[PATCH bpf-next v3 06/10] tools: bpftool: resolve calls without using imm field

[Jakub Kicinski]

On Tue, 22 May 2018 22:46:09 +0530, Sandipan Das wrote:
> Currently, we resolve the callee's address for a JITed function
> call by using the imm field of the call instruction as an offset
> from __bpf_call_base. If bpf_jit_kallsyms is enabled, we further
> use this address to get the callee's kernel symbol's name.
> 
> For some architectures, such as powerpc64, the imm field is not
> large enough to hold this offset. So, instead of assigning this
> offset to the imm field, the verifier now assigns the subprog
> id. Also, a list of kernel symbol addresses for all the JITed
> functions is provided in the program info. We now use the imm
> field as an index for this list to lookup a callee's symbol's
> address and resolve its name.
> 
> Suggested-by: Daniel Borkmann <daniel at iogearbox.net>
> Signed-off-by: Sandipan Das <sandipan at linux.vnet.ibm.com>

Reviewed-by: Jakub Kicinski <jakub.kicinski at netronome.com>