Merge tag 'trace-v6.17-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace...

Merge tag 'trace-v6.17-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix rtla and latency tooling pkg-config errors

   If libtraceevent and libtracefs is installed, but their corresponding
   '.pc' files are not installed, it reports that the libraries are
   missing and confuses the developer. Instead, report that the
   pkg-config files are missing and should be installed.

 - Fix overflow bug of the parser in trace_get_user()

   trace_get_user() uses the parsing functions to parse the user space
   strings. If the parser fails due to incorrect processing, it doesn't
   terminate the buffer with a nul byte. Add a "failed" flag to the
   parser that gets set when parsing fails and is used to know if the
   buffer is fine to use or not.

 - Remove a semicolon that was at an end of a comment line

 - Fix register_ftrace_graph() to unregister the pm notifier on error

   The register_ftrace_graph() registers a pm notifier but there's an
   error path that can exit the function without unregistering it. Since
   the function returns an error, it will never be unregistered.

 - Allocate and copy ftrace hash for reader of ftrace filter files

   When the set_ftrace_filter or set_ftrace_notrace files are open for
   read, an iterator is created and sets its hash pointer to the
   associated hash that represents filtering or notrace filtering to it.
   The issue is that the hash it points to can change while the
   iteration is happening. All the locking used to access the tracer's
   hashes are released which means those hashes can change or even be
   freed. Using the hash pointed to by the iterator can cause UAF bugs
   or similar.

   Have the read of these files allocate and copy the corresponding
   hashes and use that as that will keep them the same while the
   iterator is open. This also simplifies the code as opening it for
   write already does an allocate and copy, and now that the read is
   doing the same, there's no need to check which way it was opened on
   the release of the file, and the iterator hash can always be freed.

 - Fix function graph to copy args into temp storage

   The output of the function graph tracer shows both the entry and the
   exit of a function. When the exit is right after the entry, it
   combines the two events into one with the output of "function();",
   instead of showing:

     function() {
     }

   In order to do this, the iterator descriptor that reads the events
   includes storage that saves the entry event while it peaks at the
   next event in the ring buffer. The peek can free the entry event so
   the iterator must store the information to use it after the peek.

   With the addition of function graph tracer recording the args, where
   the args are a dynamic array in the entry event, the temp storage
   does not save them. This causes the args to be corrupted or even
   cause a read of unsafe memory.

   Add space to save the args in the temp storage of the iterator.

 - Fix race between ftrace_dump and reading trace_pipe

   ftrace_dump() is used when a crash occurs where the ftrace buffer
   will be printed to the console. But it can also be triggered by
   sysrq-z. If a sysrq-z is triggered while a task is reading trace_pipe
   it can cause a race in the ftrace_dump() where it checks if the
   buffer has content, then it checks if the next event is available,
   and then prints the output (regardless if the next event was
   available or not). Reading trace_pipe at the same time can cause it
   to not be available, and this triggers a WARN_ON in the print. Move
   the printing into the check if the next event exists or not

* tag 'trace-v6.17-rc2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ftrace: Also allocate and copy hash for reading of filter files
  ftrace: Fix potential warning in trace_printk_seq during ftrace_dump
  fgraph: Copy args in intermediate storage with entry
  trace/fgraph: Fix the warning caused by missing unregister notifier
  ring-buffer: Remove redundant semicolons
  tracing: Limit access to parser->buffer when trace_get_user failed
  rtla: Check pkg-config install
  tools/latency-collector: Check pkg-config install