From edb65ee5aa2550f6035c8fb169a359bc18acb84a Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Tue, 18 Aug 2020 21:27:59 -0700 Subject: [PATCH] selftests/bpf: Add bpffs preload test. Add a test that mounts two bpffs instances and checks progs.debug and maps.debug for sanity data. Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20200819042759.51280-5-alexei.starovoitov@gmail.com --- .../selftests/bpf/prog_tests/test_bpffs.c | 94 +++++++++++++++++++ 1 file changed, 94 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/test_bpffs.c diff --git a/tools/testing/selftests/bpf/prog_tests/test_bpffs.c b/tools/testing/selftests/bpf/prog_tests/test_bpffs.c new file mode 100644 index 000000000000..172c999e523c --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/test_bpffs.c @@ -0,0 +1,94 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ +#define _GNU_SOURCE +#include +#include +#include +#include +#include + +#define TDIR "/sys/kernel/debug" + +static int read_iter(char *file) +{ + /* 1024 should be enough to get contiguous 4 "iter" letters at some point */ + char buf[1024]; + int fd, len; + + fd = open(file, 0); + if (fd < 0) + return -1; + while ((len = read(fd, buf, sizeof(buf))) > 0) + if (strstr(buf, "iter")) { + close(fd); + return 0; + } + close(fd); + return -1; +} + +static int fn(void) +{ + int err, duration = 0; + + err = unshare(CLONE_NEWNS); + if (CHECK(err, "unshare", "failed: %d\n", errno)) + goto out; + + err = mount("", "/", "", MS_REC | MS_PRIVATE, NULL); + if (CHECK(err, "mount /", "failed: %d\n", errno)) + goto out; + + err = umount(TDIR); + if (CHECK(err, "umount " TDIR, "failed: %d\n", errno)) + goto out; + + err = mount("none", TDIR, "tmpfs", 0, NULL); + if (CHECK(err, "mount", "mount root failed: %d\n", errno)) + goto out; + + err = mkdir(TDIR "/fs1", 0777); + if (CHECK(err, "mkdir "TDIR"/fs1", "failed: %d\n", errno)) + goto out; + err = mkdir(TDIR "/fs2", 0777); + if (CHECK(err, "mkdir "TDIR"/fs2", "failed: %d\n", errno)) + goto out; + + err = mount("bpf", TDIR "/fs1", "bpf", 0, NULL); + if (CHECK(err, "mount bpffs "TDIR"/fs1", "failed: %d\n", errno)) + goto out; + err = mount("bpf", TDIR "/fs2", "bpf", 0, NULL); + if (CHECK(err, "mount bpffs " TDIR "/fs2", "failed: %d\n", errno)) + goto out; + + err = read_iter(TDIR "/fs1/maps.debug"); + if (CHECK(err, "reading " TDIR "/fs1/maps.debug", "failed\n")) + goto out; + err = read_iter(TDIR "/fs2/progs.debug"); + if (CHECK(err, "reading " TDIR "/fs2/progs.debug", "failed\n")) + goto out; +out: + umount(TDIR "/fs1"); + umount(TDIR "/fs2"); + rmdir(TDIR "/fs1"); + rmdir(TDIR "/fs2"); + umount(TDIR); + exit(err); +} + +void test_test_bpffs(void) +{ + int err, duration = 0, status = 0; + pid_t pid; + + pid = fork(); + if (CHECK(pid == -1, "clone", "clone failed %d", errno)) + return; + if (pid == 0) + fn(); + err = waitpid(pid, &status, 0); + if (CHECK(err == -1 && errno != ECHILD, "waitpid", "failed %d", errno)) + return; + if (CHECK(WEXITSTATUS(status), "bpffs test ", "failed %d", WEXITSTATUS(status))) + return; +} -- 2.20.1