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/fs/hfs/mdb.c b/fs/hfs/mdb.c
new file mode 100644
index 000000000..277de712f
--- /dev/null
+++ b/fs/hfs/mdb.c
@@ -0,0 +1,462 @@
+/*
+ *  linux/fs/hfs/mdb.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 functions for reading/writing the MDB.
+ */
+
+#include <linux/cdrom.h>
+#include <linux/blkdev.h>
+#include <linux/nls.h>
+#include <linux/slab.h>
+
+#include "hfs_fs.h"
+#include "btree.h"
+
+/*================ File-local data types ================*/
+
+/*
+ * The HFS Master Directory Block (MDB).
+ *
+ * Also known as the Volume Information Block (VIB), this structure is
+ * the HFS equivalent of a superblock.
+ *
+ * Reference: _Inside Macintosh: Files_ pages 2-59 through 2-62
+ *
+ * modified for HFS Extended
+ */
+
+static int hfs_get_last_session(struct super_block *sb,
+				sector_t *start, sector_t *size)
+{
+	struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk);
+
+	/* default values */
+	*start = 0;
+	*size = bdev_nr_sectors(sb->s_bdev);
+
+	if (HFS_SB(sb)->session >= 0) {
+		struct cdrom_tocentry te;
+	
+		if (!cdi)
+			return -EINVAL;
+
+		te.cdte_track = HFS_SB(sb)->session;
+		te.cdte_format = CDROM_LBA;
+		if (cdrom_read_tocentry(cdi, &te) ||
+		    (te.cdte_ctrl & CDROM_DATA_TRACK) != 4) {
+			pr_err("invalid session number or type of track\n");
+			return -EINVAL;
+		}
+
+		*start = (sector_t)te.cdte_addr.lba << 2;
+	} else if (cdi) {
+		struct cdrom_multisession ms_info;
+
+		ms_info.addr_format = CDROM_LBA;
+		if (cdrom_multisession(cdi, &ms_info) == 0 && ms_info.xa_flag)
+			*start = (sector_t)ms_info.addr.lba << 2;
+	}
+
+	return 0;
+}
+
+bool is_hfs_cnid_counts_valid(struct super_block *sb)
+{
+	struct hfs_sb_info *sbi = HFS_SB(sb);
+	bool corrupted = false;
+
+	if (unlikely(atomic64_read(&sbi->next_id) > U32_MAX)) {
+		pr_warn("next CNID exceeds limit\n");
+		corrupted = true;
+	}
+	if (unlikely(atomic64_read(&sbi->file_count) > U32_MAX)) {
+		pr_warn("file count exceeds limit\n");
+		corrupted = true;
+	}
+	if (unlikely(atomic64_read(&sbi->folder_count) > U32_MAX)) {
+		pr_warn("folder count exceeds limit\n");
+		corrupted = true;
+	}
+
+	return !corrupted;
+}
+
+/*
+ * hfs_sect_offset() - get byte offset within the buffer_head.
+ */
+static unsigned int hfs_sect_offset(struct super_block *sb, sector_t sec)
+{
+	loff_t start = (loff_t)sec << HFS_SECTOR_SIZE_BITS;
+
+	return start & (sb->s_blocksize - 1);
+}
+
+/*
+ * hfs_mdb_publish() - copy the in-memory primary MDB to the on-disk buffer.
+ */
+static void hfs_mdb_publish(struct hfs_sb_info *sbi)
+{
+	lock_buffer(sbi->mdb_bh);
+	memcpy(sbi->mdb_bh->b_data + sbi->mdb_offset, sbi->mdb, HFS_SECTOR_SIZE);
+	mark_buffer_dirty(sbi->mdb_bh);
+	unlock_buffer(sbi->mdb_bh);
+}
+
+/*
+ * hfs_alt_mdb_publish() - copy the in-memory alternate MDB to its buffer.
+ */
+static void hfs_alt_mdb_publish(struct hfs_sb_info *sbi)
+{
+	lock_buffer(sbi->alt_mdb_bh);
+	memcpy(sbi->alt_mdb_bh->b_data + sbi->alt_mdb_offset, sbi->alt_mdb,
+	       HFS_SECTOR_SIZE);
+	mark_buffer_dirty(sbi->alt_mdb_bh);
+	unlock_buffer(sbi->alt_mdb_bh);
+}
+
+/*
+ * hfs_mdb_get()
+ *
+ * Build the in-core MDB for a filesystem, including
+ * the B-trees and the volume bitmap.
+ */
+int hfs_mdb_get(struct super_block *sb)
+{
+	struct buffer_head *bh;
+	struct hfs_mdb *mdb, *alt_mdb;
+	unsigned int block;
+	char *ptr;
+	int off2, len, size, sect;
+	sector_t part_start, part_size;
+	loff_t off;
+	__be16 attrib;
+
+	/* set the device driver to 512-byte blocks */
+	size = sb_min_blocksize(sb, HFS_SECTOR_SIZE);
+	if (!size)
+		return -EINVAL;
+
+	if (hfs_get_last_session(sb, &part_start, &part_size))
+		return -EINVAL;
+	while (1) {
+		/* See if this is an HFS filesystem */
+		bh = sb_bread512(sb, part_start + HFS_MDB_BLK, mdb);
+		if (!bh)
+			return -EIO;
+
+		if (mdb->drSigWord == cpu_to_be16(HFS_SUPER_MAGIC))
+			break;
+		brelse(bh);
+
+		/* check for a partition block
+		 * (should do this only for cdrom/loop though)
+		 */
+		if (hfs_part_find(sb, &part_start, &part_size))
+			return -EIO;
+	}
+
+	HFS_SB(sb)->alloc_blksz = size = be32_to_cpu(mdb->drAlBlkSiz);
+	if (!size || (size & (HFS_SECTOR_SIZE - 1))) {
+		pr_err("bad allocation block size %d\n", size);
+		brelse(bh);
+		return -EIO;
+	}
+
+	size = min(HFS_SB(sb)->alloc_blksz, (u32)PAGE_SIZE);
+	/* size must be a multiple of 512 */
+	while (size & (size - 1))
+		size -= HFS_SECTOR_SIZE;
+	sect = be16_to_cpu(mdb->drAlBlSt) + part_start;
+	/* align block size to first sector */
+	while (sect & ((size - 1) >> HFS_SECTOR_SIZE_BITS))
+		size >>= 1;
+	/* align block size to weird alloc size */
+	while (HFS_SB(sb)->alloc_blksz & (size - 1))
+		size >>= 1;
+	brelse(bh);
+	if (!sb_set_blocksize(sb, size)) {
+		pr_err("unable to set blocksize to %u\n", size);
+		return -EIO;
+	}
+
+	bh = sb_bread512(sb, part_start + HFS_MDB_BLK, mdb);
+	if (!bh)
+		return -EIO;
+	if (mdb->drSigWord != cpu_to_be16(HFS_SUPER_MAGIC)) {
+		brelse(bh);
+		return -EIO;
+	}
+
+	mdb = kmemdup(mdb, HFS_SECTOR_SIZE, GFP_KERNEL);
+	if (!mdb) {
+		brelse(bh);
+		return -ENOMEM;
+	}
+
+	HFS_SB(sb)->mdb_bh = bh;
+	HFS_SB(sb)->mdb_offset = hfs_sect_offset(sb, part_start + HFS_MDB_BLK);
+	HFS_SB(sb)->mdb = mdb;
+
+	/* These parameters are read from the MDB, and never written */
+	HFS_SB(sb)->part_start = part_start;
+	HFS_SB(sb)->fs_ablocks = be16_to_cpu(mdb->drNmAlBlks);
+	HFS_SB(sb)->fs_div = HFS_SB(sb)->alloc_blksz >> sb->s_blocksize_bits;
+	HFS_SB(sb)->clumpablks = be32_to_cpu(mdb->drClpSiz) /
+				 HFS_SB(sb)->alloc_blksz;
+	if (!HFS_SB(sb)->clumpablks)
+		HFS_SB(sb)->clumpablks = 1;
+	HFS_SB(sb)->fs_start = (be16_to_cpu(mdb->drAlBlSt) + part_start) >>
+			       (sb->s_blocksize_bits - HFS_SECTOR_SIZE_BITS);
+
+	/* These parameters are read from and written to the MDB */
+	HFS_SB(sb)->free_ablocks = be16_to_cpu(mdb->drFreeBks);
+	atomic64_set(&HFS_SB(sb)->next_id, be32_to_cpu(mdb->drNxtCNID));
+	HFS_SB(sb)->root_files = be16_to_cpu(mdb->drNmFls);
+	HFS_SB(sb)->root_dirs = be16_to_cpu(mdb->drNmRtDirs);
+	atomic64_set(&HFS_SB(sb)->file_count, be32_to_cpu(mdb->drFilCnt));
+	atomic64_set(&HFS_SB(sb)->folder_count, be32_to_cpu(mdb->drDirCnt));
+
+	if (!is_hfs_cnid_counts_valid(sb)) {
+		pr_warn("filesystem possibly corrupted, running fsck.hfs is recommended. Mounting read-only.\n");
+		sb->s_flags |= SB_RDONLY;
+	}
+
+	/* TRY to get the alternate (backup) MDB. */
+	sect = part_start + part_size - 2;
+	bh = sb_bread512(sb, sect, alt_mdb);
+	if (bh) {
+		if (alt_mdb->drSigWord == cpu_to_be16(HFS_SUPER_MAGIC)) {
+			alt_mdb = kmemdup(alt_mdb, HFS_SECTOR_SIZE, GFP_KERNEL);
+			if (alt_mdb) {
+				HFS_SB(sb)->alt_mdb_bh = bh;
+				HFS_SB(sb)->alt_mdb_offset =
+					hfs_sect_offset(sb, sect);
+				HFS_SB(sb)->alt_mdb = alt_mdb;
+			} else {
+				brelse(bh);
+			}
+		} else
+			brelse(bh);
+	}
+
+	if (!HFS_SB(sb)->alt_mdb) {
+		pr_warn("unable to locate alternate MDB\n");
+		pr_warn("continuing without an alternate MDB\n");
+	}
+
+	HFS_SB(sb)->bitmap = kzalloc(8192, GFP_KERNEL);
+	if (!HFS_SB(sb)->bitmap)
+		return -EIO;
+
+	/* read in the bitmap */
+	block = be16_to_cpu(mdb->drVBMSt) + part_start;
+	off = (loff_t)block << HFS_SECTOR_SIZE_BITS;
+	size = (HFS_SB(sb)->fs_ablocks + 8) / 8;
+	ptr = (u8 *)HFS_SB(sb)->bitmap;
+	while (size) {
+		bh = sb_bread(sb, off >> sb->s_blocksize_bits);
+		if (!bh) {
+			pr_err("unable to read volume bitmap\n");
+			return -EIO;
+		}
+		off2 = off & (sb->s_blocksize - 1);
+		len = min((int)sb->s_blocksize - off2, size);
+		memcpy(ptr, bh->b_data + off2, len);
+		brelse(bh);
+		ptr += len;
+		off += len;
+		size -= len;
+	}
+
+	HFS_SB(sb)->ext_tree = hfs_btree_open(sb, HFS_EXT_CNID, hfs_ext_keycmp);
+	if (!HFS_SB(sb)->ext_tree) {
+		pr_err("unable to open extent tree\n");
+		return -EIO;
+	}
+	HFS_SB(sb)->cat_tree = hfs_btree_open(sb, HFS_CAT_CNID, hfs_cat_keycmp);
+	if (!HFS_SB(sb)->cat_tree) {
+		pr_err("unable to open catalog tree\n");
+		return -EIO;
+	}
+
+	attrib = mdb->drAtrb;
+	if (!(attrib & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
+		pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.	Mounting read-only.\n");
+		sb->s_flags |= SB_RDONLY;
+	}
+	if ((attrib & cpu_to_be16(HFS_SB_ATTRIB_SLOCK))) {
+		pr_warn("filesystem is marked locked, mounting read-only.\n");
+		sb->s_flags |= SB_RDONLY;
+	}
+	if (!sb_rdonly(sb)) {
+		/* Mark the volume uncleanly unmounted in case we crash */
+		attrib &= cpu_to_be16(~HFS_SB_ATTRIB_UNMNT);
+		attrib |= cpu_to_be16(HFS_SB_ATTRIB_INCNSTNT);
+		mdb->drAtrb = attrib;
+		be32_add_cpu(&mdb->drWrCnt, 1);
+		mdb->drLsMod = hfs_mtime();
+
+		hfs_mdb_publish(HFS_SB(sb));
+		sync_dirty_buffer(HFS_SB(sb)->mdb_bh);
+	}
+
+	return 0;
+}
+
+/*
+ * hfs_mdb_commit()
+ *
+ * Description:
+ *   This updates the MDB on disk.
+ *   It does not check, if the superblock has been modified, or
+ *   if the filesystem has been mounted read-only. It is mainly
+ *   called by hfs_sync_fs() and flush_mdb().
+ * Input Variable(s):
+ *   struct hfs_mdb *mdb: Pointer to the hfs MDB
+ *   int backup;
+ * Output Variable(s):
+ *   NONE
+ * Returns:
+ *   0 on success, -EIO if the MDB or alternate MDB buffer is no longer
+ *   valid (e.g. after a prior write error), in which case the volume is
+ *   remounted read-only.
+ * Preconditions:
+ *   'mdb' points to a "valid" (struct hfs_mdb).
+ * Postconditions:
+ *   The HFS MDB and on disk will be updated, by copying the possibly
+ *   modified fields from the in memory MDB (in native byte order) to
+ *   the disk block buffer.
+ *   If 'backup' is non-zero then the alternate MDB is also written
+ *   and the function doesn't return until it is actually on disk.
+ */
+int hfs_mdb_commit(struct super_block *sb)
+{
+	struct hfs_mdb *mdb = HFS_SB(sb)->mdb;
+	int ret = 0;
+
+	if (sb_rdonly(sb))
+		return 0;
+
+	if (!buffer_uptodate(HFS_SB(sb)->mdb_bh)) {
+		pr_err("primary MDB is corrupt, mounting read-only\n");
+		sb->s_flags |= SB_RDONLY;
+		return -EIO;
+	}
+
+	if (test_and_clear_bit(HFS_FLG_MDB_DIRTY, &HFS_SB(sb)->flags)) {
+		/* These parameters may have been modified, so write them back */
+		mdb->drLsMod = hfs_mtime();
+		mdb->drFreeBks = cpu_to_be16(HFS_SB(sb)->free_ablocks);
+		mdb->drNxtCNID =
+			cpu_to_be32((u32)atomic64_read(&HFS_SB(sb)->next_id));
+		mdb->drNmFls = cpu_to_be16(HFS_SB(sb)->root_files);
+		mdb->drNmRtDirs = cpu_to_be16(HFS_SB(sb)->root_dirs);
+		mdb->drFilCnt =
+			cpu_to_be32((u32)atomic64_read(&HFS_SB(sb)->file_count));
+		mdb->drDirCnt =
+			cpu_to_be32((u32)atomic64_read(&HFS_SB(sb)->folder_count));
+
+		hfs_inode_write_fork(HFS_SB(sb)->ext_tree->inode, mdb->drXTExtRec,
+				     &mdb->drXTFlSize, NULL);
+		hfs_inode_write_fork(HFS_SB(sb)->cat_tree->inode, mdb->drCTExtRec,
+				     &mdb->drCTFlSize, NULL);
+
+		/* write MDB to disk */
+		hfs_mdb_publish(HFS_SB(sb));
+		sync_dirty_buffer(HFS_SB(sb)->mdb_bh);
+	}
+
+	/* write the backup MDB, not returning until it is written.
+	 * we only do this when either the catalog or extents overflow
+	 * files grow. */
+	if (test_and_clear_bit(HFS_FLG_ALT_MDB_DIRTY, &HFS_SB(sb)->flags) &&
+	    HFS_SB(sb)->alt_mdb) {
+		if (!buffer_uptodate(HFS_SB(sb)->alt_mdb_bh)) {
+			pr_err("alternate MDB is corrupt, mounting read-only\n");
+			sb->s_flags |= SB_RDONLY;
+			ret = -EIO;
+			goto out;
+		}
+
+		memcpy(HFS_SB(sb)->alt_mdb, mdb, HFS_SECTOR_SIZE);
+		HFS_SB(sb)->alt_mdb->drAtrb |= cpu_to_be16(HFS_SB_ATTRIB_UNMNT);
+		HFS_SB(sb)->alt_mdb->drAtrb &= cpu_to_be16(~HFS_SB_ATTRIB_INCNSTNT);
+
+		hfs_alt_mdb_publish(HFS_SB(sb));
+		sync_dirty_buffer(HFS_SB(sb)->alt_mdb_bh);
+	}
+
+	if (test_and_clear_bit(HFS_FLG_BITMAP_DIRTY, &HFS_SB(sb)->flags)) {
+		struct buffer_head *bh;
+		sector_t block;
+		char *ptr;
+		int off, size, len;
+
+		block = be16_to_cpu(HFS_SB(sb)->mdb->drVBMSt) + HFS_SB(sb)->part_start;
+		off = (block << HFS_SECTOR_SIZE_BITS) & (sb->s_blocksize - 1);
+		block >>= sb->s_blocksize_bits - HFS_SECTOR_SIZE_BITS;
+		size = (HFS_SB(sb)->fs_ablocks + 7) / 8;
+		ptr = (u8 *)HFS_SB(sb)->bitmap;
+		while (size) {
+			bh = sb_bread(sb, block);
+			if (!bh) {
+				pr_err("unable to read volume bitmap\n");
+				break;
+			}
+			len = min((int)sb->s_blocksize - off, size);
+
+			lock_buffer(bh);
+			memcpy(bh->b_data + off, ptr, len);
+			unlock_buffer(bh);
+
+			mark_buffer_dirty(bh);
+			brelse(bh);
+			block++;
+			off = 0;
+			ptr += len;
+			size -= len;
+		}
+	}
+out:
+	return ret;
+}
+
+void hfs_mdb_close(struct super_block *sb)
+{
+	/* update volume attributes */
+	if (sb_rdonly(sb))
+		return;
+
+	if (!buffer_uptodate(HFS_SB(sb)->mdb_bh))
+		return;
+
+	HFS_SB(sb)->mdb->drAtrb |= cpu_to_be16(HFS_SB_ATTRIB_UNMNT);
+	HFS_SB(sb)->mdb->drAtrb &= cpu_to_be16(~HFS_SB_ATTRIB_INCNSTNT);
+	hfs_mdb_publish(HFS_SB(sb));
+}
+
+/*
+ * hfs_mdb_put()
+ *
+ * Release the resources associated with the in-core MDB.  */
+void hfs_mdb_put(struct super_block *sb)
+{
+	/* free the B-trees */
+	hfs_btree_close(HFS_SB(sb)->ext_tree);
+	hfs_btree_close(HFS_SB(sb)->cat_tree);
+
+	/* free the buffers holding the primary and alternate MDBs */
+	brelse(HFS_SB(sb)->mdb_bh);
+	brelse(HFS_SB(sb)->alt_mdb_bh);
+	kfree(HFS_SB(sb)->mdb);
+	kfree(HFS_SB(sb)->alt_mdb);
+
+	unload_nls(HFS_SB(sb)->nls_io);
+	unload_nls(HFS_SB(sb)->nls_disk);
+
+	kfree(HFS_SB(sb)->bitmap);
+}