diff --git a/tools/testing/selftests/bpf/prog_tests/rdonly_maps.c b/tools/testing/selftests/bpf/prog_tests/rdonly_maps.c new file mode 100644 index 000000000000..9bf9de0aaeea --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/rdonly_maps.c @@ -0,0 +1,99 @@ +// SPDX-License-Identifier: GPL-2.0 +#include + +struct bss { + unsigned did_run; + unsigned iters; + unsigned sum; +}; + +struct rdonly_map_subtest { + const char *subtest_name; + const char *prog_name; + unsigned exp_iters; + unsigned exp_sum; +}; + +void test_rdonly_maps(void) +{ + const char *prog_name_skip_loop = "raw_tracepoint/sys_enter:skip_loop"; + const char *prog_name_part_loop = "raw_tracepoint/sys_enter:part_loop"; + const char *prog_name_full_loop = "raw_tracepoint/sys_enter:full_loop"; + const char *file = "test_rdonly_maps.o"; + struct rdonly_map_subtest subtests[] = { + { "skip loop", prog_name_skip_loop, 0, 0 }, + { "part loop", prog_name_part_loop, 3, 2 + 3 + 4 }, + { "full loop", prog_name_full_loop, 4, 2 + 3 + 4 + 5 }, + }; + int i, err, zero = 0, duration = 0; + struct bpf_link *link = NULL; + struct bpf_program *prog; + struct bpf_map *bss_map; + struct bpf_object *obj; + struct bss bss; + + obj = bpf_object__open_file(file, NULL); + if (CHECK(IS_ERR(obj), "obj_open", "err %ld\n", PTR_ERR(obj))) + return; + + bpf_object__for_each_program(prog, obj) { + bpf_program__set_raw_tracepoint(prog); + } + + err = bpf_object__load(obj); + if (CHECK(err, "obj_load", "err %d errno %d\n", err, errno)) + goto cleanup; + + bss_map = bpf_object__find_map_by_name(obj, "test_rdo.bss"); + if (CHECK(!bss_map, "find_bss_map", "failed\n")) + goto cleanup; + + for (i = 0; i < ARRAY_SIZE(subtests); i++) { + const struct rdonly_map_subtest *t = &subtests[i]; + + if (!test__start_subtest(t->subtest_name)) + continue; + + prog = bpf_object__find_program_by_title(obj, t->prog_name); + if (CHECK(!prog, "find_prog", "prog '%s' not found\n", + t->prog_name)) + goto cleanup; + + memset(&bss, 0, sizeof(bss)); + err = bpf_map_update_elem(bpf_map__fd(bss_map), &zero, &bss, 0); + if (CHECK(err, "set_bss", "failed to set bss data: %d\n", err)) + goto cleanup; + + link = bpf_program__attach_raw_tracepoint(prog, "sys_enter"); + if (CHECK(IS_ERR(link), "attach_prog", "prog '%s', err %ld\n", + t->prog_name, PTR_ERR(link))) { + link = NULL; + goto cleanup; + } + + /* trigger probe */ + usleep(1); + + bpf_link__destroy(link); + link = NULL; + + err = bpf_map_lookup_elem(bpf_map__fd(bss_map), &zero, &bss); + if (CHECK(err, "get_bss", "failed to get bss data: %d\n", err)) + goto cleanup; + if (CHECK(bss.did_run == 0, "check_run", + "prog '%s' didn't run?\n", t->prog_name)) + goto cleanup; + if (CHECK(bss.iters != t->exp_iters, "check_iters", + "prog '%s' iters: %d, expected: %d\n", + t->prog_name, bss.iters, t->exp_iters)) + goto cleanup; + if (CHECK(bss.sum != t->exp_sum, "check_sum", + "prog '%s' sum: %d, expected: %d\n", + t->prog_name, bss.sum, t->exp_sum)) + goto cleanup; + } + +cleanup: + bpf_link__destroy(link); + bpf_object__close(obj); +} diff --git a/tools/testing/selftests/bpf/progs/test_rdonly_maps.c b/tools/testing/selftests/bpf/progs/test_rdonly_maps.c new file mode 100644 index 000000000000..52d94e8b214d --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_rdonly_maps.c @@ -0,0 +1,83 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2019 Facebook + +#include +#include +#include "bpf_helpers.h" + +static volatile const struct { + unsigned a[4]; + /* + * if the struct's size is multiple of 16, compiler will put it into + * .rodata.cst16 section, which is not recognized by libbpf; work + * around this by ensuring we don't have 16-aligned struct + */ + char _y; +} rdonly_values = { .a = {2, 3, 4, 5} }; + +static volatile struct { + unsigned did_run; + unsigned iters; + unsigned sum; +} res; + +SEC("raw_tracepoint/sys_enter:skip_loop") +int skip_loop(struct pt_regs *ctx) +{ + /* prevent compiler to optimize everything out */ + unsigned * volatile p = (void *)&rdonly_values.a; + unsigned iters = 0, sum = 0; + + /* we should never enter this loop */ + while (*p & 1) { + iters++; + sum += *p; + p++; + } + res.did_run = 1; + res.iters = iters; + res.sum = sum; + return 0; +} + +SEC("raw_tracepoint/sys_enter:part_loop") +int part_loop(struct pt_regs *ctx) +{ + /* prevent compiler to optimize everything out */ + unsigned * volatile p = (void *)&rdonly_values.a; + unsigned iters = 0, sum = 0; + + /* validate verifier can derive loop termination */ + while (*p < 5) { + iters++; + sum += *p; + p++; + } + res.did_run = 1; + res.iters = iters; + res.sum = sum; + return 0; +} + +SEC("raw_tracepoint/sys_enter:full_loop") +int full_loop(struct pt_regs *ctx) +{ + /* prevent compiler to optimize everything out */ + unsigned * volatile p = (void *)&rdonly_values.a; + int i = sizeof(rdonly_values.a) / sizeof(rdonly_values.a[0]); + unsigned iters = 0, sum = 0; + + /* validate verifier can allow full loop as well */ + while (i > 0 ) { + iters++; + sum += *p; + p++; + i--; + } + res.did_run = 1; + res.iters = iters; + res.sum = sum; + return 0; +} + +char _license[] SEC("license") = "GPL";