Subject: [PATCHv4 00/15] bpf: Add trampoline and dispatcher to /proc/kallsyms

From: Jiri Olsa <[email-masked]>
Date: Mon, 2 Mar 2020 15:31:39 +0100

hi,
this patchset adds trampoline and dispatcher objects
to be visible in /proc/kallsyms. The last patch also
adds sorting for all bpf objects in /proc/kallsyms.

  $ sudo cat /proc/kallsyms | tail -20
  ...
  ffffffffa050f000 t bpf_prog_5a2b06eab81b8f51    [bpf]
  ffffffffa0511000 t bpf_prog_6deef7357e7b4530    [bpf]
  ffffffffa0542000 t bpf_trampoline_13832 [bpf]
  ffffffffa0548000 t bpf_prog_96f1b5bf4e4cc6dc_mutex_lock [bpf]
  ffffffffa0572000 t bpf_prog_d1c63e29ad82c4ab_bpf_prog1  [bpf]
  ffffffffa0585000 t bpf_prog_e314084d332a5338__dissect   [bpf]
  ffffffffa0587000 t bpf_prog_59785a79eac7e5d2_mutex_unlock       [bpf]
  ffffffffa0589000 t bpf_prog_d0db6e0cac050163_mutex_lock [bpf]
  ffffffffa058d000 t bpf_prog_d8f047721e4d8321_bpf_prog2  [bpf]
  ffffffffa05df000 t bpf_trampoline_25637 [bpf]
  ffffffffa05e3000 t bpf_prog_d8f047721e4d8321_bpf_prog2  [bpf]
  ffffffffa05e5000 t bpf_prog_3b185187f1855c4c    [bpf]
  ffffffffa05e7000 t bpf_prog_d8f047721e4d8321_bpf_prog2  [bpf]
  ffffffffa05eb000 t bpf_prog_93cebb259dd5c4b2_do_sys_open        [bpf]
  ffffffffa0677000 t bpf_dispatcher_xdp   [bpf]

v4 changes:
  - add trampoline and dispatcher to kallsyms once the it's allocated [Alexei]
  - omit the symbols sorting for kallsyms [Alexei]
  - small title change in one patch [Song]
  - some function renames:
     bpf_get_prog_name to bpf_prog_ksym_set_name
     bpf_get_prog_addr_region to bpf_prog_ksym_set_addr
  - added acks to changelogs
  - I checked and there'll be conflict on perftool side with
    upcoming changes from Adrian Hunter (text poke events),
    so I think it's better if Arnaldo takes the perf changes
    via perf tree and we will solve all conflicts there

v3 changes:
  - use container_of directly in bpf_get_ksym_start  [Daniel]
  - add more changelog explanations for ksym addresses [Daniel]

v2 changes:
  - omit extra condition in __bpf_ksym_add for sorting code (Andrii)
  - rename bpf_kallsyms_tree_ops to bpf_ksym_tree (Andrii)
  - expose only executable code in kallsyms (Andrii)
  - use full trampoline key as its kallsyms id (Andrii)
  - explained the BPF_TRAMP_REPLACE case (Andrii)
  - small format changes in bpf_trampoline_link_prog/bpf_trampoline_unlink_prog (Andrii)
  - propagate error value in bpf_dispatcher_update and update kallsym if it's successful (Andrii)
  - get rid of __always_inline for bpf_ksym_tree callbacks (Andrii)
  - added KSYMBOL notification for bpf_image add/removal
  - added perf tools changes to properly display trampoline/dispatcher

For perf tool to properly display trampoline/dispatcher you need
also Arnaldo's perf/urgent branch changes. I merged everything
into following branch:

    git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf.git bpf/kallsyms

thanks,
jirka

---
Björn Töpel (1):
      bpf: Add bpf_trampoline_ name prefix for DECLARE_BPF_DISPATCHER

Jiri Olsa (14):
      x86/mm: Rename is_kernel_text to __is_kernel_text
      bpf: Add struct bpf_ksym
      bpf: Add name to struct bpf_ksym
      bpf: Move lnode list node to struct bpf_ksym
      bpf: Add bpf_ksym_tree tree
      bpf: Move bpf_tree add/del from bpf_prog_ksym_node_add/del
      bpf: Separate kallsyms add/del functions
      bpf: Add bpf_ksym_add/del functions
      bpf: Rename bpf_tree to bpf_progs_tree
      bpf: Add trampolines to kallsyms
      bpf: Add dispatchers to kallsyms
      perf tools: Synthesize bpf_trampoline/dispatcher ksymbol event
      perf tools: Set ksymbol dso as loaded on arrival
      perf annotate: Add base support for bpf_image

 arch/x86/mm/init_32.c       |  14 ++++++++----
 include/linux/bpf.h         |  55 ++++++++++++++++++++++++++++++--------------
 include/linux/filter.h      |  13 +++--------
 kernel/bpf/core.c           | 153 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++-------------------------------------
 kernel/bpf/dispatcher.c     |   1 +
 kernel/bpf/trampoline.c     |  28 +++++++++++++++++++++++
 kernel/events/core.c        |   9 ++++----
 net/core/filter.c           |   5 ++--
 tools/perf/util/annotate.c  |  20 ++++++++++++++++
 tools/perf/util/bpf-event.c |  98 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 tools/perf/util/dso.c       |   1 +
 tools/perf/util/dso.h       |   1 +
 tools/perf/util/machine.c   |  12 ++++++++++
 tools/perf/util/symbol.c    |   1 +
 14 files changed, 325 insertions(+), 86 deletions(-)