Merge tag 'probes-v7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes fixes from Masami Hiramatsu:
 "fprobe bug fixes:

   - Prevent re-registration

     Add an earlier check to reject re-registering an already active
     fprobe before its state is modified during the initialization phase

   - Robustness in failure paths:
      - Ensure fprobes are correctly removed from all internal tables
        and properly RCU-freed during registration failure
      - Make unregister_fprobe() proceed with unregistration even if
        temporary memory allocation fails

   - RCU safety in module unloading

     Avoid a potential "sleep in RCU" warning by removing a kcalloc()
     call in the module notifier path. This also tries to remove
     fprobe_hash_node even if memory allocation fails.

   - Type-aware unregistration

     Fix a bug where unregistering an fprobe did not account for
     different types (entry-only vs entry-exit) at the same address,
     which previously left "junk" entries in the underlying
     ftrace/fgraph ops

   - Unregistration of empty ftrace_ops

     Avoid unneeded performance overhead due to making registered
     ftrace_ops empty - which means 'trace all functions'. This counts
     remaining entries and unregister ftrace_ops when it becomes empty.

  Two new selftests to check above fixes:

   - Module Unloading Test:

     Specifically verifies that fprobe events on a module are correctly
     cleaned up and do not trigger 'trace-all' behavior when the module
     is removed.

   - Multiple Fprobe Events Test:

     Ensure that having multiple fprobes on the same function correctly
     manages the ftrace hash map during removal"

* tag 'probes-v7.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  selftests/ftrace: Add a testcase for multiple fprobe events
  selftests/ftrace: Add a testcase for fprobe events on module
  tracing/fprobe: Fix to unregister ftrace_ops if it is empty on module unloading
  tracing/fprobe: Check the same type fprobe on table as the unregistered one
  tracing/fprobe: Avoid kcalloc() in rcu_read_lock section
  tracing/fprobe: Remove fprobe from hash in failure path
  tracing/fprobe: Unregister fprobe even if memory allocation fails
  tracing/fprobe: Reject registration of a registered fprobe before init

Author: torvalds