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, 411 insertions, 0 deletions

diff --git a/drivers/acpi/arm64/mpam.c b/drivers/acpi/arm64/mpam.c
new file mode 100644
index 000000000..84963a20c
--- /dev/null
+++ b/drivers/acpi/arm64/mpam.c
@@ -0,0 +1,411 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2025 Arm Ltd.
+
+/* Parse the MPAM ACPI table feeding the discovered nodes into the driver */
+
+#define pr_fmt(fmt) "ACPI MPAM: " fmt
+
+#include <linux/acpi.h>
+#include <linux/arm_mpam.h>
+#include <linux/bits.h>
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
+#include <linux/platform_device.h>
+
+#include <acpi/processor.h>
+
+/*
+ * Flags for acpi_table_mpam_msc.*_interrupt_flags.
+ * See 2.1.1 Interrupt Flags, Table 5, of DEN0065B_MPAM_ACPI_3.0-bet.
+ */
+#define ACPI_MPAM_MSC_IRQ_MODE                              BIT(0)
+#define ACPI_MPAM_MSC_IRQ_TYPE_MASK                         GENMASK(2, 1)
+#define ACPI_MPAM_MSC_IRQ_TYPE_WIRED                        0
+#define ACPI_MPAM_MSC_IRQ_AFFINITY_TYPE_MASK                BIT(3)
+#define ACPI_MPAM_MSC_IRQ_AFFINITY_TYPE_PROCESSOR           0
+#define ACPI_MPAM_MSC_IRQ_AFFINITY_TYPE_PROCESSOR_CONTAINER 1
+#define ACPI_MPAM_MSC_IRQ_AFFINITY_VALID                    BIT(4)
+
+/*
+ * Encodings for the MSC node body interface type field.
+ * See 2.1 MPAM MSC node, Table 4 of DEN0065B_MPAM_ACPI_3.0-bet.
+ */
+#define ACPI_MPAM_MSC_IFACE_MMIO   0x00
+#define ACPI_MPAM_MSC_IFACE_PCC    0x0a
+
+static bool _is_ppi_partition(u32 flags)
+{
+	u32 aff_type, is_ppi;
+	bool ret;
+
+	is_ppi = FIELD_GET(ACPI_MPAM_MSC_IRQ_AFFINITY_VALID, flags);
+	if (!is_ppi)
+		return false;
+
+	aff_type = FIELD_GET(ACPI_MPAM_MSC_IRQ_AFFINITY_TYPE_MASK, flags);
+	ret = (aff_type == ACPI_MPAM_MSC_IRQ_AFFINITY_TYPE_PROCESSOR_CONTAINER);
+	if (ret)
+		pr_err_once("Partitioned interrupts not supported\n");
+
+	return ret;
+}
+
+static int acpi_mpam_register_irq(struct platform_device *pdev,
+				  u32 intid, u32 flags)
+{
+	int irq;
+	u32 int_type;
+	int trigger;
+
+	if (!intid)
+		return -EINVAL;
+
+	if (_is_ppi_partition(flags))
+		return -EINVAL;
+
+	trigger = FIELD_GET(ACPI_MPAM_MSC_IRQ_MODE, flags);
+	int_type = FIELD_GET(ACPI_MPAM_MSC_IRQ_TYPE_MASK, flags);
+	if (int_type != ACPI_MPAM_MSC_IRQ_TYPE_WIRED)
+		return -EINVAL;
+
+	irq = acpi_register_gsi(&pdev->dev, intid, trigger, ACPI_ACTIVE_HIGH);
+	if (irq < 0)
+		pr_err_once("Failed to register interrupt 0x%x with ACPI\n", intid);
+
+	return irq;
+}
+
+static void acpi_mpam_parse_irqs(struct platform_device *pdev,
+				 struct acpi_mpam_msc_node *tbl_msc,
+				 struct resource *res, int *res_idx)
+{
+	u32 flags, intid;
+	int irq;
+
+	intid = tbl_msc->overflow_interrupt;
+	flags = tbl_msc->overflow_interrupt_flags;
+	irq = acpi_mpam_register_irq(pdev, intid, flags);
+	if (irq > 0)
+		res[(*res_idx)++] = DEFINE_RES_IRQ_NAMED(irq, "overflow");
+
+	intid = tbl_msc->error_interrupt;
+	flags = tbl_msc->error_interrupt_flags;
+	irq = acpi_mpam_register_irq(pdev, intid, flags);
+	if (irq > 0)
+		res[(*res_idx)++] = DEFINE_RES_IRQ_NAMED(irq, "error");
+}
+
+static int acpi_mpam_parse_resource(struct mpam_msc *msc,
+				    struct acpi_mpam_resource_node *res)
+{
+	int level, nid;
+	u32 cache_id;
+
+	switch (res->locator_type) {
+	case ACPI_MPAM_LOCATION_TYPE_PROCESSOR_CACHE:
+		cache_id = res->locator.cache_locator.cache_reference;
+		level = find_acpi_cache_level_from_id(cache_id);
+		if (level <= 0) {
+			pr_err_once("Bad level (%d) for cache with id %u\n", level, cache_id);
+			return -EINVAL;
+		}
+		return mpam_ris_create(msc, res->ris_index, MPAM_CLASS_CACHE,
+				       level, cache_id);
+	case ACPI_MPAM_LOCATION_TYPE_MEMORY:
+		nid = pxm_to_node(res->locator.memory_locator.proximity_domain);
+		if (nid == NUMA_NO_NODE) {
+			pr_debug("Bad proximity domain %lld, using node 0 instead\n",
+				 res->locator.memory_locator.proximity_domain);
+			nid = 0;
+		}
+		return mpam_ris_create(msc, res->ris_index, MPAM_CLASS_MEMORY,
+				       MPAM_CLASS_ID_DEFAULT, nid);
+	default:
+		/* These get discovered later and are treated as unknown */
+		return 0;
+	}
+}
+
+int acpi_mpam_parse_resources(struct mpam_msc *msc,
+			      struct acpi_mpam_msc_node *tbl_msc)
+{
+	int i, err;
+	char *ptr, *table_end;
+	struct acpi_mpam_resource_node *resource;
+
+	table_end = (char *)tbl_msc + tbl_msc->length;
+	ptr = (char *)(tbl_msc + 1);
+	for (i = 0; i < tbl_msc->num_resource_nodes; i++) {
+		u64 max_deps, remaining_table;
+
+		if (ptr + sizeof(*resource) > table_end)
+			return -EINVAL;
+
+		resource = (struct acpi_mpam_resource_node *)ptr;
+
+		remaining_table = table_end - ptr;
+		max_deps = remaining_table / sizeof(struct acpi_mpam_func_deps);
+		if (resource->num_functional_deps > max_deps) {
+			pr_debug("MSC has impossible number of functional dependencies\n");
+			return -EINVAL;
+		}
+
+		err = acpi_mpam_parse_resource(msc, resource);
+		if (err)
+			return err;
+
+		ptr += sizeof(*resource);
+		ptr += resource->num_functional_deps * sizeof(struct acpi_mpam_func_deps);
+	}
+
+	return 0;
+}
+
+/*
+ * Creates the device power management link and returns true if the
+ * acpi id is valid and usable for cpu affinity.  This is the case
+ * when the linked device is a processor or a processor container.
+ */
+static bool __init parse_msc_pm_link(struct acpi_mpam_msc_node *tbl_msc,
+				     struct platform_device *pdev,
+				     u32 *acpi_id)
+{
+	char hid[sizeof(tbl_msc->hardware_id_linked_device) + 1] = { 0 };
+	bool acpi_id_valid = false;
+	struct acpi_device *buddy;
+	char uid[11];
+	int len;
+
+	memcpy(hid, &tbl_msc->hardware_id_linked_device,
+	       sizeof(tbl_msc->hardware_id_linked_device));
+
+	if (!strcmp(hid, ACPI_PROCESSOR_CONTAINER_HID)) {
+		*acpi_id = tbl_msc->instance_id_linked_device;
+		acpi_id_valid = true;
+	}
+
+	len = snprintf(uid, sizeof(uid), "%u",
+		       tbl_msc->instance_id_linked_device);
+	if (len >= sizeof(uid)) {
+		pr_debug("Failed to convert uid of device for power management.");
+		return acpi_id_valid;
+	}
+
+	buddy = acpi_dev_get_first_match_dev(hid, uid, -1);
+	if (buddy) {
+		device_link_add(&pdev->dev, &buddy->dev, DL_FLAG_STATELESS);
+		acpi_dev_put(buddy);
+	}
+
+	return acpi_id_valid;
+}
+
+static int decode_interface_type(struct acpi_mpam_msc_node *tbl_msc,
+				 enum mpam_msc_iface *iface)
+{
+	switch (tbl_msc->interface_type) {
+	case ACPI_MPAM_MSC_IFACE_MMIO:
+		*iface = MPAM_IFACE_MMIO;
+		return 0;
+	case ACPI_MPAM_MSC_IFACE_PCC:
+		*iface = MPAM_IFACE_PCC;
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+static struct platform_device * __init acpi_mpam_parse_msc(struct acpi_mpam_msc_node *tbl_msc)
+{
+	struct platform_device *pdev __free(platform_device_put) =
+		platform_device_alloc("mpam_msc", tbl_msc->identifier);
+	int next_res = 0, next_prop = 0, err;
+	/* pcc, nrdy, affinity and a sentinel */
+	struct property_entry props[4] = { 0 };
+	/* mmio, 2xirq, no sentinel. */
+	struct resource res[3] = { 0 };
+	struct acpi_device *companion;
+	enum mpam_msc_iface iface;
+	char uid[16];
+	u32 acpi_id;
+
+	if (!pdev)
+		return ERR_PTR(-ENOMEM);
+
+	/* Some power management is described in the namespace: */
+	err = snprintf(uid, sizeof(uid), "%u", tbl_msc->identifier);
+	if (err > 0 && err < sizeof(uid)) {
+		companion = acpi_dev_get_first_match_dev("ARMHAA5C", uid, -1);
+		if (companion) {
+			ACPI_COMPANION_SET(&pdev->dev, companion);
+			acpi_dev_put(companion);
+		} else {
+			pr_debug("MSC.%u: missing namespace entry\n", tbl_msc->identifier);
+		}
+	}
+
+	if (decode_interface_type(tbl_msc, &iface)) {
+		pr_debug("MSC.%u: unknown interface type\n", tbl_msc->identifier);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (iface == MPAM_IFACE_MMIO) {
+		res[next_res++] = DEFINE_RES_MEM_NAMED(tbl_msc->base_address,
+						       tbl_msc->mmio_size,
+						       "MPAM:MSC");
+	} else if (iface == MPAM_IFACE_PCC) {
+		props[next_prop++] = PROPERTY_ENTRY_U32("pcc-channel",
+							tbl_msc->base_address);
+	}
+
+	acpi_mpam_parse_irqs(pdev, tbl_msc, res, &next_res);
+
+	WARN_ON_ONCE(next_res > ARRAY_SIZE(res));
+	err = platform_device_add_resources(pdev, res, next_res);
+	if (err)
+		return ERR_PTR(err);
+
+	props[next_prop++] = PROPERTY_ENTRY_U32("arm,not-ready-us",
+						tbl_msc->max_nrdy_usec);
+
+	/*
+	 * The MSC's CPU affinity is described via its linked power
+	 * management device, but only if it points at a Processor or
+	 * Processor Container.
+	 */
+	if (parse_msc_pm_link(tbl_msc, pdev, &acpi_id))
+		props[next_prop++] = PROPERTY_ENTRY_U32("cpu_affinity", acpi_id);
+
+	WARN_ON_ONCE(next_prop > ARRAY_SIZE(props) - 1);
+	err = device_create_managed_software_node(&pdev->dev, props, NULL);
+	if (err)
+		return ERR_PTR(err);
+
+	/*
+	 * Stash the table entry for acpi_mpam_parse_resources() to discover
+	 * what this MSC controls.
+	 */
+	err = platform_device_add_data(pdev, tbl_msc, tbl_msc->length);
+	if (err)
+		return ERR_PTR(err);
+
+	err = platform_device_add(pdev);
+	if (err)
+		return ERR_PTR(err);
+
+	return_ptr(pdev);
+}
+
+static int __init acpi_mpam_parse(void)
+{
+	char *table_end, *table_offset;
+	struct acpi_mpam_msc_node *tbl_msc;
+	struct platform_device *pdev;
+
+	if (acpi_disabled || !system_supports_mpam())
+		return 0;
+
+	struct acpi_table_header *table __free(acpi_put_table) =
+		acpi_get_table_pointer(ACPI_SIG_MPAM, 0);
+
+	if (IS_ERR(table))
+		return 0;
+
+	if (table->revision < 1) {
+		pr_debug("MPAM ACPI table revision %d not supported\n", table->revision);
+		return 0;
+	}
+
+	table_offset = (char *)(table + 1);
+	table_end = (char *)table + table->length;
+
+	while (table_offset < table_end) {
+		tbl_msc = (struct acpi_mpam_msc_node *)table_offset;
+		if (table_offset + sizeof(*tbl_msc) > table_end ||
+		    table_offset + tbl_msc->length > table_end) {
+			pr_err("MSC entry overlaps end of ACPI table\n");
+			return -EINVAL;
+		}
+		table_offset += tbl_msc->length;
+
+		/*
+		 * If any of the reserved fields are set, make no attempt to
+		 * parse the MSC structure. This MSC will still be counted by
+		 * acpi_mpam_count_msc(), meaning the MPAM driver can't probe
+		 * against all MSC, and will never be enabled. There is no way
+		 * to enable it safely, because we cannot determine safe
+		 * system-wide partid and pmg ranges in this situation.
+		 */
+		if (tbl_msc->reserved || tbl_msc->reserved1 || tbl_msc->reserved2) {
+			pr_err_once("Unrecognised MSC, MPAM not usable\n");
+			pr_debug("MSC.%u: reserved field set\n", tbl_msc->identifier);
+			continue;
+		}
+
+		if (!tbl_msc->mmio_size) {
+			pr_debug("MSC.%u: marked as disabled\n", tbl_msc->identifier);
+			continue;
+		}
+
+		pdev = acpi_mpam_parse_msc(tbl_msc);
+		if (IS_ERR(pdev))
+			return PTR_ERR(pdev);
+	}
+
+	return 0;
+}
+
+/**
+ * acpi_mpam_count_msc() - Count the number of MSC described by firmware.
+ *
+ * Returns the number of MSCs, or zero for an error.
+ *
+ * This can be called before or in parallel with acpi_mpam_parse().
+ */
+int acpi_mpam_count_msc(void)
+{
+	char *table_end, *table_offset;
+	struct acpi_mpam_msc_node *tbl_msc;
+	int count = 0;
+
+	if (acpi_disabled || !system_supports_mpam())
+		return 0;
+
+	struct acpi_table_header *table __free(acpi_put_table) =
+		acpi_get_table_pointer(ACPI_SIG_MPAM, 0);
+
+	if (IS_ERR(table))
+		return 0;
+
+	if (table->revision < 1)
+		return 0;
+
+	table_offset = (char *)(table + 1);
+	table_end = (char *)table + table->length;
+
+	while (table_offset < table_end) {
+		tbl_msc = (struct acpi_mpam_msc_node *)table_offset;
+
+		if (table_offset + sizeof(*tbl_msc) > table_end)
+			return -EINVAL;
+		if (tbl_msc->length < sizeof(*tbl_msc))
+			return -EINVAL;
+		if (tbl_msc->length > table_end - table_offset)
+			return -EINVAL;
+		table_offset += tbl_msc->length;
+
+		if (!tbl_msc->mmio_size)
+			continue;
+
+		count++;
+	}
+
+	return count;
+}
+
+/*
+ * Call after ACPI devices have been created, which happens behind acpi_scan_init()
+ * called from subsys_initcall(). PCC requires the mailbox driver, which is
+ * initialised from postcore_initcall().
+ */
+subsys_initcall_sync(acpi_mpam_parse);