On Fri, Mar 6, 2020 at 11:19 PM Yutaro Hayakawa <[email protected]> wrote: > > Hello, > > Is there any way to get the address of the function in fentry type programs > like > kprobe type programs does by PT_REGS_IP(pt_regs)? > > I'd like to migrate my kprobe based tool[1] to fentry based one, but only this > feature is missing right now. Since the tool attaches single BPF program to > the multiple kernel functions, it needs to have function's address to identify > which function the trace data comes from. > > [1] https://github.com/YutaroHayakawa/ipftrace
I think this approach won't quite work with fentry because the same fenty type prog cannot be attached to multiple kernel functions. At load time the kernel verifier needs to hold target kernel function, check that arguments match, etc. So at that point the target function address is fixed and when fentry prog is called it will see only one 'faddr' == regs_ip. -=-=-=-=-=-=-=-=-=-=-=- Links: You receive all messages sent to this group. View/Reply Online (#1818): https://lists.iovisor.org/g/iovisor-dev/message/1818 Mute This Topic: https://lists.iovisor.org/mt/71791522/21656 Group Owner: [email protected] Unsubscribe: https://lists.iovisor.org/g/iovisor-dev/unsub [[email protected]] -=-=-=-=-=-=-=-=-=-=-=-
