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| author | Alexei Starovoitov <ast@kernel.org> | 2026-01-06 17:42:55 -0800 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-01-06 17:44:20 -0800 |
| commit | a8d506759231124efb911a3bd14d1ec2d9de15a1 (patch) | |
| tree | 0e453f4c69264feebf84df75d99a687e0ade6399 /kernel | |
| parent | ea180ffbd27ce5abf2a06329fe1fc8d20dc9becf (diff) | |
| parent | b81d5e9d965e0af2c1f21fc392a23e598171f9d6 (diff) | |
Merge branch 'bpf-verifier-allow-calling-arena-functions-when-holding-bpf-lock'
Emil Tsalapatis says:
====================
bpf/verifier: Allow calling arena functions when holding BPF lock
BPF arena-related kfuncs now cannot sleep, so they are safe to call
while holding a spinlock. However, the verifier still rejects
programs that do so. Update the verifier to allow arena kfunc
calls while holding a lock.
Signed-off-by: Emil Tsalapatis <emil@etsalapatis.com>
Changes v1->v2: (https://lore.kernel.org/r/20260106-arena-under-lock-v1-0-6ca9c121d826@etsalapatis.com)
- Added patch to account for active locks in_sleepable_context() (AI)
====================
Link: https://patch.msgid.link/20260106-arena-under-lock-v2-0-378e9eab3066@etsalapatis.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/bpf/verifier.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 9394b0de2ef0..53635ea2e41b 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -11466,6 +11466,7 @@ static inline bool in_sleepable_context(struct bpf_verifier_env *env) { return !env->cur_state->active_rcu_locks && !env->cur_state->active_preempt_locks && + !env->cur_state->active_locks && !env->cur_state->active_irq_id && in_sleepable(env); } @@ -12372,6 +12373,7 @@ enum special_kfunc_type { KF_bpf_task_work_schedule_resume_impl, KF_bpf_arena_alloc_pages, KF_bpf_arena_free_pages, + KF_bpf_arena_reserve_pages, }; BTF_ID_LIST(special_kfunc_list) @@ -12448,6 +12450,7 @@ BTF_ID(func, bpf_task_work_schedule_signal_impl) BTF_ID(func, bpf_task_work_schedule_resume_impl) BTF_ID(func, bpf_arena_alloc_pages) BTF_ID(func, bpf_arena_free_pages) +BTF_ID(func, bpf_arena_reserve_pages) static bool is_task_work_add_kfunc(u32 func_id) { @@ -12883,10 +12886,17 @@ static bool is_bpf_res_spin_lock_kfunc(u32 btf_id) btf_id == special_kfunc_list[KF_bpf_res_spin_unlock_irqrestore]; } +static bool is_bpf_arena_kfunc(u32 btf_id) +{ + return btf_id == special_kfunc_list[KF_bpf_arena_alloc_pages] || + btf_id == special_kfunc_list[KF_bpf_arena_free_pages] || + btf_id == special_kfunc_list[KF_bpf_arena_reserve_pages]; +} + static bool kfunc_spin_allowed(u32 btf_id) { return is_bpf_graph_api_kfunc(btf_id) || is_bpf_iter_num_api_kfunc(btf_id) || - is_bpf_res_spin_lock_kfunc(btf_id); + is_bpf_res_spin_lock_kfunc(btf_id) || is_bpf_arena_kfunc(btf_id); } static bool is_sync_callback_calling_kfunc(u32 btf_id) |