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, 552 insertions, 0 deletions

diff --git a/fs/hfs/extent.c b/fs/hfs/extent.c
new file mode 100644
index 000000000..f066a99a8
--- /dev/null
+++ b/fs/hfs/extent.c
@@ -0,0 +1,552 @@
+/*
+ *  linux/fs/hfs/extent.c
+ *
+ * Copyright (C) 1995-1997  Paul H. Hargrove
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ * This file may be distributed under the terms of the GNU General Public License.
+ *
+ * This file contains the functions related to the extents B-tree.
+ */
+
+#include <linux/pagemap.h>
+
+#include "hfs_fs.h"
+#include "btree.h"
+
+/*================ File-local functions ================*/
+
+/*
+ * build_key
+ */
+static void hfs_ext_build_key(hfs_btree_key *key, u32 cnid, u16 block, u8 type)
+{
+	key->key_len = 7;
+	key->ext.FkType = type;
+	key->ext.FNum = cpu_to_be32(cnid);
+	key->ext.FABN = cpu_to_be16(block);
+}
+
+/*
+ * hfs_ext_compare()
+ *
+ * Description:
+ *   This is the comparison function used for the extents B-tree.  In
+ *   comparing extent B-tree entries, the file id is the most
+ *   significant field (compared as unsigned ints); the fork type is
+ *   the second most significant field (compared as unsigned chars);
+ *   and the allocation block number field is the least significant
+ *   (compared as unsigned ints).
+ * Input Variable(s):
+ *   struct hfs_ext_key *key1: pointer to the first key to compare
+ *   struct hfs_ext_key *key2: pointer to the second key to compare
+ * Output Variable(s):
+ *   NONE
+ * Returns:
+ *   int: negative if key1<key2, positive if key1>key2, and 0 if key1==key2
+ * Preconditions:
+ *   key1 and key2 point to "valid" (struct hfs_ext_key)s.
+ * Postconditions:
+ *   This function has no side-effects */
+int hfs_ext_keycmp(const btree_key *key1, const btree_key *key2)
+{
+	__be32 fnum1, fnum2;
+	__be16 block1, block2;
+
+	fnum1 = key1->ext.FNum;
+	fnum2 = key2->ext.FNum;
+	if (fnum1 != fnum2)
+		return be32_to_cpu(fnum1) < be32_to_cpu(fnum2) ? -1 : 1;
+	if (key1->ext.FkType != key2->ext.FkType)
+		return key1->ext.FkType < key2->ext.FkType ? -1 : 1;
+
+	block1 = key1->ext.FABN;
+	block2 = key2->ext.FABN;
+	if (block1 == block2)
+		return 0;
+	return be16_to_cpu(block1) < be16_to_cpu(block2) ? -1 : 1;
+}
+
+/*
+ * hfs_ext_find_block
+ *
+ * Find a block within an extent record
+ */
+u16 hfs_ext_find_block(struct hfs_extent *ext, u16 off)
+{
+	int i;
+	u16 count;
+
+	for (i = 0; i < 3; ext++, i++) {
+		count = be16_to_cpu(ext->count);
+		if (off < count)
+			return be16_to_cpu(ext->block) + off;
+		off -= count;
+	}
+	/* panic? */
+	return 0;
+}
+
+static int hfs_ext_block_count(struct hfs_extent *ext)
+{
+	int i;
+	u16 count = 0;
+
+	for (i = 0; i < 3; ext++, i++)
+		count += be16_to_cpu(ext->count);
+	return count;
+}
+
+static u16 hfs_ext_lastblock(struct hfs_extent *ext)
+{
+	int i;
+
+	ext += 2;
+	for (i = 0; i < 2; ext--, i++)
+		if (ext->count)
+			break;
+	return be16_to_cpu(ext->block) + be16_to_cpu(ext->count);
+}
+
+static int __hfs_ext_write_extent(struct inode *inode, struct hfs_find_data *fd)
+{
+	int res;
+
+	hfs_ext_build_key(fd->search_key, inode->i_ino, HFS_I(inode)->cached_start,
+			  HFS_IS_RSRC(inode) ?  HFS_FK_RSRC : HFS_FK_DATA);
+	res = hfs_brec_find(fd);
+	if (HFS_I(inode)->flags & HFS_FLG_EXT_NEW) {
+		if (res != -ENOENT)
+			return res;
+		/* Fail early and avoid ENOSPC during the btree operation */
+		res = hfs_bmap_reserve(fd->tree, fd->tree->depth + 1);
+		if (res)
+			return res;
+		hfs_brec_insert(fd, HFS_I(inode)->cached_extents, sizeof(hfs_extent_rec));
+		HFS_I(inode)->flags &= ~(HFS_FLG_EXT_DIRTY|HFS_FLG_EXT_NEW);
+	} else {
+		if (res)
+			return res;
+		hfs_bnode_write(fd->bnode, HFS_I(inode)->cached_extents, fd->entryoffset, fd->entrylength);
+		HFS_I(inode)->flags &= ~HFS_FLG_EXT_DIRTY;
+	}
+	return 0;
+}
+
+int hfs_ext_write_extent(struct inode *inode)
+{
+	struct hfs_find_data fd;
+	int res = 0;
+
+	if (HFS_I(inode)->flags & HFS_FLG_EXT_DIRTY) {
+		res = hfs_find_init(HFS_SB(inode->i_sb)->ext_tree, &fd);
+		if (res)
+			return res;
+		res = __hfs_ext_write_extent(inode, &fd);
+		hfs_find_exit(&fd);
+	}
+	return res;
+}
+
+static inline int __hfs_ext_read_extent(struct hfs_find_data *fd, struct hfs_extent *extent,
+					u32 cnid, u32 block, u8 type)
+{
+	int res;
+
+	hfs_ext_build_key(fd->search_key, cnid, block, type);
+	fd->key->ext.FNum = 0;
+	res = hfs_brec_find(fd);
+	if (res && res != -ENOENT)
+		return res;
+	if (fd->key->ext.FNum != fd->search_key->ext.FNum ||
+	    fd->key->ext.FkType != fd->search_key->ext.FkType)
+		return -ENOENT;
+	if (fd->entrylength != sizeof(hfs_extent_rec))
+		return -EIO;
+	hfs_bnode_read(fd->bnode, extent, fd->entryoffset, sizeof(hfs_extent_rec));
+	return 0;
+}
+
+static inline int __hfs_ext_cache_extent(struct hfs_find_data *fd, struct inode *inode, u32 block)
+{
+	int res;
+
+	if (HFS_I(inode)->flags & HFS_FLG_EXT_DIRTY) {
+		res = __hfs_ext_write_extent(inode, fd);
+		if (res)
+			return res;
+	}
+
+	res = __hfs_ext_read_extent(fd, HFS_I(inode)->cached_extents, inode->i_ino,
+				    block, HFS_IS_RSRC(inode) ? HFS_FK_RSRC : HFS_FK_DATA);
+	if (!res) {
+		HFS_I(inode)->cached_start = be16_to_cpu(fd->key->ext.FABN);
+		HFS_I(inode)->cached_blocks = hfs_ext_block_count(HFS_I(inode)->cached_extents);
+	} else {
+		HFS_I(inode)->cached_start = HFS_I(inode)->cached_blocks = 0;
+		HFS_I(inode)->flags &= ~(HFS_FLG_EXT_DIRTY|HFS_FLG_EXT_NEW);
+	}
+	return res;
+}
+
+static int hfs_ext_read_extent(struct inode *inode, u16 block)
+{
+	struct hfs_find_data fd;
+	int res;
+
+	if (block >= HFS_I(inode)->cached_start &&
+	    block < HFS_I(inode)->cached_start + HFS_I(inode)->cached_blocks)
+		return 0;
+
+	res = hfs_find_init(HFS_SB(inode->i_sb)->ext_tree, &fd);
+	if (!res) {
+		res = __hfs_ext_cache_extent(&fd, inode, block);
+		hfs_find_exit(&fd);
+	}
+	return res;
+}
+
+static void hfs_dump_extent(struct hfs_extent *extent)
+{
+	int i;
+
+	hfs_dbg("extent:   ");
+	for (i = 0; i < 3; i++)
+		hfs_dbg(" block %u, count %u",
+			be16_to_cpu(extent[i].block),
+			be16_to_cpu(extent[i].count));
+	hfs_dbg("\n");
+}
+
+static int hfs_add_extent(struct hfs_extent *extent, u16 offset,
+			  u16 alloc_block, u16 block_count)
+{
+	u16 count, start;
+	int i;
+
+	hfs_dump_extent(extent);
+	for (i = 0; i < 3; extent++, i++) {
+		count = be16_to_cpu(extent->count);
+		if (offset == count) {
+			start = be16_to_cpu(extent->block);
+			if (alloc_block != start + count) {
+				if (++i >= 3)
+					return -ENOSPC;
+				extent++;
+				extent->block = cpu_to_be16(alloc_block);
+			} else
+				block_count += count;
+			extent->count = cpu_to_be16(block_count);
+			return 0;
+		} else if (offset < count)
+			break;
+		offset -= count;
+	}
+	/* panic? */
+	return -EIO;
+}
+
+static int hfs_free_extents(struct super_block *sb, struct hfs_extent *extent,
+			    u16 offset, u16 block_nr)
+{
+	u16 count, start;
+	int i;
+
+	hfs_dump_extent(extent);
+	for (i = 0; i < 3; extent++, i++) {
+		count = be16_to_cpu(extent->count);
+		if (offset == count)
+			goto found;
+		else if (offset < count)
+			break;
+		offset -= count;
+	}
+	/* panic? */
+	return -EIO;
+found:
+	for (;;) {
+		start = be16_to_cpu(extent->block);
+		if (count <= block_nr) {
+			hfs_clear_vbm_bits(sb, start, count);
+			extent->block = 0;
+			extent->count = 0;
+			block_nr -= count;
+		} else {
+			count -= block_nr;
+			hfs_clear_vbm_bits(sb, start + count, block_nr);
+			extent->count = cpu_to_be16(count);
+			block_nr = 0;
+		}
+		if (!block_nr || !i)
+			return 0;
+		i--;
+		extent--;
+		count = be16_to_cpu(extent->count);
+	}
+}
+
+int hfs_free_fork(struct super_block *sb, struct hfs_cat_file *file, int type)
+{
+	struct hfs_find_data fd;
+	u32 total_blocks, blocks, start;
+	u32 cnid = be32_to_cpu(file->FlNum);
+	struct hfs_extent *extent;
+	int res, i;
+
+	if (type == HFS_FK_DATA) {
+		total_blocks = be32_to_cpu(file->PyLen);
+		extent = file->ExtRec;
+	} else {
+		total_blocks = be32_to_cpu(file->RPyLen);
+		extent = file->RExtRec;
+	}
+	total_blocks /= HFS_SB(sb)->alloc_blksz;
+	if (!total_blocks)
+		return 0;
+
+	blocks = 0;
+	for (i = 0; i < 3; i++)
+		blocks += be16_to_cpu(extent[i].count);
+
+	res = hfs_free_extents(sb, extent, blocks, blocks);
+	if (res)
+		return res;
+	if (total_blocks == blocks)
+		return 0;
+
+	res = hfs_find_init(HFS_SB(sb)->ext_tree, &fd);
+	if (res)
+		return res;
+	do {
+		res = __hfs_ext_read_extent(&fd, extent, cnid, total_blocks, type);
+		if (res)
+			break;
+		start = be16_to_cpu(fd.key->ext.FABN);
+		hfs_free_extents(sb, extent, total_blocks - start, total_blocks);
+		hfs_brec_remove(&fd);
+		total_blocks = start;
+	} while (total_blocks > blocks);
+	hfs_find_exit(&fd);
+
+	return res;
+}
+
+/*
+ * hfs_get_block
+ */
+int hfs_get_block(struct inode *inode, sector_t block,
+		  struct buffer_head *bh_result, int create)
+{
+	struct super_block *sb;
+	u16 dblock, ablock;
+	int res;
+
+	sb = inode->i_sb;
+	/* Convert inode block to disk allocation block */
+	ablock = (u32)block / HFS_SB(sb)->fs_div;
+
+	if (block >= HFS_I(inode)->fs_blocks) {
+		if (!create)
+			return 0;
+		if (block > HFS_I(inode)->fs_blocks)
+			return -EIO;
+		if (ablock >= HFS_I(inode)->alloc_blocks) {
+			res = hfs_extend_file(inode);
+			if (res)
+				return res;
+		}
+	} else
+		create = 0;
+
+	if (ablock < HFS_I(inode)->first_blocks) {
+		dblock = hfs_ext_find_block(HFS_I(inode)->first_extents, ablock);
+		goto done;
+	}
+
+	mutex_lock(&HFS_I(inode)->extents_lock);
+	res = hfs_ext_read_extent(inode, ablock);
+	if (!res)
+		dblock = hfs_ext_find_block(HFS_I(inode)->cached_extents,
+					    ablock - HFS_I(inode)->cached_start);
+	else {
+		mutex_unlock(&HFS_I(inode)->extents_lock);
+		return -EIO;
+	}
+	mutex_unlock(&HFS_I(inode)->extents_lock);
+
+done:
+	map_bh(bh_result, sb, HFS_SB(sb)->fs_start +
+	       dblock * HFS_SB(sb)->fs_div +
+	       (u32)block % HFS_SB(sb)->fs_div);
+
+	if (create) {
+		set_buffer_new(bh_result);
+		HFS_I(inode)->phys_size += sb->s_blocksize;
+		HFS_I(inode)->fs_blocks++;
+		inode_add_bytes(inode, sb->s_blocksize);
+		mark_inode_dirty(inode);
+	}
+	return 0;
+}
+
+int hfs_extend_file(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+	u32 start, len, goal;
+	int res;
+
+	mutex_lock(&HFS_I(inode)->extents_lock);
+	if (HFS_I(inode)->alloc_blocks == HFS_I(inode)->first_blocks)
+		goal = hfs_ext_lastblock(HFS_I(inode)->first_extents);
+	else {
+		res = hfs_ext_read_extent(inode, HFS_I(inode)->alloc_blocks);
+		if (res)
+			goto out;
+		goal = hfs_ext_lastblock(HFS_I(inode)->cached_extents);
+	}
+
+	len = HFS_I(inode)->clump_blocks;
+	start = hfs_vbm_search_free(sb, goal, &len);
+	if (!len) {
+		res = -ENOSPC;
+		goto out;
+	}
+
+	hfs_dbg("ino %llu, start %u, len %u\n", inode->i_ino, start, len);
+	if (HFS_I(inode)->alloc_blocks == HFS_I(inode)->first_blocks) {
+		if (!HFS_I(inode)->first_blocks) {
+			hfs_dbg("first_extent: start %u, len %u\n",
+				start, len);
+			/* no extents yet */
+			HFS_I(inode)->first_extents[0].block = cpu_to_be16(start);
+			HFS_I(inode)->first_extents[0].count = cpu_to_be16(len);
+			res = 0;
+		} else {
+			/* try to append to extents in inode */
+			res = hfs_add_extent(HFS_I(inode)->first_extents,
+					     HFS_I(inode)->alloc_blocks,
+					     start, len);
+			if (res == -ENOSPC)
+				goto insert_extent;
+		}
+		if (!res) {
+			hfs_dump_extent(HFS_I(inode)->first_extents);
+			HFS_I(inode)->first_blocks += len;
+		}
+	} else {
+		res = hfs_add_extent(HFS_I(inode)->cached_extents,
+				     HFS_I(inode)->alloc_blocks -
+				     HFS_I(inode)->cached_start,
+				     start, len);
+		if (!res) {
+			hfs_dump_extent(HFS_I(inode)->cached_extents);
+			HFS_I(inode)->flags |= HFS_FLG_EXT_DIRTY;
+			HFS_I(inode)->cached_blocks += len;
+		} else if (res == -ENOSPC)
+			goto insert_extent;
+	}
+out:
+	mutex_unlock(&HFS_I(inode)->extents_lock);
+	if (!res) {
+		HFS_I(inode)->alloc_blocks += len;
+		mark_inode_dirty(inode);
+		if (inode->i_ino < HFS_FIRSTUSER_CNID)
+			set_bit(HFS_FLG_ALT_MDB_DIRTY, &HFS_SB(sb)->flags);
+		set_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags);
+		hfs_mark_mdb_dirty(sb);
+	}
+	return res;
+
+insert_extent:
+	hfs_dbg("insert new extent\n");
+	res = hfs_ext_write_extent(inode);
+	if (res)
+		goto out;
+
+	memset(HFS_I(inode)->cached_extents, 0, sizeof(hfs_extent_rec));
+	HFS_I(inode)->cached_extents[0].block = cpu_to_be16(start);
+	HFS_I(inode)->cached_extents[0].count = cpu_to_be16(len);
+	hfs_dump_extent(HFS_I(inode)->cached_extents);
+	HFS_I(inode)->flags |= HFS_FLG_EXT_DIRTY|HFS_FLG_EXT_NEW;
+	HFS_I(inode)->cached_start = HFS_I(inode)->alloc_blocks;
+	HFS_I(inode)->cached_blocks = len;
+
+	res = 0;
+	goto out;
+}
+
+void hfs_file_truncate(struct inode *inode)
+{
+	struct super_block *sb = inode->i_sb;
+	struct hfs_find_data fd;
+	u16 blk_cnt, alloc_cnt, start;
+	u32 size;
+	int res;
+
+	hfs_dbg("ino %llu, phys_size %llu -> i_size %llu\n",
+		inode->i_ino, (long long)HFS_I(inode)->phys_size,
+		inode->i_size);
+	if (inode->i_size > HFS_I(inode)->phys_size) {
+		struct address_space *mapping = inode->i_mapping;
+		void *fsdata = NULL;
+		struct folio *folio;
+
+		/* XXX: Can use generic_cont_expand? */
+		size = inode->i_size - 1;
+		res = hfs_write_begin(NULL, mapping, size + 1, 0, &folio,
+				&fsdata);
+		if (!res) {
+			res = generic_write_end(NULL, mapping, size + 1, 0, 0,
+					folio, fsdata);
+		}
+		if (res)
+			inode->i_size = HFS_I(inode)->phys_size;
+		return;
+	} else if (inode->i_size == HFS_I(inode)->phys_size)
+		return;
+	size = inode->i_size + HFS_SB(sb)->alloc_blksz - 1;
+	blk_cnt = size / HFS_SB(sb)->alloc_blksz;
+	alloc_cnt = HFS_I(inode)->alloc_blocks;
+	if (blk_cnt == alloc_cnt)
+		goto out;
+
+	mutex_lock(&HFS_I(inode)->extents_lock);
+	res = hfs_find_init(HFS_SB(sb)->ext_tree, &fd);
+	if (res) {
+		mutex_unlock(&HFS_I(inode)->extents_lock);
+		/* XXX: We lack error handling of hfs_file_truncate() */
+		return;
+	}
+	while (1) {
+		if (alloc_cnt == HFS_I(inode)->first_blocks) {
+			hfs_free_extents(sb, HFS_I(inode)->first_extents,
+					 alloc_cnt, alloc_cnt - blk_cnt);
+			hfs_dump_extent(HFS_I(inode)->first_extents);
+			HFS_I(inode)->first_blocks = blk_cnt;
+			break;
+		}
+		res = __hfs_ext_cache_extent(&fd, inode, alloc_cnt);
+		if (res)
+			break;
+		start = HFS_I(inode)->cached_start;
+		hfs_free_extents(sb, HFS_I(inode)->cached_extents,
+				 alloc_cnt - start, alloc_cnt - blk_cnt);
+		hfs_dump_extent(HFS_I(inode)->cached_extents);
+		if (blk_cnt > start) {
+			HFS_I(inode)->flags |= HFS_FLG_EXT_DIRTY;
+			break;
+		}
+		alloc_cnt = start;
+		HFS_I(inode)->cached_start = HFS_I(inode)->cached_blocks = 0;
+		HFS_I(inode)->flags &= ~(HFS_FLG_EXT_DIRTY|HFS_FLG_EXT_NEW);
+		hfs_brec_remove(&fd);
+	}
+	hfs_find_exit(&fd);
+	mutex_unlock(&HFS_I(inode)->extents_lock);
+
+	HFS_I(inode)->alloc_blocks = blk_cnt;
+out:
+	HFS_I(inode)->phys_size = inode->i_size;
+	HFS_I(inode)->fs_blocks = (inode->i_size + sb->s_blocksize - 1) >> sb->s_blocksize_bits;
+	inode_set_bytes(inode, HFS_I(inode)->fs_blocks << sb->s_blocksize_bits);
+	mark_inode_dirty(inode);
+}