[PATCHv2 0/8] x86/ftrace: Add direct batch interface

From: Jiri Olsa <jolsa@redhat.com>
To: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Andrii Nakryiko <andriin@fb.com>
Subject: [PATCHv2 0/8] x86/ftrace: Add direct batch interface
Date: Fri,  8 Oct 2021 11:13:28 +0200	[thread overview]
Message-ID: <20211008091336.33616-1-jolsa@kernel.org> (raw)

hi,
adding interface to maintain multiple direct functions
within single calls. It's a base for follow up bpf batch
attach functionality.

New interface:

  int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)
  int unregister_ftrace_direct_multi(struct ftrace_ops *ops)
  int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr)

that allows to register/unregister/modify direct function 'addr'
with struct ftrace_ops object. The ops filter can be updated
before with ftrace_set_filter_ip calls

  1) patches (1-4) that fix the ftrace graph tracing over the function
     with direct trampolines attached
  2) patches (5-8) that add batch interface for ftrace direct function
     register/unregister/modify

Also available at (based on Steven's ftrace/core branch):
  https://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git
  ftrace/direct

v2 changes:
  - added comments to API functions
  - move common cleanup code to new remove_direct_functions_hash
    function
  - added addr argument to unregister_ftrace_direct_multi API,
    to properly cleanup direct_functions hash
  - added missing unregister_ftrace_direct call to trampoline/graph
    selftest
  - added comment to modify_ftrace_direct_multi about non-callback
    gap between ftrace_shutdown and ftrace_startup

thanks,
jirka

---
Jiri Olsa (6):
      x86/ftrace: Remove extra orig rax move
      tracing: Add trampoline/graph selftest
      ftrace: Add ftrace_add_rec_direct function
      ftrace: Add multi direct register/unregister interface
      ftrace: Add multi direct modify interface
      ftrace/samples: Add multi direct interface test module

Steven Rostedt (VMware) (2):
      x86/ftrace: Remove fault protection code in prepare_ftrace_return
      x86/ftrace: Make function graph use ftrace directly

 arch/x86/include/asm/ftrace.h        |   9 +++-
 arch/x86/kernel/ftrace.c             |  71 +++++++++++++++---------------
 arch/x86/kernel/ftrace_64.S          |  30 +------------
 include/linux/ftrace.h               |  26 +++++++++++
 kernel/trace/fgraph.c                |   6 ++-
 kernel/trace/ftrace.c                | 268 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------------
 kernel/trace/trace_selftest.c        |  54 ++++++++++++++++++++++-
 samples/ftrace/Makefile              |   1 +
 samples/ftrace/ftrace-direct-multi.c |  52 ++++++++++++++++++++++
 9 files changed, 420 insertions(+), 97 deletions(-)
 create mode 100644 samples/ftrace/ftrace-direct-multi.c