diff options
| author | Jiri Olsa <jolsa@kernel.org> | 2024-04-30 13:28:26 +0200 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2024-04-30 09:45:53 -0700 |
| commit | 5c919acef85147886eb2abf86fb147f94680a8b0 (patch) | |
| tree | 045b9f1176ff8ddecdf9fe1b31f2b7e19aa4aa16 /kernel/bpf/verifier.c | |
| parent | adf46d88ae4b2557f7e2e02547a25fb866935711 (diff) | |
bpf: Add support for kprobe session cookie
Adding support for cookie within the session of kprobe multi
entry and return program.
The session cookie is u64 value and can be retrieved be new
kfunc bpf_session_cookie, which returns pointer to the cookie
value. The bpf program can use the pointer to store (on entry)
and load (on return) the value.
The cookie value is implemented via fprobe feature that allows
to share values between entry and return ftrace fprobe callbacks.
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/20240430112830.1184228-4-jolsa@kernel.org
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 5d42db05315e..7360f04f9ec7 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -11063,6 +11063,7 @@ enum special_kfunc_type { KF_bpf_preempt_disable, KF_bpf_preempt_enable, KF_bpf_iter_css_task_new, + KF_bpf_session_cookie, }; BTF_SET_START(special_kfunc_set) @@ -11123,6 +11124,7 @@ BTF_ID(func, bpf_iter_css_task_new) #else BTF_ID_UNUSED #endif +BTF_ID(func, bpf_session_cookie) static bool is_kfunc_ret_null(struct bpf_kfunc_call_arg_meta *meta) { @@ -12294,6 +12296,11 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, } } + if (meta.func_id == special_kfunc_list[KF_bpf_session_cookie]) { + meta.r0_size = sizeof(u64); + meta.r0_rdonly = false; + } + if (is_bpf_wq_set_callback_impl_kfunc(meta.func_id)) { err = push_callback_call(env, insn, insn_idx, meta.subprogno, set_timer_callback_state); |