From patchwork Mon Apr 10 19:07:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dave Marchevsky X-Patchwork-Id: 13206657 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C03F7C77B6F for ; Mon, 10 Apr 2023 19:09:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229619AbjDJTJF (ORCPT ); Mon, 10 Apr 2023 15:09:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229720AbjDJTJE (ORCPT ); Mon, 10 Apr 2023 15:09:04 -0400 Received: from mx0a-00082601.pphosted.com (mx0b-00082601.pphosted.com [67.231.153.30]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B848170B for ; Mon, 10 Apr 2023 12:09:02 -0700 (PDT) Received: from pps.filterd (m0001303.ppops.net [127.0.0.1]) by m0001303.ppops.net (8.17.1.19/8.17.1.19) with ESMTP id 33AJ0RvC007381 for ; Mon, 10 Apr 2023 12:09:01 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=facebook; bh=RgGKMyY6RwCophLREc9PwtK523q5z+hOeq/NaCbv5Bs=; b=qgGvUisn5WIp73wJqkL+XPqWiOnGemeoWCQfJkQRtzHLpstzyhWK1Na03qQ/5RxfDQfN dDPWJngf49KZBYG5Kmxq3sElHrhNpzXgxEAfnjQgkfz931f/W9D50lQnvItLssMbAtrM SDHrAvAD0xok4D5cFXbtQcRTjHeJA/JxIWo= Received: from mail.thefacebook.com ([163.114.132.120]) by m0001303.ppops.net (PPS) with ESMTPS id 3pvdugkk0b-4 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 10 Apr 2023 12:09:01 -0700 Received: from twshared21709.17.frc2.facebook.com (2620:10d:c085:108::8) by mail.thefacebook.com (2620:10d:c085:11d::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.17; Mon, 10 Apr 2023 12:08:59 -0700 Received: by devbig077.ldc1.facebook.com (Postfix, from userid 158236) id 6158F1BB3FD03; Mon, 10 Apr 2023 12:08:46 -0700 (PDT) From: Dave Marchevsky To: CC: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Kernel Team , Dave Marchevsky Subject: [PATCH v1 bpf-next 9/9] selftests/bpf: Add refcounted_kptr tests Date: Mon, 10 Apr 2023 12:07:53 -0700 Message-ID: <20230410190753.2012798-10-davemarchevsky@fb.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230410190753.2012798-1-davemarchevsky@fb.com> References: <20230410190753.2012798-1-davemarchevsky@fb.com> MIME-Version: 1.0 X-FB-Internal: Safe X-Proofpoint-GUID: g32SAtVWyG1IcXJqjG_bKJZ9WUPMJ_ho X-Proofpoint-ORIG-GUID: g32SAtVWyG1IcXJqjG_bKJZ9WUPMJ_ho X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-04-10_14,2023-04-06_03,2023-02-09_01 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Test refcounted local kptr functionality added in previous patches in the series. Usecases which pass verification: * Add refcounted local kptr to both tree and list. Then, read and - possibly, depending on test variant - delete from tree, then list. * Also test doing read-and-maybe-delete in opposite order * Stash a refcounted local kptr in a map_value, then add it to a rbtree. Read from both, possibly deleting after tree read. * Add refcounted local kptr to both tree and list. Then, try reading and deleting twice from one of the collections. * bpf_refcount_acquire of just-added non-owning ref should work, as should bpf_refcount_acquire of owning ref just out of bpf_obj_new Usecases which fail verification: * The simple successful bpf_refcount_acquire cases from above should both fail to verify if the newly-acquired owning ref is not dropped Signed-off-by: Dave Marchevsky --- .../bpf/prog_tests/refcounted_kptr.c | 18 + .../selftests/bpf/progs/refcounted_kptr.c | 410 ++++++++++++++++++ .../bpf/progs/refcounted_kptr_fail.c | 72 +++ 3 files changed, 500 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c create mode 100644 tools/testing/selftests/bpf/progs/refcounted_kptr.c create mode 100644 tools/testing/selftests/bpf/progs/refcounted_kptr_fail.c diff --git a/tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c b/tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c new file mode 100644 index 000000000000..2ab23832062d --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c @@ -0,0 +1,18 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */ + +#include +#include + +#include "refcounted_kptr.skel.h" +#include "refcounted_kptr_fail.skel.h" + +void test_refcounted_kptr(void) +{ + RUN_TESTS(refcounted_kptr); +} + +void test_refcounted_kptr_fail(void) +{ + RUN_TESTS(refcounted_kptr_fail); +} diff --git a/tools/testing/selftests/bpf/progs/refcounted_kptr.c b/tools/testing/selftests/bpf/progs/refcounted_kptr.c new file mode 100644 index 000000000000..b444e4cb07fb --- /dev/null +++ b/tools/testing/selftests/bpf/progs/refcounted_kptr.c @@ -0,0 +1,410 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include +#include +#include "bpf_misc.h" +#include "bpf_experimental.h" + +struct node_data { + long key; + long list_data; + struct bpf_rb_node r; + struct bpf_list_node l; + struct bpf_refcount ref; +}; + +struct map_value { + struct node_data __kptr *node; +}; + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __type(key, int); + __type(value, struct map_value); + __uint(max_entries, 1); +} stashed_nodes SEC(".maps"); + +struct node_acquire { + long key; + long data; + struct bpf_rb_node node; + struct bpf_refcount refcount; +}; + +#define private(name) SEC(".bss." #name) __hidden __attribute__((aligned(8))) +private(A) struct bpf_spin_lock lock; +private(A) struct bpf_rb_root root __contains(node_data, r); +private(A) struct bpf_list_head head __contains(node_data, l); + +private(B) struct bpf_spin_lock alock; +private(B) struct bpf_rb_root aroot __contains(node_acquire, node); + +static bool less(struct bpf_rb_node *node_a, const struct bpf_rb_node *node_b) +{ + struct node_data *a; + struct node_data *b; + + a = container_of(node_a, struct node_data, r); + b = container_of(node_b, struct node_data, r); + + return a->key < b->key; +} + +static bool less_a(struct bpf_rb_node *a, const struct bpf_rb_node *b) +{ + struct node_acquire *node_a; + struct node_acquire *node_b; + + node_a = container_of(a, struct node_acquire, node); + node_b = container_of(b, struct node_acquire, node); + + return node_a->key < node_b->key; +} + +static __always_inline +long __insert_in_tree_and_list(struct bpf_list_head *head, + struct bpf_rb_root *root, + struct bpf_spin_lock *lock) +{ + struct node_data *n, *m; + + n = bpf_obj_new(typeof(*n)); + if (!n) + return -1; + + m = bpf_refcount_acquire(n); + m->key = 123; + m->list_data = 456; + + bpf_spin_lock(lock); + if (bpf_rbtree_add(root, &n->r, less)) { + /* Failure to insert - unexpected */ + bpf_spin_unlock(lock); + bpf_obj_drop(m); + return -2; + } + bpf_spin_unlock(lock); + + bpf_spin_lock(lock); + if (bpf_list_push_front(head, &m->l)) { + /* Failure to insert - unexpected */ + bpf_spin_unlock(lock); + return -3; + } + bpf_spin_unlock(lock); + return 0; +} + +static __always_inline +long __stash_map_insert_tree(int idx, int val, struct bpf_rb_root *root, + struct bpf_spin_lock *lock) +{ + struct map_value *mapval; + struct node_data *n, *m; + + mapval = bpf_map_lookup_elem(&stashed_nodes, &idx); + if (!mapval) + return -1; + + n = bpf_obj_new(typeof(*n)); + if (!n) + return -2; + + n->key = val; + m = bpf_refcount_acquire(n); + + n = bpf_kptr_xchg(&mapval->node, n); + if (n) { + bpf_obj_drop(n); + bpf_obj_drop(m); + return -3; + } + + bpf_spin_lock(lock); + if (bpf_rbtree_add(root, &m->r, less)) { + /* Failure to insert - unexpected */ + bpf_spin_unlock(lock); + return -4; + } + bpf_spin_unlock(lock); + return 0; +} + +static __always_inline +long __read_from_tree(struct bpf_rb_root *root, struct bpf_spin_lock *lock, + bool remove_from_tree) +{ + struct bpf_rb_node *rb; + struct node_data *n; + long res = -99; + + bpf_spin_lock(lock); + + rb = bpf_rbtree_first(root); + if (!rb) { + bpf_spin_unlock(lock); + return -1; + } + + n = container_of(rb, struct node_data, r); + res = n->key; + + if (!remove_from_tree) { + bpf_spin_unlock(lock); + return res; + } + + rb = bpf_rbtree_remove(root, rb); + bpf_spin_unlock(lock); + if (!rb) { + return -2; + } + n = container_of(rb, struct node_data, r); + bpf_obj_drop(n); + return res; +} + +static __always_inline +long __read_from_list(struct bpf_list_head *head, struct bpf_spin_lock *lock, + bool remove_from_list) +{ + struct bpf_list_node *l; + struct node_data *n; + long res = -99; + + bpf_spin_lock(lock); + + l = bpf_list_pop_front(head); + if (!l) { + bpf_spin_unlock(lock); + return -1; + } + + n = container_of(l, struct node_data, l); + res = n->list_data; + + if (!remove_from_list) { + if (bpf_list_push_back(head, &n->l)) { + bpf_spin_unlock(lock); + return -2; + } + } + + bpf_spin_unlock(lock); + + if (remove_from_list) + bpf_obj_drop(n); + return res; +} + +static __always_inline +long __read_from_unstash(int idx) +{ + struct node_data *n = NULL; + struct map_value *mapval; + long val = -99; + + mapval = bpf_map_lookup_elem(&stashed_nodes, &idx); + if (!mapval) + return -1; + + n = bpf_kptr_xchg(&mapval->node, n); + if (!n) + return -2; + + val = n->key; + bpf_obj_drop(n); + return val; +} + +#define INSERT_READ_BOTH(rem_tree, rem_list, desc) \ +SEC("tc") \ +__description(desc) \ +__success __retval(579) \ +long insert_and_remove_tree_##rem_tree##_list_##rem_list(void *ctx) \ +{ \ + long err, tree_data, list_data; \ + \ + err = __insert_in_tree_and_list(&head, &root, &lock); \ + if (err) \ + return err; \ + \ + err = __read_from_tree(&root, &lock, rem_tree); \ + if (err < 0) \ + return err; \ + else \ + tree_data = err; \ + \ + err = __read_from_list(&head, &lock, rem_list); \ + if (err < 0) \ + return err; \ + else \ + list_data = err; \ + \ + return tree_data + list_data; \ +} + +/* After successful insert of struct node_data into both collections: + * - it should have refcount = 2 + * - removing / not removing the node_data from a collection after + * reading should have no effect on ability to read / remove from + * the other collection + */ +INSERT_READ_BOTH(true, true, "insert_read_both: remove from tree + list"); +INSERT_READ_BOTH(false, false, "insert_read_both: remove from neither"); +INSERT_READ_BOTH(true, false, "insert_read_both: remove from tree"); +INSERT_READ_BOTH(false, true, "insert_read_both: remove from list"); + +#undef INSERT_READ_BOTH +#define INSERT_READ_BOTH(rem_tree, rem_list, desc) \ +SEC("tc") \ +__description(desc) \ +__success __retval(579) \ +long insert_and_remove_lf_tree_##rem_tree##_list_##rem_list(void *ctx) \ +{ \ + long err, tree_data, list_data; \ + \ + err = __insert_in_tree_and_list(&head, &root, &lock); \ + if (err) \ + return err; \ + \ + err = __read_from_list(&head, &lock, rem_list); \ + if (err < 0) \ + return err; \ + else \ + list_data = err; \ + \ + err = __read_from_tree(&root, &lock, rem_tree); \ + if (err < 0) \ + return err; \ + else \ + tree_data = err; \ + \ + return tree_data + list_data; \ +} + +/* Similar to insert_read_both, but list data is read and possibly removed + * first + * + * Results should be no different than reading and possibly removing rbtree + * node first + */ +INSERT_READ_BOTH(true, true, "insert_read_both_list_first: remove from tree + list"); +INSERT_READ_BOTH(false, false, "insert_read_both_list_first: remove from neither"); +INSERT_READ_BOTH(true, false, "insert_read_both_list_first: remove from tree"); +INSERT_READ_BOTH(false, true, "insert_read_both_list_first: remove from list"); + +#define INSERT_DOUBLE_READ_AND_DEL(read_fn, read_root, desc) \ +SEC("tc") \ +__description(desc) \ +__success __retval(-1) \ +long insert_double_##read_fn##_and_del_##read_root(void *ctx) \ +{ \ + long err, list_data; \ + \ + err = __insert_in_tree_and_list(&head, &root, &lock); \ + if (err) \ + return err; \ + \ + err = read_fn(&read_root, &lock, true); \ + if (err < 0) \ + return err; \ + else \ + list_data = err; \ + \ + err = read_fn(&read_root, &lock, true); \ + if (err < 0) \ + return err; \ + \ + return err + list_data; \ +} + +/* Insert into both tree and list, then try reading-and-removing from either twice + * + * The second read-and-remove should fail on read step since the node has + * already been removed + */ +INSERT_DOUBLE_READ_AND_DEL(__read_from_tree, root, "insert_double_del: 2x read-and-del from tree"); +INSERT_DOUBLE_READ_AND_DEL(__read_from_list, head, "insert_double_del: 2x read-and-del from list"); + +#define INSERT_STASH_READ(rem_tree, desc) \ +SEC("tc") \ +__description(desc) \ +__success __retval(84) \ +long insert_rbtree_and_stash__del_tree_##rem_tree(void *ctx) \ +{ \ + long err, tree_data, map_data; \ + \ + err = __stash_map_insert_tree(0, 42, &root, &lock); \ + if (err) \ + return err; \ + \ + err = __read_from_tree(&root, &lock, rem_tree); \ + if (err < 0) \ + return err; \ + else \ + tree_data = err; \ + \ + err = __read_from_unstash(0); \ + if (err < 0) \ + return err; \ + else \ + map_data = err; \ + \ + return tree_data + map_data; \ +} + +/* Stash a refcounted node in map_val, insert same node into tree, then try + * reading data from tree then unstashed map_val, possibly removing from tree + * + * Removing from tree should have no effect on map_val kptr validity + */ +INSERT_STASH_READ(true, "insert_stash_read: remove from tree"); +INSERT_STASH_READ(false, "insert_stash_read: don't remove from tree"); + +SEC("tc") +__success +long rbtree_refcounted_node_ref_escapes(void *ctx) +{ + struct node_acquire *n, *m; + + n = bpf_obj_new(typeof(*n)); + if (!n) + return 1; + + bpf_spin_lock(&alock); + bpf_rbtree_add(&aroot, &n->node, less_a); + m = bpf_refcount_acquire(n); + bpf_spin_unlock(&alock); + + m->key = 2; + bpf_obj_drop(m); + return 0; +} + +SEC("tc") +__success +long rbtree_refcounted_node_ref_escapes_owning_input(void *ctx) +{ + struct node_acquire *n, *m; + + n = bpf_obj_new(typeof(*n)); + if (!n) + return 1; + + m = bpf_refcount_acquire(n); + m->key = 2; + + bpf_spin_lock(&alock); + bpf_rbtree_add(&aroot, &n->node, less_a); + bpf_spin_unlock(&alock); + + bpf_obj_drop(m); + + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/refcounted_kptr_fail.c b/tools/testing/selftests/bpf/progs/refcounted_kptr_fail.c new file mode 100644 index 000000000000..efcb308f80ad --- /dev/null +++ b/tools/testing/selftests/bpf/progs/refcounted_kptr_fail.c @@ -0,0 +1,72 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include "bpf_experimental.h" +#include "bpf_misc.h" + +struct node_acquire { + long key; + long data; + struct bpf_rb_node node; + struct bpf_refcount refcount; +}; + +#define private(name) SEC(".data." #name) __hidden __attribute__((aligned(8))) +private(A) struct bpf_spin_lock glock; +private(A) struct bpf_rb_root groot __contains(node_acquire, node); + +static bool less(struct bpf_rb_node *a, const struct bpf_rb_node *b) +{ + struct node_acquire *node_a; + struct node_acquire *node_b; + + node_a = container_of(a, struct node_acquire, node); + node_b = container_of(b, struct node_acquire, node); + + return node_a->key < node_b->key; +} + +SEC("?tc") +__failure __msg("Unreleased reference id=3 alloc_insn=21") +long rbtree_refcounted_node_ref_escapes(void *ctx) +{ + struct node_acquire *n, *m; + + n = bpf_obj_new(typeof(*n)); + if (!n) + return 1; + + bpf_spin_lock(&glock); + bpf_rbtree_add(&groot, &n->node, less); + /* m becomes an owning ref but is never drop'd or added to a tree */ + m = bpf_refcount_acquire(n); + bpf_spin_unlock(&glock); + + m->key = 2; + return 0; +} + +SEC("?tc") +__failure __msg("Unreleased reference id=3 alloc_insn=9") +long rbtree_refcounted_node_ref_escapes_owning_input(void *ctx) +{ + struct node_acquire *n, *m; + + n = bpf_obj_new(typeof(*n)); + if (!n) + return 1; + + /* m becomes an owning ref but is never drop'd or added to a tree */ + m = bpf_refcount_acquire(n); + m->key = 2; + + bpf_spin_lock(&glock); + bpf_rbtree_add(&groot, &n->node, less); + bpf_spin_unlock(&glock); + + return 0; +} + +char _license[] SEC("license") = "GPL";