Commit 2ab256e9 authored by Benjamin Tissoires's avatar Benjamin Tissoires Committed by Alexei Starovoitov
Browse files

bpf: add is_async_callback_calling_insn() helper 



Currently we have a special case for BPF_FUNC_timer_set_callback,
let's introduce a helper we can extend for the kfunc that will come in
a later patch

Signed-off-by: default avatarBenjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240221-hid-bpf-sleepable-v3-3-1fb378ca6301@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent dfe6625d

kernel/bpf/verifier.c

+7 −4
Original line number Diff line number Diff line
@@ -528,6 +528,11 @@ static bool is_sync_callback_calling_insn(struct bpf_insn *insn) 
	       (bpf_pseudo_kfunc_call(insn) && is_sync_callback_calling_kfunc(insn->imm));

}









static bool is_async_callback_calling_insn(struct bpf_insn *insn)









{









	return bpf_helper_call(insn) && is_async_callback_calling_function(insn->imm);









}

















static bool is_storage_get_function(enum bpf_func_id func_id)









{









	return func_id == BPF_FUNC_sk_storage_get ||








@@ -9445,9 +9450,7 @@ static int push_callback_call(struct bpf_verifier_env *env, struct bpf_insn *ins







		return -EFAULT;









	}

















	if (insn->code == (BPF_JMP | BPF_CALL) &&









	    insn->src_reg == 0 &&









	    insn->imm == BPF_FUNC_timer_set_callback) {









	if (is_async_callback_calling_insn(insn)) {









		struct bpf_verifier_state *async_cb;

















		/* there is no real recursion here. timer callbacks are async */








@@ -15588,7 +15591,7 @@ static int visit_insn(int t, struct bpf_verifier_env *env)







		return DONE_EXPLORING;

















	case BPF_CALL:









		if (insn->src_reg == 0 && insn->imm == BPF_FUNC_timer_set_callback)









		if (is_async_callback_calling_insn(insn))









			/* Mark this call insn as a prune point to trigger









			 * is_state_visited() check before call itself is









			 * processed by __check_func_call(). Otherwise new