From 9f2c156f90a422b4897a8c2831076a96a31413d1 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 7 Mar 2024 17:08:11 -0800 Subject: selftests/bpf: Add bpf_arena_list test. 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 Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20240308010812.89848-14-alexei.starovoitov@gmail.com --- tools/testing/selftests/bpf/bpf_arena_alloc.h | 67 ++++++++++++++++ tools/testing/selftests/bpf/bpf_arena_list.h | 92 ++++++++++++++++++++++ .../testing/selftests/bpf/prog_tests/arena_list.c | 68 ++++++++++++++++ tools/testing/selftests/bpf/progs/arena_list.c | 87 ++++++++++++++++++++ 4 files changed, 314 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 (limited to 'tools/testing/selftests') 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..c27678299e0c --- /dev/null +++ b/tools/testing/selftests/bpf/bpf_arena_alloc.h @@ -0,0 +1,67 @@ +/* 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 + +#ifdef __BPF__ +#define NR_CPUS (sizeof(struct cpumask) * 8) + +static void __arena * __arena page_frag_cur_page[NR_CPUS]; +static int __arena page_frag_cur_offset[NR_CPUS]; + +/* Simple page_frag allocator */ +static inline void __arena* bpf_alloc(unsigned int size) +{ + __u64 __arena *obj_cnt; + __u32 cpu = bpf_get_smp_processor_id(); + void __arena *page = page_frag_cur_page[cpu]; + int __arena *cur_offset = &page_frag_cur_offset[cpu]; + 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); + page_frag_cur_page[cpu] = 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); +} +#else +static inline void __arena* bpf_alloc(unsigned int size) { return NULL; } +static inline void bpf_free(void __arena *addr) {} +#endif 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..b99b9f408eff --- /dev/null +++ b/tools/testing/selftests/bpf/bpf_arena_list.h @@ -0,0 +1,92 @@ +/* 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; } +#define cond_break ({}) +#endif + +/* Safely walk link list elements. Deletion of elements is allowed. */ +#define list_for_each_entry(pos, head, member) \ + for (void * ___tmp = (pos = list_entry_safe((head)->first, \ + typeof(*(pos)), member), \ + (void *)0); \ + pos && ({ ___tmp = (void *)pos->member.next; 1; }); \ + cond_break, \ + 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 +#include +#include + +#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..cd35b8448435 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/arena_list.c @@ -0,0 +1,87 @@ +// 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 */ +#ifdef __TARGET_ARCH_arm64 + __ulong(map_extra, 0x1ull << 32); /* start of mmap() region */ +#else + __ulong(map_extra, 0x1ull << 44); /* start of mmap() region */ +#endif +} 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; + +#ifdef __BPF_FEATURE_ARENA_CAST +long __arena arena_sum; +int __arena test_val = 1; +struct arena_list_head __arena global_head; +#else +long arena_sum SEC(".arena.1"); +int test_val SEC(".arena.1"); +#endif + +int zero; + +SEC("syscall") +int arena_list_add(void *ctx) +{ +#ifdef __BPF_FEATURE_ARENA_CAST + __u64 i; + + list_head = &global_head; + + for (i = zero; i < cnt; cond_break, i++) { + 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"; -- cgit v1.2.3-59-g8ed1b