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, 478 insertions, 0 deletions

diff --git a/drivers/md/dm-pcache/cache.c b/drivers/md/dm-pcache/cache.c
new file mode 100644
index 000000000..b0b3e2167
--- /dev/null
+++ b/drivers/md/dm-pcache/cache.c
@@ -0,0 +1,478 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <linux/blk_types.h>
+
+#include "cache.h"
+#include "cache_dev.h"
+#include "backing_dev.h"
+#include "dm_pcache.h"
+
+struct kmem_cache *key_cache;
+
+static inline struct pcache_cache_info *get_cache_info_addr(struct pcache_cache *cache)
+{
+	return (struct pcache_cache_info *)((char *)cache->cache_info_addr +
+						(size_t)cache->info_index * PCACHE_CACHE_INFO_SIZE);
+}
+
+static void cache_info_write(struct pcache_cache *cache)
+{
+	struct pcache_cache_info *cache_info = &cache->cache_info;
+
+	cache_info->header.seq++;
+	cache_info->header.crc = pcache_meta_crc(&cache_info->header,
+						sizeof(struct pcache_cache_info));
+
+	cache->info_index = (cache->info_index + 1) % PCACHE_META_INDEX_MAX;
+	memcpy_flushcache(get_cache_info_addr(cache), cache_info,
+			sizeof(struct pcache_cache_info));
+	pmem_wmb();
+}
+
+static void cache_info_init_default(struct pcache_cache *cache);
+static int cache_info_init(struct pcache_cache *cache, struct pcache_cache_options *opts)
+{
+	struct dm_pcache *pcache = CACHE_TO_PCACHE(cache);
+	struct pcache_cache_info *cache_info_addr;
+
+	cache_info_addr = pcache_meta_find_latest(&cache->cache_info_addr->header,
+						sizeof(struct pcache_cache_info),
+						PCACHE_CACHE_INFO_SIZE,
+						&cache->cache_info);
+	if (IS_ERR(cache_info_addr))
+		return PTR_ERR(cache_info_addr);
+
+	if (cache_info_addr) {
+		if (opts->data_crc !=
+				(cache->cache_info.flags & PCACHE_CACHE_FLAGS_DATA_CRC)) {
+			pcache_dev_err(pcache, "invalid option for data_crc: %s, expected: %s",
+					opts->data_crc ? "true" : "false",
+					cache->cache_info.flags & PCACHE_CACHE_FLAGS_DATA_CRC ? "true" : "false");
+			return -EINVAL;
+		}
+
+		cache->info_index = ((char *)cache_info_addr - (char *)cache->cache_info_addr) / PCACHE_CACHE_INFO_SIZE;
+
+		return 0;
+	}
+
+	/* init cache_info for new cache */
+	cache_info_init_default(cache);
+	cache_mode_set(cache, opts->cache_mode);
+	if (opts->data_crc)
+		cache->cache_info.flags |= PCACHE_CACHE_FLAGS_DATA_CRC;
+
+	return 0;
+}
+
+static void cache_info_set_gc_percent(struct pcache_cache_info *cache_info, u8 percent)
+{
+	cache_info->flags &= ~PCACHE_CACHE_FLAGS_GC_PERCENT_MASK;
+	cache_info->flags |= FIELD_PREP(PCACHE_CACHE_FLAGS_GC_PERCENT_MASK, percent);
+}
+
+int pcache_cache_set_gc_percent(struct pcache_cache *cache, u8 percent)
+{
+	if (percent > PCACHE_CACHE_GC_PERCENT_MAX || percent < PCACHE_CACHE_GC_PERCENT_MIN)
+		return -EINVAL;
+
+	mutex_lock(&cache->cache_info_lock);
+	cache_info_set_gc_percent(&cache->cache_info, percent);
+
+	cache_info_write(cache);
+	mutex_unlock(&cache->cache_info_lock);
+
+	return 0;
+}
+
+void cache_pos_encode(struct pcache_cache *cache,
+			     struct pcache_cache_pos_onmedia *pos_onmedia_base,
+			     struct pcache_cache_pos *pos, u64 seq, u32 *index)
+{
+	struct pcache_cache_pos_onmedia pos_onmedia;
+	struct pcache_cache_pos_onmedia *pos_onmedia_addr = pos_onmedia_base + *index;
+
+	pos_onmedia.cache_seg_id = pos->cache_seg->cache_seg_id;
+	pos_onmedia.seg_off = pos->seg_off;
+	pos_onmedia.header.seq = seq;
+	pos_onmedia.header.crc = cache_pos_onmedia_crc(&pos_onmedia);
+
+	*index = (*index + 1) % PCACHE_META_INDEX_MAX;
+
+	memcpy_flushcache(pos_onmedia_addr, &pos_onmedia, sizeof(struct pcache_cache_pos_onmedia));
+	pmem_wmb();
+}
+
+int cache_pos_decode(struct pcache_cache *cache,
+			    struct pcache_cache_pos_onmedia *pos_onmedia,
+			    struct pcache_cache_pos *pos, u64 *seq, u32 *index)
+{
+	struct pcache_cache_pos_onmedia latest, *latest_addr;
+
+	latest_addr = pcache_meta_find_latest(&pos_onmedia->header,
+					sizeof(struct pcache_cache_pos_onmedia),
+					sizeof(struct pcache_cache_pos_onmedia),
+					&latest);
+	if (IS_ERR(latest_addr))
+		return PTR_ERR(latest_addr);
+
+	if (!latest_addr)
+		return -EIO;
+
+	if (!cache_seg_id_valid(cache, latest.cache_seg_id))
+		return -EIO;
+
+	pos->cache_seg = &cache->segments[latest.cache_seg_id];
+
+	if (latest.seg_off >= pos->cache_seg->segment.data_size)
+		return -EIO;
+
+	pos->seg_off = latest.seg_off;
+	*seq = latest.header.seq;
+	*index = (latest_addr - pos_onmedia);
+
+	return 0;
+}
+
+static inline void cache_info_set_seg_id(struct pcache_cache *cache, u32 seg_id)
+{
+	cache->cache_info.seg_id = seg_id;
+}
+
+static int cache_init(struct dm_pcache *pcache)
+{
+	struct pcache_cache *cache = &pcache->cache;
+	struct pcache_backing_dev *backing_dev = &pcache->backing_dev;
+	struct pcache_cache_dev *cache_dev = &pcache->cache_dev;
+	int ret;
+
+	cache->segments = kvzalloc_objs(struct pcache_cache_segment,
+					cache_dev->seg_num);
+	if (!cache->segments) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	cache->seg_map = kvcalloc(BITS_TO_LONGS(cache_dev->seg_num), sizeof(unsigned long), GFP_KERNEL);
+	if (!cache->seg_map) {
+		ret = -ENOMEM;
+		goto free_segments;
+	}
+
+	cache->backing_dev = backing_dev;
+	cache->cache_dev = &pcache->cache_dev;
+	cache->n_segs = cache_dev->seg_num;
+	atomic_set(&cache->gc_errors, 0);
+	atomic_set(&cache->writeback_errors, 0);
+	spin_lock_init(&cache->seg_map_lock);
+	spin_lock_init(&cache->key_head_lock);
+
+	mutex_init(&cache->cache_info_lock);
+	mutex_init(&cache->key_tail_lock);
+	mutex_init(&cache->dirty_tail_lock);
+	mutex_init(&cache->writeback_lock);
+
+	INIT_DELAYED_WORK(&cache->writeback_work, cache_writeback_fn);
+	INIT_DELAYED_WORK(&cache->gc_work, pcache_cache_gc_fn);
+	INIT_WORK(&cache->clean_work, clean_fn);
+
+	return 0;
+
+free_segments:
+	kvfree(cache->segments);
+err:
+	return ret;
+}
+
+static void cache_exit(struct pcache_cache *cache)
+{
+	kvfree(cache->seg_map);
+	kvfree(cache->segments);
+}
+
+static void cache_info_init_default(struct pcache_cache *cache)
+{
+	struct pcache_cache_info *cache_info = &cache->cache_info;
+
+	memset(cache_info, 0, sizeof(*cache_info));
+	cache_info->n_segs = cache->cache_dev->seg_num;
+	cache_info_set_gc_percent(cache_info, PCACHE_CACHE_GC_PERCENT_DEFAULT);
+}
+
+static int cache_tail_init(struct pcache_cache *cache)
+{
+	struct dm_pcache *pcache = CACHE_TO_PCACHE(cache);
+	bool new_cache = !(cache->cache_info.flags & PCACHE_CACHE_FLAGS_INIT_DONE);
+	int ret;
+
+	if (new_cache) {
+		__set_bit(0, cache->seg_map);
+
+		cache->key_head.cache_seg = &cache->segments[0];
+		cache->key_head.seg_off = 0;
+		cache_pos_copy(&cache->key_tail, &cache->key_head);
+		cache_pos_copy(&cache->dirty_tail, &cache->key_head);
+
+		cache_encode_dirty_tail(cache);
+		cache_encode_key_tail(cache);
+	} else {
+		if (cache_decode_key_tail(cache) || cache_decode_dirty_tail(cache)) {
+			pcache_dev_err(pcache, "Corrupted key tail or dirty tail.\n");
+			return -EIO;
+		}
+
+		ret = cache_verify_dirty_tail(cache);
+		if (ret) {
+			pcache_dev_err(pcache, "dirty tail chain does not terminate (crafted cache image?)\n");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static int get_seg_id(struct pcache_cache *cache,
+		      struct pcache_cache_segment *prev_cache_seg,
+		      bool new_cache, u32 *seg_id)
+{
+	struct dm_pcache *pcache = CACHE_TO_PCACHE(cache);
+	struct pcache_cache_dev *cache_dev = cache->cache_dev;
+	int ret;
+
+	if (new_cache) {
+		ret = cache_dev_get_empty_segment_id(cache_dev, seg_id);
+		if (ret) {
+			pcache_dev_err(pcache, "no available segment\n");
+			goto err;
+		}
+
+		if (prev_cache_seg)
+			cache_seg_set_next_seg(prev_cache_seg, *seg_id);
+		else
+			cache_info_set_seg_id(cache, *seg_id);
+	} else {
+		if (prev_cache_seg) {
+			struct pcache_segment_info *prev_seg_info;
+
+			prev_seg_info = &prev_cache_seg->cache_seg_info;
+			if (!segment_info_has_next(prev_seg_info)) {
+				ret = -EFAULT;
+				goto err;
+			}
+			*seg_id = prev_cache_seg->cache_seg_info.next_seg;
+		} else {
+			*seg_id = cache->cache_info.seg_id;
+		}
+
+		if (*seg_id >= cache_dev->seg_num) {
+			pcache_dev_err(pcache, "invalid segment id %u from cache device (seg_num %u)\n",
+				       *seg_id, cache_dev->seg_num);
+			ret = -EIO;
+			goto err;
+		}
+	}
+	return 0;
+err:
+	return ret;
+}
+
+static int cache_segs_init(struct pcache_cache *cache)
+{
+	struct pcache_cache_segment *prev_cache_seg = NULL;
+	struct pcache_cache_info *cache_info = &cache->cache_info;
+	bool new_cache = !(cache->cache_info.flags & PCACHE_CACHE_FLAGS_INIT_DONE);
+	u32 seg_id;
+	int ret;
+	u32 i;
+
+	if (cache_info->n_segs > cache->cache_dev->seg_num) {
+		pcache_dev_err(CACHE_TO_PCACHE(cache),
+			       "cache_info n_segs %u exceeds cache device segments %u\n",
+			       cache_info->n_segs, cache->cache_dev->seg_num);
+		return -EIO;
+	}
+
+	for (i = 0; i < cache_info->n_segs; i++) {
+		ret = get_seg_id(cache, prev_cache_seg, new_cache, &seg_id);
+		if (ret)
+			goto err;
+
+		ret = cache_seg_init(cache, seg_id, i, new_cache);
+		if (ret)
+			goto err;
+
+		prev_cache_seg = &cache->segments[i];
+	}
+	return 0;
+err:
+	return ret;
+}
+
+static int cache_init_req_keys(struct pcache_cache *cache, u32 n_paral)
+{
+	struct dm_pcache *pcache = CACHE_TO_PCACHE(cache);
+	u32 n_subtrees;
+	int ret;
+	u32 i, cpu;
+
+	/* Calculate number of cache trees based on the device size */
+	n_subtrees = DIV_ROUND_UP(cache->dev_size << SECTOR_SHIFT, PCACHE_CACHE_SUBTREE_SIZE);
+	ret = cache_tree_init(cache, &cache->req_key_tree, n_subtrees);
+	if (ret)
+		goto err;
+
+	cache->n_ksets = n_paral;
+	cache->ksets = kvcalloc(cache->n_ksets, PCACHE_KSET_SIZE, GFP_KERNEL);
+	if (!cache->ksets) {
+		ret = -ENOMEM;
+		goto req_tree_exit;
+	}
+
+	/*
+	 * Initialize each kset with a spinlock and delayed work for flushing.
+	 * Each kset is associated with one queue to ensure independent handling
+	 * of cache keys across multiple queues, maximizing multiqueue concurrency.
+	 */
+	for (i = 0; i < cache->n_ksets; i++) {
+		struct pcache_cache_kset *kset = get_kset(cache, i);
+
+		kset->cache = cache;
+		spin_lock_init(&kset->kset_lock);
+		INIT_DELAYED_WORK(&kset->flush_work, kset_flush_fn);
+	}
+
+	cache->data_heads = alloc_percpu(struct pcache_cache_data_head);
+	if (!cache->data_heads) {
+		ret = -ENOMEM;
+		goto free_kset;
+	}
+
+	for_each_possible_cpu(cpu) {
+		struct pcache_cache_data_head *h =
+			per_cpu_ptr(cache->data_heads, cpu);
+		h->head_pos.cache_seg = NULL;
+	}
+
+	/*
+	 * Replay persisted cache keys using cache_replay.
+	 * This function loads and replays cache keys from previously stored
+	 * ksets, allowing the cache to restore its state after a restart.
+	 */
+	ret = cache_replay(cache);
+	if (ret) {
+		pcache_dev_err(pcache, "failed to replay keys\n");
+		goto free_heads;
+	}
+
+	return 0;
+
+free_heads:
+	free_percpu(cache->data_heads);
+free_kset:
+	kvfree(cache->ksets);
+req_tree_exit:
+	cache_tree_exit(&cache->req_key_tree);
+err:
+	return ret;
+}
+
+static void cache_destroy_req_keys(struct pcache_cache *cache)
+{
+	u32 i;
+
+	for (i = 0; i < cache->n_ksets; i++) {
+		struct pcache_cache_kset *kset = get_kset(cache, i);
+
+		cancel_delayed_work_sync(&kset->flush_work);
+	}
+
+	free_percpu(cache->data_heads);
+	kvfree(cache->ksets);
+	cache_tree_exit(&cache->req_key_tree);
+}
+
+int pcache_cache_start(struct dm_pcache *pcache)
+{
+	struct pcache_backing_dev *backing_dev = &pcache->backing_dev;
+	struct pcache_cache *cache = &pcache->cache;
+	struct pcache_cache_options *opts = &pcache->opts;
+	int ret;
+
+	ret = cache_init(pcache);
+	if (ret)
+		return ret;
+
+	cache->cache_info_addr = CACHE_DEV_CACHE_INFO(cache->cache_dev);
+	cache->cache_ctrl = CACHE_DEV_CACHE_CTRL(cache->cache_dev);
+	backing_dev->cache = cache;
+	cache->dev_size = backing_dev->dev_size;
+
+	ret = cache_info_init(cache, opts);
+	if (ret)
+		goto cache_exit;
+
+	ret = cache_segs_init(cache);
+	if (ret)
+		goto cache_exit;
+
+	ret = cache_tail_init(cache);
+	if (ret)
+		goto cache_exit;
+
+	ret = cache_init_req_keys(cache, num_online_cpus());
+	if (ret)
+		goto cache_exit;
+
+	ret = cache_writeback_init(cache);
+	if (ret)
+		goto destroy_keys;
+
+	cache->cache_info.flags |= PCACHE_CACHE_FLAGS_INIT_DONE;
+	cache_info_write(cache);
+	queue_delayed_work(cache_get_wq(cache), &cache->gc_work, 0);
+
+	return 0;
+
+destroy_keys:
+	cache_destroy_req_keys(cache);
+cache_exit:
+	cache_exit(cache);
+
+	return ret;
+}
+
+void pcache_cache_stop(struct dm_pcache *pcache)
+{
+	struct pcache_cache *cache = &pcache->cache;
+
+	pcache_cache_flush(cache);
+
+	cancel_delayed_work_sync(&cache->gc_work);
+	flush_work(&cache->clean_work);
+	cache_writeback_exit(cache);
+
+	if (cache->req_key_tree.n_subtrees)
+		cache_destroy_req_keys(cache);
+
+	cache_exit(cache);
+}
+
+struct workqueue_struct *cache_get_wq(struct pcache_cache *cache)
+{
+	struct dm_pcache *pcache = CACHE_TO_PCACHE(cache);
+
+	return pcache->task_wq;
+}
+
+int pcache_cache_init(void)
+{
+	key_cache = KMEM_CACHE(pcache_cache_key, 0);
+	if (!key_cache)
+		return -ENOMEM;
+
+	return 0;
+}
+
+void pcache_cache_exit(void)
+{
+	kmem_cache_destroy(key_cache);
+}