selftests/bpf: Add refcounted_kptr tests
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 <davemarchevsky@fb.com> Link: https://lore.kernel.org/r/20230415201811.343116-10-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Dave Marchevsky
Alexei Starovoitov
parent
3e81740a90
commit
6147f15131
18
tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c
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18
tools/testing/selftests/bpf/prog_tests/refcounted_kptr.c
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@ -0,0 +1,18 @@
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// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
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#include <test_progs.h>
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#include <network_helpers.h>
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#include "refcounted_kptr.skel.h"
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#include "refcounted_kptr_fail.skel.h"
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void test_refcounted_kptr(void)
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{
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RUN_TESTS(refcounted_kptr);
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}
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void test_refcounted_kptr_fail(void)
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{
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RUN_TESTS(refcounted_kptr_fail);
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}
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406
tools/testing/selftests/bpf/progs/refcounted_kptr.c
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406
tools/testing/selftests/bpf/progs/refcounted_kptr.c
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@ -0,0 +1,406 @@
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// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
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#include <vmlinux.h>
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#include <bpf/bpf_tracing.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_core_read.h>
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#include "bpf_misc.h"
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#include "bpf_experimental.h"
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struct node_data {
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long key;
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long list_data;
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struct bpf_rb_node r;
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struct bpf_list_node l;
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struct bpf_refcount ref;
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};
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struct map_value {
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struct node_data __kptr *node;
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};
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struct {
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__uint(type, BPF_MAP_TYPE_ARRAY);
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__type(key, int);
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__type(value, struct map_value);
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__uint(max_entries, 1);
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} stashed_nodes SEC(".maps");
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struct node_acquire {
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long key;
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long data;
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struct bpf_rb_node node;
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struct bpf_refcount refcount;
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};
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#define private(name) SEC(".bss." #name) __hidden __attribute__((aligned(8)))
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private(A) struct bpf_spin_lock lock;
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private(A) struct bpf_rb_root root __contains(node_data, r);
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private(A) struct bpf_list_head head __contains(node_data, l);
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private(B) struct bpf_spin_lock alock;
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private(B) struct bpf_rb_root aroot __contains(node_acquire, node);
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static bool less(struct bpf_rb_node *node_a, const struct bpf_rb_node *node_b)
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{
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struct node_data *a;
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struct node_data *b;
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a = container_of(node_a, struct node_data, r);
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b = container_of(node_b, struct node_data, r);
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return a->key < b->key;
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}
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static bool less_a(struct bpf_rb_node *a, const struct bpf_rb_node *b)
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{
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struct node_acquire *node_a;
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struct node_acquire *node_b;
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node_a = container_of(a, struct node_acquire, node);
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node_b = container_of(b, struct node_acquire, node);
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return node_a->key < node_b->key;
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}
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static long __insert_in_tree_and_list(struct bpf_list_head *head,
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struct bpf_rb_root *root,
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struct bpf_spin_lock *lock)
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{
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struct node_data *n, *m;
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n = bpf_obj_new(typeof(*n));
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if (!n)
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return -1;
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m = bpf_refcount_acquire(n);
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m->key = 123;
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m->list_data = 456;
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bpf_spin_lock(lock);
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if (bpf_rbtree_add(root, &n->r, less)) {
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/* Failure to insert - unexpected */
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bpf_spin_unlock(lock);
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bpf_obj_drop(m);
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return -2;
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}
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bpf_spin_unlock(lock);
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bpf_spin_lock(lock);
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if (bpf_list_push_front(head, &m->l)) {
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/* Failure to insert - unexpected */
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bpf_spin_unlock(lock);
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return -3;
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}
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bpf_spin_unlock(lock);
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return 0;
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}
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static long __stash_map_insert_tree(int idx, int val, struct bpf_rb_root *root,
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struct bpf_spin_lock *lock)
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{
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struct map_value *mapval;
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struct node_data *n, *m;
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mapval = bpf_map_lookup_elem(&stashed_nodes, &idx);
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if (!mapval)
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return -1;
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n = bpf_obj_new(typeof(*n));
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if (!n)
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return -2;
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n->key = val;
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m = bpf_refcount_acquire(n);
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n = bpf_kptr_xchg(&mapval->node, n);
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if (n) {
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bpf_obj_drop(n);
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bpf_obj_drop(m);
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return -3;
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}
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bpf_spin_lock(lock);
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if (bpf_rbtree_add(root, &m->r, less)) {
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/* Failure to insert - unexpected */
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bpf_spin_unlock(lock);
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return -4;
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}
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bpf_spin_unlock(lock);
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return 0;
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}
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static long __read_from_tree(struct bpf_rb_root *root,
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struct bpf_spin_lock *lock,
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bool remove_from_tree)
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{
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struct bpf_rb_node *rb;
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struct node_data *n;
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long res = -99;
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bpf_spin_lock(lock);
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rb = bpf_rbtree_first(root);
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if (!rb) {
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bpf_spin_unlock(lock);
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return -1;
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}
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n = container_of(rb, struct node_data, r);
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res = n->key;
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if (!remove_from_tree) {
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bpf_spin_unlock(lock);
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return res;
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}
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rb = bpf_rbtree_remove(root, rb);
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bpf_spin_unlock(lock);
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if (!rb)
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return -2;
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n = container_of(rb, struct node_data, r);
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bpf_obj_drop(n);
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return res;
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}
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static long __read_from_list(struct bpf_list_head *head,
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struct bpf_spin_lock *lock,
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bool remove_from_list)
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{
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struct bpf_list_node *l;
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struct node_data *n;
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long res = -99;
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bpf_spin_lock(lock);
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l = bpf_list_pop_front(head);
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if (!l) {
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bpf_spin_unlock(lock);
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return -1;
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}
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n = container_of(l, struct node_data, l);
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res = n->list_data;
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if (!remove_from_list) {
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if (bpf_list_push_back(head, &n->l)) {
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bpf_spin_unlock(lock);
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return -2;
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}
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}
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bpf_spin_unlock(lock);
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if (remove_from_list)
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bpf_obj_drop(n);
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return res;
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}
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static long __read_from_unstash(int idx)
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{
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struct node_data *n = NULL;
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struct map_value *mapval;
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long val = -99;
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mapval = bpf_map_lookup_elem(&stashed_nodes, &idx);
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if (!mapval)
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return -1;
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n = bpf_kptr_xchg(&mapval->node, n);
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if (!n)
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return -2;
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val = n->key;
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bpf_obj_drop(n);
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return val;
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}
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#define INSERT_READ_BOTH(rem_tree, rem_list, desc) \
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SEC("tc") \
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__description(desc) \
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__success __retval(579) \
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long insert_and_remove_tree_##rem_tree##_list_##rem_list(void *ctx) \
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{ \
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long err, tree_data, list_data; \
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\
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err = __insert_in_tree_and_list(&head, &root, &lock); \
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if (err) \
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return err; \
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\
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err = __read_from_tree(&root, &lock, rem_tree); \
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if (err < 0) \
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return err; \
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else \
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tree_data = err; \
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\
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err = __read_from_list(&head, &lock, rem_list); \
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if (err < 0) \
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return err; \
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else \
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list_data = err; \
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\
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return tree_data + list_data; \
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}
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/* After successful insert of struct node_data into both collections:
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* - it should have refcount = 2
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* - removing / not removing the node_data from a collection after
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* reading should have no effect on ability to read / remove from
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* the other collection
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*/
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INSERT_READ_BOTH(true, true, "insert_read_both: remove from tree + list");
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INSERT_READ_BOTH(false, false, "insert_read_both: remove from neither");
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INSERT_READ_BOTH(true, false, "insert_read_both: remove from tree");
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INSERT_READ_BOTH(false, true, "insert_read_both: remove from list");
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#undef INSERT_READ_BOTH
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#define INSERT_READ_BOTH(rem_tree, rem_list, desc) \
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SEC("tc") \
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__description(desc) \
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__success __retval(579) \
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long insert_and_remove_lf_tree_##rem_tree##_list_##rem_list(void *ctx) \
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{ \
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long err, tree_data, list_data; \
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\
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err = __insert_in_tree_and_list(&head, &root, &lock); \
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if (err) \
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return err; \
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\
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err = __read_from_list(&head, &lock, rem_list); \
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if (err < 0) \
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return err; \
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else \
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list_data = err; \
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\
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err = __read_from_tree(&root, &lock, rem_tree); \
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if (err < 0) \
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return err; \
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else \
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tree_data = err; \
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\
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return tree_data + list_data; \
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}
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/* Similar to insert_read_both, but list data is read and possibly removed
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* first
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*
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* Results should be no different than reading and possibly removing rbtree
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* node first
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*/
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INSERT_READ_BOTH(true, true, "insert_read_both_list_first: remove from tree + list");
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INSERT_READ_BOTH(false, false, "insert_read_both_list_first: remove from neither");
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INSERT_READ_BOTH(true, false, "insert_read_both_list_first: remove from tree");
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INSERT_READ_BOTH(false, true, "insert_read_both_list_first: remove from list");
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#define INSERT_DOUBLE_READ_AND_DEL(read_fn, read_root, desc) \
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SEC("tc") \
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__description(desc) \
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__success __retval(-1) \
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long insert_double_##read_fn##_and_del_##read_root(void *ctx) \
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{ \
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long err, list_data; \
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\
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err = __insert_in_tree_and_list(&head, &root, &lock); \
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if (err) \
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return err; \
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\
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err = read_fn(&read_root, &lock, true); \
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if (err < 0) \
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return err; \
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else \
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list_data = err; \
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\
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err = read_fn(&read_root, &lock, true); \
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if (err < 0) \
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return err; \
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\
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return err + list_data; \
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}
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/* Insert into both tree and list, then try reading-and-removing from either twice
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*
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* The second read-and-remove should fail on read step since the node has
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* already been removed
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*/
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INSERT_DOUBLE_READ_AND_DEL(__read_from_tree, root, "insert_double_del: 2x read-and-del from tree");
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INSERT_DOUBLE_READ_AND_DEL(__read_from_list, head, "insert_double_del: 2x read-and-del from list");
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#define INSERT_STASH_READ(rem_tree, desc) \
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SEC("tc") \
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__description(desc) \
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__success __retval(84) \
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long insert_rbtree_and_stash__del_tree_##rem_tree(void *ctx) \
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{ \
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long err, tree_data, map_data; \
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\
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err = __stash_map_insert_tree(0, 42, &root, &lock); \
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if (err) \
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return err; \
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\
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err = __read_from_tree(&root, &lock, rem_tree); \
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if (err < 0) \
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return err; \
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else \
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tree_data = err; \
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\
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err = __read_from_unstash(0); \
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if (err < 0) \
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return err; \
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else \
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map_data = err; \
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\
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return tree_data + map_data; \
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}
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/* Stash a refcounted node in map_val, insert same node into tree, then try
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* reading data from tree then unstashed map_val, possibly removing from tree
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*
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* Removing from tree should have no effect on map_val kptr validity
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*/
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INSERT_STASH_READ(true, "insert_stash_read: remove from tree");
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INSERT_STASH_READ(false, "insert_stash_read: don't remove from tree");
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SEC("tc")
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__success
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long rbtree_refcounted_node_ref_escapes(void *ctx)
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{
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struct node_acquire *n, *m;
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n = bpf_obj_new(typeof(*n));
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if (!n)
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return 1;
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bpf_spin_lock(&alock);
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bpf_rbtree_add(&aroot, &n->node, less_a);
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m = bpf_refcount_acquire(n);
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bpf_spin_unlock(&alock);
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m->key = 2;
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bpf_obj_drop(m);
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return 0;
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}
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SEC("tc")
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__success
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long rbtree_refcounted_node_ref_escapes_owning_input(void *ctx)
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{
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struct node_acquire *n, *m;
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n = bpf_obj_new(typeof(*n));
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if (!n)
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return 1;
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m = bpf_refcount_acquire(n);
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m->key = 2;
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bpf_spin_lock(&alock);
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bpf_rbtree_add(&aroot, &n->node, less_a);
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bpf_spin_unlock(&alock);
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bpf_obj_drop(m);
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return 0;
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}
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char _license[] SEC("license") = "GPL";
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72
tools/testing/selftests/bpf/progs/refcounted_kptr_fail.c
Normal file
72
tools/testing/selftests/bpf/progs/refcounted_kptr_fail.c
Normal file
@ -0,0 +1,72 @@
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// SPDX-License-Identifier: GPL-2.0
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#include <vmlinux.h>
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#include <bpf/bpf_tracing.h>
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#include <bpf/bpf_helpers.h>
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#include <bpf/bpf_core_read.h>
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#include "bpf_experimental.h"
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#include "bpf_misc.h"
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struct node_acquire {
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long key;
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long data;
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struct bpf_rb_node node;
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struct bpf_refcount refcount;
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};
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#define private(name) SEC(".data." #name) __hidden __attribute__((aligned(8)))
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private(A) struct bpf_spin_lock glock;
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private(A) struct bpf_rb_root groot __contains(node_acquire, node);
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static bool less(struct bpf_rb_node *a, const struct bpf_rb_node *b)
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{
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struct node_acquire *node_a;
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struct node_acquire *node_b;
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node_a = container_of(a, struct node_acquire, node);
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node_b = container_of(b, struct node_acquire, node);
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return node_a->key < node_b->key;
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}
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SEC("?tc")
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__failure __msg("Unreleased reference id=3 alloc_insn=21")
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long rbtree_refcounted_node_ref_escapes(void *ctx)
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{
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struct node_acquire *n, *m;
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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";
|
||||
Loading…
x
Reference in New Issue
Block a user