From 0dcac272540613d41c05e89679e4ddb978b612f1 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Mar 2022 13:24:09 +0100 Subject: bpf: Add multi kprobe link Adding new link type BPF_LINK_TYPE_KPROBE_MULTI that attaches kprobe program through fprobe API. The fprobe API allows to attach probe on multiple functions at once very fast, because it works on top of ftrace. On the other hand this limits the probe point to the function entry or return. The kprobe program gets the same pt_regs input ctx as when it's attached through the perf API. Adding new attach type BPF_TRACE_KPROBE_MULTI that allows attachment kprobe to multiple function with new link. User provides array of addresses or symbols with count to attach the kprobe program to. The new link_create uapi interface looks like: struct { __u32 flags; __u32 cnt; __aligned_u64 syms; __aligned_u64 addrs; } kprobe_multi; The flags field allows single BPF_TRACE_KPROBE_MULTI bit to create return multi kprobe. Signed-off-by: Masami Hiramatsu Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220316122419.933957-4-jolsa@kernel.org --- include/uapi/linux/bpf.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 99fab54ae9c0..d77f47af7752 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -997,6 +997,7 @@ enum bpf_attach_type { BPF_SK_REUSEPORT_SELECT, BPF_SK_REUSEPORT_SELECT_OR_MIGRATE, BPF_PERF_EVENT, + BPF_TRACE_KPROBE_MULTI, __MAX_BPF_ATTACH_TYPE }; @@ -1011,6 +1012,7 @@ enum bpf_link_type { BPF_LINK_TYPE_NETNS = 5, BPF_LINK_TYPE_XDP = 6, BPF_LINK_TYPE_PERF_EVENT = 7, + BPF_LINK_TYPE_KPROBE_MULTI = 8, MAX_BPF_LINK_TYPE, }; @@ -1118,6 +1120,11 @@ enum bpf_link_type { */ #define BPF_F_XDP_HAS_FRAGS (1U << 5) +/* link_create.kprobe_multi.flags used in LINK_CREATE command for + * BPF_TRACE_KPROBE_MULTI attach type to create return probe. + */ +#define BPF_F_KPROBE_MULTI_RETURN (1U << 0) + /* When BPF ldimm64's insn[0].src_reg != 0 then this can have * the following extensions: * @@ -1475,6 +1482,12 @@ union bpf_attr { */ __u64 bpf_cookie; } perf_event; + struct { + __u32 flags; + __u32 cnt; + __aligned_u64 syms; + __aligned_u64 addrs; + } kprobe_multi; }; } link_create; -- cgit v1.2.3 From ca74823c6e16dd42b7cf60d9fdde80e2a81a67bb Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Wed, 16 Mar 2022 13:24:12 +0100 Subject: bpf: Add cookie support to programs attached with kprobe multi link Adding support to call bpf_get_attach_cookie helper from kprobe programs attached with kprobe multi link. The cookie is provided by array of u64 values, where each value is paired with provided function address or symbol with the same array index. When cookie array is provided it's sorted together with addresses (check bpf_kprobe_multi_cookie_swap). This way we can find cookie based on the address in bpf_get_attach_cookie helper. Suggested-by: Andrii Nakryiko Signed-off-by: Jiri Olsa Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20220316122419.933957-7-jolsa@kernel.org --- include/uapi/linux/bpf.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index d77f47af7752..7604e7d5438f 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1487,6 +1487,7 @@ union bpf_attr { __u32 cnt; __aligned_u64 syms; __aligned_u64 addrs; + __aligned_u64 cookies; } kprobe_multi; }; } link_create; -- cgit v1.2.3