1 // SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause 2 /* Copyright (c) 2025 Isovalent */ 3 4 #include <test_progs.h> 5 #include <bpf/btf.h> 6 #include <sys/stat.h> 7 #include <sys/mman.h> 8 #include <fcntl.h> 9 #include <unistd.h> 10 11 static void test_btf_mmap_sysfs(const char *path, struct btf *base) 12 { 13 struct stat st; 14 __u64 btf_size, end; 15 void *raw_data = NULL; 16 int fd = -1; 17 long page_size; 18 struct btf *btf = NULL; 19 20 page_size = sysconf(_SC_PAGESIZE); 21 if (!ASSERT_GE(page_size, 0, "get_page_size")) 22 goto cleanup; 23 24 if (!ASSERT_OK(stat(path, &st), "stat_btf")) 25 goto cleanup; 26 27 btf_size = st.st_size; 28 end = (btf_size + page_size - 1) / page_size * page_size; 29 30 fd = open(path, O_RDONLY); 31 if (!ASSERT_GE(fd, 0, "open_btf")) 32 goto cleanup; 33 34 raw_data = mmap(NULL, btf_size, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); 35 if (!ASSERT_EQ(raw_data, MAP_FAILED, "mmap_btf_writable")) 36 goto cleanup; 37 38 raw_data = mmap(NULL, btf_size, PROT_READ, MAP_SHARED, fd, 0); 39 if (!ASSERT_EQ(raw_data, MAP_FAILED, "mmap_btf_shared")) 40 goto cleanup; 41 42 raw_data = mmap(NULL, end + 1, PROT_READ, MAP_PRIVATE, fd, 0); 43 if (!ASSERT_EQ(raw_data, MAP_FAILED, "mmap_btf_invalid_size")) 44 goto cleanup; 45 46 raw_data = mmap(NULL, end, PROT_READ, MAP_PRIVATE, fd, 0); 47 if (!ASSERT_OK_PTR(raw_data, "mmap_btf")) 48 goto cleanup; 49 50 if (!ASSERT_EQ(mprotect(raw_data, btf_size, PROT_READ | PROT_WRITE), -1, 51 "mprotect_writable")) 52 goto cleanup; 53 54 if (!ASSERT_EQ(mprotect(raw_data, btf_size, PROT_READ | PROT_EXEC), -1, 55 "mprotect_executable")) 56 goto cleanup; 57 58 /* Check padding is zeroed */ 59 for (int i = btf_size; i < end; i++) { 60 if (((__u8 *)raw_data)[i] != 0) { 61 PRINT_FAIL("tail of BTF is not zero at page offset %d\n", i); 62 goto cleanup; 63 } 64 } 65 66 btf = btf__new_split(raw_data, btf_size, base); 67 if (!ASSERT_OK_PTR(btf, "parse_btf")) 68 goto cleanup; 69 70 cleanup: 71 btf__free(btf); 72 if (raw_data && raw_data != MAP_FAILED) 73 munmap(raw_data, btf_size); 74 if (fd >= 0) 75 close(fd); 76 } 77 78 void test_btf_sysfs(void) 79 { 80 test_btf_mmap_sysfs("/sys/kernel/btf/vmlinux", NULL); 81 } 82