Messages in this thread | | | From | Andrii Nakryiko <> | Date | Wed, 5 Jan 2022 20:30:56 -0800 | Subject | Re: [PATCH 08/13] bpf: Add kprobe link for attaching raw kprobes |
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On Tue, Jan 4, 2022 at 12:10 AM Jiri Olsa <jolsa@redhat.com> wrote: > > Adding new link type BPF_LINK_TYPE_KPROBE to attach kprobes > directly through register_kprobe/kretprobe API. > > Adding new attach type BPF_TRACE_RAW_KPROBE that enables > such link for kprobe program. > > The new link allows to create multiple kprobes link by using > new link_create interface: > > struct { > __aligned_u64 addrs; > __u32 cnt; > __u64 bpf_cookie;
I'm afraid bpf_cookie has to be different for each addr, otherwise it's severely limiting. So it would be an array of cookies alongside an array of addresses
> } kprobe; > > Plus new flag BPF_F_KPROBE_RETURN for link_create.flags to > create return probe. > > Signed-off-by: Jiri Olsa <jolsa@kernel.org> > --- > include/linux/bpf_types.h | 1 + > include/uapi/linux/bpf.h | 12 +++ > kernel/bpf/syscall.c | 191 ++++++++++++++++++++++++++++++++- > tools/include/uapi/linux/bpf.h | 12 +++ > 4 files changed, 211 insertions(+), 5 deletions(-) >
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> @@ -1111,6 +1113,11 @@ enum bpf_link_type { > */ > #define BPF_F_SLEEPABLE (1U << 4) > > +/* link_create flags used in LINK_CREATE command for BPF_TRACE_RAW_KPROBE > + * attach type. > + */ > +#define BPF_F_KPROBE_RETURN (1U << 0) > +
we have plenty of flexibility to have per-link type fields, so why not add `bool is_retprobe` next to addrs and cnt?
> /* When BPF ldimm64's insn[0].src_reg != 0 then this can have > * the following extensions: > * > @@ -1465,6 +1472,11 @@ union bpf_attr { > */ > __u64 bpf_cookie; > } perf_event; > + struct { > + __aligned_u64 addrs; > + __u32 cnt; > + __u64 bpf_cookie; > + } kprobe; > }; > } link_create; >
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