From: Benjamin Tissoires <bentiss@kernel.org>
To: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
John Fastabend <john.fastabend@gmail.com>,
Andrii Nakryiko <andrii@kernel.org>,
Martin KaFai Lau <martin.lau@linux.dev>,
Eduard Zingerman <eddyz87@gmail.com>, Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
KP Singh <kpsingh@kernel.org>,
Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
Jiri Olsa <jolsa@kernel.org>, Jiri Kosina <jikos@kernel.org>,
Benjamin Tissoires <benjamin.tissoires@redhat.com>,
Jonathan Corbet <corbet@lwn.net>, Shuah Khan <shuah@kernel.org>
Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-input@vger.kernel.org, linux-doc@vger.kernel.org,
linux-kselftest@vger.kernel.org,
Benjamin Tissoires <bentiss@kernel.org>
Subject: [PATCH RFC bpf-next v3 07/16] bpf/helpers: mark the callback of bpf_timer_set_sleepable_cb() as sleepable
Date: Wed, 21 Feb 2024 17:25:23 +0100 [thread overview]
Message-ID: <20240221-hid-bpf-sleepable-v3-7-1fb378ca6301@kernel.org> (raw)
In-Reply-To: <20240221-hid-bpf-sleepable-v3-0-1fb378ca6301@kernel.org>
Now that we have bpf_timer_set_sleepable_cb() available and working, we
can tag the attached callback as sleepable, and let the verifier check
in the correct context the calls and kfuncs.
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
---
new in v3 (split from v2 02/10)
---
include/linux/bpf_verifier.h | 2 ++
kernel/bpf/verifier.c | 16 +++++++++++++++-
2 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index 84365e6dd85d..789ef5fec547 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -426,6 +426,7 @@ struct bpf_verifier_state {
* while they are still in use.
*/
bool used_as_loop_entry;
+ bool in_sleepable;
/* first and last insn idx of this verifier state */
u32 first_insn_idx;
@@ -626,6 +627,7 @@ struct bpf_subprog_info {
bool is_async_cb: 1;
bool is_exception_cb: 1;
bool args_cached: 1;
+ bool is_sleepable: 1;
u8 arg_cnt;
struct bpf_subprog_arg_info args[MAX_BPF_FUNC_REG_ARGS];
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 91e583c6feba..4766c43606c4 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -505,6 +505,8 @@ 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);
+static bool is_bpf_timer_set_sleepable_cb_kfunc(u32 btf_id);
+
static bool is_sync_callback_calling_function(enum bpf_func_id func_id)
{
return func_id == BPF_FUNC_for_each_map_elem ||
@@ -1422,6 +1424,7 @@ static int copy_verifier_state(struct bpf_verifier_state *dst_state,
}
dst_state->speculative = src->speculative;
dst_state->active_rcu_lock = src->active_rcu_lock;
+ dst_state->in_sleepable = src->in_sleepable;
dst_state->curframe = src->curframe;
dst_state->active_lock.ptr = src->active_lock.ptr;
dst_state->active_lock.id = src->active_lock.id;
@@ -2421,6 +2424,7 @@ static struct bpf_verifier_state *push_async_cb(struct bpf_verifier_env *env,
* Initialize it similar to do_check_common().
*/
elem->st.branches = 1;
+ elem->st.in_sleepable = env->subprog_info[subprog].is_sleepable;
frame = kzalloc(sizeof(*frame), GFP_KERNEL);
if (!frame)
goto err;
@@ -5265,7 +5269,8 @@ static int map_kptr_match_type(struct bpf_verifier_env *env,
static bool in_sleepable(struct bpf_verifier_env *env)
{
- return env->prog->aux->sleepable;
+ return env->prog->aux->sleepable ||
+ (env->cur_state && env->cur_state->in_sleepable);
}
/* The non-sleepable programs and sleepable programs with explicit bpf_rcu_read_lock()
@@ -9478,6 +9483,7 @@ static int push_callback_call(struct bpf_verifier_env *env, struct bpf_insn *ins
/* there is no real recursion here. timer callbacks are async */
env->subprog_info[subprog].is_async_cb = true;
+ env->subprog_info[subprog].is_sleepable = is_bpf_timer_set_sleepable_cb_kfunc(insn->imm);
async_cb = push_async_cb(env, env->subprog_info[subprog].start,
insn_idx, subprog);
if (!async_cb)
@@ -11361,6 +11367,11 @@ static bool is_bpf_throw_kfunc(struct bpf_insn *insn)
insn->imm == special_kfunc_list[KF_bpf_throw];
}
+static bool is_bpf_timer_set_sleepable_cb_kfunc(u32 btf_id)
+{
+ return btf_id == special_kfunc_list[KF_bpf_timer_set_sleepable_cb];
+}
+
static bool is_callback_calling_kfunc(u32 btf_id)
{
return is_sync_callback_calling_kfunc(btf_id) ||
@@ -16830,6 +16841,9 @@ static bool states_equal(struct bpf_verifier_env *env,
if (old->active_rcu_lock != cur->active_rcu_lock)
return false;
+ if (old->in_sleepable != cur->in_sleepable)
+ return false;
+
/* for states to be equal callsites have to be the same
* and all frame states need to be equivalent
*/
--
2.43.0
next prev parent reply other threads:[~2024-02-21 16:25 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-21 16:25 [PATCH RFC bpf-next v3 00/16] sleepable bpf_timer (was: allow HID-BPF to do device IOs) Benjamin Tissoires
2024-02-21 16:25 ` [PATCH RFC bpf-next v3 01/16] bpf/verifier: allow more maps in sleepable bpf programs Benjamin Tissoires
2024-02-21 16:25 ` [PATCH RFC bpf-next v3 02/16] bpf/verifier: introduce in_sleepable() helper Benjamin Tissoires
2024-02-23 1:56 ` Alexei Starovoitov
2024-02-23 19:46 ` Benjamin Tissoires
2024-02-21 16:25 ` [PATCH RFC bpf-next v3 03/16] bpf/verifier: add is_async_callback_calling_insn() helper Benjamin Tissoires
2024-02-21 16:25 ` [PATCH RFC bpf-next v3 04/16] bpf/helpers: introduce sleepable bpf_timers Benjamin Tissoires
2024-02-22 8:05 ` Benjamin Tissoires
2024-02-22 11:50 ` Toke Høiland-Jørgensen
2024-02-22 20:47 ` Alexei Starovoitov
2024-02-22 22:40 ` Eduard Zingerman
2024-02-27 14:27 ` Benjamin Tissoires
2024-02-21 16:25 ` [PATCH RFC bpf-next v3 05/16] bpf/verifier: add bpf_timer as a kfunc capable type Benjamin Tissoires
2024-02-23 0:22 ` Eduard Zingerman
2024-02-23 0:26 ` Eduard Zingerman
2024-02-23 14:54 ` Eduard Zingerman
2024-02-21 16:25 ` [PATCH RFC bpf-next v3 06/16] bpf/helpers: introduce bpf_timer_set_sleepable_cb() kfunc Benjamin Tissoires
2024-02-22 20:53 ` Alexei Starovoitov
2024-02-23 15:10 ` Eduard Zingerman
2024-02-21 16:25 ` Benjamin Tissoires [this message]
2024-02-23 15:35 ` [PATCH RFC bpf-next v3 07/16] bpf/helpers: mark the callback of bpf_timer_set_sleepable_cb() as sleepable Eduard Zingerman
2024-02-21 16:25 ` [PATCH RFC bpf-next v3 08/16] bpf/verifier: do_misc_fixups for is_bpf_timer_set_sleepable_cb_kfunc Benjamin Tissoires
2024-02-23 16:00 ` Eduard Zingerman
2024-02-27 16:18 ` Benjamin Tissoires
2024-02-27 16:36 ` Eduard Zingerman
2024-02-27 16:51 ` Benjamin Tissoires
2024-02-28 1:49 ` Alexei Starovoitov
2024-02-28 11:01 ` Benjamin Tissoires
2024-02-21 16:25 ` [PATCH RFC bpf-next v3 09/16] HID: bpf/dispatch: regroup kfuncs definitions Benjamin Tissoires
2024-02-22 20:17 ` Eduard Zingerman
2024-02-23 19:44 ` Benjamin Tissoires
2024-02-21 16:25 ` [PATCH RFC bpf-next v3 10/16] HID: bpf: export hid_hw_output_report as a BPF kfunc Benjamin Tissoires
2024-02-21 16:25 ` [PATCH RFC bpf-next v3 11/16] selftests/hid: Add test for hid_bpf_hw_output_report Benjamin Tissoires
2024-02-21 16:25 ` [PATCH RFC bpf-next v3 12/16] HID: bpf: allow to inject HID event from BPF Benjamin Tissoires
2024-02-21 16:25 ` [PATCH RFC bpf-next v3 13/16] selftests/hid: add tests for hid_bpf_input_report Benjamin Tissoires
2024-02-21 16:25 ` [PATCH RFC bpf-next v3 14/16] HID: bpf: allow to use bpf_timer_set_sleepable_cb() in tracing callbacks Benjamin Tissoires
2024-02-21 16:25 ` [PATCH RFC bpf-next v3 15/16] selftests/hid: add test for bpf_timer Benjamin Tissoires
2024-02-21 16:25 ` [PATCH RFC bpf-next v3 16/16] selftests/hid: add KASAN to the VM tests Benjamin Tissoires
2024-02-23 16:19 ` [PATCH RFC bpf-next v3 00/16] sleepable bpf_timer (was: allow HID-BPF to do device IOs) Eduard Zingerman
2024-02-23 19:42 ` Benjamin Tissoires
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