Poll program is a helper to ftracetest, thus make it a
generic file and remove it from being run as a test.

Currently when executing tests using
    $ make run_tests
      CC       poll
    TAP version 13
    1..2
    # timeout set to 0
    # selftests: ftrace: poll
    # Error: Polling file is not specified
    not ok 1 selftests: ftrace: poll # exit=255

Fix this by using TEST_GEN_FILES to build the 'poll' binary as a helper
rather than as a test.

Fixes: 80c3e28528ff ("selftests/tracing: Add hist poll() support test")

Link: https://lore.kernel.org/r/20250409044632.363285-1-Ayush.jain3@amd.com
Signed-off-by: Ayush Jain <Ayush.jain3@amd.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Pull tracing fixes from Steven Rostedt:

 - Initialize hash variables in ftrace subops logic

   The fix that simplified the ftrace subops logic opened a path where
   some variables could be used without being initialized, and done
   subtly where the compiler did not catch it. Initialize those
   variables to the EMPTY_HASH, which is the default hash.

 - Reinitialize the hash pointers after they are freed

   Some of the hash pointers in the subop logic were freed but may still
   be referenced later. To prevent use-after-free bugs, initialize them
   back to the EMPTY_HASH.

 - Free the ftrace hashes when they are replaced

   The fix that simplified the subops logic updated some hash pointers,
   but left the original hash that they were pointing to where they are
   no longer used. This caused a memory leak. Free the hashes that are
   pointed to by the pointers when they are replaced.

 - Fix size initialization of ftrace direct function hash

   The ftrace direct function hash used by BPF initialized the hash size
   incorrectly. It checked the size of items to a hard coded 32, which
   made the hash bit size of 5. The hash size is supposed to be limited
   by the bit size of the hash, as the bitmask is allowed to be greater
   than 5. Rework the size check to first pass the number of elements to
   fls() and then compare that to FTRACE_HASH_MAX_BITS before allocating
   the hash.

 - Fix format output of ftrace_graph_ent_entry event

   The field depth of the ftrace_graph_ent_entry event is of size 4 but
   the output showed it as unsigned long and use "%lu". Change it to
   unsigned int and use "%u" in the print format that is displayed to
   user space.

 - Fix the trace event filter on strings

   Events can be filtered on numbers or string values. The return value
   checked from strncpy_from_kernel_nofault() and
   strncpy_from_user_nofault() was used to determine if reading the
   strings would fault or not. It would return fault if the value was
   non zero, which is basically meant that it was always considering the
   read as a fault.

 - Add selftest to test trace event string filtering

   In order to catch the breakage of the string filtering, add a self
   test to make sure that it continues to work.

* tag 'trace-v6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: selftests: Add testing a user string to filters
  tracing: Fix filter string testing
  ftrace: Fix type of ftrace_graph_ent_entry.depth
  ftrace: fix incorrect hash size in register_ftrace_direct()
  ftrace: Free ftrace hashes after they are replaced in the subops code
  ftrace: Reinitialize hash to EMPTY_HASH after freeing
  ftrace: Initialize variables for ftrace_startup/shutdown_subops()

Running the following commands was broken:

  # cd /sys/kernel/tracing
  # echo "filename.ustring ~ \"/proc*\"" > events/syscalls/sys_enter_openat/filter
  # echo 1 > events/syscalls/sys_enter_openat/enable
  # ls /proc/$$/maps
  # cat trace

And would produce nothing when it should have produced something like:

      ls-1192    [007] .....  8169.828333: sys_openat(dfd: ffffffffffffff9c, filename: 7efc18359904, flags: 80000, mode: 0)

Add a test to check this case so that it will be caught if it breaks
again.

Link: https://lore.kernel.org/linux-trace-kernel/20250417183003.505835fb@gandalf.local.home/

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Link: https://lore.kernel.org/20250418101208.38dc81f5@gandalf.local.home
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

bash and dash evaluate variables differently.
dash will evaluate '\\' every time it is read whereas bash does not.

  TEST_STRING="$TEST_STRING \\$i"
  echo $TEST_STRING

With i=123
On bash, that will print "\123"
but on dash, that will print the escape sequence of \123 as the \ will be
interpreted again in the echo.

The dynevent_limitations.tc test created a very large list of arguments to
test the maximum number of arguments to pass to the dynamic events file.
It had a loop of:

   TEST_STRING=$1
   # Acceptable
   for i in `seq 1 $MAX_ARGS`; do
     TEST_STRING="$TEST_STRING \\$i"
   done
   echo "$TEST_STRING" >> dynamic_events

This worked fine on bash, but when run on dash it failed.

This was due to dash interpreting the "\\$i" twice. Once when it was
assigned to TEST_STRING and a second time with the echo $TEST_STRING.

bash does not process the backslash more than the first time.

To solve this, assign a double backslash to a variable "bs" and then echo
it to "ts". If "ts" changes, it is dash, if not, it is bash. Then update
"bs" accordingly, and use that to assign TEST_STRING.

Now this could possibly just check if "$BASH" is defined or not, but this
is testing if the issue exists and not just which shell is being used.

Link: https://lore.kernel.org/r/20250414210900.4de5e8b9@gandalf.local.home
Fixes: 581a7b26ab364 ("selftests/ftrace: Add dynamic events argument limitation test case")
Reported-by: Mark Brown <broonie@kernel.org>
Closes: https://lore.kernel.org/all/350786cc-9e40-4396-ab95-4f10d69122fb@sirena.org.uk/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

A bug was discovered that showed the accounting of the subops of the
ftrace_ops filtering was incorrect. Add a new test to better test the
filtering.

This test creates two instances, where it will add various filters to both
the set_ftrace_filter and the set_ftrace_notrace files and enable
function_graph. Then it looks into the enabled_functions file to make sure
that the filters are behaving correctly.

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Andy Chiu <andybnac@gmail.com>
Link: https://lore.kernel.org/20250409152720.380778379@goodmis.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Pull probes updates from Masami Hiramatsu:

 - probe-events: Add comments about entry data storing code to clarify
   where and how the entry data is stored for function return events.

 - probe-events: Log error for exceeding the number of arguments to help
   user to identify error reason via tracefs/error_log file.

 - Improve the ftracetest selftests:
    - Expand the tprobe event test to check if it can correctly find the
      wrong format tracepoint name.
    - Add new syntax error test to check whether error_log correctly
      indicates a wrong character in the tracepoint name.
    - Add a new dynamic events argument limitation test case which
      checks max number of probe arguments.

* tag 'probes-v6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: probe-events: Add comments about entry data storing code
  selftests/ftrace: Add dynamic events argument limitation test case
  selftests/ftrace: Add new syntax error test
  selftests/ftrace: Expand the tprobe event test to check wrong format
  tracing: probe-events: Log error for exceeding the number of arguments

Pull Kselftest updates from Shuah Khan:

 - Fix bugs and clean up code in tracing, ftrace, and user_events tests

 - Add missing executables to ftrace gitignore

* tag 'linux_kselftest-next-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest:
  selftests/ftrace: add 'poll' binary to gitignore
  selftests/ftrace: Use readelf to find entry point in uprobe test
  selftests/user_events: Fix failures caused by test code
  selftests/tracing: Allow some more tests to run in instances
  selftests/ftrace: Clean up triggers after setting them
  selftests/tracing: Test only toplevel README file not the instances

Add argument limitation test case for dynamic events.
This is a boudary check for the maximum number of the probe
event arguments.

Link: https://lore.kernel.org/all/174055078295.4079315.14702008939511417359.stgit@mhiramat.tok.corp.google.com/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

Add BAD_TP_NAME syntax error message check.

Link: https://lore.kernel.org/all/174055077485.4079315.3624012056141021755.stgit@mhiramat.tok.corp.google.com/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

Expand the tprobe event test case to check wrong tracepoint
format.

Link: https://lore.kernel.org/all/174055076681.4079315.16941322116874021804.stgit@mhiramat.tok.corp.google.com/

Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>