From 8df839ae23b8c581bdac4b6970d029d65a415852 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 7 Mar 2024 17:08:12 -0800 Subject: selftests/bpf: Add bpf_arena_htab test. bpf_arena_htab.h - hash table implemented as bpf program Signed-off-by: Alexei Starovoitov Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20240308010812.89848-15-alexei.starovoitov@gmail.com --- tools/testing/selftests/bpf/DENYLIST.aarch64 | 1 + tools/testing/selftests/bpf/DENYLIST.s390x | 1 + tools/testing/selftests/bpf/bpf_arena_htab.h | 100 +++++++++++++++++++++ .../testing/selftests/bpf/prog_tests/arena_htab.c | 88 ++++++++++++++++++ tools/testing/selftests/bpf/progs/arena_htab.c | 48 ++++++++++ tools/testing/selftests/bpf/progs/arena_htab_asm.c | 5 ++ 6 files changed, 243 insertions(+) create mode 100644 tools/testing/selftests/bpf/bpf_arena_htab.h create mode 100644 tools/testing/selftests/bpf/prog_tests/arena_htab.c create mode 100644 tools/testing/selftests/bpf/progs/arena_htab.c create mode 100644 tools/testing/selftests/bpf/progs/arena_htab_asm.c diff --git a/tools/testing/selftests/bpf/DENYLIST.aarch64 b/tools/testing/selftests/bpf/DENYLIST.aarch64 index f9101651747b55..d8ade15e278989 100644 --- a/tools/testing/selftests/bpf/DENYLIST.aarch64 +++ b/tools/testing/selftests/bpf/DENYLIST.aarch64 @@ -11,3 +11,4 @@ fill_link_info/kretprobe_multi_link_info # bpf_program__attach_kprobe_mu fill_link_info/kprobe_multi_invalid_ubuff # bpf_program__attach_kprobe_multi_opts unexpected error: -95 missed/kprobe_recursion # missed_kprobe_recursion__attach unexpected error: -95 (errno 95) verifier_arena # JIT does not support arena +arena_htab # JIT does not support arena diff --git a/tools/testing/selftests/bpf/DENYLIST.s390x b/tools/testing/selftests/bpf/DENYLIST.s390x index aa8a620f3318d2..f4a2f66a683ddb 100644 --- a/tools/testing/selftests/bpf/DENYLIST.s390x +++ b/tools/testing/selftests/bpf/DENYLIST.s390x @@ -5,3 +5,4 @@ get_stack_raw_tp # user_stack corrupted user stack stacktrace_build_id # compare_map_keys stackid_hmap vs. stackmap err -2 errno 2 (?) verifier_iterating_callbacks verifier_arena # JIT does not support arena +arena_htab # JIT does not support arena diff --git a/tools/testing/selftests/bpf/bpf_arena_htab.h b/tools/testing/selftests/bpf/bpf_arena_htab.h new file mode 100644 index 00000000000000..acc01a876668ec --- /dev/null +++ b/tools/testing/selftests/bpf/bpf_arena_htab.h @@ -0,0 +1,100 @@ +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */ +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ +#pragma once +#include +#include "bpf_arena_alloc.h" +#include "bpf_arena_list.h" + +struct htab_bucket { + struct arena_list_head head; +}; +typedef struct htab_bucket __arena htab_bucket_t; + +struct htab { + htab_bucket_t *buckets; + int n_buckets; +}; +typedef struct htab __arena htab_t; + +static inline htab_bucket_t *__select_bucket(htab_t *htab, __u32 hash) +{ + htab_bucket_t *b = htab->buckets; + + cast_kern(b); + return &b[hash & (htab->n_buckets - 1)]; +} + +static inline arena_list_head_t *select_bucket(htab_t *htab, __u32 hash) +{ + return &__select_bucket(htab, hash)->head; +} + +struct hashtab_elem { + int hash; + int key; + int value; + struct arena_list_node hash_node; +}; +typedef struct hashtab_elem __arena hashtab_elem_t; + +static hashtab_elem_t *lookup_elem_raw(arena_list_head_t *head, __u32 hash, int key) +{ + hashtab_elem_t *l; + + list_for_each_entry(l, head, hash_node) + if (l->hash == hash && l->key == key) + return l; + + return NULL; +} + +static int htab_hash(int key) +{ + return key; +} + +__weak int htab_lookup_elem(htab_t *htab __arg_arena, int key) +{ + hashtab_elem_t *l_old; + arena_list_head_t *head; + + cast_kern(htab); + head = select_bucket(htab, key); + l_old = lookup_elem_raw(head, htab_hash(key), key); + if (l_old) + return l_old->value; + return 0; +} + +__weak int htab_update_elem(htab_t *htab __arg_arena, int key, int value) +{ + hashtab_elem_t *l_new = NULL, *l_old; + arena_list_head_t *head; + + cast_kern(htab); + head = select_bucket(htab, key); + l_old = lookup_elem_raw(head, htab_hash(key), key); + + l_new = bpf_alloc(sizeof(*l_new)); + if (!l_new) + return -ENOMEM; + l_new->key = key; + l_new->hash = htab_hash(key); + l_new->value = value; + + list_add_head(&l_new->hash_node, head); + if (l_old) { + list_del(&l_old->hash_node); + bpf_free(l_old); + } + return 0; +} + +void htab_init(htab_t *htab) +{ + void __arena *buckets = bpf_arena_alloc_pages(&arena, NULL, 2, NUMA_NO_NODE, 0); + + cast_user(buckets); + htab->buckets = buckets; + htab->n_buckets = 2 * PAGE_SIZE / sizeof(struct htab_bucket); +} diff --git a/tools/testing/selftests/bpf/prog_tests/arena_htab.c b/tools/testing/selftests/bpf/prog_tests/arena_htab.c new file mode 100644 index 00000000000000..0766702de84657 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/arena_htab.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ +#include +#include +#include + +#include "arena_htab_asm.skel.h" +#include "arena_htab.skel.h" + +#define PAGE_SIZE 4096 + +#include "bpf_arena_htab.h" + +static void test_arena_htab_common(struct htab *htab) +{ + int i; + + printf("htab %p buckets %p n_buckets %d\n", htab, htab->buckets, htab->n_buckets); + ASSERT_OK_PTR(htab->buckets, "htab->buckets shouldn't be NULL"); + for (i = 0; htab->buckets && i < 16; i += 4) { + /* + * Walk htab buckets and link lists since all pointers are correct, + * though they were written by bpf program. + */ + int val = htab_lookup_elem(htab, i); + + ASSERT_EQ(i, val, "key == value"); + } +} + +static void test_arena_htab_llvm(void) +{ + LIBBPF_OPTS(bpf_test_run_opts, opts); + struct arena_htab *skel; + struct htab *htab; + size_t arena_sz; + void *area; + int ret; + + skel = arena_htab__open_and_load(); + if (!ASSERT_OK_PTR(skel, "arena_htab__open_and_load")) + return; + + area = bpf_map__initial_value(skel->maps.arena, &arena_sz); + /* fault-in a page with pgoff == 0 as sanity check */ + *(volatile int *)area = 0x55aa; + + /* bpf prog will allocate more pages */ + ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.arena_htab_llvm), &opts); + ASSERT_OK(ret, "ret"); + ASSERT_OK(opts.retval, "retval"); + if (skel->bss->skip) { + printf("%s:SKIP:compiler doesn't support arena_cast\n", __func__); + test__skip(); + goto out; + } + htab = skel->bss->htab_for_user; + test_arena_htab_common(htab); +out: + arena_htab__destroy(skel); +} + +static void test_arena_htab_asm(void) +{ + LIBBPF_OPTS(bpf_test_run_opts, opts); + struct arena_htab_asm *skel; + struct htab *htab; + int ret; + + skel = arena_htab_asm__open_and_load(); + if (!ASSERT_OK_PTR(skel, "arena_htab_asm__open_and_load")) + return; + + ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.arena_htab_asm), &opts); + ASSERT_OK(ret, "ret"); + ASSERT_OK(opts.retval, "retval"); + htab = skel->bss->htab_for_user; + test_arena_htab_common(htab); + arena_htab_asm__destroy(skel); +} + +void test_arena_htab(void) +{ + if (test__start_subtest("arena_htab_llvm")) + test_arena_htab_llvm(); + if (test__start_subtest("arena_htab_asm")) + test_arena_htab_asm(); +} diff --git a/tools/testing/selftests/bpf/progs/arena_htab.c b/tools/testing/selftests/bpf/progs/arena_htab.c new file mode 100644 index 00000000000000..b7bb712cacfdcc --- /dev/null +++ b/tools/testing/selftests/bpf/progs/arena_htab.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ +#include +#include +#include +#include +#include "bpf_experimental.h" + +struct { + __uint(type, BPF_MAP_TYPE_ARENA); + __uint(map_flags, BPF_F_MMAPABLE); + __uint(max_entries, 100); /* number of pages */ +} arena SEC(".maps"); + +#include "bpf_arena_htab.h" + +void __arena *htab_for_user; +bool skip = false; + +int zero = 0; + +SEC("syscall") +int arena_htab_llvm(void *ctx) +{ +#if defined(__BPF_FEATURE_ARENA_CAST) || defined(BPF_ARENA_FORCE_ASM) + struct htab __arena *htab; + __u64 i; + + htab = bpf_alloc(sizeof(*htab)); + cast_kern(htab); + htab_init(htab); + + /* first run. No old elems in the table */ + for (i = zero; i < 1000; i++) + htab_update_elem(htab, i, i); + + /* should replace all elems with new ones */ + for (i = zero; i < 1000; i++) + htab_update_elem(htab, i, i); + cast_user(htab); + htab_for_user = htab; +#else + skip = true; +#endif + return 0; +} + +char _license[] SEC("license") = "GPL"; diff --git a/tools/testing/selftests/bpf/progs/arena_htab_asm.c b/tools/testing/selftests/bpf/progs/arena_htab_asm.c new file mode 100644 index 00000000000000..6cd70ea12f0d7e --- /dev/null +++ b/tools/testing/selftests/bpf/progs/arena_htab_asm.c @@ -0,0 +1,5 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ +#define BPF_ARENA_FORCE_ASM +#define arena_htab_llvm arena_htab_asm +#include "arena_htab.c" -- cgit 1.2.3-korg