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, 395 insertions, 0 deletions

diff --git a/lib/test_parman.c b/lib/test_parman.c
new file mode 100644
index 000000000..28f095118
--- /dev/null
+++ b/lib/test_parman.c
@@ -0,0 +1,395 @@
+/*
+ * lib/test_parman.c - Test module for parman
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Jiri Pirko <jiri@mellanox.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/prandom.h>
+#include <linux/parman.h>
+
+#define TEST_PARMAN_PRIO_SHIFT 7 /* defines number of prios for testing */
+#define TEST_PARMAN_PRIO_COUNT BIT(TEST_PARMAN_PRIO_SHIFT)
+#define TEST_PARMAN_PRIO_MASK (TEST_PARMAN_PRIO_COUNT - 1)
+
+#define TEST_PARMAN_ITEM_SHIFT 13 /* defines a total number
+				   * of items for testing
+				   */
+#define TEST_PARMAN_ITEM_COUNT BIT(TEST_PARMAN_ITEM_SHIFT)
+#define TEST_PARMAN_ITEM_MASK (TEST_PARMAN_ITEM_COUNT - 1)
+
+#define TEST_PARMAN_BASE_SHIFT 8
+#define TEST_PARMAN_BASE_COUNT BIT(TEST_PARMAN_BASE_SHIFT)
+#define TEST_PARMAN_RESIZE_STEP_SHIFT 7
+#define TEST_PARMAN_RESIZE_STEP_COUNT BIT(TEST_PARMAN_RESIZE_STEP_SHIFT)
+
+#define TEST_PARMAN_BULK_MAX_SHIFT (2 + TEST_PARMAN_RESIZE_STEP_SHIFT)
+#define TEST_PARMAN_BULK_MAX_COUNT BIT(TEST_PARMAN_BULK_MAX_SHIFT)
+#define TEST_PARMAN_BULK_MAX_MASK (TEST_PARMAN_BULK_MAX_COUNT - 1)
+
+#define TEST_PARMAN_RUN_BUDGET (TEST_PARMAN_ITEM_COUNT * 256)
+
+struct test_parman_prio {
+	struct parman_prio parman_prio;
+	unsigned long priority;
+};
+
+struct test_parman_item {
+	struct parman_item parman_item;
+	struct test_parman_prio *prio;
+	bool used;
+};
+
+struct test_parman {
+	struct parman *parman;
+	struct test_parman_item **prio_array;
+	unsigned long prio_array_limit;
+	struct test_parman_prio prios[TEST_PARMAN_PRIO_COUNT];
+	struct test_parman_item items[TEST_PARMAN_ITEM_COUNT];
+	struct rnd_state rnd;
+	unsigned long run_budget;
+	unsigned long bulk_budget;
+	bool bulk_noop;
+	unsigned int used_items;
+};
+
+#define ITEM_PTRS_SIZE(count) (sizeof(struct test_parman_item *) * (count))
+
+static int test_parman_resize(void *priv, unsigned long new_count)
+{
+	struct test_parman *test_parman = priv;
+	struct test_parman_item **prio_array;
+	unsigned long old_count;
+
+	prio_array = krealloc(test_parman->prio_array,
+			      ITEM_PTRS_SIZE(new_count), GFP_KERNEL);
+	if (new_count == 0)
+		return 0;
+	if (!prio_array)
+		return -ENOMEM;
+	old_count = test_parman->prio_array_limit;
+	if (new_count > old_count)
+		memset(&prio_array[old_count], 0,
+		       ITEM_PTRS_SIZE(new_count - old_count));
+	test_parman->prio_array = prio_array;
+	test_parman->prio_array_limit = new_count;
+	return 0;
+}
+
+static void test_parman_move(void *priv, unsigned long from_index,
+			     unsigned long to_index, unsigned long count)
+{
+	struct test_parman *test_parman = priv;
+	struct test_parman_item **prio_array = test_parman->prio_array;
+
+	memmove(&prio_array[to_index], &prio_array[from_index],
+		ITEM_PTRS_SIZE(count));
+	memset(&prio_array[from_index], 0, ITEM_PTRS_SIZE(count));
+}
+
+static const struct parman_ops test_parman_lsort_ops = {
+	.base_count	= TEST_PARMAN_BASE_COUNT,
+	.resize_step	= TEST_PARMAN_RESIZE_STEP_COUNT,
+	.resize		= test_parman_resize,
+	.move		= test_parman_move,
+	.algo		= PARMAN_ALGO_TYPE_LSORT,
+};
+
+static void test_parman_rnd_init(struct test_parman *test_parman)
+{
+	prandom_seed_state(&test_parman->rnd, 3141592653589793238ULL);
+}
+
+static u32 test_parman_rnd_get(struct test_parman *test_parman)
+{
+	return prandom_u32_state(&test_parman->rnd);
+}
+
+static unsigned long test_parman_priority_gen(struct test_parman *test_parman)
+{
+	unsigned long priority;
+	int i;
+
+again:
+	priority = test_parman_rnd_get(test_parman);
+	if (priority == 0)
+		goto again;
+
+	for (i = 0; i < TEST_PARMAN_PRIO_COUNT; i++) {
+		struct test_parman_prio *prio = &test_parman->prios[i];
+
+		if (prio->priority == 0)
+			break;
+		if (prio->priority == priority)
+			goto again;
+	}
+	return priority;
+}
+
+static void test_parman_prios_init(struct test_parman *test_parman)
+{
+	int i;
+
+	for (i = 0; i < TEST_PARMAN_PRIO_COUNT; i++) {
+		struct test_parman_prio *prio = &test_parman->prios[i];
+
+		/* Assign random uniqueue priority to each prio structure */
+		prio->priority = test_parman_priority_gen(test_parman);
+		parman_prio_init(test_parman->parman, &prio->parman_prio,
+				 prio->priority);
+	}
+}
+
+static void test_parman_prios_fini(struct test_parman *test_parman)
+{
+	int i;
+
+	for (i = 0; i < TEST_PARMAN_PRIO_COUNT; i++) {
+		struct test_parman_prio *prio = &test_parman->prios[i];
+
+		parman_prio_fini(&prio->parman_prio);
+	}
+}
+
+static void test_parman_items_init(struct test_parman *test_parman)
+{
+	int i;
+
+	for (i = 0; i < TEST_PARMAN_ITEM_COUNT; i++) {
+		struct test_parman_item *item = &test_parman->items[i];
+		unsigned int prio_index = test_parman_rnd_get(test_parman) &
+					  TEST_PARMAN_PRIO_MASK;
+
+		/* Assign random prio to each item structure */
+		item->prio = &test_parman->prios[prio_index];
+	}
+}
+
+static void test_parman_items_fini(struct test_parman *test_parman)
+{
+	int i;
+
+	for (i = 0; i < TEST_PARMAN_ITEM_COUNT; i++) {
+		struct test_parman_item *item = &test_parman->items[i];
+
+		if (!item->used)
+			continue;
+		parman_item_remove(test_parman->parman,
+				   &item->prio->parman_prio,
+				   &item->parman_item);
+	}
+}
+
+static struct test_parman *test_parman_create(const struct parman_ops *ops)
+{
+	struct test_parman *test_parman;
+	int err;
+
+	test_parman = kzalloc_obj(*test_parman);
+	if (!test_parman)
+		return ERR_PTR(-ENOMEM);
+	err = test_parman_resize(test_parman, TEST_PARMAN_BASE_COUNT);
+	if (err)
+		goto err_resize;
+	test_parman->parman = parman_create(ops, test_parman);
+	if (!test_parman->parman) {
+		err = -ENOMEM;
+		goto err_parman_create;
+	}
+	test_parman_rnd_init(test_parman);
+	test_parman_prios_init(test_parman);
+	test_parman_items_init(test_parman);
+	test_parman->run_budget = TEST_PARMAN_RUN_BUDGET;
+	return test_parman;
+
+err_parman_create:
+	test_parman_resize(test_parman, 0);
+err_resize:
+	kfree(test_parman);
+	return ERR_PTR(err);
+}
+
+static void test_parman_destroy(struct test_parman *test_parman)
+{
+	test_parman_items_fini(test_parman);
+	test_parman_prios_fini(test_parman);
+	parman_destroy(test_parman->parman);
+	test_parman_resize(test_parman, 0);
+	kfree(test_parman);
+}
+
+static bool test_parman_run_check_budgets(struct test_parman *test_parman)
+{
+	if (test_parman->run_budget-- == 0)
+		return false;
+	if (test_parman->bulk_budget-- != 0)
+		return true;
+
+	test_parman->bulk_budget = test_parman_rnd_get(test_parman) &
+				   TEST_PARMAN_BULK_MAX_MASK;
+	test_parman->bulk_noop = test_parman_rnd_get(test_parman) & 1;
+	return true;
+}
+
+static int test_parman_run(struct test_parman *test_parman)
+{
+	unsigned int i = test_parman_rnd_get(test_parman);
+	int err;
+
+	while (test_parman_run_check_budgets(test_parman)) {
+		unsigned int item_index = i++ & TEST_PARMAN_ITEM_MASK;
+		struct test_parman_item *item = &test_parman->items[item_index];
+
+		if (test_parman->bulk_noop)
+			continue;
+
+		if (!item->used) {
+			err = parman_item_add(test_parman->parman,
+					      &item->prio->parman_prio,
+					      &item->parman_item);
+			if (err)
+				return err;
+			test_parman->prio_array[item->parman_item.index] = item;
+			test_parman->used_items++;
+		} else {
+			test_parman->prio_array[item->parman_item.index] = NULL;
+			parman_item_remove(test_parman->parman,
+					   &item->prio->parman_prio,
+					   &item->parman_item);
+			test_parman->used_items--;
+		}
+		item->used = !item->used;
+	}
+	return 0;
+}
+
+static int test_parman_check_array(struct test_parman *test_parman,
+				   bool gaps_allowed)
+{
+	unsigned int last_unused_items = 0;
+	unsigned long last_priority = 0;
+	unsigned int used_items = 0;
+	int i;
+
+	if (test_parman->prio_array_limit < TEST_PARMAN_BASE_COUNT) {
+		pr_err("Array limit is lower than the base count (%lu < %lu)\n",
+		       test_parman->prio_array_limit, TEST_PARMAN_BASE_COUNT);
+		return -EINVAL;
+	}
+
+	for (i = 0; i < test_parman->prio_array_limit; i++) {
+		struct test_parman_item *item = test_parman->prio_array[i];
+
+		if (!item) {
+			last_unused_items++;
+			continue;
+		}
+		if (last_unused_items && !gaps_allowed) {
+			pr_err("Gap found in array even though they are forbidden\n");
+			return -EINVAL;
+		}
+
+		last_unused_items = 0;
+		used_items++;
+
+		if (item->prio->priority < last_priority) {
+			pr_err("Item belongs under higher priority then the last one (current: %lu, previous: %lu)\n",
+			       item->prio->priority, last_priority);
+			return -EINVAL;
+		}
+		last_priority = item->prio->priority;
+
+		if (item->parman_item.index != i) {
+			pr_err("Item has different index in compare to where it actually is (%lu != %d)\n",
+			       item->parman_item.index, i);
+			return -EINVAL;
+		}
+	}
+
+	if (used_items != test_parman->used_items) {
+		pr_err("Number of used items in array does not match (%u != %u)\n",
+		       used_items, test_parman->used_items);
+		return -EINVAL;
+	}
+
+	if (last_unused_items >= TEST_PARMAN_RESIZE_STEP_COUNT) {
+		pr_err("Number of unused item at the end of array is bigger than resize step (%u >= %lu)\n",
+		       last_unused_items, TEST_PARMAN_RESIZE_STEP_COUNT);
+		return -EINVAL;
+	}
+
+	pr_info("Priority array check successful\n");
+
+	return 0;
+}
+
+static int test_parman_lsort(void)
+{
+	struct test_parman *test_parman;
+	int err;
+
+	test_parman = test_parman_create(&test_parman_lsort_ops);
+	if (IS_ERR(test_parman))
+		return PTR_ERR(test_parman);
+
+	err = test_parman_run(test_parman);
+	if (err)
+		goto out;
+
+	err = test_parman_check_array(test_parman, false);
+	if (err)
+		goto out;
+out:
+	test_parman_destroy(test_parman);
+	return err;
+}
+
+static int __init test_parman_init(void)
+{
+	return test_parman_lsort();
+}
+
+static void __exit test_parman_exit(void)
+{
+}
+
+module_init(test_parman_init);
+module_exit(test_parman_exit);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("Jiri Pirko <jiri@mellanox.com>");
+MODULE_DESCRIPTION("Test module for parman");