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, 240 insertions, 0 deletions

diff --git a/fs/hfsplus/wrapper.c b/fs/hfsplus/wrapper.c
new file mode 100644
index 000000000..30cf4fe78
--- /dev/null
+++ b/fs/hfsplus/wrapper.c
@@ -0,0 +1,240 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/hfsplus/wrapper.c
+ *
+ * Copyright (C) 2001
+ * Brad Boyer (flar@allandria.com)
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ *
+ * Handling of HFS wrappers around HFS+ volumes
+ */
+
+#include <linux/fs.h>
+#include <linux/blkdev.h>
+#include <linux/cdrom.h>
+#include <linux/unaligned.h>
+
+#include "hfsplus_fs.h"
+#include "hfsplus_raw.h"
+
+struct hfsplus_wd {
+	u32 ablk_size;
+	u16 ablk_start;
+	u16 embed_start;
+	u16 embed_count;
+};
+
+/**
+ * hfsplus_submit_bio - Perform block I/O
+ * @sb: super block of volume for I/O
+ * @sector: block to read or write, for blocks of HFSPLUS_SECTOR_SIZE bytes
+ * @buf: buffer for I/O
+ * @data: output pointer for location of requested data
+ * @opf: I/O operation type and flags
+ *
+ * The unit of I/O is hfsplus_min_io_size(sb), which may be bigger than
+ * HFSPLUS_SECTOR_SIZE, and @buf must be sized accordingly. On reads
+ * @data will return a pointer to the start of the requested sector,
+ * which may not be the same location as @buf.
+ *
+ * If @sector is not aligned to the bdev logical block size it will
+ * be rounded down. For writes this means that @buf should contain data
+ * that starts at the rounded-down address. As long as the data was
+ * read using hfsplus_submit_bio() and the same buffer is used things
+ * will work correctly.
+ *
+ * Returns: %0 on success else -errno code
+ */
+int hfsplus_submit_bio(struct super_block *sb, sector_t sector,
+		       void *buf, void **data, blk_opf_t opf)
+{
+	u64 io_size = hfsplus_min_io_size(sb);
+	loff_t start = (loff_t)sector << HFSPLUS_SECTOR_SHIFT;
+	int offset = start & (io_size - 1);
+
+	if ((opf & REQ_OP_MASK) != REQ_OP_WRITE && data)
+		*data = (u8 *)buf + offset;
+
+	/*
+	 * Align sector to hardware sector size and find offset. We assume that
+	 * io_size is a power of two, which _should_ be true.
+	 */
+	sector &= ~((io_size >> HFSPLUS_SECTOR_SHIFT) - 1);
+	return bdev_rw_virt(sb->s_bdev, sector, buf, io_size, opf);
+}
+
+static int hfsplus_read_mdb(void *bufptr, struct hfsplus_wd *wd)
+{
+	u32 extent;
+	u16 attrib;
+	__be16 sig;
+
+	sig = *(__be16 *)(bufptr + HFSP_WRAPOFF_EMBEDSIG);
+	if (sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIG) &&
+	    sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIGX))
+		return 0;
+
+	attrib = be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ATTRIB));
+	if (!(attrib & HFSP_WRAP_ATTRIB_SLOCK) ||
+	   !(attrib & HFSP_WRAP_ATTRIB_SPARED))
+		return 0;
+
+	wd->ablk_size =
+		be32_to_cpu(*(__be32 *)(bufptr + HFSP_WRAPOFF_ABLKSIZE));
+	if (wd->ablk_size < HFSPLUS_SECTOR_SIZE)
+		return 0;
+	if (wd->ablk_size % HFSPLUS_SECTOR_SIZE)
+		return 0;
+	wd->ablk_start =
+		be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ABLKSTART));
+
+	extent = get_unaligned_be32(bufptr + HFSP_WRAPOFF_EMBEDEXT);
+	wd->embed_start = (extent >> 16) & 0xFFFF;
+	wd->embed_count = extent & 0xFFFF;
+
+	return 1;
+}
+
+static int hfsplus_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 (HFSPLUS_SB(sb)->session >= 0) {
+		struct cdrom_tocentry te;
+
+		if (!cdi)
+			return -EINVAL;
+
+		te.cdte_track = HFSPLUS_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;
+}
+
+/* Find the volume header and fill in some minimum bits in superblock */
+/* Takes in super block, returns true if good data read */
+int hfsplus_read_wrapper(struct super_block *sb)
+{
+	struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
+	struct hfsplus_wd wd;
+	sector_t part_start, part_size;
+	u32 blocksize;
+	int error = 0;
+
+	error = -EINVAL;
+	blocksize = sb_min_blocksize(sb, HFSPLUS_SECTOR_SIZE);
+	if (!blocksize)
+		goto out;
+
+	sbi->min_io_size = blocksize;
+
+	if (hfsplus_get_last_session(sb, &part_start, &part_size))
+		goto out;
+
+	error = -ENOMEM;
+	sbi->s_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL);
+	if (!sbi->s_vhdr_buf)
+		goto out;
+	sbi->s_backup_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL);
+	if (!sbi->s_backup_vhdr_buf)
+		goto out_free_vhdr;
+
+reread:
+	error = hfsplus_submit_bio(sb, part_start + HFSPLUS_VOLHEAD_SECTOR,
+				   sbi->s_vhdr_buf, (void **)&sbi->s_vhdr,
+				   REQ_OP_READ);
+	if (error)
+		goto out_free_backup_vhdr;
+
+	error = -EINVAL;
+	switch (sbi->s_vhdr->signature) {
+	case cpu_to_be16(HFSPLUS_VOLHEAD_SIGX):
+		set_bit(HFSPLUS_SB_HFSX, &sbi->flags);
+		fallthrough;
+	case cpu_to_be16(HFSPLUS_VOLHEAD_SIG):
+		break;
+	case cpu_to_be16(HFSP_WRAP_MAGIC):
+		if (!hfsplus_read_mdb(sbi->s_vhdr, &wd))
+			goto out_free_backup_vhdr;
+		wd.ablk_size >>= HFSPLUS_SECTOR_SHIFT;
+		part_start += (sector_t)wd.ablk_start +
+			       (sector_t)wd.embed_start * wd.ablk_size;
+		part_size = (sector_t)wd.embed_count * wd.ablk_size;
+		goto reread;
+	default:
+		/*
+		 * Check for a partition block.
+		 *
+		 * (should do this only for cdrom/loop though)
+		 */
+		if (hfs_part_find(sb, &part_start, &part_size))
+			goto out_free_backup_vhdr;
+		goto reread;
+	}
+
+	error = hfsplus_submit_bio(sb, part_start + part_size - 2,
+				   sbi->s_backup_vhdr_buf,
+				   (void **)&sbi->s_backup_vhdr, REQ_OP_READ);
+	if (error)
+		goto out_free_backup_vhdr;
+
+	error = -EINVAL;
+	if (sbi->s_backup_vhdr->signature != sbi->s_vhdr->signature) {
+		pr_warn("invalid secondary volume header\n");
+		goto out_free_backup_vhdr;
+	}
+
+	blocksize = be32_to_cpu(sbi->s_vhdr->blocksize);
+
+	/*
+	 * Block size must be at least as large as a sector and a multiple of 2.
+	 */
+	if (blocksize < HFSPLUS_SECTOR_SIZE || ((blocksize - 1) & blocksize))
+		goto out_free_backup_vhdr;
+	sbi->alloc_blksz = blocksize;
+	sbi->alloc_blksz_shift = ilog2(blocksize);
+	blocksize = min_t(u32, sbi->alloc_blksz, PAGE_SIZE);
+
+	/*
+	 * Align block size to block offset.
+	 */
+	while (part_start & ((blocksize >> HFSPLUS_SECTOR_SHIFT) - 1))
+		blocksize >>= 1;
+
+	if (sb_set_blocksize(sb, blocksize) != blocksize) {
+		pr_err("unable to set blocksize to %u!\n", blocksize);
+		goto out_free_backup_vhdr;
+	}
+
+	sbi->blockoffset =
+		part_start >> (sb->s_blocksize_bits - HFSPLUS_SECTOR_SHIFT);
+	sbi->part_start = part_start;
+	sbi->sect_count = part_size;
+	sbi->fs_shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits;
+	return 0;
+
+out_free_backup_vhdr:
+	kfree(sbi->s_backup_vhdr_buf);
+out_free_vhdr:
+	kfree(sbi->s_vhdr_buf);
+out:
+	return error;
+}