Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 375 insertions, 0 deletions

diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
new file mode 100644
index 000000000..858320b6e
--- /dev/null
+++ b/drivers/block/Kconfig
@@ -0,0 +1,375 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Block device driver configuration
+#
+
+menuconfig BLK_DEV
+	bool "Block devices"
+	depends on BLOCK
+	default y
+	help
+	  Say Y here to get to see options for various different block device
+	  drivers. This option alone does not add any kernel code.
+
+	  If you say N, all options in this submenu will be skipped and disabled;
+	  only do this if you know what you are doing.
+
+if BLK_DEV
+
+source "drivers/block/null_blk/Kconfig"
+source "drivers/block/rnull/Kconfig"
+
+config BLK_DEV_FD
+	tristate "Normal floppy disk support"
+	depends on ARCH_MAY_HAVE_PC_FDC
+	help
+	  If you want to use the floppy disk drive(s) of your PC under Linux,
+	  say Y. Information about this driver, especially important for IBM
+	  Thinkpad users, is contained in
+	  <file:Documentation/admin-guide/blockdev/floppy.rst>.
+	  That file also contains the location of the Floppy driver FAQ as
+	  well as location of the fdutils package used to configure additional
+	  parameters of the driver at run time.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called floppy.
+
+config BLK_DEV_FD_RAWCMD
+	bool "Support for raw floppy disk commands (DEPRECATED)"
+	depends on BLK_DEV_FD
+	help
+	  If you want to use actual physical floppies and expect to do
+	  special low-level hardware accesses to them (access and use
+	  non-standard formats, for example), then enable this.
+
+	  Note that the code enabled by this option is rarely used and
+	  might be unstable or insecure, and distros should not enable it.
+
+	  Note: FDRAWCMD is deprecated and will be removed from the kernel
+	  in the near future.
+
+	  If unsure, say N.
+
+config AMIGA_FLOPPY
+	tristate "Amiga floppy support"
+	depends on AMIGA
+
+config ATARI_FLOPPY
+	tristate "Atari floppy support"
+	depends on ATARI
+
+config MAC_FLOPPY
+	tristate "Support for PowerMac floppy"
+	depends on PPC_PMAC && !PPC_PMAC64
+	help
+	  If you have a SWIM-3 (Super Woz Integrated Machine 3; from Apple)
+	  floppy controller, say Y here. Most commonly found in PowerMacs.
+
+config BLK_DEV_SWIM
+	tristate "Support for SWIM Macintosh floppy"
+	depends on M68K && MAC && !HIGHMEM
+	help
+	  You should select this option if you want floppy support
+	  and you don't have a II, IIfx, Q900, Q950 or AV series.
+
+config AMIGA_Z2RAM
+	tristate "Amiga Zorro II ramdisk support"
+	depends on ZORRO
+	help
+	  This enables support for using Chip RAM and Zorro II RAM as a
+	  ramdisk or as a swap partition. Say Y if you want to include this
+	  driver in the kernel.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called z2ram.
+
+config N64CART
+	bool "N64 cart support"
+	depends on MACH_NINTENDO64
+	help
+	  Support for the N64 cart.
+
+config CDROM
+	tristate
+
+config GDROM
+	tristate "SEGA Dreamcast GD-ROM drive"
+	depends on SH_DREAMCAST
+	select CDROM
+	help
+	  A standard SEGA Dreamcast comes with a modified CD ROM drive called a
+	  "GD-ROM" by SEGA to signify it is capable of reading special disks
+	  with up to 1 GB of data. This drive will also read standard CD ROM
+	  disks. Select this option to access any disks in your GD ROM drive.
+	  Most users will want to say "Y" here.
+	  You can also build this as a module which will be called gdrom.
+
+source "drivers/block/mtip32xx/Kconfig"
+
+source "drivers/block/zram/Kconfig"
+
+config BLK_DEV_UBD
+	bool "Virtual block device"
+	depends on UML
+	help
+          The User-Mode Linux port includes a driver called UBD which will let
+          you access arbitrary files on the host computer as block devices.
+          Unless you know that you do not need such virtual block devices say
+          Y here.
+
+config BLK_DEV_UBD_SYNC
+	bool "Always do synchronous disk IO for UBD"
+	depends on BLK_DEV_UBD
+	help
+	  Writes to the virtual block device are not immediately written to the
+	  host's disk; this may cause problems if, for example, the User-Mode
+	  Linux 'Virtual Machine' uses a journalling filesystem and the host
+	  computer crashes.
+
+          Synchronous operation (i.e. always writing data to the host's disk
+          immediately) is configurable on a per-UBD basis by using a special
+          kernel command line option.  Alternatively, you can say Y here to
+          turn on synchronous operation by default for all block devices.
+
+          If you're running a journalling file system (like xfs, for
+          example) in your virtual machine, you will want to say Y here.  If
+          you care for the safety of the data in your virtual machine, Y is a
+          wise choice too.  In all other cases (for example, if you're just
+          playing around with User-Mode Linux) you can choose N.
+
+config BLK_DEV_COW_COMMON
+	bool
+	default BLK_DEV_UBD
+
+config BLK_DEV_LOOP
+	tristate "Loopback device support"
+	help
+	  Saying Y here will allow you to use a regular file as a block
+	  device; you can then create a file system on that block device and
+	  mount it just as you would mount other block devices such as hard
+	  drive partitions, CD-ROM drives or floppy drives. The loop devices
+	  are block special device files with major number 7 and typically
+	  called /dev/loop0, /dev/loop1 etc.
+
+	  This is useful if you want to check an ISO 9660 file system before
+	  burning the CD, or if you want to use floppy images without first
+	  writing them to floppy. Furthermore, some Linux distributions avoid
+	  the need for a dedicated Linux partition by keeping their complete
+	  root file system inside a DOS FAT file using this loop device
+	  driver.
+
+	  To use the loop device, you need the losetup utility, found in the
+	  util-linux package, see
+	  <https://www.kernel.org/pub/linux/utils/util-linux/>.
+
+	  The loop device driver can also be used to "hide" a file system in
+	  a disk partition, floppy, or regular file, either using encryption
+	  (scrambling the data) or steganography (hiding the data in the low
+	  bits of, say, a sound file). This is also safe if the file resides
+	  on a remote file server.
+
+	  Note that this loop device has nothing to do with the loopback
+	  device used for network connections from the machine to itself.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called loop.
+
+	  Most users will answer N here.
+
+config BLK_DEV_LOOP_MIN_COUNT
+	int "Number of loop devices to pre-create at init time"
+	depends on BLK_DEV_LOOP
+	default 8
+	help
+	  Static number of loop devices to be unconditionally pre-created
+	  at init time.
+
+	  This default value can be overwritten on the kernel command
+	  line or with module-parameter loop.max_loop.
+
+	  The historic default is 8. If a late 2011 version of losetup(8)
+	  is used, it can be set to 0, since needed loop devices can be
+	  dynamically allocated with the /dev/loop-control interface.
+
+source "drivers/block/drbd/Kconfig"
+
+config BLK_DEV_NBD
+	tristate "Network block device support"
+	depends on NET
+	help
+	  Saying Y here will allow your computer to be a client for network
+	  block devices, i.e. it will be able to use block devices exported by
+	  servers (mount file systems on them etc.). Communication between
+	  client and server works over TCP/IP networking, but to the client
+	  program this is hidden: it looks like a regular local file access to
+	  a block device special file such as /dev/nd0.
+
+	  Network block devices also allows you to run a block-device in
+	  userland (making server and client physically the same computer,
+	  communicating using the loopback network device).
+
+	  Read <file:Documentation/admin-guide/blockdev/nbd.rst> for more information,
+	  especially about where to find the server code, which runs in user
+	  space and does not need special kernel support.
+
+	  Note that this has nothing to do with the network file systems NFS
+	  or Coda; you can say N here even if you intend to use NFS or Coda.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called nbd.
+
+	  If unsure, say N.
+
+config BLK_DEV_RAM
+	tristate "RAM block device support"
+	help
+	  Saying Y here will allow you to use a portion of your RAM memory as
+	  a block device, so that you can make file systems on it, read and
+	  write to it and do all the other things that you can do with normal
+	  block devices (such as hard drives). It is usually used to load and
+	  store a copy of a minimal root file system off of a floppy into RAM
+	  during the initial install of Linux.
+
+	  Note that the kernel command line option "ramdisk=XX" is now obsolete.
+	  For details, read <file:Documentation/admin-guide/blockdev/ramdisk.rst>.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called brd. An alias "rd" has been defined
+	  for historical reasons.
+
+	  Most normal users won't need the RAM disk functionality, and can
+	  thus say N here.
+
+config BLK_DEV_RAM_COUNT
+	int "Default number of RAM disks"
+	default "16"
+	depends on BLK_DEV_RAM
+	help
+	  The default value is 16 RAM disks. Change this if you know what you
+	  are doing. If you boot from a filesystem that needs to be extracted
+	  in memory, you will need at least one RAM disk (e.g. root on cramfs).
+
+config BLK_DEV_RAM_SIZE
+	int "Default RAM disk size (kbytes)"
+	depends on BLK_DEV_RAM
+	default "4096"
+	help
+	  The default value is 4096 kilobytes. Only change this if you know
+	  what you are doing.
+
+config ATA_OVER_ETH
+	tristate "ATA over Ethernet support"
+	depends on NET
+	help
+	This driver provides Support for ATA over Ethernet block
+	devices like the Coraid EtherDrive (R) Storage Blade.
+
+config SUNVDC
+	tristate "Sun Virtual Disk Client support"
+	depends on SUN_LDOMS
+	help
+	  Support for virtual disk devices as a client under Sun
+	  Logical Domains.
+
+source "drivers/s390/block/Kconfig"
+
+config XEN_BLKDEV_FRONTEND
+	tristate "Xen virtual block device support"
+	depends on XEN
+	default y
+	select XEN_XENBUS_FRONTEND
+	help
+	  This driver implements the front-end of the Xen virtual
+	  block device driver.  It communicates with a back-end driver
+	  in another domain which drives the actual block device.
+
+config XEN_BLKDEV_BACKEND
+	tristate "Xen block-device backend driver"
+	depends on XEN_BACKEND
+	help
+	  The block-device backend driver allows the kernel to export its
+	  block devices to other guests via a high-performance shared-memory
+	  interface.
+
+	  The corresponding Linux frontend driver is enabled by the
+	  CONFIG_XEN_BLKDEV_FRONTEND configuration option.
+
+	  The backend driver attaches itself to a any block device specified
+	  in the XenBus configuration. There are no limits to what the block
+	  device as long as it has a major and minor.
+
+	  If you are compiling a kernel to run in a Xen block backend driver
+	  domain (often this is domain 0) you should say Y here. To
+	  compile this driver as a module, chose M here: the module
+	  will be called xen-blkback.
+
+
+config VIRTIO_BLK
+	tristate "Virtio block driver"
+	depends on VIRTIO
+	select SG_POOL
+	help
+	  This is the virtual block driver for virtio.  It can be used with
+          QEMU based VMMs (like KVM or Xen).  Say Y or M.
+
+config BLK_DEV_RBD
+	tristate "Rados block device (RBD)"
+	depends on INET && BLOCK
+	select CEPH_LIB
+	help
+	  Say Y here if you want include the Rados block device, which stripes
+	  a block device over objects stored in the Ceph distributed object
+	  store.
+
+	  More information at http://ceph.newdream.net/.
+
+	  If unsure, say N.
+
+config BLK_DEV_UBLK
+	tristate "Userspace block driver (Experimental)"
+	select IO_URING
+	help
+	  io_uring based userspace block driver. Together with ublk server, ublk
+	  has been working well, but interface with userspace or command data
+	  definition isn't finalized yet, and might change according to future
+	  requirement, so mark is as experimental now.
+
+config BLKDEV_UBLK_LEGACY_OPCODES
+	bool "Support legacy command opcode"
+	depends on BLK_DEV_UBLK
+	default y
+	help
+	  ublk driver started to take plain command encoding, which turns out
+	  one bad way. The traditional ioctl command opcode encodes more
+	  info and basically defines each code uniquely, so opcode conflict
+	  is avoided, and driver can handle wrong command easily, meantime it
+	  may help security subsystem to audit io_uring command.
+
+	  Say Y if your application still uses legacy command opcode.
+
+	  Say N if you don't want to support legacy command opcode. It is
+	  suggested to enable N if your application(ublk server) switches to
+	  ioctl command encoding.
+
+source "drivers/block/rnbd/Kconfig"
+
+config BLK_DEV_ZONED_LOOP
+	tristate "Zoned loopback device support"
+	depends on BLK_DEV_ZONED
+	help
+	  Saying Y here will allow you to use create a zoned block device using
+	  regular files for zones (one file per zones). This is useful to test
+	  file systems, device mapper and applications that support zoned block
+	  devices. To create a zoned loop device, no user utility is needed, a
+	  zoned loop device can be created (or re-started) using a command
+	  like:
+
+	  echo "add id=0,zone_size_mb=256,capacity_mb=16384,conv_zones=11" > \
+		/dev/zloop-control
+
+	  See Documentation/admin-guide/blockdev/zoned_loop.rst for usage
+	  details.
+
+	  If unsure, say N.
+
+endif # BLK_DEV