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 for (off = 0; off < sizeof(file_contents); off += page_sz) { 56 if (!ASSERT_OK(madvise(addr + off, page_sz, MADV_PAGEOUT), 57 "madvise pageout")) 58 return errno; 59 } 60 61 return 0; 62 } 63 64 static void run_test(const char *prog_name) 65 { 66 struct file_reader *skel; 67 struct bpf_program *prog; 68 int err, fd; 69 70 err = initialize_file_contents(); 71 if (!ASSERT_OK(err, "initialize file contents")) 72 return; 73 74 skel = file_reader__open(); 75 if (!ASSERT_OK_PTR(skel, "file_reader__open")) 76 return; 77 78 bpf_object__for_each_program(prog, skel->obj) { 79 bpf_program__set_autoload(prog, strcmp(bpf_program__name(prog), prog_name) == 0); 80 } 81 82 memcpy(skel->bss->user_buf, file_contents, sizeof(file_contents)); 83 skel->bss->pid = getpid(); 84 85 err = file_reader__load(skel); 86 if (!ASSERT_OK(err, "file_reader__load")) 87 goto cleanup; 88 89 err = file_reader__attach(skel); 90 if (!ASSERT_OK(err, "file_reader__attach")) 91 goto cleanup; 92 93 fd = open("/proc/self/exe", O_RDONLY); 94 if (fd >= 0) 95 close(fd); 96 97 ASSERT_EQ(skel->bss->err, 0, "err"); 98 ASSERT_EQ(skel->bss->run_success, 1, "run_success"); 99 cleanup: 100 file_reader__destroy(skel); 101 } 102 103 void test_file_reader(void) 104 { 105 if (test__start_subtest("on_open_expect_fault")) 106 run_test("on_open_expect_fault"); 107 108 if (test__start_subtest("on_open_validate_file_read")) 109 run_test("on_open_validate_file_read"); 110 111 if (test__start_subtest("negative")) 112 RUN_TESTS(file_reader_fail); 113 } 114