1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2025 Meta Platforms, Inc. and affiliates. */ 3 4 #include <test_progs.h> 5 #include <network_helpers.h> 6 #include "file_reader.skel.h" 7 #include "file_reader_fail.skel.h" 8 #include <dlfcn.h> 9 #include <sys/mman.h> 10 #include <sys/stat.h> 11 12 const char *user_ptr = "hello world"; 13 char file_contents[256000]; 14 void *addr; 15 __u64 beyond_eof_offset; 16 17 void *get_executable_base_addr(void) 18 { 19 Dl_info info; 20 21 if (!dladdr((void *)&get_executable_base_addr, &info)) { 22 fprintf(stderr, "dladdr failed\n"); 23 return NULL; 24 } 25 26 return info.dli_fbase; 27 } 28 29 static int initialize_file_contents(void) 30 { 31 struct stat st; 32 int fd, page_sz = sysconf(_SC_PAGESIZE); 33 ssize_t n = 0, cur; 34 35 fd = open("/proc/self/exe", O_RDONLY); 36 if (!ASSERT_OK_FD(fd, "Open /proc/self/exe\n")) 37 return 1; 38 if (!ASSERT_OK(fstat(fd, &st), "fstat /proc/self/exe")) { 39 close(fd); 40 return 1; 41 } 42 beyond_eof_offset = st.st_size + (1ULL << 30); 43 44 do { 45 cur = read(fd, file_contents + n, sizeof(file_contents) - n); 46 if (!ASSERT_GT(cur, 0, "read success")) 47 break; 48 n += cur; 49 } while (n < sizeof(file_contents)); 50 51 close(fd); 52 53 if (!ASSERT_EQ(n, sizeof(file_contents), "Read /proc/self/exe\n")) 54 return 1; 55 56 addr = get_executable_base_addr(); 57 if (!ASSERT_NEQ(addr, NULL, "get executable address")) 58 return 1; 59 60 /* page-align base file address */ 61 addr = (void *)((unsigned long)addr & ~(page_sz - 1)); 62 63 return 0; 64 } 65 66 static void run_test(const char *prog_name) 67 { 68 struct file_reader *skel; 69 struct bpf_program *prog; 70 int err, fd; 71 72 err = initialize_file_contents(); 73 if (!ASSERT_OK(err, "initialize file contents")) 74 return; 75 76 skel = file_reader__open(); 77 if (!ASSERT_OK_PTR(skel, "file_reader__open")) 78 return; 79 80 bpf_object__for_each_program(prog, skel->obj) { 81 bpf_program__set_autoload(prog, strcmp(bpf_program__name(prog), prog_name) == 0); 82 } 83 84 memcpy(skel->bss->user_buf, file_contents, sizeof(file_contents)); 85 skel->bss->pid = getpid(); 86 skel->bss->beyond_eof_offset = beyond_eof_offset; 87 88 err = file_reader__load(skel); 89 if (!ASSERT_OK(err, "file_reader__load")) 90 goto cleanup; 91 92 /* 93 * Page out range 0..512K, use 0..256K for positive tests and 94 * 256K..512K for negative tests expecting page faults 95 */ 96 if (!ASSERT_OK(madvise(addr, sizeof(file_contents) * 2, MADV_PAGEOUT), 97 "madvise pageout")) 98 goto cleanup; 99 100 err = file_reader__attach(skel); 101 if (!ASSERT_OK(err, "file_reader__attach")) 102 goto cleanup; 103 104 fd = open("/proc/self/exe", O_RDONLY); 105 if (fd >= 0) 106 close(fd); 107 108 ASSERT_EQ(skel->bss->err, 0, "err"); 109 ASSERT_EQ(skel->bss->run_success, 1, "run_success"); 110 cleanup: 111 file_reader__destroy(skel); 112 } 113 114 void test_file_reader(void) 115 { 116 if (test__start_subtest("on_open_expect_fault")) 117 run_test("on_open_expect_fault"); 118 119 if (test__start_subtest("on_open_validate_file_read")) 120 run_test("on_open_validate_file_read"); 121 122 if (test__start_subtest("on_open_non_sleepable_first")) 123 run_test("on_open_non_sleepable_first"); 124 125 if (test__start_subtest("on_open_sleepable_first")) 126 run_test("on_open_sleepable_first"); 127 128 if (test__start_subtest("negative")) 129 RUN_TESTS(file_reader_fail); 130 } 131