From: Joanne Koong <joannelkoong@gmail.com>
To: bpf@vger.kernel.org
Cc: martin.lau@kernel.org, andrii@kernel.org, ast@kernel.org,
memxor@gmail.com, daniel@iogearbox.net, netdev@vger.kernel.org,
toke@kernel.org, Joanne Koong <joannelkoong@gmail.com>
Subject: [PATCH v13 bpf-next 05/10] bpf: Refactor verifier dynptr into get_dynptr_arg_reg
Date: Wed, 1 Mar 2023 07:49:48 -0800 [thread overview]
Message-ID: <20230301154953.641654-6-joannelkoong@gmail.com> (raw)
In-Reply-To: <20230301154953.641654-1-joannelkoong@gmail.com>
This commit refactors the logic for determining which register in a
function is the dynptr into "get_dynptr_arg_reg". This will be used
in the future when the dynptr reg for BPF_FUNC_dynptr_write will need
to be obtained in order to support writes for skb dynptrs.
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
---
kernel/bpf/verifier.c | 80 +++++++++++++++++++++++++++----------------
1 file changed, 50 insertions(+), 30 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 82e39fc5ed05..8fd2f26a8977 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -6689,6 +6689,28 @@ int check_func_arg_reg_off(struct bpf_verifier_env *env,
}
}
+static struct bpf_reg_state *get_dynptr_arg_reg(struct bpf_verifier_env *env,
+ const struct bpf_func_proto *fn,
+ struct bpf_reg_state *regs)
+{
+ struct bpf_reg_state *state = NULL;
+ int i;
+
+ for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++)
+ if (arg_type_is_dynptr(fn->arg_type[i])) {
+ if (state) {
+ verbose(env, "verifier internal error: multiple dynptr args\n");
+ return NULL;
+ }
+ state = ®s[BPF_REG_1 + i];
+ }
+
+ if (!state)
+ verbose(env, "verifier internal error: no dynptr arg found\n");
+
+ return state;
+}
+
static int dynptr_id(struct bpf_verifier_env *env, struct bpf_reg_state *reg)
{
struct bpf_func_state *state = func(env, reg);
@@ -8326,43 +8348,41 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
}
break;
case BPF_FUNC_dynptr_data:
- for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) {
- if (arg_type_is_dynptr(fn->arg_type[i])) {
- struct bpf_reg_state *reg = ®s[BPF_REG_1 + i];
- int id, ref_obj_id;
-
- if (meta.dynptr_id) {
- verbose(env, "verifier internal error: meta.dynptr_id already set\n");
- return -EFAULT;
- }
-
- if (meta.ref_obj_id) {
- verbose(env, "verifier internal error: meta.ref_obj_id already set\n");
- return -EFAULT;
- }
+ {
+ struct bpf_reg_state *reg;
+ int id, ref_obj_id;
- id = dynptr_id(env, reg);
- if (id < 0) {
- verbose(env, "verifier internal error: failed to obtain dynptr id\n");
- return id;
- }
+ reg = get_dynptr_arg_reg(env, fn, regs);
+ if (!reg)
+ return -EFAULT;
- ref_obj_id = dynptr_ref_obj_id(env, reg);
- if (ref_obj_id < 0) {
- verbose(env, "verifier internal error: failed to obtain dynptr ref_obj_id\n");
- return ref_obj_id;
- }
- meta.dynptr_id = id;
- meta.ref_obj_id = ref_obj_id;
- break;
- }
+ if (meta.dynptr_id) {
+ verbose(env, "verifier internal error: meta.dynptr_id already set\n");
+ return -EFAULT;
}
- if (i == MAX_BPF_FUNC_REG_ARGS) {
- verbose(env, "verifier internal error: no dynptr in bpf_dynptr_data()\n");
+ if (meta.ref_obj_id) {
+ verbose(env, "verifier internal error: meta.ref_obj_id already set\n");
return -EFAULT;
}
+
+ id = dynptr_id(env, reg);
+ if (id < 0) {
+ verbose(env, "verifier internal error: failed to obtain dynptr id\n");
+ return id;
+ }
+
+ ref_obj_id = dynptr_ref_obj_id(env, reg);
+ if (ref_obj_id < 0) {
+ verbose(env, "verifier internal error: failed to obtain dynptr ref_obj_id\n");
+ return ref_obj_id;
+ }
+
+ meta.dynptr_id = id;
+ meta.ref_obj_id = ref_obj_id;
+
break;
+ }
case BPF_FUNC_user_ringbuf_drain:
err = __check_func_call(env, insn, insn_idx_p, meta.subprogno,
set_user_ringbuf_callback_state);
--
2.34.1
next prev parent reply other threads:[~2023-03-01 15:51 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-01 15:49 [PATCH v13 bpf-next 00/10] Add skb + xdp dynptrs Joanne Koong
2023-03-01 15:49 ` [PATCH v13 bpf-next 01/10] bpf: Support "sk_buff" and "xdp_buff" as valid kfunc arg types Joanne Koong
2023-03-01 15:49 ` [PATCH v13 bpf-next 02/10] bpf: Refactor process_dynptr_func Joanne Koong
2023-03-01 15:49 ` [PATCH v13 bpf-next 03/10] bpf: Allow initializing dynptrs in kfuncs Joanne Koong
2023-03-06 7:36 ` Kumar Kartikeya Dwivedi
2023-03-07 6:53 ` Joanne Koong
2023-03-07 23:53 ` Andrii Nakryiko
2023-03-01 15:49 ` [PATCH v13 bpf-next 04/10] bpf: Define no-ops for externally called bpf dynptr functions Joanne Koong
2023-03-01 15:49 ` Joanne Koong [this message]
2023-03-01 15:49 ` [PATCH v13 bpf-next 06/10] bpf: Add __uninit kfunc annotation Joanne Koong
2023-03-01 15:49 ` [PATCH v13 bpf-next 07/10] bpf: Add skb dynptrs Joanne Koong
2023-03-01 15:49 ` [PATCH v13 bpf-next 08/10] bpf: Add xdp dynptrs Joanne Koong
2023-03-01 15:49 ` [PATCH v13 bpf-next 09/10] bpf: Add bpf_dynptr_slice and bpf_dynptr_slice_rdwr Joanne Koong
2023-03-02 3:29 ` kernel test robot
2023-03-02 3:53 ` Joanne Koong
2023-03-06 7:10 ` Kumar Kartikeya Dwivedi
2023-03-07 2:23 ` Alexei Starovoitov
2023-03-07 10:22 ` Kumar Kartikeya Dwivedi
2023-03-07 15:45 ` Alexei Starovoitov
2023-03-07 17:35 ` Kumar Kartikeya Dwivedi
2023-03-08 0:01 ` Andrii Nakryiko
2023-03-10 21:15 ` Alexei Starovoitov
2023-03-10 21:29 ` Andrii Nakryiko
2023-03-10 21:54 ` Kumar Kartikeya Dwivedi
2023-03-10 21:54 ` Alexei Starovoitov
2023-03-13 6:31 ` Joanne Koong
2023-03-13 14:41 ` Kumar Kartikeya Dwivedi
2023-03-16 18:55 ` Andrii Nakryiko
2023-03-27 7:47 ` Joanne Koong
2023-03-28 21:42 ` Andrii Nakryiko
2023-04-09 0:22 ` Joanne Koong
2023-04-12 19:05 ` Andrii Nakryiko
2023-03-10 21:38 ` Kumar Kartikeya Dwivedi
2023-03-10 21:49 ` Alexei Starovoitov
2023-03-01 15:49 ` [PATCH v13 bpf-next 10/10] selftests/bpf: tests for using dynptrs to parse skb and xdp buffers Joanne Koong
2023-03-01 18:08 ` Alexei Starovoitov
2023-03-01 18:43 ` Andrii Nakryiko
2023-03-02 4:28 ` Joanne Koong
2023-03-08 1:55 ` Ilya Leoshkevich
2023-03-08 7:22 ` Joanne Koong
2023-03-08 14:24 ` Ilya Leoshkevich
2023-03-09 8:13 ` Joanne Koong
2023-03-10 3:40 ` Ilya Leoshkevich
2023-03-10 5:12 ` Stanislav Fomichev
2023-03-10 17:43 ` Alexei Starovoitov
2023-03-01 18:10 ` [PATCH v13 bpf-next 00/10] Add skb + xdp dynptrs patchwork-bot+netdevbpf
2023-03-08 8:16 ` Jakub Kicinski
2023-03-08 17:08 ` Andrii Nakryiko
2023-03-08 17:28 ` Jakub Kicinski
2023-03-08 19:02 ` Andrii Nakryiko
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