It looks like the generic implementation based on __s_async suffix works well enough. So let's use it.
Note: - currently we lose the return value range - the second argument is not of type PTR_TO_MAP_KEY
Signed-off-by: Benjamin Tissoires bentiss@kernel.org
---
This is an RFC, and is not meant to be fully reviewed/applied as it is. I'm posting this to show what I wanted to explain in https://lore.kernel.org/bpf/mhkzkf4e23uvljtmwizwcxyuyat2tmfxn33xb4t7waafgmsa... --- kernel/bpf/verifier.c | 27 ++++----------------------- 1 file changed, 4 insertions(+), 23 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index cc4dab81b306..6fba9e2caa83 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -511,7 +511,6 @@ static bool is_dynptr_ref_function(enum bpf_func_id func_id) }
static bool is_sync_callback_calling_kfunc(u32 btf_id); -static bool is_async_callback_calling_kfunc(u32 btf_id); static bool is_callback_calling_kfunc(u32 btf_id); static bool is_bpf_throw_kfunc(struct bpf_insn *insn);
@@ -544,8 +543,7 @@ static bool is_sync_callback_calling_insn(struct bpf_insn *insn)
static bool is_async_callback_calling_insn(struct bpf_insn *insn) { - return (bpf_helper_call(insn) && is_async_callback_calling_function(insn->imm)) || - (bpf_pseudo_kfunc_call(insn) && is_async_callback_calling_kfunc(insn->imm)); + return bpf_helper_call(insn) && is_async_callback_calling_function(insn->imm); }
static bool is_may_goto_insn(struct bpf_insn *insn) @@ -9560,15 +9558,14 @@ static int push_callback_call(struct bpf_verifier_env *env, struct bpf_insn *ins return -EFAULT; }
- if (is_async_callback_calling_insn(insn) || (kfunc_meta && kfunc_meta->async_cb.enabled)) { + if (kfunc_meta && kfunc_meta->async_cb.enabled) { struct bpf_verifier_state *async_cb;
/* there is no real recursion here. timer and workqueue callbacks are async */ env->subprog_info[subprog].is_async_cb = true; async_cb = push_async_cb(env, env->subprog_info[subprog].start, insn_idx, subprog, - (is_bpf_wq_set_callback_impl_kfunc(insn->imm) || - (kfunc_meta && kfunc_meta->async_cb.sleepable))); + kfunc_meta && kfunc_meta->async_cb.sleepable); if (!async_cb) return -EFAULT; callee = async_cb->frame[0]; @@ -11534,11 +11531,6 @@ static bool is_sync_callback_calling_kfunc(u32 btf_id) return btf_id == special_kfunc_list[KF_bpf_rbtree_add_impl]; }
-static bool is_async_callback_calling_kfunc(u32 btf_id) -{ - return btf_id == special_kfunc_list[KF_bpf_wq_set_callback_impl]; -} - static bool is_bpf_throw_kfunc(struct bpf_insn *insn) { return bpf_pseudo_kfunc_call(insn) && insn->off == 0 && @@ -11552,8 +11544,7 @@ static bool is_bpf_wq_set_callback_impl_kfunc(u32 btf_id)
static bool is_callback_calling_kfunc(u32 btf_id) { - return is_sync_callback_calling_kfunc(btf_id) || - is_async_callback_calling_kfunc(btf_id); + return is_sync_callback_calling_kfunc(btf_id); }
static bool is_rbtree_lock_required_kfunc(u32 btf_id) @@ -12465,16 +12456,6 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, } }
- 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, &meta); - if (err) { - verbose(env, "kfunc %s#%d failed callback verification\n", - func_name, meta.func_id); - return err; - } - } - if (meta.async_cb.enabled) { err = push_callback_call(env, insn, insn_idx, meta.subprogno, set_generic_callback_state, &meta);