bpf/prog_tests/test_bpffs.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /* Copyright (c) 2020 Facebook */
0003 #define _GNU_SOURCE
0004 #include <stdio.h>
0005 #include <sched.h>
0006 #include <sys/mount.h>
0007 #include <sys/stat.h>
0008 #include <sys/types.h>
0009 #include <test_progs.h>
0010
0011 #define TDIR "/sys/kernel/debug"
0012
0013 static int read_iter(char *file)
0014 {
0015     /* 1024 should be enough to get contiguous 4 "iter" letters at some point */
0016     char buf[1024];
0017     int fd, len;
0018
0019     fd = open(file, 0);
0020     if (fd < 0)
0021         return -1;
0022     while ((len = read(fd, buf, sizeof(buf))) > 0) {
0023         buf[sizeof(buf) - 1] = '\0';
0024         if (strstr(buf, "iter")) {
0025             close(fd);
0026             return 0;
0027         }
0028     }
0029     close(fd);
0030     return -1;
0031 }
0032
0033 static int fn(void)
0034 {
0035     struct stat a, b, c;
0036     int err, map;
0037
0038     err = unshare(CLONE_NEWNS);
0039     if (!ASSERT_OK(err, "unshare"))
0040         goto out;
0041
0042     err = mount("", "/", "", MS_REC | MS_PRIVATE, NULL);
0043     if (!ASSERT_OK(err, "mount /"))
0044         goto out;
0045
0046     err = umount(TDIR);
0047     if (!ASSERT_OK(err, "umount " TDIR))
0048         goto out;
0049
0050     err = mount("none", TDIR, "tmpfs", 0, NULL);
0051     if (!ASSERT_OK(err, "mount tmpfs"))
0052         goto out;
0053
0054     err = mkdir(TDIR "/fs1", 0777);
0055     if (!ASSERT_OK(err, "mkdir " TDIR "/fs1"))
0056         goto out;
0057     err = mkdir(TDIR "/fs2", 0777);
0058     if (!ASSERT_OK(err, "mkdir " TDIR "/fs2"))
0059         goto out;
0060
0061     err = mount("bpf", TDIR "/fs1", "bpf", 0, NULL);
0062     if (!ASSERT_OK(err, "mount bpffs " TDIR "/fs1"))
0063         goto out;
0064     err = mount("bpf", TDIR "/fs2", "bpf", 0, NULL);
0065     if (!ASSERT_OK(err, "mount bpffs " TDIR "/fs2"))
0066         goto out;
0067
0068     err = read_iter(TDIR "/fs1/maps.debug");
0069     if (!ASSERT_OK(err, "reading " TDIR "/fs1/maps.debug"))
0070         goto out;
0071     err = read_iter(TDIR "/fs2/progs.debug");
0072     if (!ASSERT_OK(err, "reading " TDIR "/fs2/progs.debug"))
0073         goto out;
0074
0075     err = mkdir(TDIR "/fs1/a", 0777);
0076     if (!ASSERT_OK(err, "creating " TDIR "/fs1/a"))
0077         goto out;
0078     err = mkdir(TDIR "/fs1/a/1", 0777);
0079     if (!ASSERT_OK(err, "creating " TDIR "/fs1/a/1"))
0080         goto out;
0081     err = mkdir(TDIR "/fs1/b", 0777);
0082     if (!ASSERT_OK(err, "creating " TDIR "/fs1/b"))
0083         goto out;
0084
0085     map = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, 4, 4, 1, NULL);
0086     if (!ASSERT_GT(map, 0, "create_map(ARRAY)"))
0087         goto out;
0088     err = bpf_obj_pin(map, TDIR "/fs1/c");
0089     if (!ASSERT_OK(err, "pin map"))
0090         goto out;
0091     close(map);
0092
0093     /* Check that RENAME_EXCHANGE works for directories. */
0094     err = stat(TDIR "/fs1/a", &a);
0095     if (!ASSERT_OK(err, "stat(" TDIR "/fs1/a)"))
0096         goto out;
0097     err = renameat2(0, TDIR "/fs1/a", 0, TDIR "/fs1/b", RENAME_EXCHANGE);
0098     if (!ASSERT_OK(err, "renameat2(/fs1/a, /fs1/b, RENAME_EXCHANGE)"))
0099         goto out;
0100     err = stat(TDIR "/fs1/b", &b);
0101     if (!ASSERT_OK(err, "stat(" TDIR "/fs1/b)"))
0102         goto out;
0103     if (!ASSERT_EQ(a.st_ino, b.st_ino, "b should have a's inode"))
0104         goto out;
0105     err = access(TDIR "/fs1/b/1", F_OK);
0106     if (!ASSERT_OK(err, "access(" TDIR "/fs1/b/1)"))
0107         goto out;
0108
0109     /* Check that RENAME_EXCHANGE works for mixed file types. */
0110     err = stat(TDIR "/fs1/c", &c);
0111     if (!ASSERT_OK(err, "stat(" TDIR "/fs1/map)"))
0112         goto out;
0113     err = renameat2(0, TDIR "/fs1/c", 0, TDIR "/fs1/b", RENAME_EXCHANGE);
0114     if (!ASSERT_OK(err, "renameat2(/fs1/c, /fs1/b, RENAME_EXCHANGE)"))
0115         goto out;
0116     err = stat(TDIR "/fs1/b", &b);
0117     if (!ASSERT_OK(err, "stat(" TDIR "/fs1/b)"))
0118         goto out;
0119     if (!ASSERT_EQ(c.st_ino, b.st_ino, "b should have c's inode"))
0120         goto out;
0121     err = access(TDIR "/fs1/c/1", F_OK);
0122     if (!ASSERT_OK(err, "access(" TDIR "/fs1/c/1)"))
0123         goto out;
0124
0125     /* Check that RENAME_NOREPLACE works. */
0126     err = renameat2(0, TDIR "/fs1/b", 0, TDIR "/fs1/a", RENAME_NOREPLACE);
0127     if (!ASSERT_ERR(err, "renameat2(RENAME_NOREPLACE)")) {
0128         err = -EINVAL;
0129         goto out;
0130     }
0131     err = access(TDIR "/fs1/b", F_OK);
0132     if (!ASSERT_OK(err, "access(" TDIR "/fs1/b)"))
0133         goto out;
0134
0135 out:
0136     umount(TDIR "/fs1");
0137     umount(TDIR "/fs2");
0138     rmdir(TDIR "/fs1");
0139     rmdir(TDIR "/fs2");
0140     umount(TDIR);
0141     exit(err);
0142 }
0143
0144 void test_test_bpffs(void)
0145 {
0146     int err, duration = 0, status = 0;
0147     pid_t pid;
0148
0149     pid = fork();
0150     if (CHECK(pid == -1, "clone", "clone failed %d", errno))
0151         return;
0152     if (pid == 0)
0153         fn();
0154     err = waitpid(pid, &status, 0);
0155     if (CHECK(err == -1 && errno != ECHILD, "waitpid", "failed %d", errno))
0156         return;
0157     if (CHECK(WEXITSTATUS(status), "bpffs test ", "failed %d", WEXITSTATUS(status)))
0158         return;
0159 }