test_bpffs.c (4115B)
1// SPDX-License-Identifier: GPL-2.0 2/* Copyright (c) 2020 Facebook */ 3#define _GNU_SOURCE 4#include <stdio.h> 5#include <sched.h> 6#include <sys/mount.h> 7#include <sys/stat.h> 8#include <sys/types.h> 9#include <test_progs.h> 10 11#define TDIR "/sys/kernel/debug" 12 13static int read_iter(char *file) 14{ 15 /* 1024 should be enough to get contiguous 4 "iter" letters at some point */ 16 char buf[1024]; 17 int fd, len; 18 19 fd = open(file, 0); 20 if (fd < 0) 21 return -1; 22 while ((len = read(fd, buf, sizeof(buf))) > 0) { 23 buf[sizeof(buf) - 1] = '\0'; 24 if (strstr(buf, "iter")) { 25 close(fd); 26 return 0; 27 } 28 } 29 close(fd); 30 return -1; 31} 32 33static int fn(void) 34{ 35 struct stat a, b, c; 36 int err, map; 37 38 err = unshare(CLONE_NEWNS); 39 if (!ASSERT_OK(err, "unshare")) 40 goto out; 41 42 err = mount("", "/", "", MS_REC | MS_PRIVATE, NULL); 43 if (!ASSERT_OK(err, "mount /")) 44 goto out; 45 46 err = umount(TDIR); 47 if (!ASSERT_OK(err, "umount " TDIR)) 48 goto out; 49 50 err = mount("none", TDIR, "tmpfs", 0, NULL); 51 if (!ASSERT_OK(err, "mount tmpfs")) 52 goto out; 53 54 err = mkdir(TDIR "/fs1", 0777); 55 if (!ASSERT_OK(err, "mkdir " TDIR "/fs1")) 56 goto out; 57 err = mkdir(TDIR "/fs2", 0777); 58 if (!ASSERT_OK(err, "mkdir " TDIR "/fs2")) 59 goto out; 60 61 err = mount("bpf", TDIR "/fs1", "bpf", 0, NULL); 62 if (!ASSERT_OK(err, "mount bpffs " TDIR "/fs1")) 63 goto out; 64 err = mount("bpf", TDIR "/fs2", "bpf", 0, NULL); 65 if (!ASSERT_OK(err, "mount bpffs " TDIR "/fs2")) 66 goto out; 67 68 err = read_iter(TDIR "/fs1/maps.debug"); 69 if (!ASSERT_OK(err, "reading " TDIR "/fs1/maps.debug")) 70 goto out; 71 err = read_iter(TDIR "/fs2/progs.debug"); 72 if (!ASSERT_OK(err, "reading " TDIR "/fs2/progs.debug")) 73 goto out; 74 75 err = mkdir(TDIR "/fs1/a", 0777); 76 if (!ASSERT_OK(err, "creating " TDIR "/fs1/a")) 77 goto out; 78 err = mkdir(TDIR "/fs1/a/1", 0777); 79 if (!ASSERT_OK(err, "creating " TDIR "/fs1/a/1")) 80 goto out; 81 err = mkdir(TDIR "/fs1/b", 0777); 82 if (!ASSERT_OK(err, "creating " TDIR "/fs1/b")) 83 goto out; 84 85 map = bpf_map_create(BPF_MAP_TYPE_ARRAY, NULL, 4, 4, 1, NULL); 86 if (!ASSERT_GT(map, 0, "create_map(ARRAY)")) 87 goto out; 88 err = bpf_obj_pin(map, TDIR "/fs1/c"); 89 if (!ASSERT_OK(err, "pin map")) 90 goto out; 91 close(map); 92 93 /* Check that RENAME_EXCHANGE works for directories. */ 94 err = stat(TDIR "/fs1/a", &a); 95 if (!ASSERT_OK(err, "stat(" TDIR "/fs1/a)")) 96 goto out; 97 err = renameat2(0, TDIR "/fs1/a", 0, TDIR "/fs1/b", RENAME_EXCHANGE); 98 if (!ASSERT_OK(err, "renameat2(/fs1/a, /fs1/b, RENAME_EXCHANGE)")) 99 goto out; 100 err = stat(TDIR "/fs1/b", &b); 101 if (!ASSERT_OK(err, "stat(" TDIR "/fs1/b)")) 102 goto out; 103 if (!ASSERT_EQ(a.st_ino, b.st_ino, "b should have a's inode")) 104 goto out; 105 err = access(TDIR "/fs1/b/1", F_OK); 106 if (!ASSERT_OK(err, "access(" TDIR "/fs1/b/1)")) 107 goto out; 108 109 /* Check that RENAME_EXCHANGE works for mixed file types. */ 110 err = stat(TDIR "/fs1/c", &c); 111 if (!ASSERT_OK(err, "stat(" TDIR "/fs1/map)")) 112 goto out; 113 err = renameat2(0, TDIR "/fs1/c", 0, TDIR "/fs1/b", RENAME_EXCHANGE); 114 if (!ASSERT_OK(err, "renameat2(/fs1/c, /fs1/b, RENAME_EXCHANGE)")) 115 goto out; 116 err = stat(TDIR "/fs1/b", &b); 117 if (!ASSERT_OK(err, "stat(" TDIR "/fs1/b)")) 118 goto out; 119 if (!ASSERT_EQ(c.st_ino, b.st_ino, "b should have c's inode")) 120 goto out; 121 err = access(TDIR "/fs1/c/1", F_OK); 122 if (!ASSERT_OK(err, "access(" TDIR "/fs1/c/1)")) 123 goto out; 124 125 /* Check that RENAME_NOREPLACE works. */ 126 err = renameat2(0, TDIR "/fs1/b", 0, TDIR "/fs1/a", RENAME_NOREPLACE); 127 if (!ASSERT_ERR(err, "renameat2(RENAME_NOREPLACE)")) { 128 err = -EINVAL; 129 goto out; 130 } 131 err = access(TDIR "/fs1/b", F_OK); 132 if (!ASSERT_OK(err, "access(" TDIR "/fs1/b)")) 133 goto out; 134 135out: 136 umount(TDIR "/fs1"); 137 umount(TDIR "/fs2"); 138 rmdir(TDIR "/fs1"); 139 rmdir(TDIR "/fs2"); 140 umount(TDIR); 141 exit(err); 142} 143 144void test_test_bpffs(void) 145{ 146 int err, duration = 0, status = 0; 147 pid_t pid; 148 149 pid = fork(); 150 if (CHECK(pid == -1, "clone", "clone failed %d", errno)) 151 return; 152 if (pid == 0) 153 fn(); 154 err = waitpid(pid, &status, 0); 155 if (CHECK(err == -1 && errno != ECHILD, "waitpid", "failed %d", errno)) 156 return; 157 if (CHECK(WEXITSTATUS(status), "bpffs test ", "failed %d", WEXITSTATUS(status))) 158 return; 159}