From: Amery Hung <ameryhung@gmail.com>
To: bpf@vger.kernel.org
Cc: alexei.starovoitov@gmail.com, andrii@kernel.org,
daniel@iogearbox.net, eddyz87@gmail.com, memxor@gmail.com,
ameryhung@gmail.com, kernel-team@meta.com
Subject: [PATCH bpf-next v1 11/18] bpf: Classify kfunc mem_size args from BTF without register state
Date: Wed, 22 Jul 2026 22:07:59 -0700 [thread overview]
Message-ID: <20260723050806.1158442-12-ameryhung@gmail.com> (raw)
In-Reply-To: <20260723050806.1158442-1-ameryhung@gmail.com>
check_kfunc_args() already makes sure a scalar value is passed to a
scalar kfunc argument. Drop the check in is_kfunc_arg_mem_size() and
is_kfunc_arg_const_mem_size() to further decouple
get_kfunc_ptr_arg_type() from register state (a prerequisite for
generating a helper-like prototype from kfunc's BTF).
Signed-off-by: Amery Hung <ameryhung@gmail.com>
---
kernel/bpf/verifier.c | 20 +++++++++-----------
1 file changed, 9 insertions(+), 11 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 83f7afb86dfe..d77b590e0469 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -10801,26 +10801,24 @@ static bool is_kfunc_rcu_protected(struct bpf_call_arg_meta *meta)
}
static bool is_kfunc_arg_mem_size(const struct btf *btf,
- const struct btf_param *arg,
- const struct bpf_reg_state *reg)
+ const struct btf_param *arg)
{
const struct btf_type *t;
t = btf_type_skip_modifiers(btf, arg->type, NULL);
- if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE)
+ if (!btf_type_is_scalar(t))
return false;
return btf_param_match_suffix(btf, arg, "__sz");
}
static bool is_kfunc_arg_const_mem_size(const struct btf *btf,
- const struct btf_param *arg,
- const struct bpf_reg_state *reg)
+ const struct btf_param *arg)
{
const struct btf_type *t;
t = btf_type_skip_modifiers(btf, arg->type, NULL);
- if (!btf_type_is_scalar(t) || reg->type != SCALAR_VALUE)
+ if (!btf_type_is_scalar(t))
return false;
return btf_param_match_suffix(btf, arg, "__szk");
@@ -11354,7 +11352,7 @@ bool bpf_is_kfunc_pkt_changing(struct bpf_call_arg_meta *meta)
}
static enum kfunc_ptr_arg_type
-get_kfunc_ptr_arg_type(struct bpf_verifier_env *env, struct bpf_func_state *caller,
+get_kfunc_ptr_arg_type(struct bpf_verifier_env *env,
struct bpf_reg_state *regs, struct bpf_call_arg_meta *meta,
const struct btf_type *t, const struct btf_type *ref_t,
const char *ref_tname, const struct btf_param *args,
@@ -11368,8 +11366,8 @@ get_kfunc_ptr_arg_type(struct bpf_verifier_env *env, struct bpf_func_state *call
return KF_ARG_PTR_TO_CTX;
if (arg + 1 < nargs &&
- (is_kfunc_arg_mem_size(meta->btf, &args[arg + 1], get_func_arg_reg(caller, regs, arg + 1)) ||
- is_kfunc_arg_const_mem_size(meta->btf, &args[arg + 1], get_func_arg_reg(caller, regs, arg + 1))))
+ (is_kfunc_arg_mem_size(meta->btf, &args[arg + 1]) ||
+ is_kfunc_arg_const_mem_size(meta->btf, &args[arg + 1])))
arg_mem_size = true;
/* In this function, we verify the kfunc's BTF as per the argument type,
@@ -12100,7 +12098,7 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_call_arg_me
}
if (is_kfunc_arg_constant(meta->btf, &args[i]) ||
- is_kfunc_arg_const_mem_size(meta->btf, &args[i], reg)) {
+ is_kfunc_arg_const_mem_size(meta->btf, &args[i])) {
ret = process_const_arg(env, reg, argno, meta);
if (ret < 0)
return ret;
@@ -12145,7 +12143,7 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_call_arg_me
ref_t = btf_type_skip_modifiers(btf, t->type, &ref_id);
ref_tname = btf_name_by_offset(btf, ref_t->name_off);
- kf_arg_type = get_kfunc_ptr_arg_type(env, caller, regs, meta, t, ref_t, ref_tname,
+ kf_arg_type = get_kfunc_ptr_arg_type(env, regs, meta, t, ref_t, ref_tname,
args, i, nargs, argno, reg);
if (kf_arg_type < 0)
return kf_arg_type;
--
2.52.0
next prev parent reply other threads:[~2026-07-23 5:08 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-23 5:07 [PATCH bpf-next v1 00/18] Generate bpf_func_proto for kfunc Amery Hung
2026-07-23 5:07 ` [PATCH bpf-next v1 01/18] bpf: Drop process_timer_func wrappers Amery Hung
2026-07-23 5:07 ` [PATCH bpf-next v1 02/18] bpf: Unify const map ptr argument checking for helpers and kfuncs Amery Hung
2026-07-23 5:25 ` sashiko-bot
2026-07-23 5:07 ` [PATCH bpf-next v1 03/18] bpf: Split kfunc map argument into __const_map and __map Amery Hung
2026-07-23 5:35 ` sashiko-bot
2026-07-23 5:07 ` [PATCH bpf-next v1 04/18] bpf: Pass kfunc meta to mem and mem_size check Amery Hung
2026-07-23 5:07 ` [PATCH bpf-next v1 05/18] bpf: Check helper and kfunc mem+size arguments identically Amery Hung
2026-07-23 5:52 ` sashiko-bot
2026-07-23 5:07 ` [PATCH bpf-next v1 06/18] selftests/bpf: Add tests for helper and kfunc mem+size arguments Amery Hung
2026-07-23 5:42 ` sashiko-bot
2026-07-23 5:07 ` [PATCH bpf-next v1 07/18] bpf: Check fixed-size mem args of helpers and kfuncs the same way Amery Hung
2026-07-23 5:57 ` sashiko-bot
2026-07-23 5:07 ` [PATCH bpf-next v1 08/18] bpf: Express ARG_CONST_SIZE_OR_ZERO as ARG_CONST_SIZE | SCALAR_MAYBE_ZERO Amery Hung
2026-07-23 5:07 ` [PATCH bpf-next v1 09/18] bpf: Rename ARG_CONST_SIZE{,_OR_ZERO} to ARG_MEM_SIZE{,_OR_ZERO} Amery Hung
2026-07-23 5:07 ` [PATCH bpf-next v1 10/18] bpf: Fold __szk const size handling into the scalar arg path Amery Hung
2026-07-23 5:07 ` Amery Hung [this message]
2026-07-23 5:08 ` [PATCH bpf-next v1 12/18] bpf: Handle NULL kfunc pointer args without a KF_ARG_PTR_TO_NULL type Amery Hung
2026-07-23 5:08 ` [PATCH bpf-next v1 13/18] bpf: Distinguish fixed- and variable-size kfunc mem args with MEM_FIXED_SIZE Amery Hung
2026-07-23 5:08 ` [PATCH bpf-next v1 14/18] bpf: Check helper mem+size in ARG_PTR_TO_MEM case Amery Hung
2026-07-23 5:08 ` [PATCH bpf-next v1 15/18] bpf: Classify kfunc pointer arguments from BTF, resolve type against the register Amery Hung
2026-07-23 7:27 ` sashiko-bot
2026-07-23 5:08 ` [PATCH bpf-next v1 16/18] bpf: Tag nullable kfunc pointer args with PTR_MAYBE_NULL Amery Hung
2026-07-23 5:08 ` [PATCH bpf-next v1 17/18] bpf: Classify scalar kfunc arguments from BTF Amery Hung
2026-07-23 8:01 ` sashiko-bot
2026-07-23 5:08 ` [PATCH bpf-next v1 18/18] bpf: Generate kfunc argument prototype at add-call time Amery Hung
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