+
+	list_for_each_entry(rentry, &resource_list, node) {
+		if (resource_type(rentry->res) == IORESOURCE_MEM)
+			mem = rentry->res->start;
+		else if (resource_type(rentry->res) == IORESOURCE_IRQ)
+			irq = rentry->res->start;
+	}
+
+	acpi_dev_free_resource_list(&resource_list);
+
+	/* Consider initial zero values as resource not found */
+	if (mem == 0 && irq == 0)
+		return 0;
+
+	si = (const struct acpi_csrt_shared_info *)&grp[1];
+
+	/* Match device by MMIO */
+	if (si->mmio_base_low != lower_32_bits(mem) ||
+	    si->mmio_base_high != upper_32_bits(mem))
+		return 0;
+
+	/*
+	 * acpi_gsi_to_irq() can't be used because some platforms do not save
+	 * registered IRQs in the MP table. Instead we just try to register
+	 * the GSI, which is the core part of the above mentioned function.
+	 */
+	ret = acpi_register_gsi(NULL, si->gsi_interrupt, si->interrupt_mode, si->interrupt_polarity);
+	if (ret < 0)
+		return 0;
+
+	/* Match device by Linux vIRQ */
+	if (ret != irq)
+		return 0;
+
+	dev_dbg(&adev->dev, "matches with %.4s%04X (rev %u)\n",
+		(char *)&grp->vendor_id, grp->device_id, grp->revision);
+
+	/* Check if the request line range is available */
+	if (si->base_request_line == 0 && si->num_handshake_signals == 0)
+		return 0;
+
+	/* Set up DMA mask based on value from CSRT */
+	ret = dma_coerce_mask_and_coherent(&adev->dev,
+					   DMA_BIT_MASK(si->dma_address_width));
+	if (ret)
+		return 0;
+
+	adma->base_request_line = si->base_request_line;
+	adma->end_request_line = si->base_request_line +
+				 si->num_handshake_signals - 1;
+
+	dev_dbg(&adev->dev, "request line base: 0x%04x end: 0x%04x\n",
+		adma->base_request_line, adma->end_request_line);
+
+	return 1;
+}
+
+/**
+ * acpi_dma_parse_csrt - parse CSRT to extract additional DMA resources
+ * @adev:	ACPI device to match with
+ * @adma:	struct acpi_dma of the given DMA controller
+ *
+ * CSRT or Core System Resources Table is a proprietary ACPI table
+ * introduced by Microsoft. This table can contain devices that are not in
+ * the system DSDT table. In particular DMA controllers might be described
+ * here.
+ *
+ * We are using this table to get the request line range of the specific DMA
+ * controller to be used later.
+ */
+static void acpi_dma_parse_csrt(struct acpi_device *adev, struct acpi_dma *adma)
+{
+	struct acpi_csrt_group *grp, *end;
+	struct acpi_table_csrt *csrt;
+	acpi_status status;
+	int ret;
+
+	status = acpi_get_table(ACPI_SIG_CSRT, 0,
+				(struct acpi_table_header **)&csrt);
+	if (ACPI_FAILURE(status)) {
+		if (status != AE_NOT_FOUND)
+			dev_warn(&adev->dev, "failed to get the CSRT table\n");
+		return;
+	}
+
+	grp = (struct acpi_csrt_group *)(csrt + 1);
+	end = (struct acpi_csrt_group *)((void *)csrt + csrt->header.length);
+
+	while (grp < end) {
+		ret = acpi_dma_parse_resource_group(grp, adev, adma);
+		if (ret < 0) {
+			dev_warn(&adev->dev,
+				 "error in parsing resource group\n");
+			break;
+		}
+
+		grp = (struct acpi_csrt_group *)((void *)grp + grp->length);
+	}
+
+	acpi_put_table((struct acpi_table_header *)csrt);
+}
+
+/**
+ * acpi_dma_controller_register - Register a DMA controller to ACPI DMA helpers
+ * @dev:		struct device of DMA controller
+ * @acpi_dma_xlate:	translation function which converts a dma specifier
+ *			into a dma_chan structure
+ * @data:		pointer to controller specific data to be used by
+ *			translation function
+ *
+ * Allocated memory should be freed with appropriate acpi_dma_controller_free()
+ * call.
+ *
+ * Return:
+ * 0 on success or appropriate errno value on error.
+ */
+int acpi_dma_controller_register(struct device *dev,
+		struct dma_chan *(*acpi_dma_xlate)
+		(struct acpi_dma_spec *, struct acpi_dma *),
+		void *data)
+{
+	struct acpi_device *adev;
+	struct acpi_dma	*adma;
+
+	if (!dev || !acpi_dma_xlate)
+		return -EINVAL;
+
+	/* Check if the device was enumerated by ACPI */
+	adev = ACPI_COMPANION(dev);
+	if (!adev)
+		return -EINVAL;
+
+	adma = kzalloc_obj(*adma);
+	if (!adma)
+		return -ENOMEM;
+
+	adma->dev = dev;
+	adma->acpi_dma_xlate = acpi_dma_xlate;
+	adma->data = data;
+
+	acpi_dma_parse_csrt(adev, adma);
+
+	/* Now queue acpi_dma controller structure in list */
+	mutex_lock(&acpi_dma_lock);
+	list_add_tail(&adma->dma_controllers, &acpi_dma_list);
+	mutex_unlock(&acpi_dma_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(acpi_dma_controller_register);
+
+/**
+ * acpi_dma_controller_free - Remove a DMA controller from ACPI DMA helpers list
+ * @dev:	struct device of DMA controller
+ *
+ * Memory allocated by acpi_dma_controller_register() is freed here.
+ *
+ * Return:
+ * 0 on success or appropriate errno value on error.
+ */
+int acpi_dma_controller_free(struct device *dev)
+{
+	struct acpi_dma *adma;
+
+	if (!dev)
+		return -EINVAL;
+
+	mutex_lock(&acpi_dma_lock);
+
+	list_for_each_entry(adma, &acpi_dma_list, dma_controllers)
+		if (adma->dev == dev) {
+			list_del(&adma->dma_controllers);
+			mutex_unlock(&acpi_dma_lock);
+			kfree(adma);
+			return 0;
+		}
+
+	mutex_unlock(&acpi_dma_lock);
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(acpi_dma_controller_free);
+
+static void devm_acpi_dma_free(void *dev)
+{
+	acpi_dma_controller_free(dev);
+}
+
+/**
+ * devm_acpi_dma_controller_register - resource managed acpi_dma_controller_register()
+ * @dev:		device that is registering this DMA controller
+ * @acpi_dma_xlate:	translation function
+ * @data:		pointer to controller specific data
+ *
+ * Managed acpi_dma_controller_register(). DMA controller registered by this
+ * function are automatically freed on driver detach. See
+ * acpi_dma_controller_register() for more information.
+ *
+ * Return:
+ * 0 on success or appropriate errno value on error.
+ */
+int devm_acpi_dma_controller_register(struct device *dev,
+		struct dma_chan *(*acpi_dma_xlate)
+		(struct acpi_dma_spec *, struct acpi_dma *),
+		void *data)
+{
+	int ret;
+
+	ret = acpi_dma_controller_register(dev, acpi_dma_xlate, data);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(dev, devm_acpi_dma_free, dev);
+}
+EXPORT_SYMBOL_GPL(devm_acpi_dma_controller_register);
+
+/**
+ * acpi_dma_update_dma_spec - prepare dma specifier to pass to translation function
+ * @adma:	struct acpi_dma of DMA controller
+ * @dma_spec:	dma specifier to update
+ *
+ * Accordingly to ACPI 5.0 Specification Table 6-170 "Fixed DMA Resource
+ * Descriptor":
+ *	DMA Request Line bits is a platform-relative number uniquely
+ *	identifying the request line assigned. Request line-to-Controller
+ *	mapping is done in a controller-specific OS driver.
+ * That's why we can safely adjust slave_id when the appropriate controller is
+ * found.
+ *
+ * Return:
+ * 0, if no information is available, -1 on mismatch, and 1 otherwise.
+ */
+static int acpi_dma_update_dma_spec(struct acpi_dma *adma,
+		struct acpi_dma_spec *dma_spec)
+{
+	/* Set link to the DMA controller device */
+	dma_spec->dev = adma->dev;
+
+	/* Check if the request line range is available */
+	if (adma->base_request_line == 0 && adma->end_request_line == 0)
+		return 0;
+
+	/* Check if slave_id falls to the range */
+	if (dma_spec->slave_id < adma->base_request_line ||
+	    dma_spec->slave_id > adma->end_request_line)
+		return -1;
+
+	/*
+	 * Here we adjust slave_id. It should be a relative number to the base
+	 * request line.
+	 */
+	dma_spec->slave_id -= adma->base_request_line;
+
+	return 1;
+}
+
+struct acpi_dma_parser_data {
+	struct acpi_dma_spec dma_spec;
+	size_t index;
+	size_t n;
+};
+
+/**
+ * acpi_dma_parse_fixed_dma - Parse FixedDMA ACPI resources to a DMA specifier
+ * @res:	struct acpi_resource to get FixedDMA resources from
+ * @data:	pointer to a helper struct acpi_dma_parser_data
+ */
+static int acpi_dma_parse_fixed_dma(struct acpi_resource *res, void *data)
+{
+	struct acpi_dma_parser_data *pdata = data;
+
+	if (res->type == ACPI_RESOURCE_TYPE_FIXED_DMA) {
+		struct acpi_resource_fixed_dma *dma = &res->data.fixed_dma;
+
+		if (pdata->n++ == pdata->index) {
+			pdata->dma_spec.chan_id = dma->channels;
+			pdata->dma_spec.slave_id = dma->request_lines;
+		}
+	}
+
+	/* Tell the ACPI core to skip this resource */
+	return 1;
+}
+
+/**
+ * acpi_dma_request_slave_chan_by_index - Get the DMA slave channel
+ * @dev:	struct device to get DMA request from
+ * @index:	index of FixedDMA descriptor for @dev
+ *
+ * Return:
+ * Pointer to appropriate dma channel on success or an error pointer.
+ */
+struct dma_chan *acpi_dma_request_slave_chan_by_index(struct device *dev,
+		size_t index)
+{
+	struct acpi_dma_parser_data pdata;
+	struct acpi_dma_spec *dma_spec = &pdata.dma_spec;
+	struct acpi_device *adev = ACPI_COMPANION(dev);
+	struct list_head resource_list;
+	struct acpi_dma *adma;
+	struct dma_chan *chan = NULL;
+	int found;
+	int ret;
+
+	memset(&pdata, 0, sizeof(pdata));
+	pdata.index = index;
+
+	/* Initial values for the request line and channel */
+	dma_spec->chan_id = -1;
+	dma_spec->slave_id = -1;
+
+	INIT_LIST_HEAD(&resource_list);
+	ret = acpi_dev_get_resources(adev, &resource_list,
+				     acpi_dma_parse_fixed_dma, &pdata);
+	acpi_dev_free_resource_list(&resource_list);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	if (dma_spec->slave_id < 0 || dma_spec->chan_id < 0)
+		return ERR_PTR(-ENODEV);
+
+	mutex_lock(&acpi_dma_lock);
+
+	list_for_each_entry(adma, &acpi_dma_list, dma_controllers) {
+		/*
+		 * We are not going to call translation function if slave_id
+		 * doesn't fall to the request range.
+		 */
+		found = acpi_dma_update_dma_spec(adma, dma_spec);
+		if (found < 0)
+			continue;
+		chan = adma->acpi_dma_xlate(dma_spec, adma);
+		/*
+		 * Try to get a channel only from the DMA controller that
+		 * matches the slave_id. See acpi_dma_update_dma_spec()
+		 * description for the details.
+		 */
+		if (found > 0 || chan)
+			break;
+	}
+
+	mutex_unlock(&acpi_dma_lock);
+	return chan ? chan : ERR_PTR(-EPROBE_DEFER);
+}
+EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_index);
+
+/**
+ * acpi_dma_request_slave_chan_by_name - Get the DMA slave channel
+ * @dev:	struct device to get DMA request from
+ * @name:	represents corresponding FixedDMA descriptor for @dev
+ *
+ * In order to support both Device Tree and ACPI in a single driver we
+ * translate the names "tx" and "rx" here based on the most common case where
+ * the first FixedDMA descriptor is TX and second is RX.
+ *
+ * If the device has "dma-names" property the FixedDMA descriptor indices
+ * are retrieved based on those. Otherwise the function falls back using
+ * hardcoded indices.
+ *
+ * Return:
+ * Pointer to appropriate dma channel on success or an error pointer.
+ */
+struct dma_chan *acpi_dma_request_slave_chan_by_name(struct device *dev,
+		const char *name)
+{
+	int index;
+
+	index = device_property_match_string(dev, "dma-names", name);
+	if (index < 0) {
+		if (!strcmp(name, "tx"))
+			index = 0;
+		else if (!strcmp(name, "rx"))
+			index = 1;
+		else
+			return ERR_PTR(-ENODEV);
+	}
+
+	dev_dbg(dev, "Looking for DMA channel \"%s\" at index %d...\n", name, index);
+	return acpi_dma_request_slave_chan_by_index(dev, index);
+}
+EXPORT_SYMBOL_GPL(acpi_dma_request_slave_chan_by_name);
+
+/**
+ * acpi_dma_simple_xlate - Simple ACPI DMA engine translation helper
+ * @dma_spec: pointer to ACPI DMA specifier
+ * @adma: pointer to ACPI DMA controller data
+ *
+ * A simple translation function for ACPI based devices. Passes &struct
+ * dma_spec to the DMA controller driver provided filter function.
+ *
+ * Return:
+ * Pointer to the channel if found or %NULL otherwise.
+ */
+struct dma_chan *acpi_dma_simple_xlate(struct acpi_dma_spec *dma_spec,
+		struct acpi_dma *adma)
+{
+	struct acpi_dma_filter_info *info = adma->data;
+
+	if (!info || !info->filter_fn)
+		return NULL;
+
+	return dma_request_channel(info->dma_cap, info->filter_fn, dma_spec);
+}
+EXPORT_SYMBOL_GPL(acpi_dma_simple_xlate);