bpf: Add support for kprobe session context

Adding struct bpf_session_run_ctx object to hold session related
data, which is atm is_return bool and data pointer coming in
following changes.

Placing bpf_session_run_ctx layer in between bpf_run_ctx and
bpf_kprobe_multi_run_ctx so the session data can be retrieved
regardless of if it's kprobe_multi or uprobe_multi link, which
support is coming in future. This way both kprobe_multi and
uprobe_multi can use same kfuncs to access the session data.

Adding bpf_session_is_return kfunc that returns true if the
bpf program is executed from the exit probe of the kprobe multi
link attached in wrapper mode. It returns false otherwise.

Adding new kprobe hook for kprobe program type.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20240430112830.1184228-3-jolsa@kernel.org

1 files changed, 3 insertions, 0 deletions

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 8291fbfd27b1..821063660d9f 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -218,6 +218,7 @@ enum btf_kfunc_hook {
 	BTF_KFUNC_HOOK_SOCKET_FILTER,
 	BTF_KFUNC_HOOK_LWT,
 	BTF_KFUNC_HOOK_NETFILTER,
+	BTF_KFUNC_HOOK_KPROBE,
 	BTF_KFUNC_HOOK_MAX,
 };
 
@@ -8157,6 +8158,8 @@ static int bpf_prog_type_to_kfunc_hook(enum bpf_prog_type prog_type)
 		return BTF_KFUNC_HOOK_LWT;
 	case BPF_PROG_TYPE_NETFILTER:
 		return BTF_KFUNC_HOOK_NETFILTER;
+	case BPF_PROG_TYPE_KPROBE:
+		return BTF_KFUNC_HOOK_KPROBE;
 	default:
 		return BTF_KFUNC_HOOK_MAX;
 	}