From: Alexei Starovoitov <ast@xxxxxxxxxx> bpf_arena_alloc.h - implements page_frag allocator as a bpf program. bpf_arena_list.h - doubly linked link list as a bpf program. Compiled as a bpf program and as native C code. Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx> --- tools/testing/selftests/bpf/DENYLIST.aarch64 | 1 + tools/testing/selftests/bpf/DENYLIST.s390x | 1 + tools/testing/selftests/bpf/bpf_arena_alloc.h | 58 +++++++++++ tools/testing/selftests/bpf/bpf_arena_list.h | 95 +++++++++++++++++++ .../selftests/bpf/prog_tests/arena_list.c | 68 +++++++++++++ .../testing/selftests/bpf/progs/arena_list.c | 76 +++++++++++++++ 6 files changed, 299 insertions(+) create mode 100644 tools/testing/selftests/bpf/bpf_arena_alloc.h create mode 100644 tools/testing/selftests/bpf/bpf_arena_list.h create mode 100644 tools/testing/selftests/bpf/prog_tests/arena_list.c create mode 100644 tools/testing/selftests/bpf/progs/arena_list.c diff --git a/tools/testing/selftests/bpf/DENYLIST.aarch64 b/tools/testing/selftests/bpf/DENYLIST.aarch64 index 8e70af386e52..83a3d9bee59c 100644 --- a/tools/testing/selftests/bpf/DENYLIST.aarch64 +++ b/tools/testing/selftests/bpf/DENYLIST.aarch64 @@ -12,3 +12,4 @@ 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 # JIT does not support arena diff --git a/tools/testing/selftests/bpf/DENYLIST.s390x b/tools/testing/selftests/bpf/DENYLIST.s390x index ded440277f6e..9293b88a327e 100644 --- a/tools/testing/selftests/bpf/DENYLIST.s390x +++ b/tools/testing/selftests/bpf/DENYLIST.s390x @@ -4,3 +4,4 @@ exceptions # JIT does not support calling kfunc bpf_throw (excepti get_stack_raw_tp # user_stack corrupted user stack (no backchain userspace) stacktrace_build_id # compare_map_keys stackid_hmap vs. stackmap err -2 errno 2 (?) verifier_arena # JIT does not support arena +arena # JIT does not support arena diff --git a/tools/testing/selftests/bpf/bpf_arena_alloc.h b/tools/testing/selftests/bpf/bpf_arena_alloc.h new file mode 100644 index 000000000000..0f4cb399b4c7 --- /dev/null +++ b/tools/testing/selftests/bpf/bpf_arena_alloc.h @@ -0,0 +1,58 @@ +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */ +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ +#pragma once +#include "bpf_arena_common.h" + +#ifndef __round_mask +#define __round_mask(x, y) ((__typeof__(x))((y)-1)) +#endif +#ifndef round_up +#define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1) +#endif + +void __arena *cur_page; +int cur_offset; + +/* Simple page_frag allocator */ +static inline void __arena* bpf_alloc(unsigned int size) +{ + __u64 __arena *obj_cnt; + void __arena *page = cur_page; + int offset; + + size = round_up(size, 8); + if (size >= PAGE_SIZE - 8) + return NULL; + if (!page) { +refill: + page = bpf_arena_alloc_pages(&arena, NULL, 1, NUMA_NO_NODE, 0); + if (!page) + return NULL; + cast_kern(page); + cur_page = page; + cur_offset = PAGE_SIZE - 8; + obj_cnt = page + PAGE_SIZE - 8; + *obj_cnt = 0; + } else { + cast_kern(page); + obj_cnt = page + PAGE_SIZE - 8; + } + + offset = cur_offset - size; + if (offset < 0) + goto refill; + + (*obj_cnt)++; + cur_offset = offset; + return page + offset; +} + +static inline void bpf_free(void __arena *addr) +{ + __u64 __arena *obj_cnt; + + addr = (void __arena *)(((long)addr) & ~(PAGE_SIZE - 1)); + obj_cnt = addr + PAGE_SIZE - 8; + if (--(*obj_cnt) == 0) + bpf_arena_free_pages(&arena, addr, 1); +} diff --git a/tools/testing/selftests/bpf/bpf_arena_list.h b/tools/testing/selftests/bpf/bpf_arena_list.h new file mode 100644 index 000000000000..31fd744dfb72 --- /dev/null +++ b/tools/testing/selftests/bpf/bpf_arena_list.h @@ -0,0 +1,95 @@ +/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */ +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ +#pragma once +#include "bpf_arena_common.h" + +struct arena_list_node; + +typedef struct arena_list_node __arena arena_list_node_t; + +struct arena_list_node { + arena_list_node_t *next; + arena_list_node_t * __arena *pprev; +}; + +struct arena_list_head { + struct arena_list_node __arena *first; +}; +typedef struct arena_list_head __arena arena_list_head_t; + +#define list_entry(ptr, type, member) arena_container_of(ptr, type, member) + +#define list_entry_safe(ptr, type, member) \ + ({ typeof(*ptr) * ___ptr = (ptr); \ + ___ptr ? ({ cast_kern(___ptr); list_entry(___ptr, type, member); }) : NULL; \ + }) + +#ifndef __BPF__ +static inline void *bpf_iter_num_new(struct bpf_iter_num *it, int i, int j) { return NULL; } +static inline void bpf_iter_num_destroy(struct bpf_iter_num *it) {} +static inline bool bpf_iter_num_next(struct bpf_iter_num *it) { return true; } +#endif + +/* Safely walk link list of up to 1M elements. Deletion of elements is allowed. */ +#define list_for_each_entry(pos, head, member) \ + for (struct bpf_iter_num ___it __attribute__((aligned(8), \ + cleanup(bpf_iter_num_destroy))), \ + * ___tmp = ( \ + bpf_iter_num_new(&___it, 0, (1000000)), \ + pos = list_entry_safe((head)->first, \ + typeof(*(pos)), member), \ + (void)bpf_iter_num_destroy, (void *)0); \ + bpf_iter_num_next(&___it) && pos && \ + ({ ___tmp = (void *)pos->member.next; 1; }); \ + pos = list_entry_safe((void __arena *)___tmp, typeof(*(pos)), member)) + +static inline void list_add_head(arena_list_node_t *n, arena_list_head_t *h) +{ + arena_list_node_t *first = h->first, * __arena *tmp; + + cast_user(first); + cast_kern(n); + WRITE_ONCE(n->next, first); + cast_kern(first); + if (first) { + tmp = &n->next; + cast_user(tmp); + WRITE_ONCE(first->pprev, tmp); + } + cast_user(n); + WRITE_ONCE(h->first, n); + + tmp = &h->first; + cast_user(tmp); + cast_kern(n); + WRITE_ONCE(n->pprev, tmp); +} + +static inline void __list_del(arena_list_node_t *n) +{ + arena_list_node_t *next = n->next, *tmp; + arena_list_node_t * __arena *pprev = n->pprev; + + cast_user(next); + cast_kern(pprev); + tmp = *pprev; + cast_kern(tmp); + WRITE_ONCE(tmp, next); + if (next) { + cast_user(pprev); + cast_kern(next); + WRITE_ONCE(next->pprev, pprev); + } +} + +#define POISON_POINTER_DELTA 0 + +#define LIST_POISON1 ((void __arena *) 0x100 + POISON_POINTER_DELTA) +#define LIST_POISON2 ((void __arena *) 0x122 + POISON_POINTER_DELTA) + +static inline void list_del(arena_list_node_t *n) +{ + __list_del(n); + n->next = LIST_POISON1; + n->pprev = LIST_POISON2; +} diff --git a/tools/testing/selftests/bpf/prog_tests/arena_list.c b/tools/testing/selftests/bpf/prog_tests/arena_list.c new file mode 100644 index 000000000000..e61886debab1 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/arena_list.c @@ -0,0 +1,68 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ +#include <test_progs.h> +#include <sys/mman.h> +#include <network_helpers.h> + +#define PAGE_SIZE 4096 + +#include "bpf_arena_list.h" +#include "arena_list.skel.h" + +struct elem { + struct arena_list_node node; + __u64 value; +}; + +static int list_sum(struct arena_list_head *head) +{ + struct elem __arena *n; + int sum = 0; + + list_for_each_entry(n, head, node) + sum += n->value; + return sum; +} + +static void test_arena_list_add_del(int cnt) +{ + LIBBPF_OPTS(bpf_test_run_opts, opts); + struct arena_list *skel; + int expected_sum = (u64)cnt * (cnt - 1) / 2; + int ret, sum; + + skel = arena_list__open_and_load(); + if (!ASSERT_OK_PTR(skel, "arena_list__open_and_load")) + return; + + skel->bss->cnt = cnt; + ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.arena_list_add), &opts); + ASSERT_OK(ret, "ret_add"); + ASSERT_OK(opts.retval, "retval"); + if (skel->bss->skip) { + printf("%s:SKIP:compiler doesn't support arena_cast\n", __func__); + test__skip(); + goto out; + } + sum = list_sum(skel->bss->list_head); + ASSERT_EQ(sum, expected_sum, "sum of elems"); + ASSERT_EQ(skel->arena->arena_sum, expected_sum, "__arena sum of elems"); + ASSERT_EQ(skel->arena->test_val, cnt + 1, "num of elems"); + + ret = bpf_prog_test_run_opts(bpf_program__fd(skel->progs.arena_list_del), &opts); + ASSERT_OK(ret, "ret_del"); + sum = list_sum(skel->bss->list_head); + ASSERT_EQ(sum, 0, "sum of list elems after del"); + ASSERT_EQ(skel->bss->list_sum, expected_sum, "sum of list elems computed by prog"); + ASSERT_EQ(skel->arena->arena_sum, expected_sum, "__arena sum of elems"); +out: + arena_list__destroy(skel); +} + +void test_arena_list(void) +{ + if (test__start_subtest("arena_list_1")) + test_arena_list_add_del(1); + if (test__start_subtest("arena_list_1000")) + test_arena_list_add_del(1000); +} diff --git a/tools/testing/selftests/bpf/progs/arena_list.c b/tools/testing/selftests/bpf/progs/arena_list.c new file mode 100644 index 000000000000..04ebcdd98f10 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/arena_list.c @@ -0,0 +1,76 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ +#include <vmlinux.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> +#include <bpf/bpf_core_read.h> +#include "bpf_experimental.h" + +struct { + __uint(type, BPF_MAP_TYPE_ARENA); + __uint(map_flags, BPF_F_MMAPABLE); + __uint(max_entries, 1000); /* number of pages */ + __ulong(map_extra, 2ull << 44); /* start of mmap() region */ +} arena SEC(".maps"); + +#include "bpf_arena_alloc.h" +#include "bpf_arena_list.h" + +struct elem { + struct arena_list_node node; + __u64 value; +}; + +struct arena_list_head __arena *list_head; +int list_sum; +int cnt; +bool skip = false; + +long __arena arena_sum; +int __arena test_val = 1; +struct arena_list_head __arena global_head; + +SEC("syscall") +int arena_list_add(void *ctx) +{ +#ifdef __BPF_FEATURE_ARENA_CAST + __u64 i; + + list_head = &global_head; + + bpf_for(i, 0, cnt) { + struct elem __arena *n = bpf_alloc(sizeof(*n)); + + test_val++; + n->value = i; + arena_sum += i; + list_add_head(&n->node, list_head); + } +#else + skip = true; +#endif + return 0; +} + +SEC("syscall") +int arena_list_del(void *ctx) +{ +#ifdef __BPF_FEATURE_ARENA_CAST + struct elem __arena *n; + int sum = 0; + + arena_sum = 0; + list_for_each_entry(n, list_head, node) { + sum += n->value; + arena_sum += n->value; + list_del(&n->node); + bpf_free(n); + } + list_sum = sum; +#else + skip = true; +#endif + return 0; +} + +char _license[] SEC("license") = "GPL"; -- 2.34.1