1 #include <darwintest.h> 2 #include <fcntl.h> 3 #include <sys/mman.h> 4 #include <darwintest_utils.h> 5 #include <mach/vm_page_size.h> 6 7 /** Verify that F_ADDSIGS does not page fault off the end of the user blob 8 * 1. Find VA space for 3 pages 9 * 2. Unmap the last page 10 * 3. Start fs_blob_start at PAGE_SIZE + 1 bytes away from the end of the 11 * VA region (such that any read of more than PAGE_SIZE + 1 bytes will fault) 12 * 4. Call fcntl with the arguments and verify the output is not EFAULT 13 */ 14 T_DECL(fcntl_addsig, "Verify that fcntl(F_ADDSIGS) doesn't EFAULT", T_META_NAMESPACE("xnu.vfs")) { 15 void* blob_space = mmap(NULL, vm_page_size * 3, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, -1, 0); 16 T_ASSERT_NE(blob_space, MAP_FAILED, "Blob Region: %p [%zd]", blob_space, vm_page_size); 17 18 T_ASSERT_POSIX_SUCCESS(munmap((char*)blob_space + (vm_page_size * 2), vm_page_size), NULL); 19 20 size_t blob_size = vm_page_size + 1; 21 char* blob_start = ((char*)blob_space) + (vm_page_size * 2) - blob_size; 22 fsignatures_t args = { .fs_file_start = 0, .fs_blob_start = blob_start, .fs_blob_size = blob_size}; 23 24 // Create test file to operate on 25 const char * tmp_dir = dt_tmpdir(); 26 char tmp_file_name[PATH_MAX]; 27 sprintf(tmp_file_name, "%s/foo", tmp_dir); 28 FILE* tmp_file = fopen(tmp_file_name, "wx"); 29 fprintf(tmp_file, "Just some random content"); 30 fclose(tmp_file); 31 32 int fd = open(tmp_file_name, O_RDONLY); 33 T_ASSERT_POSIX_SUCCESS(fd, "tmp file: %s", tmp_file_name); 34 35 // This command will fail, but should not fail with EFAULT 36 int result = fcntl(fd, F_ADDSIGS, &args); 37 int error = errno; 38 T_QUIET; T_EXPECT_EQ(result, -1, NULL); 39 // EBADEXEC is expected, but not required for success of this test 40 T_EXPECT_NE(error, EFAULT, "fcntl: %d (%d:%s)", result, error, strerror(error)); 41 } 42