Some tracepoints have a registration function that gets enabled when the
tracepoint is enabled. There may be cases that the registraction function
must fail (for example, can't allocate enough memory). In this case, the
tracepoint should also fail to register, otherwise the user would not know
why the tracepoint is not working.

Cc: David Howells <dhowells@redhat.com>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Both rb_end_commit() and rb_set_commit_to_write() are in the fast path of
the ring buffer recording. Make sure they are always inlined.

Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.orgReported-by: NAndi Kleen <andi@firstfloor.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The function rb_update_write_stamp() is in the hotpath of the ring buffer
recording. Make sure that it is inlined as well. There's not many places
that call it.

Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.orgReported-by: NAndi Kleen <andi@firstfloor.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

There's several small helper functions in ring_buffer.c that are used in the
hot path. For some reason, even though they are marked inline, gcc tends not
to enforce it. Make sure these functions are always inlined.

Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.orgReported-by: NAndi Kleen <andi@firstfloor.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The function __buffer_unlock_commit() is called in a few places outside of
trace.c. But for the most part, it should really be inlined, as it is in the
hot path of the trace_events. For the callers outside of trace.c, create a
new function trace_buffer_unlock_commit_nostack(), as the reason it was used
was to avoid the stack tracing that trace_buffer_unlock_commit() could do.

Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.orgReported-by: NAndi Kleen <andi@firstfloor.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Currently, when tracepoint_printk is set (enabled by the "tp_printk" kernel
command line), it causes trace events to print via printk(). This is a very
dangerous operation, but is useful for debugging.

The issue is, it's seldom used, but it is always checked even if it's not
enabled by the kernel command line. Instead of having this feature called by
a branch against a variable, turn that variable into a static key, and this
will remove the test and jump.

To simplify things, the functions output_printk() and
trace_event_buffer_commit() were moved from trace_events.c to trace.c.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The rb_event_data() is the fast path of getting the ring buffer data from an
event. Externally, ring_buffer_event_data() is used to access this function.
But unfortunately, rb_event_data() is not inlined, and calling
ring_buffer_event_data() causes that function to be called again. Force
rb_event_data() to be inlined to lower the number of operations needed when
calling ring_buffer_event_data().

Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.orgReported-by: NAndi Kleen <andi@firstfloor.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The function rb_reserved_next_event() is called by two functions:
ring_buffer_lock_reserve() and ring_buffer_write(). This is in a very hot
path of the tracing code, and it is best that they are not functions. The
two callers are basically wrapers for rb_reserver_next_event(). Removing the
function calls can save execution time in the hotpath of tracing.

Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.orgReported-by: NAndi Kleen <andi@firstfloor.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

As Andi Kleen pointed out in the Link below, the trace events has quite a
bit of code execution. A lot of that happens to be calling functions, where
some of them should simply be inlined. One of these functions happens to be
trace_buffer_lock_reserve() which is also a global, but it is used
throughout the file it is defined in. Create a __trace_buffer_lock_reserve()
that is always inlined that the file can benefit from.

Link: http://lkml.kernel.org/r/20161121183700.GW26852@two.firstfloor.orgReported-by: NAndi Kleen <andi@firstfloor.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The creation of the set_event_pid file was assigned to a variable "entry"
but that variable was never used. Ideally, it should be used to check if the
file was created and warn if it was not.

The files header_page, header_event should also be checked and a warning if
they fail to be created.

The "enable" file was moved up, as it is a more crucial file to have and a
hard failure (return -ENOMEM) should be returned if it is not created.
Reported-by: NDavid Binderman <dcb314@hotmail.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

If CONFIG_STM_SOURCE_FTRACE is selected, Function trace data can be
writen to sink via STM, all functions that related to writing data
packets to STM should be marked 'notrace' to avoid being traced by
Ftrace, otherwise the program would stall into an endless loop.

Link: http://lkml.kernel.org/r/1479715043-6534-7-git-send-email-zhang.chunyan@linaro.orgSigned-off-by: NChunyan Zhang <zhang.chunyan@linaro.org>
Acked-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

If CONFIG_STM_SOURCE_FTRACE is selected, Function trace data can be
writen to sink via STM, all functions that related to writing data
packets to STM should be marked 'notrace' to avoid being traced by
Ftrace, otherwise the program would stall into an endless loop.

Link: http://lkml.kernel.org/r/1479715043-6534-6-git-send-email-zhang.chunyan@linaro.orgSigned-off-by: NChunyan Zhang <zhang.chunyan@linaro.org>
Acked-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

If CONFIG_STM_SOURCE_FTRACE is selected, Function trace data can be
writen to sink via STM, all functions that related to writing data
packets to STM should be marked 'notrace' to avoid being traced by
Ftrace, otherwise the program would stall into an endless loop.

Link: http://lkml.kernel.org/r/1479715043-6534-5-git-send-email-zhang.chunyan@linaro.orgSigned-off-by: NChunyan Zhang <zhang.chunyan@linaro.org>
Acked-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

If CONFIG_STM_SOURCE_FTRACE is selected, Function trace data can be
writen to sink via STM, all functions that related to writing data
packets to STM should be marked 'notrace' to avoid being traced by
Ftrace, otherwise the program would stall into an endless loop.

Link: http://lkml.kernel.org/r/1479715043-6534-4-git-send-email-zhang.chunyan@linaro.orgSigned-off-by: NChunyan Zhang <zhang.chunyan@linaro.org>
Acked-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

This patch adds a driver that models itself as an stm_source called
stm_ftrace. Once the stm device and stm_ftrace have been linked via
sysfs, the driver registers itself as a trace_export and everything
passed to the interface from Ftrace subsystem will end up in the STM
trace engine.

Link: http://lkml.kernel.org/r/1479715043-6534-3-git-send-email-zhang.chunyan@linaro.orgSigned-off-by: NChunyan Zhang <zhang.chunyan@linaro.org>
Acked-by: NAlexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Currently Function traces can be only exported to the ring buffer. This
adds a trace_export concept which can process traces and export
them to a registered destination as an addition to the current
one that outputs to Ftrace - i.e. ring buffer.

In this way, if we want function traces to be sent to other destinations
rather than only to the ring buffer, we just need to register a new
trace_export and implement its own .write() function for writing traces to
storage.

With this patch, only function tracing (trace type is TRACE_FN)
is supported.

Link: http://lkml.kernel.org/r/1479715043-6534-2-git-send-email-zhang.chunyan@linaro.orgSigned-off-by: NChunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Add a testcase for types of kprobe event. This checks
kprobe event can accept and correctly expressed the
arguments typed as s32, u32, x32 and bitfield.

Here is the test result.
  -----
  # ./ftracetest test.d/kprobe/kprobe_args_type.tc
  === Ftrace unit tests ===
  [1] Kprobes event arguments with types	[PASS]

  # of passed:  1
  # of failed:  0
  # of unresolved:  0
  # of untested:  0
  # of unsupported:  0
  # of xfailed:  0
  # of undefined(test bug):  0
  -----

Link: http://lkml.kernel.org/r/147928409063.22982.3499119203875115458.stgit@devboxSigned-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Add function filter glob matching test case.
This checks whether the kernel supports glob matching
(front match, end match, middle match, side match,
character class and '?').

Here is the test result.
  -----
  ./ftracetest test.d/ftrace/func-filter-glob.tc
  === Ftrace unit tests ===
  [1] ftrace - function glob filters	[PASS]

  # of passed:  1
  # of failed:  0
  # of unresolved:  0
  # of untested:  0
  # of unsupported:  0
  # of xfailed:  0
  # of undefined(test bug):  0
  -----

Link: http://lkml.kernel.org/r/147928407589.22982.16364174511117104303.stgit@devboxSigned-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Introduce TMPDIR variable which is removed after each test
is done, so that the test script can put their temporary
files in that.

Link: http://lkml.kernel.org/r/147928406116.22982.8761924340108532378.stgit@devboxSigned-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Hide ftracetest result log directory from git.

Link: http://lkml.kernel.org/r/147928404640.22982.13173364949326289032.stgit@devboxSigned-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Since histogram trigger id.syscall depends on CONFIG_FTRACE_SYSCALLS,
a testcase in trigger-modifier test fails if that config is disabled.

Fix this bug by using flexible pattern to check the histogram output.

Link: http://lkml.kernel.org/r/147928402670.22982.15589445159052676877.stgit@devboxSigned-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

If "snapshot" special file doesn't exist, that kernel does
not support snapshot and snapshot trigger too. In that case
snapshot trigger test results to unsupported instead of fail.

Link: http://lkml.kernel.org/r/147928401215.22982.10411665829041109794.stgit@devboxSigned-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Since the verbose error logs scrolls out previous test results
--quiet option suppress to show such message.

e.g.
 # ./ftracetest -q
=== Ftrace unit tests ===
[1] Basic trace file check	[PASS]
[2] Basic test for tracers	[PASS]
[3] Basic trace clock test	[PASS]
[4] Basic event tracing check	[PASS]
[5] event tracing - enable/disable with event level files	[PASS]
[6] event tracing - restricts events based on pid	[PASS]
[7] event tracing - enable/disable with subsystem level files	[PASS]
[8] event tracing - enable/disable with top level files	[PASS]
[9] ftrace - function graph filters with stack tracer	[UNSUPPORTED]
[10] ftrace - function graph filters	[UNSUPPORTED]
[11] ftrace - function profiler with function tracing	[UNSUPPORTED]
[12] Test creation and deletion of trace instances while setting an event
	[PASS]
[13] Test creation and deletion of trace instances	[PASS]
[14] Kprobe dynamic event - adding and removing	[UNSUPPORTED]
[15] Kprobe dynamic event - busy event check	[UNSUPPORTED]
[16] Kprobe dynamic event with arguments	[UNSUPPORTED]
[17] Kprobe dynamic event with function tracer	[UNSUPPORTED]
[18] Kretprobe dynamic event with arguments	[UNSUPPORTED]
[19] event trigger - test event enable/disable trigger	[PASS]
[20] event trigger - test trigger filter	[PASS]
[21] event trigger - test histogram modifiers	[UNSUPPORTED]
[22] event trigger - test histogram trigger	[UNSUPPORTED]
[23] event trigger - test multiple histogram triggers	[UNSUPPORTED]
[24] event trigger - test snapshot-trigger	[FAIL]
[25] event trigger - test stacktrace-trigger	[PASS]
[26] event trigger - test traceon/off trigger	[PASS]

# of passed:  14
# of failed:  1
# of unresolved:  0
# of untested:  0
# of unsupported:  11
# of xfailed:  0
# of undefined(test bug):  0

Link: http://lkml.kernel.org/r/147928399712.22982.8284640390982775052.stgit@devboxSigned-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Reset ftrace to initial state before running each test.
This fixes some test cases to enable tracing before starting
trace test. This can avoid false-positive failure when
previous testcase fails while disabling tracing.

Link: http://lkml.kernel.org/r/147928398192.22982.7767460638302113002.stgit@devboxSigned-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Suggested-by: NSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

A new file is created:

 /sys/kernel/debug/tracing/trace_marker_raw

This allows for appications to create data structures and write the binary
data directly into it, and then read the trace data out from trace_pipe_raw
into the same type of data structure. This saves on converting numbers into
ASCII that would be required by trace_marker.
Suggested-by: NOlof Johansson <olof@lixom.net>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

In similar spirit to x86 and arm64 support, add a make_nop_arm()
to replace calls to mcount with a nop in sections that aren't
traced.

Link: http://lkml.kernel.org/r/20161018234200.5804-1-sboyd@codeaurora.orgAcked-by: NRussell King <rmk+kernel@armlinux.org.uk>
Acked-by: NRabin Vincent <rabin@rab.in>
Signed-off-by: NStephen Boyd <sboyd@codeaurora.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Allow wakeup_dl tracer to be used by instances, like wakeup tracer
and wakeup_rt tracer.

Link: http://lkml.kernel.org/r/1479093553-31264-1-git-send-email-zhouchengming1@huawei.comSigned-off-by: NZhou Chengming <zhouchengming1@huawei.com>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

The trace_events_file.c filter logic can be a bit complex. I copy this into
a userspace program where I can debug it a bit easier. One issue is the op
is defined in most places as an int instead of as an enum, and gdb just
gives the value when debugging. Having the actual op name shown in gdb is
more useful.

This has no functionality change, but helps in debugging when the file is
debugged in user space.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Currently the filter logic for comparisons (like greater-than and less-than)
are used, they share the same function and a switch statement is used to
jump to the comparison type to perform. This is done in the extreme hot path
of the tracing code, and it does not take much more space to create a
unique comparison function to perform each type of comparison and remove the
switch statement.

Also, a bug was found where the binary and operation for 64 bits could fail
if the resulting bits were greater than 32 bits, because the result was
passed into a 32 bit variable. This was fixed when adding the separate
binary and function.
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Use glob_match() to support flexible glob wildcards (*,?)
and character classes ([) for ftrace.
Since the full glob matching is slower than the current
partial matching routines(*pat, pat*, *pat*), this leaves
those routines and just add MATCH_GLOB for complex glob
expression.

e.g.
----
[root@localhost tracing]# echo 'sched*group' > set_ftrace_filter
[root@localhost tracing]# cat set_ftrace_filter
sched_free_group
sched_change_group
sched_create_group
sched_online_group
sched_destroy_group
sched_offline_group
[root@localhost tracing]# echo '[Ss]y[Ss]_*' > set_ftrace_filter
[root@localhost tracing]# head set_ftrace_filter
sys_arch_prctl
sys_rt_sigreturn
sys_ioperm
SyS_iopl
sys_modify_ldt
SyS_mmap
SyS_set_thread_area
SyS_get_thread_area
SyS_set_tid_address
sys_fork
----

Link: http://lkml.kernel.org/r/147566869501.29136.6462645009894738056.stgit@devboxAcked-by: NNamhyung Kim <namhyung@kernel.org>
Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

When a module is first loaded and its function ip records are added to the
ftrace list of functions to modify, they are set to DISABLED, as their text
is still in a read only state. When the module is fully loaded, and can be
updated, the flag is cleared, and if their's any functions that should be
tracing them, it is updated at that moment.

But there's several locations that do record accounting and should ignore
records that are marked as disabled, or they can cause issues.

Alexei already fixed one location, but others need to be addressed.

Cc: stable@vger.kernel.org
Fixes: b7ffffbb "ftrace: Add infrastructure for delayed enabling of module functions"
Reported-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

ftrace_shutdown() checks for sanity of ftrace records
and if dyn_ftrace->flags is not zero, it will warn.
It can happen that 'flags' are set to FTRACE_FL_DISABLED at this point,
since some module was loaded, but before ftrace_module_enable()
cleared the flags for this module.

In other words the module.c is doing:
ftrace_module_init(mod); // calls ftrace_update_code() that sets flags=FTRACE_FL_DISABLED
... // here ftrace_shutdown() is called that warns, since
err = prepare_coming_module(mod); // didn't have a chance to clear FTRACE_FL_DISABLED

Fix it by ignoring disabled records.
It's similar to what __ftrace_hash_rec_update() is already doing.

Link: http://lkml.kernel.org/r/1478560460-3818619-1-git-send-email-ast@fb.com

Cc: stable@vger.kernel.org
Fixes: b7ffffbb "ftrace: Add infrastructure for delayed enabling of module functions"
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Pull KVM fixes from Paolo Bonzini:
 "ARM fixes.  There are a couple pending x86 patches but they'll have to
  wait for next week"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: arm/arm64: vgic: Kick VCPUs when queueing already pending IRQs
  KVM: arm/arm64: vgic: Prevent access to invalid SPIs
  arm/arm64: KVM: Perform local TLB invalidation when multiplexing vcpus on a single CPU

Merge media fixes from Mauro Carvalho Chehab:
 "This contains two patches fixing problems with my patch series meant
  to make USB drivers to work again after the DMA on stack changes.

  The last patch on this series is actually not related to DMA on stack.
  It solves a longstanding bug affecting module unload, causing
  module_put() to be called twice. It was reported by the user who
  reported and tested the issues with the gp8psk driver with the DMA
  fixup patches. As we're late at -rc cycle, maybe you prefer to not
  apply it right now. If this is the case, I'll add to the pile of
  patches for 4.10.

  Exceptionally this time, I'm sending the patches via e-mail, because
  I'm on another trip, and won't be able to use the usual procedure
  until Monday. Also, it is only three patches, and you followed already
  the discussions about the first one"

* emailed patches from Mauro Carvalho Chehab <mchehab@osg.samsung.com>:
  gp8psk: Fix DVB frontend attach
  gp8psk: fix gp8psk_usb_in_op() logic
  dvb-usb: move data_mutex to struct dvb_usb_device

Pull char/misc fixes from Greg KH:
 "Here are three small driver fixes for some reported issues for
  4.9-rc5.

  One for the hyper-v subsystem, fixing up a naming issue that showed up
  in 4.9-rc1, one mei driver fix, and one fix for parallel ports,
  resolving a reported regression.

  All have been in linux-next with no reported issues"

* tag 'char-misc-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  ppdev: fix double-free of pp->pdev->name
  vmbus: make sysfs names consistent with PCI
  mei: bus: fix received data size check in NFC fixup

Pull driver core fixes from Greg KH:
 "Here are two driver core fixes for 4.9-rc5.

  The first resolves an issue with some drivers not liking to be unbound
  and bound again (if CONFIG_DEBUG_TEST_DRIVER_REMOVE is enabled), which
  solves some reported problems with graphics and storage drivers. The
  other resolves a smatch error with the 4.9-rc1 driver core changes
  around this feature.

  Both have been in linux-next with no reported issues"

* tag 'driver-core-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  driver core: fix smatch warning on dev->bus check
  driver core: skip removal test for non-removable drivers

Pull staging/IIO fixes from Grek KH:
 "Here are a few small staging and iio driver fixes for reported issues.

  The last one was cherry-picked from my -next branch to resolve a build
  warning that Arnd fixed, in his quest to be able to turn
  -Wmaybe-uninitialized back on again. That patch, and all of the
  others, have been in linux-next for a while with no reported issues"

* tag 'staging-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  iio: maxim_thermocouple: detect invalid storage size in read()
  staging: nvec: remove managed resource from PS2 driver
  Revert "staging: nvec: ps2: change serio type to passthrough"
  drivers: staging: nvec: remove bogus reset command for PS/2 interface
  staging: greybus: arche-platform: fix device reference leak
  staging: comedi: ni_tio: fix buggy ni_tio_clock_period_ps() return value
  staging: sm750fb: Fix bugs introduced by early commits
  iio: hid-sensors: Increase the precision of scale to fix wrong reading interpretation.
  iio: orientation: hid-sensor-rotation: Add PM function (fix non working driver)
  iio: st_sensors: fix scale configuration for h3lis331dl
  staging: iio: ad5933: avoid uninitialized variable in error case

Pull USB / PHY fixes from Greg KH:
 "Here are a number of small USB and PHY driver fixes for 4.9-rc5

  Nothing major, just small fixes for reported issues, all of these have
  been in linux-next for a while with no reported issues"

* tag 'usb-4.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  USB: cdc-acm: fix TIOCMIWAIT
  cdc-acm: fix uninitialized variable
  drivers/usb: Skip auto handoff for TI and RENESAS usb controllers
  usb: musb: remove duplicated actions
  usb: musb: da8xx: Don't print phy error on -EPROBE_DEFER
  phy: sun4i: check PMU presence when poking unknown bit of pmu
  phy-rockchip-pcie: remove deassert of phy_rst from exit callback
  phy: da8xx-usb: rename the ohci device to ohci-da8xx
  phy: Add reset callback for not generic phy
  uwb: fix device reference leaks
  usb: gadget: u_ether: remove interrupt throttling
  usb: dwc3: st: add missing <linux/pinctrl/consumer.h> include
  usb: dwc3: Fix error handling for core init

Pull more block fixes from Jens Axboe:
 "Since I mistakenly left out the lightnvm regression fix yesterday and
  the aoeblk seems adequately tested at this point, might as well send
  out another pull to make -rc5"

* 'for-linus' of git://git.kernel.dk/linux-block:
  aoe: fix crash in page count manipulation
  lightnvm: invalid offset calculation for lba_shift