Re: [RFCv3 00/19] x86/ftrace/bpf: Add batch support for direct/tracing attach

On Sun, Jun 20, 2021 at 8:47 PM Alexei Starovoitov
[off-list ref] wrote:

On Sun, Jun 20, 2021 at 9:57 AM Yonghong Song [off-list ref] wrote:

quoted

quoted

ah right, should have checked it.. so how about we change
trampoline code to store ip in ctx-8 and make bpf_get_func_ip(ctx)
to return [ctx-8]

This should work. Thanks!

+1
and pls make it always inline into single LDX insn in the verifier.
For both mass attach and normal fentry/fexit.

Yep.

And we should do it for kprobes (trivial, PT_REGS_IP(ctx)) and
kretprobe (less trivial but simple from inside the kernel, Masami
showed how to do it in one of the previous emails). I hope BPF infra
allows inlining of helpers for some program types but not the others.