Re: [PATCH] bpftool: Allow to read btf as raw data

On Fri, 25 Oct 2019 22:03:51 +0200, Jiri Olsa wrote:

On Fri, Oct 25, 2019 at 11:39:01AM -0700, Jakub Kicinski wrote:

quoted

On Thu, 24 Oct 2019 15:30:25 +0200, Jiri Olsa wrote:  

quoted

The bpftool interface stays the same, but now it's possible
to run it over BTF raw data, like:

  $ bpftool btf dump file /sys/kernel/btf/vmlinux
  [1] INT '(anon)' size=4 bits_offset=0 nr_bits=32 encoding=(none)
  [2] INT 'long unsigned int' size=8 bits_offset=0 nr_bits=64 encoding=(none)
  [3] CONST '(anon)' type_id=2

Signed-off-by: Jiri Olsa <jolsa@kernel.org>  

Acked-by: Jakub Kicinski <redacted>  

[root@ibm-z-107 bpftool]# ./bpftool btf dump file /sys/kernel/btf/vmlinux  | head -3
[1] INT '(anon)' size=4 bits_offset=0 nr_bits=32 encoding=(none)
[2] INT 'long unsigned int' size=8 bits_offset=0 nr_bits=64 encoding=(none)
[3] CONST '(anon)' type_id=2
[root@ibm-z-107 bpftool]# lscpu | grep Endian
Byte Order:          Big Endian

Thanks for checking! I thought the on-disk format is fixed like the
ELF magic number. But if two bads make a right then all is good ☺️