Subject: Re: [PATCH 00/14] bpf: Add trampoline and dispatcher to /proc/kallsyms

From: Arnaldo Carvalho de Melo <[email-masked]>
Date: Tue, 11 Feb 2020 16:13:47 -0300

Em Sat, Feb 08, 2020 at 04:41:55PM +0100, Jiri Olsa escreveu:
> 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.

This will allow those to appear in profiles, right? That would be
interesting to explicitely state, i.e. the _why_ of this patch, not just
the _what_.

Thanks,

- Arnaldo
 
>   $ 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]
> 
> thanks,
> jirka
> 
> 
> ---
> Björn Töpel (1):
>       bpf: Add bpf_trampoline_ name prefix for DECLARE_BPF_DISPATCHER
> 
> Jiri Olsa (13):
>       x86/mm: Rename is_kernel_text to __is_kernel_text
>       bpf: Add struct bpf_ksym
>       bpf: Add name to struct bpf_ksym
>       bpf: Add lnode list node to struct bpf_ksym
>       bpf: Add bpf_kallsyms_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: Re-initialize lnode in bpf_ksym_del
>       bpf: Rename bpf_tree to bpf_progs_tree
>       bpf: Add trampolines to kallsyms
>       bpf: Add dispatchers to kallsyms
>       bpf: Sort bpf kallsyms symbols
> 
>  arch/x86/mm/init_32.c   |  14 ++++++----
>  include/linux/bpf.h     |  54 ++++++++++++++++++++++++++------------
>  include/linux/filter.h  |  13 +++-------
>  kernel/bpf/core.c       | 182 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--------------------------------
>  kernel/bpf/dispatcher.c |   6 +++++
>  kernel/bpf/trampoline.c |  23 ++++++++++++++++
>  kernel/events/core.c    |   4 +--
>  net/core/filter.c       |   5 ++--
>  8 files changed, 219 insertions(+), 82 deletions(-)
> 

-- 

- Arnaldo