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