diff options
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 485 |
1 files changed, 383 insertions, 102 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 36f5a9455205..87ff414899cf 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -172,7 +172,7 @@ static bool bpf_global_percpu_ma_set; /* verifier_state + insn_idx are pushed to stack when branch is encountered */ struct bpf_verifier_stack_elem { - /* verifer state is 'st' + /* verifier state is 'st' * before processing instruction 'insn_idx' * and after processing instruction 'prev_insn_idx' */ @@ -190,11 +190,6 @@ struct bpf_verifier_stack_elem { #define BPF_MAP_KEY_POISON (1ULL << 63) #define BPF_MAP_KEY_SEEN (1ULL << 62) -#define BPF_MAP_PTR_UNPRIV 1UL -#define BPF_MAP_PTR_POISON ((void *)((0xeB9FUL << 1) + \ - POISON_POINTER_DELTA)) -#define BPF_MAP_PTR(X) ((struct bpf_map *)((X) & ~BPF_MAP_PTR_UNPRIV)) - #define BPF_GLOBAL_PERCPU_MA_MAX_SIZE 512 static int acquire_reference_state(struct bpf_verifier_env *env, int insn_idx); @@ -209,21 +204,22 @@ static bool is_trusted_reg(const struct bpf_reg_state *reg); static bool bpf_map_ptr_poisoned(const struct bpf_insn_aux_data *aux) { - return BPF_MAP_PTR(aux->map_ptr_state) == BPF_MAP_PTR_POISON; + return aux->map_ptr_state.poison; } static bool bpf_map_ptr_unpriv(const struct bpf_insn_aux_data *aux) { - return aux->map_ptr_state & BPF_MAP_PTR_UNPRIV; + return aux->map_ptr_state.unpriv; } static void bpf_map_ptr_store(struct bpf_insn_aux_data *aux, - const struct bpf_map *map, bool unpriv) + struct bpf_map *map, + bool unpriv, bool poison) { - BUILD_BUG_ON((unsigned long)BPF_MAP_PTR_POISON & BPF_MAP_PTR_UNPRIV); unpriv |= bpf_map_ptr_unpriv(aux); - aux->map_ptr_state = (unsigned long)map | - (unpriv ? BPF_MAP_PTR_UNPRIV : 0UL); + aux->map_ptr_state.unpriv = unpriv; + aux->map_ptr_state.poison = poison; + aux->map_ptr_state.map_ptr = map; } static bool bpf_map_key_poisoned(const struct bpf_insn_aux_data *aux) @@ -336,6 +332,10 @@ struct bpf_kfunc_call_arg_meta { u8 spi; u8 frameno; } iter; + struct { + struct bpf_map *ptr; + int uid; + } map; u64 mem_size; }; @@ -501,8 +501,12 @@ static bool is_dynptr_ref_function(enum bpf_func_id func_id) } static bool is_sync_callback_calling_kfunc(u32 btf_id); +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_wq_set_callback_impl_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 || @@ -530,7 +534,8 @@ static bool is_sync_callback_calling_insn(struct bpf_insn *insn) static bool is_async_callback_calling_insn(struct bpf_insn *insn) { - return bpf_helper_call(insn) && is_async_callback_calling_function(insn->imm); + return (bpf_helper_call(insn) && is_async_callback_calling_function(insn->imm)) || + (bpf_pseudo_kfunc_call(insn) && is_async_callback_calling_kfunc(insn->imm)); } static bool is_may_goto_insn(struct bpf_insn *insn) @@ -1429,6 +1434,8 @@ 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->active_preempt_lock = src->active_preempt_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; @@ -1842,6 +1849,8 @@ static void mark_ptr_not_null_reg(struct bpf_reg_state *reg) */ if (btf_record_has_field(map->inner_map_meta->record, BPF_TIMER)) reg->map_uid = reg->id; + if (btf_record_has_field(map->inner_map_meta->record, BPF_WORKQUEUE)) + reg->map_uid = reg->id; } else if (map->map_type == BPF_MAP_TYPE_XSKMAP) { reg->type = PTR_TO_XDP_SOCK; } else if (map->map_type == BPF_MAP_TYPE_SOCKMAP || @@ -2135,7 +2144,7 @@ static void __reg64_deduce_bounds(struct bpf_reg_state *reg) static void __reg_deduce_mixed_bounds(struct bpf_reg_state *reg) { /* Try to tighten 64-bit bounds from 32-bit knowledge, using 32-bit - * values on both sides of 64-bit range in hope to have tigher range. + * values on both sides of 64-bit range in hope to have tighter range. * E.g., if r1 is [0x1'00000000, 0x3'80000000], and we learn from * 32-bit signed > 0 operation that s32 bounds are now [1; 0x7fffffff]. * With this, we can substitute 1 as low 32-bits of _low_ 64-bit bound @@ -2143,7 +2152,7 @@ static void __reg_deduce_mixed_bounds(struct bpf_reg_state *reg) * _high_ 64-bit bound (0x380000000 -> 0x37fffffff) and arrive at a * better overall bounds for r1 as [0x1'000000001; 0x3'7fffffff]. * We just need to make sure that derived bounds we are intersecting - * with are well-formed ranges in respecitve s64 or u64 domain, just + * with are well-formed ranges in respective s64 or u64 domain, just * like we do with similar kinds of 32-to-64 or 64-to-32 adjustments. */ __u64 new_umin, new_umax; @@ -2402,7 +2411,7 @@ static void init_func_state(struct bpf_verifier_env *env, /* Similar to push_stack(), but for async callbacks */ static struct bpf_verifier_state *push_async_cb(struct bpf_verifier_env *env, int insn_idx, int prev_insn_idx, - int subprog) + int subprog, bool is_sleepable) { struct bpf_verifier_stack_elem *elem; struct bpf_func_state *frame; @@ -2429,6 +2438,7 @@ 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 = is_sleepable; frame = kzalloc(sizeof(*frame), GFP_KERNEL); if (!frame) goto err; @@ -3615,7 +3625,8 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx, * sreg needs precision before this insn */ bt_clear_reg(bt, dreg); - bt_set_reg(bt, sreg); + if (sreg != BPF_REG_FP) + bt_set_reg(bt, sreg); } else { /* dreg = K * dreg needs precision after this insn. @@ -3631,7 +3642,8 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx, * both dreg and sreg need precision * before this insn */ - bt_set_reg(bt, sreg); + if (sreg != BPF_REG_FP) + bt_set_reg(bt, sreg); } /* else dreg += K * dreg still needs precision before this insn */ @@ -5274,7 +5286,8 @@ bad_type: static bool in_sleepable(struct bpf_verifier_env *env) { - return env->prog->sleepable; + return env->prog->sleepable || + (env->cur_state && env->cur_state->in_sleepable); } /* The non-sleepable programs and sleepable programs with explicit bpf_rcu_read_lock() @@ -5297,6 +5310,7 @@ BTF_ID(struct, cgroup) BTF_ID(struct, bpf_cpumask) #endif BTF_ID(struct, task_struct) +BTF_ID(struct, bpf_crypto_ctx) BTF_SET_END(rcu_protected_types) static bool rcu_protected_object(const struct btf *btf, u32 btf_id) @@ -6972,6 +6986,9 @@ static int check_mem_access(struct bpf_verifier_env *env, int insn_idx, u32 regn return err; } +static int save_aux_ptr_type(struct bpf_verifier_env *env, enum bpf_reg_type type, + bool allow_trust_mismatch); + static int check_atomic(struct bpf_verifier_env *env, int insn_idx, struct bpf_insn *insn) { int load_reg; @@ -7032,7 +7049,7 @@ static int check_atomic(struct bpf_verifier_env *env, int insn_idx, struct bpf_i is_pkt_reg(env, insn->dst_reg) || is_flow_key_reg(env, insn->dst_reg) || is_sk_reg(env, insn->dst_reg) || - is_arena_reg(env, insn->dst_reg)) { + (is_arena_reg(env, insn->dst_reg) && !bpf_jit_supports_insn(insn, true))) { verbose(env, "BPF_ATOMIC stores into R%d %s is not allowed\n", insn->dst_reg, reg_type_str(env, reg_state(env, insn->dst_reg)->type)); @@ -7068,6 +7085,11 @@ static int check_atomic(struct bpf_verifier_env *env, int insn_idx, struct bpf_i if (err) return err; + if (is_arena_reg(env, insn->dst_reg)) { + err = save_aux_ptr_type(env, PTR_TO_ARENA, false); + if (err) + return err; + } /* Check whether we can write into the same memory. */ err = check_mem_access(env, insn_idx, insn->dst_reg, insn->off, BPF_SIZE(insn->code), BPF_WRITE, -1, true, false); @@ -7590,6 +7612,23 @@ static int process_timer_func(struct bpf_verifier_env *env, int regno, return 0; } +static int process_wq_func(struct bpf_verifier_env *env, int regno, + struct bpf_kfunc_call_arg_meta *meta) +{ + struct bpf_reg_state *regs = cur_regs(env), *reg = ®s[regno]; + struct bpf_map *map = reg->map_ptr; + u64 val = reg->var_off.value; + + if (map->record->wq_off != val + reg->off) { + verbose(env, "off %lld doesn't point to 'struct bpf_wq' that is at %d\n", + val + reg->off, map->record->wq_off); + return -EINVAL; + } + meta->map.uid = reg->map_uid; + meta->map.ptr = map; + return 0; +} + static int process_kptr_func(struct bpf_verifier_env *env, int regno, struct bpf_call_arg_meta *meta) { @@ -9484,7 +9523,7 @@ static int push_callback_call(struct bpf_verifier_env *env, struct bpf_insn *ins */ env->subprog_info[subprog].is_cb = true; if (bpf_pseudo_kfunc_call(insn) && - !is_sync_callback_calling_kfunc(insn->imm)) { + !is_callback_calling_kfunc(insn->imm)) { verbose(env, "verifier bug: kfunc %s#%d not marked as callback-calling\n", func_id_name(insn->imm), insn->imm); return -EFAULT; @@ -9498,10 +9537,11 @@ static int push_callback_call(struct bpf_verifier_env *env, struct bpf_insn *ins if (is_async_callback_calling_insn(insn)) { struct bpf_verifier_state *async_cb; - /* there is no real recursion here. timer callbacks are async */ + /* there is no real recursion here. timer and workqueue callbacks are async */ env->subprog_info[subprog].is_async_cb = true; async_cb = push_async_cb(env, env->subprog_info[subprog].start, - insn_idx, subprog); + insn_idx, subprog, + is_bpf_wq_set_callback_impl_kfunc(insn->imm)); if (!async_cb) return -EFAULT; callee = async_cb->frame[0]; @@ -9561,6 +9601,13 @@ static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn, return -EINVAL; } + /* Only global subprogs cannot be called with preemption disabled. */ + if (env->cur_state->active_preempt_lock) { + verbose(env, "global function calls are not allowed with preemption disabled,\n" + "use static function instead\n"); + return -EINVAL; + } + if (err) { verbose(env, "Caller passes invalid args into func#%d ('%s')\n", subprog, sub_name); @@ -9653,12 +9700,8 @@ static int set_map_elem_callback_state(struct bpf_verifier_env *env, struct bpf_map *map; int err; - if (bpf_map_ptr_poisoned(insn_aux)) { - verbose(env, "tail_call abusing map_ptr\n"); - return -EINVAL; - } - - map = BPF_MAP_PTR(insn_aux->map_ptr_state); + /* valid map_ptr and poison value does not matter */ + map = insn_aux->map_ptr_state.map_ptr; if (!map->ops->map_set_for_each_callback_args || !map->ops->map_for_each_callback) { verbose(env, "callback function not allowed for map\n"); @@ -10017,12 +10060,12 @@ record_func_map(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta, return -EACCES; } - if (!BPF_MAP_PTR(aux->map_ptr_state)) + if (!aux->map_ptr_state.map_ptr) + bpf_map_ptr_store(aux, meta->map_ptr, + !meta->map_ptr->bypass_spec_v1, false); + else if (aux->map_ptr_state.map_ptr != meta->map_ptr) bpf_map_ptr_store(aux, meta->map_ptr, - !meta->map_ptr->bypass_spec_v1); - else if (BPF_MAP_PTR(aux->map_ptr_state) != meta->map_ptr) - bpf_map_ptr_store(aux, BPF_MAP_PTR_POISON, - !meta->map_ptr->bypass_spec_v1); + !meta->map_ptr->bypass_spec_v1, true); return 0; } @@ -10201,8 +10244,8 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn if (env->ops->get_func_proto) fn = env->ops->get_func_proto(func_id, env->prog); if (!fn) { - verbose(env, "unknown func %s#%d\n", func_id_name(func_id), - func_id); + verbose(env, "program of this type cannot use helper %s#%d\n", + func_id_name(func_id), func_id); return -EINVAL; } @@ -10251,6 +10294,17 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn env->insn_aux_data[insn_idx].storage_get_func_atomic = true; } + if (env->cur_state->active_preempt_lock) { + if (fn->might_sleep) { + verbose(env, "sleepable helper %s#%d in non-preemptible region\n", + func_id_name(func_id), func_id); + return -EINVAL; + } + + if (in_sleepable(env) && is_storage_get_function(func_id)) + env->insn_aux_data[insn_idx].storage_get_func_atomic = true; + } + meta.func_id = func_id; /* check args */ for (i = 0; i < MAX_BPF_FUNC_REG_ARGS; i++) { @@ -10839,6 +10893,7 @@ enum { KF_ARG_LIST_NODE_ID, KF_ARG_RB_ROOT_ID, KF_ARG_RB_NODE_ID, + KF_ARG_WORKQUEUE_ID, }; BTF_ID_LIST(kf_arg_btf_ids) @@ -10847,6 +10902,7 @@ BTF_ID(struct, bpf_list_head) BTF_ID(struct, bpf_list_node) BTF_ID(struct, bpf_rb_root) BTF_ID(struct, bpf_rb_node) +BTF_ID(struct, bpf_wq) static bool __is_kfunc_ptr_arg_type(const struct btf *btf, const struct btf_param *arg, int type) @@ -10890,6 +10946,11 @@ static bool is_kfunc_arg_rbtree_node(const struct btf *btf, const struct btf_par return __is_kfunc_ptr_arg_type(btf, arg, KF_ARG_RB_NODE_ID); } +static bool is_kfunc_arg_wq(const struct btf *btf, const struct btf_param *arg) +{ + return __is_kfunc_ptr_arg_type(btf, arg, KF_ARG_WORKQUEUE_ID); +} + static bool is_kfunc_arg_callback(struct bpf_verifier_env *env, const struct btf *btf, const struct btf_param *arg) { @@ -10959,6 +11020,7 @@ enum kfunc_ptr_arg_type { KF_ARG_PTR_TO_NULL, KF_ARG_PTR_TO_CONST_STR, KF_ARG_PTR_TO_MAP, + KF_ARG_PTR_TO_WORKQUEUE, }; enum special_kfunc_type { @@ -10984,6 +11046,9 @@ enum special_kfunc_type { KF_bpf_percpu_obj_new_impl, KF_bpf_percpu_obj_drop_impl, KF_bpf_throw, + KF_bpf_wq_set_callback_impl, + KF_bpf_preempt_disable, + KF_bpf_preempt_enable, KF_bpf_iter_css_task_new, }; @@ -11008,6 +11073,7 @@ BTF_ID(func, bpf_dynptr_clone) BTF_ID(func, bpf_percpu_obj_new_impl) BTF_ID(func, bpf_percpu_obj_drop_impl) BTF_ID(func, bpf_throw) +BTF_ID(func, bpf_wq_set_callback_impl) #ifdef CONFIG_CGROUPS BTF_ID(func, bpf_iter_css_task_new) #endif @@ -11036,6 +11102,9 @@ BTF_ID(func, bpf_dynptr_clone) BTF_ID(func, bpf_percpu_obj_new_impl) BTF_ID(func, bpf_percpu_obj_drop_impl) BTF_ID(func, bpf_throw) +BTF_ID(func, bpf_wq_set_callback_impl) +BTF_ID(func, bpf_preempt_disable) +BTF_ID(func, bpf_preempt_enable) #ifdef CONFIG_CGROUPS BTF_ID(func, bpf_iter_css_task_new) #else @@ -11062,6 +11131,16 @@ static bool is_kfunc_bpf_rcu_read_unlock(struct bpf_kfunc_call_arg_meta *meta) return meta->func_id == special_kfunc_list[KF_bpf_rcu_read_unlock]; } +static bool is_kfunc_bpf_preempt_disable(struct bpf_kfunc_call_arg_meta *meta) +{ + return meta->func_id == special_kfunc_list[KF_bpf_preempt_disable]; +} + +static bool is_kfunc_bpf_preempt_enable(struct bpf_kfunc_call_arg_meta *meta) +{ + return meta->func_id == special_kfunc_list[KF_bpf_preempt_enable]; +} + static enum kfunc_ptr_arg_type get_kfunc_ptr_arg_type(struct bpf_verifier_env *env, struct bpf_kfunc_call_arg_meta *meta, @@ -11115,6 +11194,9 @@ get_kfunc_ptr_arg_type(struct bpf_verifier_env *env, if (is_kfunc_arg_map(meta->btf, &args[argno])) return KF_ARG_PTR_TO_MAP; + if (is_kfunc_arg_wq(meta->btf, &args[argno])) + return KF_ARG_PTR_TO_WORKQUEUE; + if ((base_type(reg->type) == PTR_TO_BTF_ID || reg2btf_ids[base_type(reg->type)])) { if (!btf_type_is_struct(ref_t)) { verbose(env, "kernel function %s args#%d pointer type %s %s is not supported\n", @@ -11366,12 +11448,28 @@ static bool is_sync_callback_calling_kfunc(u32 btf_id) return btf_id == special_kfunc_list[KF_bpf_rbtree_add_impl]; } +static bool is_async_callback_calling_kfunc(u32 btf_id) +{ + return btf_id == special_kfunc_list[KF_bpf_wq_set_callback_impl]; +} + static bool is_bpf_throw_kfunc(struct bpf_insn *insn) { return bpf_pseudo_kfunc_call(insn) && insn->off == 0 && insn->imm == special_kfunc_list[KF_bpf_throw]; } +static bool is_bpf_wq_set_callback_impl_kfunc(u32 btf_id) +{ + return btf_id == special_kfunc_list[KF_bpf_wq_set_callback_impl]; +} + +static bool is_callback_calling_kfunc(u32 btf_id) +{ + return is_sync_callback_calling_kfunc(btf_id) || + is_async_callback_calling_kfunc(btf_id); +} + static bool is_rbtree_lock_required_kfunc(u32 btf_id) { return is_bpf_rbtree_api_kfunc(btf_id); @@ -11716,6 +11814,34 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ case KF_ARG_PTR_TO_NULL: continue; case KF_ARG_PTR_TO_MAP: + if (!reg->map_ptr) { + verbose(env, "pointer in R%d isn't map pointer\n", regno); + return -EINVAL; + } + if (meta->map.ptr && reg->map_ptr->record->wq_off >= 0) { + /* Use map_uid (which is unique id of inner map) to reject: + * inner_map1 = bpf_map_lookup_elem(outer_map, key1) + * inner_map2 = bpf_map_lookup_elem(outer_map, key2) + * if (inner_map1 && inner_map2) { + * wq = bpf_map_lookup_elem(inner_map1); + * if (wq) + * // mismatch would have been allowed + * bpf_wq_init(wq, inner_map2); + * } + * + * Comparing map_ptr is enough to distinguish normal and outer maps. + */ + if (meta->map.ptr != reg->map_ptr || + meta->map.uid != reg->map_uid) { + verbose(env, + "workqueue pointer in R1 map_uid=%d doesn't match map pointer in R2 map_uid=%d\n", + meta->map.uid, reg->map_uid); + return -EINVAL; + } + } + meta->map.ptr = reg->map_ptr; + meta->map.uid = reg->map_uid; + fallthrough; case KF_ARG_PTR_TO_ALLOC_BTF_ID: case KF_ARG_PTR_TO_BTF_ID: if (!is_kfunc_trusted_args(meta) && !is_kfunc_rcu(meta)) @@ -11748,6 +11874,7 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ case KF_ARG_PTR_TO_CALLBACK: case KF_ARG_PTR_TO_REFCOUNTED_KPTR: case KF_ARG_PTR_TO_CONST_STR: + case KF_ARG_PTR_TO_WORKQUEUE: /* Trusted by default */ break; default: @@ -12034,6 +12161,15 @@ static int check_kfunc_args(struct bpf_verifier_env *env, struct bpf_kfunc_call_ if (ret) return ret; break; + case KF_ARG_PTR_TO_WORKQUEUE: + if (reg->type != PTR_TO_MAP_VALUE) { + verbose(env, "arg#%d doesn't point to a map value\n", i); + return -EINVAL; + } + ret = process_wq_func(env, regno, meta); + if (ret < 0) + return ret; + break; } } @@ -12093,11 +12229,11 @@ static int check_return_code(struct bpf_verifier_env *env, int regno, const char static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, int *insn_idx_p) { - const struct btf_type *t, *ptr_type; + bool sleepable, rcu_lock, rcu_unlock, preempt_disable, preempt_enable; u32 i, nargs, ptr_type_id, release_ref_obj_id; struct bpf_reg_state *regs = cur_regs(env); const char *func_name, *ptr_type_name; - bool sleepable, rcu_lock, rcu_unlock; + const struct btf_type *t, *ptr_type; struct bpf_kfunc_call_arg_meta meta; struct bpf_insn_aux_data *insn_aux; int err, insn_idx = *insn_idx_p; @@ -12145,9 +12281,22 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, } } + if (is_bpf_wq_set_callback_impl_kfunc(meta.func_id)) { + err = push_callback_call(env, insn, insn_idx, meta.subprogno, + set_timer_callback_state); + if (err) { + verbose(env, "kfunc %s#%d failed callback verification\n", + func_name, meta.func_id); + return err; + } + } + rcu_lock = is_kfunc_bpf_rcu_read_lock(&meta); rcu_unlock = is_kfunc_bpf_rcu_read_unlock(&meta); + preempt_disable = is_kfunc_bpf_preempt_disable(&meta); + preempt_enable = is_kfunc_bpf_preempt_enable(&meta); + if (env->cur_state->active_rcu_lock) { struct bpf_func_state *state; struct bpf_reg_state *reg; @@ -12180,6 +12329,22 @@ static int check_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, return -EINVAL; } + if (env->cur_state->active_preempt_lock) { + if (preempt_disable) { + env->cur_state->active_preempt_lock++; + } else if (preempt_enable) { + env->cur_state->active_preempt_lock--; + } else if (sleepable) { + verbose(env, "kernel func %s is sleepable within non-preemptible region\n", func_name); + return -EACCES; + } + } else if (preempt_disable) { + env->cur_state->active_preempt_lock++; + } else if (preempt_enable) { + verbose(env, "unmatched attempt to enable preemption (kernel function %s)\n", func_name); + return -EINVAL; + } + /* In case of release function, we get register number of refcounted * PTR_TO_BTF_ID in bpf_kfunc_arg_meta, do the release now. */ @@ -13318,7 +13483,6 @@ static void scalar32_min_max_and(struct bpf_reg_state *dst_reg, bool src_known = tnum_subreg_is_const(src_reg->var_off); bool dst_known = tnum_subreg_is_const(dst_reg->var_off); struct tnum var32_off = tnum_subreg(dst_reg->var_off); - s32 smin_val = src_reg->s32_min_value; u32 umax_val = src_reg->u32_max_value; if (src_known && dst_known) { @@ -13331,18 +13495,16 @@ static void scalar32_min_max_and(struct bpf_reg_state *dst_reg, */ dst_reg->u32_min_value = var32_off.value; dst_reg->u32_max_value = min(dst_reg->u32_max_value, umax_val); - if (dst_reg->s32_min_value < 0 || smin_val < 0) { - /* Lose signed bounds when ANDing negative numbers, - * ain't nobody got time for that. - */ - dst_reg->s32_min_value = S32_MIN; - dst_reg->s32_max_value = S32_MAX; - } else { - /* ANDing two positives gives a positive, so safe to - * cast result into s64. - */ + + /* Safe to set s32 bounds by casting u32 result into s32 when u32 + * doesn't cross sign boundary. Otherwise set s32 bounds to unbounded. + */ + if ((s32)dst_reg->u32_min_value <= (s32)dst_reg->u32_max_value) { dst_reg->s32_min_value = dst_reg->u32_min_value; dst_reg->s32_max_value = dst_reg->u32_max_value; + } else { + dst_reg->s32_min_value = S32_MIN; + dst_reg->s32_max_value = S32_MAX; } } @@ -13351,7 +13513,6 @@ static void scalar_min_max_and(struct bpf_reg_state *dst_reg, { bool src_known = tnum_is_const(src_reg->var_off); bool dst_known = tnum_is_const(dst_reg->var_off); - s64 smin_val = src_reg->smin_value; u64 umax_val = src_reg->umax_value; if (src_known && dst_known) { @@ -13364,18 +13525,16 @@ static void scalar_min_max_and(struct bpf_reg_state *dst_reg, */ dst_reg->umin_value = dst_reg->var_off.value; dst_reg->umax_value = min(dst_reg->umax_value, umax_val); - if (dst_reg->smin_value < 0 || smin_val < 0) { - /* Lose signed bounds when ANDing negative numbers, - * ain't nobody got time for that. - */ - dst_reg->smin_value = S64_MIN; - dst_reg->smax_value = S64_MAX; - } else { - /* ANDing two positives gives a positive, so safe to - * cast result into s64. - */ + + /* Safe to set s64 bounds by casting u64 result into s64 when u64 + * doesn't cross sign boundary. Otherwise set s64 bounds to unbounded. + */ + if ((s64)dst_reg->umin_value <= (s64)dst_reg->umax_value) { dst_reg->smin_value = dst_reg->umin_value; dst_reg->smax_value = dst_reg->umax_value; + } else { + dst_reg->smin_value = S64_MIN; + dst_reg->smax_value = S64_MAX; } /* We may learn something more from the var_off */ __update_reg_bounds(dst_reg); @@ -13387,7 +13546,6 @@ static void scalar32_min_max_or(struct bpf_reg_state *dst_reg, bool src_known = tnum_subreg_is_const(src_reg->var_off); bool dst_known = tnum_subreg_is_const(dst_reg->var_off); struct tnum var32_off = tnum_subreg(dst_reg->var_off); - s32 smin_val = src_reg->s32_min_value; u32 umin_val = src_reg->u32_min_value; if (src_known && dst_known) { @@ -13400,18 +13558,16 @@ static void scalar32_min_max_or(struct bpf_reg_state *dst_reg, */ dst_reg->u32_min_value = max(dst_reg->u32_min_value, umin_val); dst_reg->u32_max_value = var32_off.value | var32_off.mask; - if (dst_reg->s32_min_value < 0 || smin_val < 0) { - /* Lose signed bounds when ORing negative numbers, - * ain't nobody got time for that. - */ - dst_reg->s32_min_value = S32_MIN; - dst_reg->s32_max_value = S32_MAX; - } else { - /* ORing two positives gives a positive, so safe to - * cast result into s64. - */ + + /* Safe to set s32 bounds by casting u32 result into s32 when u32 + * doesn't cross sign boundary. Otherwise set s32 bounds to unbounded. + */ + if ((s32)dst_reg->u32_min_value <= (s32)dst_reg->u32_max_value) { dst_reg->s32_min_value = dst_reg->u32_min_value; dst_reg->s32_max_value = dst_reg->u32_max_value; + } else { + dst_reg->s32_min_value = S32_MIN; + dst_reg->s32_max_value = S32_MAX; } } @@ -13420,7 +13576,6 @@ static void scalar_min_max_or(struct bpf_reg_state *dst_reg, { bool src_known = tnum_is_const(src_reg->var_off); bool dst_known = tnum_is_const(dst_reg->var_off); - s64 smin_val = src_reg->smin_value; u64 umin_val = src_reg->umin_value; if (src_known && dst_known) { @@ -13433,18 +13588,16 @@ static void scalar_min_max_or(struct bpf_reg_state *dst_reg, */ dst_reg->umin_value = max(dst_reg->umin_value, umin_val); dst_reg->umax_value = dst_reg->var_off.value | dst_reg->var_off.mask; - if (dst_reg->smin_value < 0 || smin_val < 0) { - /* Lose signed bounds when ORing negative numbers, - * ain't nobody got time for that. - */ - dst_reg->smin_value = S64_MIN; - dst_reg->smax_value = S64_MAX; - } else { - /* ORing two positives gives a positive, so safe to - * cast result into s64. - */ + + /* Safe to set s64 bounds by casting u64 result into s64 when u64 + * doesn't cross sign boundary. Otherwise set s64 bounds to unbounded. + */ + if ((s64)dst_reg->umin_value <= (s64)dst_reg->umax_value) { dst_reg->smin_value = dst_reg->umin_value; dst_reg->smax_value = dst_reg->umax_value; + } else { + dst_reg->smin_value = S64_MIN; + dst_reg->smax_value = S64_MAX; } /* We may learn something more from the var_off */ __update_reg_bounds(dst_reg); @@ -13456,7 +13609,6 @@ static void scalar32_min_max_xor(struct bpf_reg_state *dst_reg, bool src_known = tnum_subreg_is_const(src_reg->var_off); bool dst_known = tnum_subreg_is_const(dst_reg->var_off); struct tnum var32_off = tnum_subreg(dst_reg->var_off); - s32 smin_val = src_reg->s32_min_value; if (src_known && dst_known) { __mark_reg32_known(dst_reg, var32_off.value); @@ -13467,10 +13619,10 @@ static void scalar32_min_max_xor(struct bpf_reg_state *dst_reg, dst_reg->u32_min_value = var32_off.value; dst_reg->u32_max_value = var32_off.value | var32_off.mask; - if (dst_reg->s32_min_value >= 0 && smin_val >= 0) { - /* XORing two positive sign numbers gives a positive, - * so safe to cast u32 result into s32. - */ + /* Safe to set s32 bounds by casting u32 result into s32 when u32 + * doesn't cross sign boundary. Otherwise set s32 bounds to unbounded. + */ + if ((s32)dst_reg->u32_min_value <= (s32)dst_reg->u32_max_value) { dst_reg->s32_min_value = dst_reg->u32_min_value; dst_reg->s32_max_value = dst_reg->u32_max_value; } else { @@ -13484,7 +13636,6 @@ static void scalar_min_max_xor(struct bpf_reg_state *dst_reg, { bool src_known = tnum_is_const(src_reg->var_off); bool dst_known = tnum_is_const(dst_reg->var_off); - s64 smin_val = src_reg->smin_value; if (src_known && dst_known) { /* dst_reg->var_off.value has been updated earlier */ @@ -13496,10 +13647,10 @@ static void scalar_min_max_xor(struct bpf_reg_state *dst_reg, dst_reg->umin_value = dst_reg->var_off.value; dst_reg->umax_value = dst_reg->var_off.value | dst_reg->var_off.mask; - if (dst_reg->smin_value >= 0 && smin_val >= 0) { - /* XORing two positive sign numbers gives a positive, - * so safe to cast u64 result into s64. - */ + /* Safe to set s64 bounds by casting u64 result into s64 when u64 + * doesn't cross sign boundary. Otherwise set s64 bounds to unbounded. + */ + if ((s64)dst_reg->umin_value <= (s64)dst_reg->umax_value) { dst_reg->smin_value = dst_reg->umin_value; dst_reg->smax_value = dst_reg->umax_value; } else { @@ -14726,7 +14877,7 @@ static void regs_refine_cond_op(struct bpf_reg_state *reg1, struct bpf_reg_state /* Adjusts the register min/max values in the case that the dst_reg and * src_reg are both SCALAR_VALUE registers (or we are simply doing a BPF_K - * check, in which case we havea fake SCALAR_VALUE representing insn->imm). + * check, in which case we have a fake SCALAR_VALUE representing insn->imm). * Technically we can do similar adjustments for pointers to the same object, * but we don't support that right now. */ @@ -15341,6 +15492,11 @@ static int check_ld_abs(struct bpf_verifier_env *env, struct bpf_insn *insn) return -EINVAL; } + if (env->cur_state->active_preempt_lock) { + verbose(env, "BPF_LD_[ABS|IND] cannot be used inside bpf_preempt_disable-ed region\n"); + return -EINVAL; + } + if (regs[ctx_reg].type != PTR_TO_CTX) { verbose(env, "at the time of BPF_LD_ABS|IND R6 != pointer to skb\n"); @@ -16908,6 +17064,12 @@ static bool states_equal(struct bpf_verifier_env *env, if (old->active_rcu_lock != cur->active_rcu_lock) return false; + if (old->active_preempt_lock != cur->active_preempt_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 */ @@ -17364,7 +17526,7 @@ hit: err = propagate_liveness(env, &sl->state, cur); /* if previous state reached the exit with precision and - * current state is equivalent to it (except precsion marks) + * current state is equivalent to it (except precision marks) * the precision needs to be propagated back in * the current state. */ @@ -17542,7 +17704,7 @@ static bool reg_type_mismatch(enum bpf_reg_type src, enum bpf_reg_type prev) } static int save_aux_ptr_type(struct bpf_verifier_env *env, enum bpf_reg_type type, - bool allow_trust_missmatch) + bool allow_trust_mismatch) { enum bpf_reg_type *prev_type = &env->insn_aux_data[env->insn_idx].ptr_type; @@ -17560,7 +17722,7 @@ static int save_aux_ptr_type(struct bpf_verifier_env *env, enum bpf_reg_type typ * src_reg == stack|map in some other branch. * Reject it. */ - if (allow_trust_missmatch && + if (allow_trust_mismatch && base_type(type) == PTR_TO_BTF_ID && base_type(*prev_type) == PTR_TO_BTF_ID) { /* @@ -17856,6 +18018,13 @@ process_bpf_exit_full: return -EINVAL; } + if (env->cur_state->active_preempt_lock && !env->cur_state->curframe) { + verbose(env, "%d bpf_preempt_enable%s missing\n", + env->cur_state->active_preempt_lock, + env->cur_state->active_preempt_lock == 1 ? " is" : "(s) are"); + return -EINVAL; + } + /* We must do check_reference_leak here before * prepare_func_exit to handle the case when * state->curframe > 0, it may be a callback @@ -18153,6 +18322,13 @@ static int check_map_prog_compatibility(struct bpf_verifier_env *env, } } + if (btf_record_has_field(map->record, BPF_WORKQUEUE)) { + if (is_tracing_prog_type(prog_type)) { + verbose(env, "tracing progs cannot use bpf_wq yet\n"); + return -EINVAL; + } + } + if ((bpf_prog_is_offloaded(prog->aux) || bpf_map_is_offloaded(map)) && !bpf_offload_prog_map_match(prog, map)) { verbose(env, "offload device mismatch between prog and map\n"); @@ -18348,6 +18524,8 @@ static int resolve_pseudo_ldimm64(struct bpf_verifier_env *env) } if (env->used_map_cnt >= MAX_USED_MAPS) { + verbose(env, "The total number of maps per program has reached the limit of %u\n", + MAX_USED_MAPS); fdput(f); return -E2BIG; } @@ -18962,6 +19140,12 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env) insn->code == (BPF_ST | BPF_MEM | BPF_W) || insn->code == (BPF_ST | BPF_MEM | BPF_DW)) { type = BPF_WRITE; + } else if ((insn->code == (BPF_STX | BPF_ATOMIC | BPF_W) || + insn->code == (BPF_STX | BPF_ATOMIC | BPF_DW)) && + env->insn_aux_data[i + delta].ptr_type == PTR_TO_ARENA) { + insn->code = BPF_STX | BPF_PROBE_ATOMIC | BPF_SIZE(insn->code); + env->prog->aux->num_exentries++; + continue; } else { continue; } @@ -19148,12 +19332,19 @@ static int jit_subprogs(struct bpf_verifier_env *env) env->insn_aux_data[i].call_imm = insn->imm; /* point imm to __bpf_call_base+1 from JITs point of view */ insn->imm = 1; - if (bpf_pseudo_func(insn)) + if (bpf_pseudo_func(insn)) { +#if defined(MODULES_VADDR) + u64 addr = MODULES_VADDR; +#else + u64 addr = VMALLOC_START; +#endif /* jit (e.g. x86_64) may emit fewer instructions * if it learns a u32 imm is the same as a u64 imm. - * Force a non zero here. + * Set close enough to possible prog address. */ - insn[1].imm = 1; + insn[0].imm = (u32)addr; + insn[1].imm = addr >> 32; + } } err = bpf_prog_alloc_jited_linfo(prog); @@ -19226,6 +19417,9 @@ static int jit_subprogs(struct bpf_verifier_env *env) BPF_CLASS(insn->code) == BPF_ST) && BPF_MODE(insn->code) == BPF_PROBE_MEM32) num_exentries++; + if (BPF_CLASS(insn->code) == BPF_STX && + BPF_MODE(insn->code) == BPF_PROBE_ATOMIC) + num_exentries++; } func[i]->aux->num_exentries = num_exentries; func[i]->aux->tail_call_reachable = env->subprog_info[i].tail_call_reachable; @@ -19557,6 +19751,13 @@ static int fixup_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn, desc->func_id == special_kfunc_list[KF_bpf_rdonly_cast]) { insn_buf[0] = BPF_MOV64_REG(BPF_REG_0, BPF_REG_1); *cnt = 1; + } else if (is_bpf_wq_set_callback_impl_kfunc(desc->func_id)) { + struct bpf_insn ld_addrs[2] = { BPF_LD_IMM64(BPF_REG_4, (long)env->prog->aux) }; + + insn_buf[0] = ld_addrs[0]; + insn_buf[1] = ld_addrs[1]; + insn_buf[2] = *insn; + *cnt = 3; } return 0; } @@ -19832,7 +20033,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env) !bpf_map_ptr_unpriv(aux)) { struct bpf_jit_poke_descriptor desc = { .reason = BPF_POKE_REASON_TAIL_CALL, - .tail_call.map = BPF_MAP_PTR(aux->map_ptr_state), + .tail_call.map = aux->map_ptr_state.map_ptr, .tail_call.key = bpf_map_key_immediate(aux), .insn_idx = i + delta, }; @@ -19861,7 +20062,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env) return -EINVAL; } - map_ptr = BPF_MAP_PTR(aux->map_ptr_state); + map_ptr = aux->map_ptr_state.map_ptr; insn_buf[0] = BPF_JMP_IMM(BPF_JGE, BPF_REG_3, map_ptr->max_entries, 2); insn_buf[1] = BPF_ALU32_IMM(BPF_AND, BPF_REG_3, @@ -19969,7 +20170,7 @@ static int do_misc_fixups(struct bpf_verifier_env *env) if (bpf_map_ptr_poisoned(aux)) goto patch_call_imm; - map_ptr = BPF_MAP_PTR(aux->map_ptr_state); + map_ptr = aux->map_ptr_state.map_ptr; ops = map_ptr->ops; if (insn->imm == BPF_FUNC_map_lookup_elem && ops->map_gen_lookup) { @@ -20075,6 +20276,30 @@ patch_map_ops_generic: goto next_insn; } +#ifdef CONFIG_X86_64 + /* Implement bpf_get_smp_processor_id() inline. */ + if (insn->imm == BPF_FUNC_get_smp_processor_id && + prog->jit_requested && bpf_jit_supports_percpu_insn()) { + /* BPF_FUNC_get_smp_processor_id inlining is an + * optimization, so if pcpu_hot.cpu_number is ever + * changed in some incompatible and hard to support + * way, it's fine to back out this inlining logic + */ + insn_buf[0] = BPF_MOV32_IMM(BPF_REG_0, (u32)(unsigned long)&pcpu_hot.cpu_number); + insn_buf[1] = BPF_MOV64_PERCPU_REG(BPF_REG_0, BPF_REG_0); + insn_buf[2] = BPF_LDX_MEM(BPF_W, BPF_REG_0, BPF_REG_0, 0); + cnt = 3; + + new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt); + if (!new_prog) + return -ENOMEM; + + delta += cnt - 1; + env->prog = prog = new_prog; + insn = new_prog->insnsi + i + delta; + goto next_insn; + } +#endif /* Implement bpf_get_func_arg inline. */ if (prog_type == BPF_PROG_TYPE_TRACING && insn->imm == BPF_FUNC_get_func_arg) { @@ -20158,6 +20383,62 @@ patch_map_ops_generic: goto next_insn; } + /* Implement bpf_get_branch_snapshot inline. */ + if (IS_ENABLED(CONFIG_PERF_EVENTS) && + prog->jit_requested && BITS_PER_LONG == 64 && + insn->imm == BPF_FUNC_get_branch_snapshot) { + /* We are dealing with the following func protos: + * u64 bpf_get_branch_snapshot(void *buf, u32 size, u64 flags); + * int perf_snapshot_branch_stack(struct perf_branch_entry *entries, u32 cnt); + */ + const u32 br_entry_size = sizeof(struct perf_branch_entry); + + /* struct perf_branch_entry is part of UAPI and is + * used as an array element, so extremely unlikely to + * ever grow or shrink + */ + BUILD_BUG_ON(br_entry_size != 24); + + /* if (unlikely(flags)) return -EINVAL */ + insn_buf[0] = BPF_JMP_IMM(BPF_JNE, BPF_REG_3, 0, 7); + + /* Transform size (bytes) into number of entries (cnt = size / 24). + * But to avoid expensive division instruction, we implement + * divide-by-3 through multiplication, followed by further + * division by 8 through 3-bit right shift. + * Refer to book "Hacker's Delight, 2nd ed." by Henry S. Warren, Jr., + * p. 227, chapter "Unsigned Division by 3" for details and proofs. + * + * N / 3 <=> M * N / 2^33, where M = (2^33 + 1) / 3 = 0xaaaaaaab. + */ + insn_buf[1] = BPF_MOV32_IMM(BPF_REG_0, 0xaaaaaaab); + insn_buf[2] = BPF_ALU64_REG(BPF_MUL, BPF_REG_2, BPF_REG_0); + insn_buf[3] = BPF_ALU64_IMM(BPF_RSH, BPF_REG_2, 36); + + /* call perf_snapshot_branch_stack implementation */ + insn_buf[4] = BPF_EMIT_CALL(static_call_query(perf_snapshot_branch_stack)); + /* if (entry_cnt == 0) return -ENOENT */ + insn_buf[5] = BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 4); + /* return entry_cnt * sizeof(struct perf_branch_entry) */ + insn_buf[6] = BPF_ALU32_IMM(BPF_MUL, BPF_REG_0, br_entry_size); + insn_buf[7] = BPF_JMP_A(3); + /* return -EINVAL; */ + insn_buf[8] = BPF_MOV64_IMM(BPF_REG_0, -EINVAL); + insn_buf[9] = BPF_JMP_A(1); + /* return -ENOENT; */ + insn_buf[10] = BPF_MOV64_IMM(BPF_REG_0, -ENOENT); + cnt = 11; + + new_prog = bpf_patch_insn_data(env, i + delta, insn_buf, cnt); + if (!new_prog) + return -ENOMEM; + + delta += cnt - 1; + env->prog = prog = new_prog; + insn = new_prog->insnsi + i + delta; + continue; + } + /* Implement bpf_kptr_xchg inline */ if (prog->jit_requested && BITS_PER_LONG == 64 && insn->imm == BPF_FUNC_kptr_xchg && |