diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 62bba7a4876f..0654d2ffadc1 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -492,6 +492,35 @@ static inline bool btf_record_has_field(const struct btf_record *rec, enum btf_f return rec->field_mask & type; } +static inline bool btf_field_is_nmi_safe(enum btf_field_type type) +{ + switch (type) { + case BPF_SPIN_LOCK: + case BPF_RES_SPIN_LOCK: + case BPF_TIMER: + case BPF_WORKQUEUE: + case BPF_TASK_WORK: + case BPF_KPTR_UNREF: + case BPF_REFCOUNT: + return true; + default: + return false; + } +} + +static inline bool btf_record_has_nmi_unsafe_fields(const struct btf_record *rec) +{ + int i; + + if (IS_ERR_OR_NULL(rec)) + return false; + for (i = 0; i < rec->cnt; i++) { + if (!btf_field_is_nmi_safe(rec->fields[i].type)) + return true; + } + return false; +} + static inline void bpf_obj_init(const struct btf_record *rec, void *obj) { int i; diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 954b85609f32..eb46a81a8c51 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -205,6 +205,7 @@ static int release_reference_nomark(struct bpf_verifier_state *state, int id); static int release_reference(struct bpf_verifier_env *env, int id); static void invalidate_non_owning_refs(struct bpf_verifier_env *env); static bool in_rbtree_lock_required_cb(struct bpf_verifier_env *env); +static bool is_tracing_prog_type(enum bpf_prog_type type); static int ref_set_non_owning(struct bpf_verifier_env *env, struct bpf_reg_state *reg); static bool is_trusted_reg(struct bpf_verifier_env *env, const struct bpf_reg_state *reg); @@ -12881,6 +12882,7 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, int *insn_idx_p) { bool sleepable, rcu_lock, rcu_unlock, preempt_disable, preempt_enable; + enum bpf_prog_type prog_type = resolve_prog_type(env->prog); struct bpf_reg_state *regs = cur_regs(env); const char *func_name, *ptr_type_name; const struct btf_type *t, *ptr_type; @@ -12957,6 +12959,21 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, if (err < 0) return err; + if ((is_bpf_obj_drop_kfunc(meta.func_id) || + is_bpf_percpu_obj_drop_kfunc(meta.func_id)) && (is_tracing_prog_type(prog_type) || + /* is_tracing_prog_type() for now doesn't cover non-iterator tracing progs. */ + (prog_type == BPF_PROG_TYPE_TRACING && env->prog->expected_attach_type != BPF_TRACE_ITER + && !env->prog->sleepable))) { + struct btf_struct_meta *struct_meta; + + struct_meta = btf_find_struct_meta(meta.arg_btf, meta.arg_btf_id); + if (struct_meta && btf_record_has_nmi_unsafe_fields(struct_meta->record)) { + verbose(env, "%s cannot be used in tracing programs on types with NMI unsafe fields\n", + func_name); + return -EINVAL; + } + } + if (is_bpf_rbtree_add_kfunc(meta.func_id)) { err = push_callback_call(env, insn, insn_idx, meta.subprogno, set_rbtree_add_callback_state); diff --git a/tools/testing/selftests/bpf/prog_tests/task_kfunc.c b/tools/testing/selftests/bpf/prog_tests/task_kfunc.c index 83b90335967a..e6e95c1416e6 100644 --- a/tools/testing/selftests/bpf/prog_tests/task_kfunc.c +++ b/tools/testing/selftests/bpf/prog_tests/task_kfunc.c @@ -68,6 +68,36 @@ static void run_success_test(const char *prog_name) task_kfunc_success__destroy(skel); } +static void run_syscall_success_test(const char *prog_name) +{ + LIBBPF_OPTS(bpf_test_run_opts, opts); + struct task_kfunc_success *skel; + struct bpf_program *prog; + int err; + + skel = open_load_task_kfunc_skel(); + if (!ASSERT_OK_PTR(skel, "open_load_skel")) + return; + + if (!ASSERT_OK(skel->bss->err, "pre_run_err")) + goto cleanup; + + prog = bpf_object__find_program_by_name(skel->obj, prog_name); + if (!ASSERT_OK_PTR(prog, "bpf_object__find_program_by_name")) + goto cleanup; + + err = bpf_prog_test_run_opts(bpf_program__fd(prog), &opts); + if (!ASSERT_OK(err, "bpf_prog_test_run_opts")) + goto cleanup; + if (!ASSERT_EQ(opts.retval, 0, "retval")) + goto cleanup; + + ASSERT_OK(skel->bss->err, "post_run_err"); + +cleanup: + task_kfunc_success__destroy(skel); +} + static int run_vpid_test(void *prog_name) { struct task_kfunc_success *skel; @@ -140,7 +170,6 @@ static const char * const success_tests[] = { "test_task_acquire_release_argument", "test_task_acquire_release_current", "test_task_acquire_leave_in_map", - "test_task_xchg_release", "test_task_map_acquire_release", "test_task_current_acquire_release", "test_task_from_pid_arg", @@ -151,6 +180,10 @@ static const char * const success_tests[] = { "test_task_kfunc_flavor_relo_not_found", }; +static const char * const syscall_success_tests[] = { + "test_task_xchg_release", +}; + static const char * const vpid_success_tests[] = { "test_task_from_vpid_current", "test_task_from_vpid_invalid", @@ -167,6 +200,13 @@ void test_task_kfunc(void) run_success_test(success_tests[i]); } + for (i = 0; i < ARRAY_SIZE(syscall_success_tests); i++) { + if (!test__start_subtest(syscall_success_tests[i])) + continue; + + run_syscall_success_test(syscall_success_tests[i]); + } + for (i = 0; i < ARRAY_SIZE(vpid_success_tests); i++) { if (!test__start_subtest(vpid_success_tests[i])) continue; diff --git a/tools/testing/selftests/bpf/progs/task_kfunc_success.c b/tools/testing/selftests/bpf/progs/task_kfunc_success.c index 5fb4fc19d26a..d63a79ee33dc 100644 --- a/tools/testing/selftests/bpf/progs/task_kfunc_success.c +++ b/tools/testing/selftests/bpf/progs/task_kfunc_success.c @@ -140,17 +140,17 @@ int BPF_PROG(test_task_acquire_leave_in_map, struct task_struct *task, u64 clone return 0; } -SEC("tp_btf/task_newtask") -int BPF_PROG(test_task_xchg_release, struct task_struct *task, u64 clone_flags) +SEC("syscall") +int test_task_xchg_release(const void *ctx) { - struct task_struct *kptr, *acquired; + struct task_struct *task, *kptr, *acquired; struct __tasks_kfunc_map_value *v, *local; int refcnt, refcnt_after_drop; long status; - if (!is_test_kfunc_task()) - return 0; + (void)ctx; + task = bpf_get_current_task_btf(); status = tasks_kfunc_map_insert(task); if (status) { err = 1; @@ -191,7 +191,7 @@ int BPF_PROG(test_task_xchg_release, struct task_struct *task, u64 clone_flags) return 0; } - /* Stash a copy into local kptr and check if it is released recursively */ + /* Stash a copy into local kptr and check if it is released recursively. */ acquired = bpf_task_acquire(kptr); if (!acquired) { err = 7; @@ -220,7 +220,6 @@ int BPF_PROG(test_task_xchg_release, struct task_struct *task, u64 clone_flags) } bpf_task_release(kptr); - return 0; }