diff options
Diffstat (limited to 'tools/testing')
7 files changed, 124 insertions, 10 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c b/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c index 5ca252823294..731c343897d8 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_verif_scale.c @@ -144,6 +144,12 @@ void test_verif_scale_pyperf600_nounroll() scale_test("pyperf600_nounroll.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false); } +void test_verif_scale_pyperf600_iter() +{ + /* open-coded BPF iterator version */ + scale_test("pyperf600_iter.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false); +} + void test_verif_scale_loop1() { scale_test("loop1.bpf.o", BPF_PROG_TYPE_RAW_TRACEPOINT, false); diff --git a/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c b/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c index 6558c857e620..d5b3377aa33c 100644 --- a/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c +++ b/tools/testing/selftests/bpf/prog_tests/uprobe_autoattach.c @@ -3,7 +3,6 @@ #include <test_progs.h> #include "test_uprobe_autoattach.skel.h" -#include "progs/bpf_misc.h" /* uprobe attach point */ static noinline int autoattach_trigger_func(int arg1, int arg2, int arg3, diff --git a/tools/testing/selftests/bpf/progs/bpf_misc.h b/tools/testing/selftests/bpf/progs/bpf_misc.h index f704885aa534..597688a188ae 100644 --- a/tools/testing/selftests/bpf/progs/bpf_misc.h +++ b/tools/testing/selftests/bpf/progs/bpf_misc.h @@ -75,5 +75,104 @@ #define FUNC_REG_ARG_CNT 5 #endif +struct bpf_iter_num; + +extern int bpf_iter_num_new(struct bpf_iter_num *it, int start, int end) __ksym; +extern int *bpf_iter_num_next(struct bpf_iter_num *it) __ksym; +extern void bpf_iter_num_destroy(struct bpf_iter_num *it) __ksym; + +#ifndef bpf_for_each +/* bpf_for_each(iter_type, cur_elem, args...) provides generic construct for + * using BPF open-coded iterators without having to write mundane explicit + * low-level loop logic. Instead, it provides for()-like generic construct + * that can be used pretty naturally. E.g., for some hypothetical cgroup + * iterator, you'd write: + * + * struct cgroup *cg, *parent_cg = <...>; + * + * bpf_for_each(cgroup, cg, parent_cg, CG_ITER_CHILDREN) { + * bpf_printk("Child cgroup id = %d", cg->cgroup_id); + * if (cg->cgroup_id == 123) + * break; + * } + * + * I.e., it looks almost like high-level for each loop in other languages, + * supports continue/break, and is verifiable by BPF verifier. + * + * For iterating integers, the difference betwen bpf_for_each(num, i, N, M) + * and bpf_for(i, N, M) is in that bpf_for() provides additional proof to + * verifier that i is in [N, M) range, and in bpf_for_each() case i is `int + * *`, not just `int`. So for integers bpf_for() is more convenient. + * + * Note: this macro relies on C99 feature of allowing to declare variables + * inside for() loop, bound to for() loop lifetime. It also utilizes GCC + * extension: __attribute__((cleanup(<func>))), supported by both GCC and + * Clang. + */ +#define bpf_for_each(type, cur, args...) for ( \ + /* initialize and define destructor */ \ + struct bpf_iter_##type ___it __attribute__((aligned(8), /* enforce, just in case */, \ + cleanup(bpf_iter_##type##_destroy))), \ + /* ___p pointer is just to call bpf_iter_##type##_new() *once* to init ___it */ \ + *___p = (bpf_iter_##type##_new(&___it, ##args), \ + /* this is a workaround for Clang bug: it currently doesn't emit BTF */ \ + /* for bpf_iter_##type##_destroy() when used from cleanup() attribute */ \ + (void)bpf_iter_##type##_destroy, (void *)0); \ + /* iteration and termination check */ \ + (((cur) = bpf_iter_##type##_next(&___it))); \ +) +#endif /* bpf_for_each */ + +#ifndef bpf_for +/* bpf_for(i, start, end) implements a for()-like looping construct that sets + * provided integer variable *i* to values starting from *start* through, + * but not including, *end*. It also proves to BPF verifier that *i* belongs + * to range [start, end), so this can be used for accessing arrays without + * extra checks. + * + * Note: *start* and *end* are assumed to be expressions with no side effects + * and whose values do not change throughout bpf_for() loop execution. They do + * not have to be statically known or constant, though. + * + * Note: similarly to bpf_for_each(), it relies on C99 feature of declaring for() + * loop bound variables and cleanup attribute, supported by GCC and Clang. + */ +#define bpf_for(i, start, end) for ( \ + /* initialize and define destructor */ \ + struct bpf_iter_num ___it __attribute__((aligned(8), /* enforce, just in case */ \ + cleanup(bpf_iter_num_destroy))), \ + /* ___p pointer is necessary to call bpf_iter_num_new() *once* to init ___it */ \ + *___p = (bpf_iter_num_new(&___it, (start), (end)), \ + /* this is a workaround for Clang bug: it currently doesn't emit BTF */ \ + /* for bpf_iter_num_destroy() when used from cleanup() attribute */ \ + (void)bpf_iter_num_destroy, (void *)0); \ + ({ \ + /* iteration step */ \ + int *___t = bpf_iter_num_next(&___it); \ + /* termination and bounds check */ \ + (___t && ((i) = *___t, (i) >= (start) && (i) < (end))); \ + }); \ +) +#endif /* bpf_for */ + +#ifndef bpf_repeat +/* bpf_repeat(N) performs N iterations without exposing iteration number + * + * Note: similarly to bpf_for_each(), it relies on C99 feature of declaring for() + * loop bound variables and cleanup attribute, supported by GCC and Clang. + */ +#define bpf_repeat(N) for ( \ + /* initialize and define destructor */ \ + struct bpf_iter_num ___it __attribute__((aligned(8), /* enforce, just in case */ \ + cleanup(bpf_iter_num_destroy))), \ + /* ___p pointer is necessary to call bpf_iter_num_new() *once* to init ___it */ \ + *___p = (bpf_iter_num_new(&___it, 0, (N)), \ + /* this is a workaround for Clang bug: it currently doesn't emit BTF */ \ + /* for bpf_iter_num_destroy() when used from cleanup() attribute */ \ + (void)bpf_iter_num_destroy, (void *)0); \ + bpf_iter_num_next(&___it); \ + /* nothing here */ \ +) +#endif /* bpf_repeat */ #endif diff --git a/tools/testing/selftests/bpf/progs/lsm.c b/tools/testing/selftests/bpf/progs/lsm.c index dc93887ed34c..fadfdd98707c 100644 --- a/tools/testing/selftests/bpf/progs/lsm.c +++ b/tools/testing/selftests/bpf/progs/lsm.c @@ -4,12 +4,12 @@ * Copyright 2020 Google LLC. */ -#include "bpf_misc.h" #include "vmlinux.h" +#include <errno.h> #include <bpf/bpf_core_read.h> #include <bpf/bpf_helpers.h> #include <bpf/bpf_tracing.h> -#include <errno.h> +#include "bpf_misc.h" struct { __uint(type, BPF_MAP_TYPE_ARRAY); diff --git a/tools/testing/selftests/bpf/progs/pyperf.h b/tools/testing/selftests/bpf/progs/pyperf.h index 6c7b1fb268d6..f2e7a31c8d75 100644 --- a/tools/testing/selftests/bpf/progs/pyperf.h +++ b/tools/testing/selftests/bpf/progs/pyperf.h @@ -7,6 +7,7 @@ #include <stdbool.h> #include <linux/bpf.h> #include <bpf/bpf_helpers.h> +#include "bpf_misc.h" #define FUNCTION_NAME_LEN 64 #define FILE_NAME_LEN 128 @@ -294,17 +295,22 @@ int __on_event(struct bpf_raw_tracepoint_args *ctx) if (ctx.done) return 0; #else -#ifdef NO_UNROLL +#if defined(USE_ITER) +/* no for loop, no unrolling */ +#elif defined(NO_UNROLL) #pragma clang loop unroll(disable) -#else -#ifdef UNROLL_COUNT +#elif defined(UNROLL_COUNT) #pragma clang loop unroll_count(UNROLL_COUNT) #else #pragma clang loop unroll(full) -#endif #endif /* NO_UNROLL */ /* Unwind python stack */ +#ifdef USE_ITER + int i; + bpf_for(i, 0, STACK_MAX_LEN) { +#else /* !USE_ITER */ for (int i = 0; i < STACK_MAX_LEN; ++i) { +#endif if (frame_ptr && get_frame_data(frame_ptr, pidData, &frame, &sym)) { int32_t new_symbol_id = *symbol_counter * 64 + cur_cpu; int32_t *symbol_id = bpf_map_lookup_elem(&symbolmap, &sym); diff --git a/tools/testing/selftests/bpf/progs/pyperf600_iter.c b/tools/testing/selftests/bpf/progs/pyperf600_iter.c new file mode 100644 index 000000000000..d62e1b200c30 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/pyperf600_iter.c @@ -0,0 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2023 Meta Platforms, Inc. and affiliates. +#define STACK_MAX_LEN 600 +#define SUBPROGS +#define NO_UNROLL +#define USE_ITER +#include "pyperf.h" diff --git a/tools/testing/selftests/bpf/progs/pyperf600_nounroll.c b/tools/testing/selftests/bpf/progs/pyperf600_nounroll.c index 6beff7502f4d..520b58c4f8db 100644 --- a/tools/testing/selftests/bpf/progs/pyperf600_nounroll.c +++ b/tools/testing/selftests/bpf/progs/pyperf600_nounroll.c @@ -2,7 +2,4 @@ // Copyright (c) 2019 Facebook #define STACK_MAX_LEN 600 #define NO_UNROLL -/* clang will not unroll at all. - * Total program size is around 2k insns - */ #include "pyperf.h" |